# Dendritic cells: the central partner for cancer immunity

Léo Laoubi, Elisa Gobbini, Pierre Duplouye, Margaux Hubert, Christophe Caux, Nathalie Bendriss-Vermare, Jenny Valladeau-Guilemond, Aurélien Voissière

► To cite this version:

Léo Laoubi, Elisa Gobbini, Pierre Duplouye, Margaux Hubert, Christophe Caux, et al., Dendritic cells: the central partner for cancer immunity. OncoImmunology, 2025, 14 (1), pp.2571773. 10.1080/2162402x.2025.2571773. hal-05472219

HAL Id: hal-05472219

https://hal.science/hal-05472219v1

Submitted on 22 Jan 2026

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons CC BY 4.0 - Attribution - International License
<figure><img src="image_2.png" /></figure>

REVIEW ARTICLE

<figure><img src="image_3.png" /></figure>

OPEN ACCESS

<figure><img src="image_4.png" /></figure>

Check for updates

# Dendritic cells: the central partner for cancer immunity

Léo Laoubi<sup>a,b,1</sup> ID, Elisa Gobbini<sup>a,c,1</sup> ID, Pierre Duplouye<sup>a</sup> ID, Margaux Hubert<sup>a</sup> ID, Christophe Caux<sup>a,b</sup> ID, Nathalie Bendriss-Vermare<sup>a,b</sup> ID, Jenny Valladeau-Guilemond<sup>a</sup> and Aurélien Voissière<sup>a</sup> ID

## ABSTRACT

Dendritic cells (DCs) are central players in the immune system, serving as a bridge between innate and adaptive immunity. Their unique abilities to capture, process, migrate, and present tumor-associated antigens to T cells make them essential actors in initiating and regulating anti-tumor immune responses. This review provides an overview of the phenotypic heterogeneity and functional diversity of DC in cancer immunity, with an emphasis on their interactions with other immune cells within the tumor microenvironment, highlighting their collaborative efforts in driving effective antitumor immunity. Additionally, we examined the impact of tumor-derived signals and immunosuppressive mechanisms on DC functions and their implications for DC-based cancer immunotherapy.

## ARTICLE HISTORY

Received 1 August 2025
Revised 30 September 2025
Accepted 1 October 2025

## KEYWORDS

Dendritic cell; cancer; cancer vaccination; immunotherapy; DC-based vaccines; combination therapies; tumor microenvironment; DC interactions

## Introduction

Our recent understanding of the role of the immune system in antitumor responses and immune escape has led to the development of cancer immunotherapies.<fnref n="1" /> Immune checkpoint blockade (ICB) therapy, which is designed for unleashing or enhancing the antitumor activity of T cells, has been approved for treating various cancers.² However, the efficacy of ICB is limited to some cancer patients and can trigger severe immune-related adverse events.³ This has led to the continuous investigation and/or development of new drugs, including monoclonal antibodies, small molecules, and cellular therapies targeting immune cells, with most efforts directed at T cells, while clinically available therapies directly targeting dendritic cells are still limited. Although DCs represent a very small proportion of leukocytes in the circulation and tissues, they play crucial roles in the cancer response by initiating adaptive immunity through antigen-specific T lymphocyte priming. DCs are the most effective antigen-presenting cells (APCs), capturing and processing antigens, migrating to secondary lymphoid organs (SLOs) to interact with T cells, expressing costimulatory molecules, and secreting cytokines leading to T-cell activation. Besides initiating immune responses, DCs also maintain central and peripheral tolerance.⁴ In cancer, this tolerogenic ability can become protumoral, aiding immune escape and progression.

To perform their functions, DCs continuously patrol and engulf antigens in their environment. They express a wide range of pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) and C-type lectin receptors (CLRs), which can detect pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs).⁵ Engulfment of antigens and/or engagement of PRRs dictate DCs fate toward tolerogenic or immunogenic functions.⁶,⁷ Whereas immature DCs excel in antigen uptake, upon maturation, they specialize in antigen presentation and T-cell activation through the

**CONTACT** Aurélien Voissière 🧐 Aurelien.voissiere@lyon.unicancer.fr 🧐 Centre de Recherche en Cancérologie de Lyon, Centre Léon Bérard, INSERM U1052, CNRS UMR5286, Université Claude Bernard Lyon 1, 69008, Lyon, France; Jenny Valladeau-Guilemond

<figure><img src="image_5.png" /></figure>

Jenny.valladeau-guilemond@lyon.unicancer.fr 🧐 Centre de Recherche en Cancérologie de Lyon, Centre Léon Bérard, INSERM U1052, CNRS UMR5286, Université Claude Bernard Lyon 1, Lyon, France

<figure><img src="image_6.png" /></figure>

<footnote><sup>a</sup>Centre de Recherche en Cancérologie de Lyon, Centre Léon Bérard, INSERM U1052, CNRS UMR5286, Université Claude Bernard Lyon 1, Lyon, France; <sup>b</sup>Lyon Immunotherapy for Cancer Laboratory, Cancer Research Center of Lyon, Centre Léon Bérard, Lyon, France; <sup>c</sup>Departement of Oncology, Institut Curie, Paris, France</footnote>

<footnote n="1">¹Equal contributors.</footnote>
<figure><img src="image_7.png" /></figure>

upregulation of major histocompatibility complex I and II molecules (MHC-I/II), co-stimulatory molecules (CD40, CD80, and CD86) and chemokine receptors such as CCR7, allowing migration to SLOs.⁷

DCs can be divided into subpopulations based on ontogeny, phenotype and function (Figure 1).⁸,⁹

A widely recognized distinction exists between plasmacytoid DC (pDC), monocyte-derived DC (moDC), conventional DC (cDC, type 1, and 2), and the recently defined DC3, which originate from different lineages and have distinct surface markers and functions.

In addition to transgenic mouse models which are critical for DC comprehension, continuous new insights on DCs granularity and complexity are described in both mouse and human, thanks to high dimensional multiparametric and spatial state-of-the art technologies.

This review details the current knowledge on DC diversity, interactions and functions in cancer context as well as their potential as therapeutic targets.

## Dendritic cell subsets

### cDC1

Type 1 conventional DC (cDC1) stand as a key player for initiating antitumor immunity both at the tumor site and in the lymph node. cDC1 differentiation from hematopoietic stem cells relies on the transcription factors IRF8 and BATF3¹⁰,¹¹ and growth factors such as Flt3-L and GM-CSF.¹²⁻¹⁵ cDC1 strongly express BDCA3 (CD141) and specific markers such as CLEC9A (DNGR1) and CADM1 (NECL2). Besides, XCR1 is expressed by approximately 80% of cDC1 in the blood, lungs, and spleen and has been identified as a marker of terminally differentiated cDC1.¹⁶

cDC1 lack SIRPα, making them insensitive to the CD47 “don’t eat me” signal used by tumor cells to evade immunity.¹⁷,¹⁸ cDC1 are able to recognize double-stranded RNA via TLR3, leading to the production of type I and III interferons (IFN), inflammatory cytokines and chemokines, notably IL-12, CXCL9, and CXCL10, to attract and activate T cells at inflammation sites.¹⁹,²⁰ We recently reported that their ability to produce IFN-III in breast cancer that was associated with a good prognosis.²¹ cDC1 are specialized in the cross-presentation of tumor antigens to T lymphocytes, particularly from necrotic cells, supporting their role in antitumor immunity.²¹⁻²³ The cDC1 transcriptional signature and cDC1 frequencies are associated with an increased abundance of CD8⁺T cells and natural killer (NK) cells, a better survival, and favorable responses to ICB in multiple human cancers.²¹,²⁴⁻²⁶ Moreover, cDC1 have been shown to be the only antigen-presenting cells able to transport intact antigens to the lymph nodes and prime tumor-specific CD8⁺T cells.²⁷,²⁸ cDC1 were also described to contribute to CD4⁺T cell priming through MHC-II and CD40 molecules for optimal antitumor immunity.²⁹ Expansion and activation of CD103⁺cDC1 in melanoma tumors through systemic FLT3L and intratumoral polyI:C injections potentiated responses to PD-L1 and BRAF blockade.²⁸ CD103⁺cDC1 also trigger the recruitment of effector T cells into the tumor via the production of CXCL10.²⁴ Recent studies have identified multiple tumor-intrinsic mechanisms that impair cDC1 function and development. Tumor-derived prostaglandin E2 may impair cDC1 function through EP2 and EP4 receptors, leading to IRF8 loss.³⁰ Similarly, tumor-associated IL-6 inhibits cDC1 differentiation through the induction of C/EBPβ in common dendritic cell progenitor.³¹ Furthermore, TIM4-dependent capture and engulfment of cell-associated antigens by tissue-resident lung cDC1 are inhibited during the progression of mouse lung tumors.²³ Tumor-secreted gelsolin inhibited CLEC9A-dependent cross-presentation of dead cell-associated antigens by cDC1.³² Finally, in irradiated tumors, adenosine produced through CD73 reduces cDC1 recruitment, an effect that can be reversed by CD73 blockade.³³

### cDC2

Type 2 conventional DC (cDC2) are the major population of human DC found in blood, SLOs, and nonlymphoid tissues. However, their tissue infiltration can be impacted by malignant transformation. In non-small-cell lung cancer (NSCLC), their proportion decreased compared to healthy tissue in contrast to other DC populations.³⁴
<figure><img src="image_8.png" /></figure>

<figure><img src="image_9.png" /><figcaption>**Figure 1.** Dendritic cell heterogeneity from bone-marrow to healthy or tumor tissue. Hematopoietic stem cells (HSCs) in the bone marrow have a low level of proliferation and ensure self-renewal throughout the organism's lifetime. They can differentiate into highly proliferative multipotent progenitors (MPP), which under the influence of various signals and transcription factors, differentiate into common lymphoid (CLP) or myeloid (CMP) progenitors, giving rise to all-lymphoid progenitors ALP B-cell-biased lymphoid progenitors (BLPs), granulocyte–macrophage progenitors (GMP), or monocyte–dendritic cell progenitors (MDP). ALPs differentiate into T lymphocytes (LT) and innate lymphoid cells (ILC). BLPs give rise to B lymphocytes (LB) and the majority of pre-plasmacytoid dendritic cells (pre-pDCs). Granulocyte–macrophage progenitors (GMP) differentiate into granulocytes (mast cells, basophils, neutrophils, etc.) and common monocyte progenitors (cMoPs). MDPs can also differentiate into cMoPs and common dendritic cell precursors (CDP), and uniquely demonstrated in humans, into pre-DC3s. cMoPs differentiate into monocytes, which give rise to moDCs, macrophages, or Langerhans cells (LC). Finally, CDPs differentiate into pre-cDC1, pre-cDC2, and pre-pDCs, which give rise to cDC1, cDC2, and a minority of circulating pDCs, respectively. Notably, pre-pDCs can also differentiate into transitional DC (tDC) becoming cDC2 or IL-1β-producing tDCs in the periphery. Upon tissue entry, monocytes can differentiate into monocyte-derived DCs (moDCs), macrophages (macro), or monocytic myeloid-derived suppressor cells (MDSC). In tissues, under the influence of various signals, cDC2 can specialize further into the cDC2A and cDC2B subsets.²⁵⁶ In inflamed/tumor tissue, ISGs⁺ DCs (enriched in interferon-inducible genes),⁶,³⁶,⁴⁰,²⁵⁷ CXCL9⁺ DCs or CCR7⁺ mature DC originating from cDC1 and cDC2 can be induced. CCR7⁺ mature DCs migrate to draining lymph nodes to activate specific T cells. Alternatively, DC can form aggregates with T and B cells in the tissue, eventually giving rise to tertiary lymphoid structures (TLS). All DC subsets can contribute to the activation of antigen-specific CD8⁺/CD4⁺ T cells locally or in dLNs. Trained immunity, described as the epigenetic and metabolic reprogramming of HSCs or innate immune cells, is well described after infections or vaccination but may also be driven by tumor-derived inflammation (IFN-I, IFN-γ, etc.).²⁵³,²⁵⁵ Figure Created in Biorender.</figcaption></figure>

Human cDC2 express notably BDCA1 (CD1c) and CLEC10A.³⁵ Recent single-cell analyses and mass cytometry revealed four cDC2 subclusters in healthy donor PBMC indicating their diverse functional specificities and response capabilities.³⁵ Moreover, six clusters of cDC2 have been described across 15 types of cancers.³⁶ Upon activation, cDC2 promote Th1, Th2, and Th17 responses. While the use of multiple
<figure><img src="image_10.png" /></figure>

markers may help capture cDC2 heterogeneity, defining clear boundaries between “true cDC2” and other DC subsets that share overlapping features, such as DC3 or monocyte-derived DC (moDC), also called inflammatory DC (infDC), remains a subject of investigation.

cDC2 have emerged as key regulators in the tumor microenvironment, exhibiting both pro- and antitumor functions depending on the context. Notably, cDC2 can migrate from the tumor site to tumor-draining lymph nodes (tdLNs), where they present tumor-derived antigens to CD4⁺ T cells, thereby initiating antitumor immune responses.³⁷ Moreover, the intratumoral density of cDC2 has been positively correlated with the presence of CD4⁺ T cells and improved responses to anti-PD-1 therapy in melanoma patients, particularly those with low levels of Tregs. In addition to directly presenting tumor antigens, cDC2 may also transfer antigens to lymph node-resident dendritic cells, including other cDC2, amplifying the immune response.³⁸,³⁹ Similar to cDC1, CD11b⁺ cDC2 can cross-present tumor antigens to CD8⁺ T cells in an IFN-I-dependent manner, thereby contributing to cytotoxic T cell-mediated antitumor immunity.⁴⁰ In contrast, it was also demonstrated in a mouse model that cDC2 may contribute to tumor progression by limiting antitumor CD4⁺ effector T cell responses.⁴¹

## DC3

DC3 are the newly identified subset of DC positioned between cDC2 and monocytes.⁴² However, neither cDC2 nor monocytes can differentiate into DC3 *in vitro*, suggesting DC3 is a standalone subset from an independent differentiation lineage that appears to begin early in the myeloid lineage.⁴³ Nevertheless, a recent study observed that cDC2 acquired a DC3-like phenotype (CD14⁺ CD1c⁺ CD163⁺) mediated by IL-6 and prostaglandin E2 (PGE2) in a patient-derived colorectal cancer organoid model.⁴⁴

DC3 are found in the blood of healthy donors, SLOs of systemic lupus erythematosus patients, healthy peripheral tissue and tumors.³⁵,⁴³,⁴⁵,⁴⁶ They appear to be enriched in cancer tissue and metastatic lymph nodes compared to healthy counterparts, with an abundance comparable to cDC2.³⁴,⁴³ They are able to infiltrate luminal breast cancer primary tumors and correlate with infiltration of CD8⁺ CD103⁺ D69⁺ tissue-resident memory T cells.⁴³

## Mature DC

Mature DC enriched in activation and immunoregulatory molecules are referred to as mregDC, LAMP3⁺ DC, or CCR7⁺ DC according to different studies.⁴⁷⁻⁴⁹ Transcriptomic data revealed their conservation across species and tissues⁵⁰ and showed that they can be derived from both cDC1 and cDC2 populations.³⁶,⁵¹

Mature DC are found in lymph nodes, peripheral healthy and inflamed tissues, mainly near blood vessels, but not in blood.⁴⁷,⁴⁹ They also express higher levels of costimulatory molecules (CD40, CD80, CD86, and CD83), DC-LAMP, MHC class II molecules and the chemokine receptor CCR7, allowing their migration to lymph nodes.³⁶,⁴⁷,⁵² This migration of mature DC toward sentinel tdLN is notably necessary for immunoradiotherapy efficacy.⁵³ Functionally, mature DC express high levels of inflammatory cytokines such as IL-12, IL-10, and TNF-α.⁵⁴

In the context of cancer, following tumor antigen capture, many mature DC migrate to tdLN, but some remain at the tumor site, where they can also present tumor antigens to tumor-infiltrating T cells. This local antigen presentation enhances immune activation by increasing the cytolytic activity of PD-1⁺ CD8⁺ T cells through OX40L.⁵⁵,⁵⁶ Interestingly, transcriptional differences exist between mature DC in the tumor microenvironment and those in the tdLN, suggesting distinct roles or functions in regulating immune responses at different locations.⁵⁷

Upon antigen uptake, tumor-infiltrating mature DC also upregulate a distinct set of immunoregulatory genes (Cd274 (PD-L1), Pdcd1lg2 (PD-L2), and Cd200) and maturation genes (Cd40, Ccr7, and Il12b). It was also demonstrated that PD-L1 upregulation is induced by the receptor tyrosine kinase AXL, while the induction of IL-12β depends on IFN-γ and is modulated by IL-4.⁴⁷,⁴⁸ In contrast, mature DC in peripheral healthy tissues express lower levels of PD-L1, PD-L2, and IL-12, indicating a tumor-specific maturation program promoting immune suppression.
<figure><img src="image_11.png" /></figure>

Finally, several studies have demonstrated that the presence of mature DC within tertiary lymphoid structures (TLS), defining so-called mature TLS, is associated with improved prognostic outcomes in several cancer types compared to immature TLS without mature DC.<sup>58,59</sup>

## Plasmacytoid DC (pDC)

Plasmacytoid DCs (pDCs) differ from other DCs because of their unique plasma cell-like morphology and their singular ontogeny and function. Both common dendritic cell progenitor (CDP) and common lymphoid progenitor (CLP) can give rise to pDCs.<sup>60,61</sup> Whether CLP-derived pDC must be considered as a dendritic cell or an innate immune cell is a current matter of debate.<sup>62-64</sup> Historically, contaminating AXL<sup>+</sup> "pDC-like" cells, which are part of transitional DCs (tDCs), may have skewed the characterization of proper pDCs. However, even after the removal of pDC-like cells, activated pDCs can acquire antigen-presentation capacity.<sup>65-67</sup> Phenotypically, human pDCs express CD123 (IL-3Ra) and MHC class II molecules less intensively than cDCs. Notably, TLR-activated pDCs can also cross-present antigens to CD8<sup>+</sup> T cells *in vitro* but this remains to be proven *in vivo*.<sup>68</sup>

Under steady-state conditions, pDCs are found in the blood and patrol into SLO through high endothelial venules (HEV), while they can also migrate to peripheral tissues during infections, autoimmune disorders, or tumors.<sup>69,70</sup>

pDCs recognize viral nucleic acids through TLR7 and TLR9, leading to IFN-α production through the IRF7 pathway. However, in the tumor microenvironment (TME), IFN-α production by pDCs is impaired by factors such as TGF-β, TNF-α, and PGE2.<sup>71,72</sup> Consequently, altered pDCs can promote immunosuppression and regulatory T cell expansion in various cancers.<sup>73-75</sup>

## Transitional DC/AXL<sup>+</sup> DC

As mentioned above, recent single-cell transcriptomic analyses with deep phenotyping have identified a new population of AXL<sup>+</sup> SIGLEC6<sup>+</sup> DC (AS-DC) within Lin-HLA-DR<sup>+</sup> cells, also called transitional DCs (tDCs), that encompass the so-called "pDC-like cells," which can give rise to cDC2.<sup>60,65,67,76-79</sup> AXL<sup>+</sup> SIGLEC6<sup>+</sup> tDCs were proposed to originate from pDC progenitors rather than the CDP and can give rise to CD5<sup>+</sup> CX3CR1<sup>-</sup> cDC2 (ESAM<sup>+</sup> CX3CR1<sup>-</sup> cDC2 in mice).<sup>78</sup> Moreover, in response to viral infection, tDCs can also mature and produce IL-1β.<sup>78</sup> Alternatively, it was shown that tDCs can differentiate into CX3CR1<sup>+</sup> cDC2 promoting Th17 response, demonstrating the dual potential of this population.<sup>80</sup>

However, the role of such cells in the context of cancer remains to be explored.

## Langerhans cells

The origin of Langerhans cells (LC) is equivoque, as they share transcription factors with DC and macrophages lineages, respectively.<sup>81</sup> LC can be phenotypically distinguished from cDC2 because of their increased expression of Langerin, CD1a, and EpCAM.<sup>82,83</sup> LC are found in stratified squamous epithelia, such as the epidermis and mucosal epithelia, integrated into the epithelial layer via E-cadherin, EpCAM, and tight junction proteins.

LC can induce regulatory T cells and IL-22 in response to CD1a-restricted antigens.<sup>84</sup> In contrast, LCs can mature into tumor cross-presenting cells, produce IL-15, and present mycobacterial glycolipid antigens to CD8<sup>+</sup> T cells.<sup>85-87</sup> Studies in humans have shown *ex vivo* that after migration in lymph nodes, LCs are able to activate CD8<sup>+</sup> and CD4<sup>+</sup> T cells toward Th2-type polarization.<sup>88,89</sup> Despite differences from cDC1, LCs share strong antigen priming and cross-presentation functions, as assessed by their capacity to induce MART-1-specific CD8<sup>+</sup> T cell proliferation following autologous presentation of the MART-1<sub>21-35</sub> long peptide.<sup>90</sup> Consistently, LCs appear to contribute to the antitumor response in melanoma and oral carcinoma contexts.<sup>85,91,92</sup>
<figure><img src="image_12.png" /></figure>

## Monocyte-derived DCs (moDCs)

In inflammatory settings or tumor tissues, CD14⁺ monocytes exhibit the capacity to differentiate into macrophages, monocytic myeloid-derived suppressor cells (MDSC), or monocyte-derived DCs (moDCs), also called inflammatory DCs (infDCs).⁹³,⁹⁴ Conversely, moDCs are not observed in healthy tissues. The transcription factors and growth factor receptors predominantly expressed in this DC subsets are shared with both macrophages (EGFR1, EGFR2, and CSFR1) and blood DC (IRF4, FLT3), suggesting that LnfDC/MoDC occupies an intermediate position between these two populations.⁹⁴ Notably, in mice, moDCs can be found in the classical migratory cDC2 gate (MHC-IIhi CD11chi CD11b⁺ CD24⁺), express the activation marker CD169, and cross-present tumor antigens.⁹⁵

Moreover, chemotherapy such as anthracyclines induces moDC recruitment into the tumor bed in a CCL2/CCR2-dependent manner, allowing local T cell proliferation and efficient tumor rejection.⁹⁶ Similarly, in a mouse melanoma model, the administration of local immunostimulatory agents induced tumor and lymph-node moDC, which are necessary and sufficient for T-cell-mediated antitumor response.⁹⁷

## DC cross-talk with other immune cell populations

### cDCs-T cells

The orchestration of an efficient cytotoxic immune response requires intricate interplay between DC CD4⁺ helper T cells, and CD8⁺ cytotoxic T cells (CTL). Even though both cDC1 and cDC2 are able to prime naïve T cells, *in vitro* and *in vivo* data have shown that cDC1 are more proficient in CD8 T cell activation compared to cDC2.⁹,⁹⁸ Conversely, cDC2 activate CD4⁺T cells more efficiently than cDC1.⁹,⁹⁹,¹⁰⁰ Nevertheless, cDC1 are required for the priming of OVA-specific CD4⁺T cells to respond to OVA-expressing tumors, as shown in Irf8-deficient mouse models. This finding suggests that cDC1 may be superior in MHC-II presentation to CD4⁺T cells compared to cDC2 in some tumor contexts.²⁹ This may be due to the efficient capture of tumor antigens through specific receptors, such as CLEC9A.¹⁰¹ Furthermore, following intranasal vaccination of Batf3⁻/⁻ mice with SIINFEKL-Q11 peptide nanofibers, cDC2 were able to mount a strong CD8⁺T cell response in the lung and dLN even in the absence of cDC1.¹⁰² Following this concept, using CD40L-LIPSTIC technology in a melanoma mouse model, cDC1 and cDC2 with similar hyperactivated transcriptional phenotypes (Cd80, Cd86, Cd40, Cd82, Cd200, Cd274, Nfkibiz, and Tnfaip3) were found to interact with CD4⁺ and/or CD8⁺T cells in both tumors and tumor dLNs.¹⁰³ Anti-CTLA-4 blockade largely enhanced these interactions, especially with cDC2.

Those cDC1-T cells interactions are rendered possible by the expression of CXCL9/10 and XCR1 by cDC1 that can respectively interact with CXCR3 and XCL1 expressed by CD8⁺T cells and CD4⁺T cells²⁰,¹⁰⁴⁻¹⁰⁶ (Figure 2).

In human lung cancer, organized immune hubs were shown to be associated with response to PD-1-blockade immunotherapy.¹⁰⁷ Those so-called “organized stem immunity hubs” were composed of stem-like TCF7⁺PD-1⁺CD8⁺T cells, mature DC CXCL10⁺/CXCL11⁺ macrophages, and CCL19⁺ fibroblasts but deprived of B-cell follicle characteristics of mature tertiary lymphoid structures (TLS). Inside those hubs, mature DCs were frequently in closer proximity to TCF7⁺CD4⁺T cells and Treg than to other cells. In parallel, DC-LAMP⁺ mature DCs were already shown to interact with CD4⁺PD1⁺CXCL13⁺T cells, called T helper tumor (Tht) cells, in human nonsmall cell lung carcinoma.¹⁰⁸ These Tht cells are known to correlate with better survival or response to ICB therapy.¹⁰⁸ Additionally, in D4M.3A-pOVA melanoma mouse models, CCR7⁺CXCL16⁺IL-15⁺mature DCs also interact with CXCR6⁺TCF-1⁻neg CD8⁺effector-like CTL in perivascular niches and trans-present IL-15 to support their survival in the TME.¹⁰⁹ Additionally, following neoadjuvant PD-1 blockade in hepatocellular carcinoma, responding patients exhibited a higher frequency of triads consisting of mregDCs, stem-like PD-1⁺TCF-1⁺CD8⁺T cells, and CXCL13⁺CD4⁺T cells compared to nonresponders.¹¹⁰ Some reports have highlighted the central role of cDC1 beside mature DCs in DC-T cross-talk at the tumor bed. For instance, MHC-IIhiCCR7negCXCL9⁺cDC1 form niches with TCF1⁺CD8⁺T cells, leading to their proliferation and
<figure><img src="image_13.png" /></figure>

<figure><img src="image_14.png" /><figcaption>**Figure 2.** DC interactions in the tumor microenvironment drive the local antitumor immune response. 1) Mature DC can interact with CD4⁺ helper T cells through CXCR5-CXCL13. Then, helper T cells support activation of neighboring cytotoxic CD8⁺ T cells.¹⁰⁸,¹¹⁰ 2) A part of CCR7⁺ mature DC does not migrate outside of TME, colocalize with PD-1⁺ CD8⁺ T cells, and help to reinvigorate them through OX40L-OX40 upon anti-PD-1 therapy.⁵⁷ 3) CCR7neg cDC1 can activate stem-like TCF1⁺ CD8⁺ T cells through the CXCL9-CXCR3 axis toward TCF1neg TIM3⁺ GzmB⁺ cytotoxic T cells.²⁰,²⁵⁸ 4) Colocalization of CCR7⁺ mature DC and CXCR6⁺ CD8⁺ T cells in the perivascular niche of the tumor stroma allows the survival and expansion of CD8⁺ T cells through the IL-15/IL-15R axis.¹⁰⁹ 5) Immune triads of CD11c⁺ DC, CD4⁺, and CD8⁺ T cells are associated with a stronger immune response than dyad interactions.¹¹³ 6) CD4-cDC1 crosstalk in the TME allows to both the activation of CD4⁺ T-cell functions and license cDC1 for subsequent CTL activation.²⁹,¹⁰³,¹¹⁴ 8) cDC1 can be recruited by CCL5⁺ NK cells and XCL1⁺ T cells.¹⁰⁶ In contrast, PGE2-producing tumor cells can inhibit cDC1 functions.³⁰ Figure created in Biorender.</figcaption></figure>

differentiation into IFN-γ⁺ GzmB⁺ TIM3⁺ T cells.²⁰ These niches are correlated with cancer patient survival.²⁰ In addition, we recently demonstrated that the spatial organization of cDC1 with CD8⁺ T cells is critical for the response to ICB in melanoma patients.¹¹¹ We found that the median distance between CD8⁺ T cells and cDC1 was markedly reduced in responding patients while it was not the case for pDCs and mature DCs, underlying the pivotal role of cDC1-T cell cross-talk in the context of cancer. A proficient crosstalk was described in tumors between mature CCR7⁺ cDC1, which produce high amounts of IL-12 in response to IFN-γ secreted by neighboring T or NK cells. In return, IL-12 drives CD8 antitumor activity and successful anti-PD-1 immunotherapy.¹¹²
<figure><img src="image_15.png" /></figure>

Moreover, cDC interactions with CD4⁺ and CD8⁺ T cells can be concomitant, as recently shown in a melanoma and fibrosarcoma mouse model.¹¹³ Specific CD8⁺ and CD4⁺ T cells forming a “triad” with a common CD11c⁺ DC triggered the most efficient antitumor response compared to separated “dyads” of CD8⁺-DC and CD4⁺-DC.¹¹³ Importantly, those intratumoral triads were found to be associated with responses to ICB in human patients afflicted by malignant pleural mesothelioma.¹¹³ These DC-T cell interactions can influence both DC and T cells in a positive feedback loop. For example, in a fibrosarcoma mouse model, cDC1 were essential for the early priming of both CD4⁺ and CD8⁺ T cells, while naïve CD4⁺ T cells licensed cDC1 through CD40 for efficient CD8⁺ T cell activation, in line with the importance of the CD40-CD40L interaction.²⁹,¹¹⁴⁻¹¹⁷

## DCs-regulatory T cells (Treg)

DC subsets can also interact with Treg in the TME, resulting in the upregulation of immune suppressive molecules such as IDO and a lower expression of maturation markers on the DCs surface.¹¹⁸ Besides, CTLA-4⁺ Treg infiltration impairs the capacity of tumor-associated cDC2 (TA-cDC2) to induce protective ICOS⁺ PD-1low CD4⁺ T cells within the TME in head and neck cancer, thus limiting patient survival.¹⁰⁰ Recently, it was shown in a tumor mouse model that a high dose of neoantigen peptide vaccination induced cDC2-dependent cytotoxic type 1 regulatory CD4⁺ T cells (Tr1), expressing IL-10, granzyme B, and perforin, able to eliminate cDC1 cells and thus preventing tumor rejection compared to low dose vaccination.¹¹⁹ Moreover, mregDCs were shown to recruit Treg in the perilymphatic region of the tumor stroma.¹²⁰ Treg activation was sustained in Treg-mregDC-lymphatic niches, hampering the migration of tumor antigen-bearing DC to dLNs and antitumor immunity, which predicts the worse outcome in human cancers.¹²⁰

In breast cancer, especially triple-negative breast cancer, we showed that TA-pDCs with impaired IFN-α production favor Treg expansion, which may contribute to cancer progression.⁷⁴ Moreover, in breast and ovarian cancer, tumor-associated ICOSL⁺ pDCs interact with ICOS⁺ Treg participating in TA-Treg expansion and the secretion of IL-10⁺ by TA-CD4⁺ T cells.¹²¹⁻¹²³ Finally, in human ovarian carcinoma, pDCs activate FoxP3⁺ Treg and induce suppressive IL10⁺ CCR7⁺ CD45RO⁺ CD8⁺ regulatory T cells.¹²⁴

## cDCs-NK cells

The bidirectional crosstalk between DC and NK cells has been investigated in several studies. While DC can activate NK cells, the latter can in turn affect the recruitment and maturation of DC.¹⁰⁶,¹²⁵⁻¹²⁸ FLT3L is essential for the *in situ* development and proliferation of cDCs and pDCs and is produced mainly by NK cells in the TME.²⁸,¹²⁵ Furthermore, CCL5 and XCL1 secreted by NK cells induce CCR5⁺ XCR1⁺ cDC1 migration, promoting tumor immune control.¹⁰⁶ Our team also demonstrated that TNF-α and IFN-γ produced by NK cells significantly increase the ability of moDCs and cDC1 to cross-present tumor antigens, inducing a specific CD8⁺ T cell response.¹²⁹ On the other hand, cDCs release cytokines and chemokines such as IL-12, IL-15, IL-18, and CXCL9/10 to promote NK cell activation and recruitment to tumor sites.¹³⁰ This bidirectional cross-talk between DC and NK cells forms a positive loop against cancer growth. However, it can be impaired by the production of PGE2 in cancer cells. Indeed, the latter reduces the accumulation of cDCs by impairing NK viability and chemokine production, causing immune evasion.¹⁰⁶ Finally, in human NSCLC, it was shown that DC-NK crosstalk can also be detrimental, as it impairs DC maturation, particularly through CTLA-4 on NK cells.¹³¹

## DCs-γδ T cells

Unlike conventional αβ T cells, which require antigen processing and presentation by dendritic cells (DC) via MHC molecules for priming, γδ T cells typically recognize antigens in an MHC-independent manner. They are able to recognize various surface ligands, such as phosphorylated antigens. Because of their broad antigen specificity and NK-like cytotoxicity, the importance of γδ T cells in tumor immunology has been
<figure><img src="image_16.png" /></figure>

highlighted.132 Their cytokine profile and cytotoxicity are seemingly determined by cross-talk with microenvironment components, but tumor-infiltrating γδ T cells have been reported to bear the most favorable prognostic immune population among many cancer types.133,134 However, tumor can subvert γδ T cells to exhibit tumor-promoting functions, altering the surface expression of natural cytotoxicity receptors (NCR), killer Ig-like receptors (KIR), and immune checkpoints. Several studies have suggested a bidirectional interaction between moDCs or pDCs and γδ T cells.135-138 Indeed, IFN-I produced by moDCs or pDCs was shown to trigger IFN-γ secretion by γδ T cells (Vγ9Vδ2 subset), which in turn promoted the maturation of moDCs and their secretion of IL12p70.139,140 In the context of melanoma, patients with tumor-infiltrating pDCs are able to trigger a high proportion of CD69+ γδ T cells in vitro showed a better clinical outcomes.141 Nevertheless, the positive bidirectional crosstalk between pDCs and γδ T cells was impaired in the blood of tumor patients compared to blood of healthy donors.141 The interplay between the two populations includes several immune checkpoints, such as OX40/OX40L, ICOS/ICOSL, PD1/PD-L1, 41BB/41BB-L, GITR/GITR-L, TIM3, and LAG3.141,142

## pDCs-cDC1-cDC2

The division of labor between DC subsets raises the question about their cooperation to efficiently activate the cytotoxic response against cancer antigens. However, where and how the interplay between cDC1, cDC2, pDCs and other DC subsets occurs in the tumor setting are poorly understood.

The analysis of DC subsets within dLNs during vaccinia virus infection showed that infected cDCs were able to recruit CCR5+ pDCs into CD8+ T cell priming site through CCL3/CCL4.143 Conversely, mobilized IFN-I-producing pDCs were able to increase the expression of maturation markers (CD80, CD86, and CD40) and the antigen presentation capability of XCR1+ cDC1 recruited by activated CD8+ T cells via the XCL1/XCR1 axis.143

Similarly, in the context of cancer, a study conducted on a mouse model inoculated with E.G7 tumor cells and immunized by antigen-pulsed pDCs and/or cDCs showed that, when pulsed in vitro together, pDCs can increase the capacity of cDCs to activate antigen-specific CD8+ T cells and limit tumor growth.144 This crosstalk was mainly due to cell-to-cell contact, but no specific ligand-receptor was identified.

Recently, we demonstrated that IFN-III produced by cDC1 directly promotes pDC survival, activation, and TLR7 expression in both human blood and tumors, enhancing their responsiveness to TLR7 agonists.145 Notably, it counteracts TME-induced inhibition, including suppression mediated by TGF-β or PGE2, and restores pDC production of IFN-α. This may be one of the reasons explaining that IFN-III produced by cDC1 is associated with good clinical outcomes in breast cancer.21

Moreover, the TLR7 agonist imiquimod, which is used to treat both local and distant metastases, has been shown to activate pDCs, which in turn produce systemic IFN-I, leading to DC and macrophage sensitization to local imiquimod through the upregulation of TLR7/8. This sequential activation is essential for CD8+ T cell activation and antitumor efficacy.146

## DCs-neutrophils

Neutrophils are key players of innate immunity against extracellular pathogens. They are abundant in the blood stream and invade tissue upon inflammation. Once infiltrated into the tissue, they can produce various alarmins (HMBG-1, LL-37, lactoferrin, etc.) and neutrophil extracellular traps (NETs), which positively impact DC recruitment and maturation.147-149 LL-37 can bind formyl peptide receptor 2 (FRP2) on DC or form complex with DNA. The latter drives IFN-α production by pDCs.150,151 In particular, LL-37 was shown to drive the generation of cross-presenting CD103+/CD141+ DC with enhanced costimulatory and migratory capacity, thereby boosting CD8+ T-cell priming and promoting tumor regression in preclinical cancer models.152,153 Conversely, neutrophils can also release factors such as myeloperoxidase (MPO), which can inhibit antigen uptake/processing by DC and reduce their CCR7 expression.154
<figure><img src="image_17.png" /></figure>

It is known that human activated neutrophils can induce moDC maturation *in vitro* through interaction between DC-SIGN on DC and Mac-1 on neutrophils.¹⁵⁵ It was also shown that CCL3 produced by neutrophils during Leishmania infection in mice was required to recruit moDCs to the site of infection and subsequent T cell activation in dLNs.¹⁵⁶,¹⁵⁷ Additionally, *Mycobacterium tuberculosis* (Mtb)-infected human neutrophils can produce NETs leading to IFN-I production by surrounding pDCs.¹⁵⁸

In the context of cancer, neutrophils can also produce various factors with either protumor (IL-10, iNOS) or antitumor (TNF-α) activity, highlighting their potential role in modulating DC functionality.¹⁵⁹ Further research on DC and neutrophil interplay in cancer remains to be performed.

## DCs-other myeloid populations

The crosstalk between DC and other myeloid populations, such as macrophages and mast cells, also represents a pivotal axis of immune regulation in the TME. In mammary carcinoma models, tumor-associated macrophage (TAM)-derived IL-10 suppresses IL-12 production by DC during chemotherapy, which is consistent with clinical data linking IL12A expression to better responses in breast cancer.¹⁶⁰

Importantly, therapeutic strategies targeting these suppressive myeloid compartments can enhance DC-based immunotherapy. For instance, TAM depletion using CSF-1R inhibitor improved both the survival and antitumor efficacy of bone marrow-derived DC vaccines in mesothelioma cancer models.¹⁶¹ Similarly, vaccination with genetically modified DC producing IL-12 and IL-18 not only amplifies T cell responses but also reduces TAM density in a murine colon cancer model (MC38).¹⁶²

Furthermore, in melanoma models, IFN-γ-driven activation of the enzyme aconitate decarboxylase (ACOD1) in macrophages increases itaconate production, which inhibits DC antigen presentation and cross-priming, decreases CD8+ T cell responses and promotes tumor immune escape.¹⁶³

Finally, mast cells have also been shown to contribute to tumor-mediated immunosuppression by enhancing MDSC activity through CD40L-CD40 signaling in a preclinical prostate cancer model.¹⁶⁴,¹⁶⁵

## Tumor cell death impact on DC functions

The mode of tumor cell death, such as accidental necrosis or regulated cell death (RCD), including apoptosis, immunogenic cell death (ICD), pyroptosis, necroptosis, or ferroptosis, affects how DC receive “licensing” signals and capture antigens.¹⁶⁶,¹⁶⁷ In particular, current therapies, such as chemotherapy, radiotherapy, antibody-drug conjugates (ADCc), and other targeted agents, can trigger ICD, thereby converting tumor cells into sources of immunostimulatory antigens that enhance both innate and adaptive antitumor immunity.¹⁶⁸ ICD is characterized by exposure of calreticulin (CALR) and the release of ATP, HMGB1, and type I interferons. Surface CALR promotes engulfment via CD91 and supports DC maturation and antigen presentation.¹⁶⁹ HMGB1-TLR4 signaling enhances TLR-dependent DC activation and migration to tdLN, while extracellular ATP engages P2RX7/P2Y receptors on DC to activate the NLRP3 inflammasome and induce IL-1β secretion, which is required for effective CD8+ T-cell priming.¹⁷⁰,¹⁷¹ In parallel, tumor DNA and cGAMP activate the cGAS-STING axis in DC to drive IFN-I production, which is essential for efficient cross-priming of cDC1.¹⁷² Overall, these DAMPs act as “find-me/eat-me” signals that attract DCs and promote antigen uptake, maturation, and cross-presentation.¹⁷³ While molecular pathways may vary between ICD and other RCD such as pyroptosis (caspase-gasdermin-driven lytic death) or necroptosis (RIPK3-MLKL-dependent necrotic death), they can lead to immunogenic outcomes that strongly support DC activation and antitumor response. Notably, ferroptosis (iron-dependent oxidative death) can exert a dual influence on DC as early ferroptotic tumor cells can release DAMPs that activate DC maturation and cross-priming, whereas late or uncontrolled ferroptosis may instead impair DC function and blunt antitumor immunity.¹⁷⁴,¹⁷⁵ Moreover, by providing abundant tumor antigens in an inflammatory milieu, ICD, and ICD-like death may foster epitope spreading, thereby broadening the repertoire of tumor-reactive T cells.¹⁷⁶,¹⁷⁷
<figure><img src="image_18.png" /></figure>

DC for cancer therapies

Over the past decade, the identification of immune checkpoint receptors and their targeting have revolutionized cancer treatment. However, due to strong tumor-induced immunosuppression already established in cancer patients, ICB can fail to restore efficient antitumor immunity, especially under adjuvant or metastatic conditions. Moreover, while ICB is more likely to be effective in “hot” tumors that are infiltrated by previously primed tumor-reactive T cells, alternative strategies must be considered for “cold” tumors, which are characterized by a lack of T cell infiltration.

Tumor antigen delivery as a cancer vaccine

For direct antigen delivery, the type of antigen is crucial, and several approaches are being developed using shared or personalized antigens. The emergence of whole-exome sequencing and RNA sequencing has allowed huge advances in the identification of a more tailored neoantigen repertoire. Tumor antigens are broadly classified into two categories: tumor-associated antigens (TAAs) and tumor-specific antigens (TSAs). TAAs are self-antigens that are aberrantly expressed or overexpressed in tumor cells but are also found, to a lesser extent, in normal tissues. Due to their presence in nonmalignant cells, TAAs typically exhibit low tumor specificity and limited immunogenicity. In contrast, TSAs, or neoantigens, are generated from tumor-specific somatic mutations and are absent from normal tissues. This endows TSAs with high tumor specificity and strong immunogenic potential; however, their novelty to the host immune system also results in minimal central tolerance, which may impact immune recognition.

For instance, TEDOPI is a peptide-based vaccine composed of 9 synthetic peptides from 5 TAA (HER-2/neu, CEA, MAGE 2, MAGE 3, and p53). Ninety percent of lung cancer patients express at least one of these TAA and derived peptides are presented by HLA-A2, which occurs in up to 45% of the population.¹⁷⁸ Interestingly, the phase III study ATALANTE-1 showed for the first time an overall survival gain for the vaccine strategy compared to the standard of care (mainly docetaxel or pemetrexed) in ICB-resistant NSCLC patients.¹⁷⁹ Further clinical trials are currently ongoing to explore the clinical benefit of adding the TEDOPI to immunotherapy or chemotherapy in ICB-resistant patients. However, peptide-based cancer vaccines alone are poorly immunogenic and require strong adjuvants to produce efficacious response. The importance of testing and adding a proficient costimulation was shown in MAGE-A3 trials. Melanoma-associated antigen 3 (MAGE-A3) is a cancer-testis antigen that is preferentially expressed in melanoma, myeloma, and NSCLC. A randomized phase 2 trial showed that a MAGE-A3 vaccine including TLR9 agonist (AS15) induced stronger humoral and T cell response and showed greater clinical benefit compared to TLR4-agonist-adjuvant (AS02B) MAGE-A3 vaccine.¹⁸⁰,¹⁸¹ However, a phase 3 clinical trial (DERMA) using AS15-MAGE-A3 vaccine in patients with stage IIIB or IIIC melanoma in the adjuvant setting did not show significant differences compared to placebo.¹⁸² Thus, improvement of adjuvants, identification of patient-specific neoantigens, and better selection of patients susceptible to mount a strong immune response need to be established to drive successful therapies.

More recently, driven by technological advances, the use of mRNA to deliver tumor antigens has emerged. It offers several advantages, including rapid and scalable manufacturing, low toxicity, and the capacity to encode a wide range of tumor antigens. The delivery of exogenous self-amplifying mRNAs (SAMs) encoding tumor-specific antigens into host somatic cells enables endogenous antigen production and subsequent activation of antigen-specific immune responses. Even though this strategy was initially developed for cancer treatment, its development has dramatically accelerated during the SARS-CoV-2 pandemic, resulting in the large-scale production of mRNA-based vaccines against SARS-CoV-2 over the past 5 y.¹⁸³,¹⁸⁴ This targeted mechanism may lead to more durable responses and an improved quality of life for patients while also contributing to the prevention of tumor recurrence and metastasis. For instance, the phase 2b KEYNOTE-942 trial (NCT03897881) investigated the efficacy of mRNA-4157 (V940)—a personalized mRNA-based cancer vaccine encoding patient-specific neoantigens—in combination with the immune checkpoint inhibitor pembrolizumab, as adjuvant therapy for patients with high-risk resected melanoma.¹⁸⁵ The vaccine was custom designed for each patient based on the unique mutational landscape
<figure><img src="image_19.png" /></figure>

of their tumor. The results demonstrated a significant improvement in recurrence-free survival (RFS) for combination therapy compared to pembrolizumab monotherapy. The combination tended to reduce the risk of recurrence or death by 44%, with 18-month RFS rates of 78.6% in the combination arm versus 62.2% in the monotherapy arm. The treatment was well tolerated, with a favorable safety profile and no unexpected adverse events beyond those associated with pembrolizumab. Given these promising clinical outcomes, mRNA-4157 (V940) is the first personalized mRNA-based tumor vaccine to progress into phase 3 clinical trials, representing a major milestone in the development of individualized cancer immunotherapies.<sup>186,187</sup>

Finally, given the differences in CTL activation ability of DC subsets, targeting a specific DC subpopulation for antigen delivery might increase vaccine immunogenicity. In particular, targeting and activating cDC1 *in vivo* seems to be an attractive strategy. For example, peptide vaccination with a synthetic OVA peptide fused with XCL1 showed an increased CTL response when compared to OVA with free XCL1.<sup>188</sup> Moreover, an adenovirus vaccine may be modified with an anti-CLEC9A antibody to target vaccine delivery to the cDC1 compartment.<sup>189</sup> Finally, the association of a proper adjuvant can improve the antitumor response induced by *in vivo* DC targeting. In a phase II trial of high-risk melanoma patients treated with a DC-targeted anti-DEC205-NY-ESO-1 vaccine, the use of an FLT3L adjuvant increased the activation of circulating DC and CD8<sup>+</sup>/CD4<sup>+</sup> T cells compared to vaccine alone.<sup>190</sup> However, treatment-related toxicities such as local skin reactions and lymphoproliferative disorders, have limited the development of this strategy in larger studies.

Ex vivo pulsed DC as a cancer vaccine

Instead of providing tumor antigens to DC *in vivo*, another strategy is to pulse DC *ex vivo* and deliver them to patients. In this context, the sipuleucel-T vaccine (patient-derived moDC pulsed *ex vivo* with PAP, a prostate-specific antigen, and GM-CSF) was approved in prostate cancer, because of its significant but small survival benefit over the placebo.<sup>191</sup> Other clinical trials using pulsed autologous DC are currently ongoing or terminated with preliminary mixed results.<sup>192-194</sup> For instance, in the phase 2 clinical trial NCT01446731, patients with metastatic castration-resistant prostate cancer (mCRPC) received a DC-based vaccine in combination with docetaxel chemotherapy. To do so, autologous DC were electroporated with mRNAs encoding prostate-specific antigen (PSA), prostatic acid phosphatase (PAP), survivin, and human telomerase reverse transcriptase (hTERT).<sup>195</sup> The combination therapy demonstrated an acceptable safety profile, with minimal toxicity observed. However, no significant improvements in survival outcomes were reported compared to chemotherapy alone. Conversely, the phase 1/2 trial NCT01197625 investigated the use of autologous DC transfected with total RNA extracted from high-risk prostate cancer following radical prostatectomy or with synthetic mRNAs encoding hTERT and survivin.<sup>196</sup> The treatment was well tolerated, with no significant adverse events reported. Notably, 11 out of 20 patients remained free of biochemical recurrence (BCR) for a median of 96 months. Among patients with extraprostatic extension, those who exhibited immunologic responses to the vaccine experienced significantly longer BCR compared to nonresponders.

Moreover, a phase 2 clinical trial assessed the efficacy of TriMix mRNA—comprising mRNA encoding CD40L, CD70, and caTLR4 (a constitutively active variant of Toll-like receptor 4), and mRNAs encoding one melanoma-associated antigen—for electroporating autologous DC and delivering them in combination with the anti-CTLA4 ipilimumab in patients with advanced melanoma.<sup>197</sup> This combination therapy elicited significant tumor-specific CD4<sup>+</sup> and CD8<sup>+</sup> T cell responses, particularly among patients with stage III disease. Importantly, patients demonstrating strong IFN-γ-producing CD8<sup>+</sup> T-cell responses exhibited a longer overall survival, underscoring the correlation between functional T-cell responses and clinical outcomes.<sup>198</sup>

Notably, given the complex process involved in isolating and loading autologous DC *ex vivo* in a clinical setting, allogeneic DC and “semi-allogeneic” DC (with one haplotype mismatch) have also been investigated in clinical trials. Overall, allogeneic DCs seem to induce less antitumor response than autologous or “semiallogeneic” DCs do.<sup>199-202</sup> However, in a phase II trial, vaccination of relapsed high-grade glioblastoma patients using heterokaryons (allogeneic DC fused with autologous tumor cells) significantly
<figure><img src="image_20.png" /></figure>

improved overall survival compared with that of matched nonvaccinated patients, showing the interest of boosting antigen presentation with allogeneic effects.²⁰³

MoDCs are used for the majority of DC-based therapies because of their relatively easy generation protocol via culturing patient bone marrow or blood-derived myeloid cells with GM-CSF and IL-4. MoDC vaccines are relatively safe and can induce antitumor immunity, but their clinical efficacy is limited.²⁰⁴ However, the majority of clinical trials employing this strategy were conducted prior to the emergence of modern technologies for cancer antigen identification and the adoption of differentiation protocols resulting in immature moDCs, which may have limited their immunogenic ability.²⁰⁵ As we described above, another reason for this limited efficacy may be the less efficient antigen cross-presentation and CTL activation of moDC compared to cDC, which limits their ability to induce an *in vivo* antitumor response. Finally, cDC1 and moDC vaccines seem to differ from a mechanistic point of view. Indeed, it was shown in mouse models that moDC-based vaccine efficacy requires antigen transfer to host cDC1 to mount an efficient immune response, while cDC1-based vaccines are independent of host cDCs.²⁰⁶

In this regard, more recent trials have evaluated autologous pDC and cDC2 vaccines in metastatic melanoma patients, but even though antigen-specific T cell responses have been shown in phase I/II trials,²⁰⁷⁻²⁰⁹ no relapse-free survival benefit was reached in a phase III trial comparing the combination of autologous pDC and cDC2 adjuvant therapy versus placebo in resected stage III melanoma.²¹⁰

As described above, antigen uptake by cDC1 could induce strong activation of TAA-specific CD8 T lymphocytes by cross-presentation. *Ex vivo*-generated cDC1 are similar to their natural counterparts in terms of their gene expression profile, response to poly(I:C) and cytokine production.¹² A phase I trial showed feasibility and early signs of antitumor activity induced by an intratumoral co-injection of autologous unpulsed cDC1 and cDC2 in ICB-refractory melanoma patients.²¹¹ Further studies are needed to evaluate the efficacy of vaccination using pulsed cDC1 alone in humans.

## Promoting endogenous DC activity in vivo

Directly activating DC within the tumor microenvironment may be an alternative strategy to enhance local immune priming and promote a robust systemic antitumor response against initial and new tumor epitopes. This concept is reinforced by emerging evidence highlighting the importance of epitope spreading as a key mechanism contributing to effective and sustained antitumor immunity. This process involves the expansion of the T-cell response to recognize tumor-associated antigens beyond the initially targeted epitope. Typically, epitope spreading is triggered following therapeutic interventions that mediate tumor cell lysis, leading to the release of additional tumor antigens into the microenvironment. These antigens are subsequently captured, processed, and presented by DC thereby facilitating the activation of novel T-cell clones or the re-engagement of pre-existing tumor-reactive T cells.²¹²

For instance, CD40 agonists can be exploited to activate DCs, particularly cDC1. The anti-CD40 agonist antibody sotigalimumab associated to nivolumab (anti-PD-1), was shown to provide a long-lasting tumor response in a subgroup of melanoma patients who progress to immune checkpoint inhibitors.²¹³ Conversely, the association of sotigalimumab and gemcitabine/nab-paclitaxel and/or nivolumab did not show relevant clinical benefits in advanced pancreatic cancers.²¹⁴ Interestingly, despite the absence of benefit to the intention-to-treat population, higher pretreatment frequencies of cross-presenting DC and Tbet⁺ CD4 Th1 cells were associated with longer survival. Several treatment-related toxicities, including cytokine release syndrome (CRS), hepatotoxicity, and thrombocytopenia were observed in a majority of patients.

Thus, the development of new strategies with limited side effects and even more specific delivery to DCs has been explored. For instance, bispecific antibodies targeting CD40 activation preferentially on DC by coupling CD40 agonist arm with CD11c-, DEC-205-, or CLEC9A-targeting arms showed a better safety profile compared to CD40 antibodies while triggering potent antitumor activity in mouse models.²¹⁵

Moreover, as largely used for T cells, targeting immune checkpoint receptors on DC may be interesting both at precancer and invasive cancer stages. In particular, TIM-3 blockade at the precancer stage was shown to decrease the tumor burden through enhanced antigen presentation in lung adenocarcinoma mouse models.²¹⁶ Furthermore, targeting TIM-3 in triple-negative and luminal B mouse models improved
<figure><img src="image_21.png" /></figure>

the response to paclitaxel chemotherapy in a Batf3-, Irf8-, and CXCR3-dependent manner.²¹⁷ Alternatively, the efficacy of PD-L1 blockade seems to depend more on PD-L1 expressed on DCs rather than on tumor cells.²¹⁸ Further investigations of other immune checkpoint blockades that more specifically target DCs in preclinical and clinical trials remain to be performed.

Similarly, AcTakines (activity-on-target-cytokines) consist of mutated cytokines coupled to a specific targeting domain to reduce the side effects of cytokine-based strategies to boost DCs *in vivo*. A bispecific CLEC9A/PD-L1-targeted actaferon has been recently engineered to specifically release the IFN I payload to CLEC9A⁺ cDC1 and PD-L1-positive immune and cancer cells.²¹⁹ Bispecific CLEC9A/PD-L1-targeted actaferon drove tumor control in a mouse model, accompanied by changes in the levels of various cell types, including myeloid cells, DC antigen-specific CTLs, NK, and NKT cells, as well as a decrease in tumor-resident Treg.

Conversely, engineering DC to directly overexpress cytokines, which can then be released in a paracrine manner or displayed on the cell surface, is a promising strategy to optimize cytokine delivery to interacting DC and surrounding T and B cells.¹⁶²,²²⁰,²²¹ Notably, human DC progenitors engineered to express IL-12 and FLT3L were able to differentiate into cDC1 and suppressed tumor growth in melanoma and liver models without requiring preloading of antigens.²²¹

Additionally, DC metabolic modulation represents another promising approach, since DC activity is tightly linked to their bioenergetic state.²²² For example, the increase in aerobic glycolysis (glycolytic burst) and fatty acid synthesis (FAS) induced by PRR engagement allows DC activation.²²³ In contrast, excess lipid droplet biogenesis after PPARα signaling or fatty acid oxidation induced by AMPK activation skews DCs toward a tolerogenic state.²²⁴,²²⁵ Importantly, the activity of metabolic pathways may vary depending on DC subsets, features of the microenvironment (e.g., pH, hypoxia) and the timepoint following antigen engulfment.²²⁶ Interestingly, the anti-diabetic agent metformin has been tested in the clinic to treat cancer patients because of its anti-proliferative effects on tumor cells, but it has also been described as an inducer of tolerogenic DC, which may explain mitigated clinical outcomes.²²⁷⁻²²⁹ Further preclinical and clinical investigations of pharmaceutical molecules to boost DC metabolism and override TME immunosuppression are needed.

Beyond the activation of tissue-infiltrating DC, recalling antigen presenting cells at the tumor site might be an interesting strategy to overcome resistance to cell-based therapy in cold tumors. For instance, systemic administration of the growth factor FLT3L can recall and activate CD103⁺ DC in a mouse model, enhancing tumor responses to anticancer treatments.²⁸,²³⁰ In this context, the use of chemokines as immunological adjuvants in cancer vaccines is currently under investigation. In preclinical studies, CCL21 has demonstrated the ability to enhance the recruitment and activation of DC and T lymphocytes, thereby improving antitumor immune responses across multiple cancer types.²³¹,²³²

*Ex vivo*-derived MoDCs engineered with adenoviral vectors to express CCL21, enhanced intratumoral infiltration of CD4⁺ and CD8⁺ T cells as well as DEC205⁺ cDC1 in murine models.²³³ This approach was subsequently evaluated in phase I clinical trials in NSCLC, where a subset of patients exhibited systemic antigen-specific immune responses, increased tumor infiltration by CD8⁺ T cells, and upregulation of PD-L1 within the tumor microenvironment, highlighting its potential for combination with PD-1/PD-L1 blockade.²³⁴,²³⁵

Moreover, considering the central role of T cell-DC cross-talk within the TME to elicit an effective antitumor response, a new family of bispecific dendritic-T cell engager (BiCE) was developed with the aim of promoting physical interaction between DC and T cells in the TME. CLEC9A-PD1-targeted BiCE is the first-in-class molecule able to promote the interaction between cDC1 and PD1⁺ T cells in dLN.²³⁶ In a preclinical B16-OVA melanoma mouse model, it promoted cDC1-CD8⁺ cross-talk and antitumor immunity at both the tumor bed and dLN.

Finally, a more recently innovative approach was proposed to reprogram tumor cells to exhibit dendritic cell-like functions, with the capacity to present antigens and mount tumor-specific T cell responses.²³⁷ In a murine immune-competent melanoma model, intratumoral delivery by adenoviral vectors of key transcription factors, PU.1, IRF8, and BATF3 (PIB), led to *in vivo* generation of cDC1-like cells within tumors. Moreover, it resulted in TME remodeling, the formation of TLS and the expansion of polyclonal cytotoxic and memory T cells. Interestingly, this strategy demonstrated a synergistic therapeutic effect with anti-PD-1 or anti-CTLA-4 immunotherapies. However, further
<figure><img src="image_22.png" /></figure>

investigations are needed to understand the clinical relevance of this approach, especially in the metastatic setting.

## Future of DCs in cancer

The advent of high-dimensional technologies such as mass cytometry (CyTOF), flow/spectral cytometry, and single-cell RNA sequencing (scRNA-seq) permitted extensive characterization of previously identified DC populations as well as the discovery of new DC subsets.<sup>45,50,238</sup> However, the tissue environment and the activation state of DC can significantly influence their phenotype, transcriptomic profile, and functional properties. Thus, distinguishing between new populations of cells from simply different activation states of the same cell population represents a technical challenge. While genetic fluorescent trackers can help to address this challenge in mouse models, human studies need to rely on multiomics approaches (including epigenetics, proteomics, transcriptomics, and ribosome profiling) to better delineate the evolution of DC populations within the TME, healthy tissues, and SLO.

Moreover, the above technologies require tissue dissociation and cannot provide the spatial context to demonstrate cell-to-cell interactions or niche localization, which could hint at the functional properties of subsets. In this context, technologies that preserve spatial information such as multiplex immuno-fluorescence,<sup>239-242</sup> spatial transcriptomics,<sup>243</sup> and proteomics<sup>244</sup> will be essential for accurately defining the localization of DC within their ecosystem and better understanding of their neighborhood and functions.

Moreover, DC must be seen as an evolutive compartment throughout tumor development in terms of phenotype, interaction, and function. The comparison of DC in the TME and SLO at different cancer stages will bring key insights to predict cancer progression and establish new immune interception therapies and cancer vaccines.<sup>216,245,246</sup> Despite the poor clinical efficacy of historical DC-based vaccine strategies for solid cancers, especially in advanced stages, new technologies promoting DC activation, DC-T cell cross-talk, and limiting the treatment-related side effects at the early stage may pave the way for a new era of DC-based cancer therapies.

From this therapeutic perspective, understanding of DC subset heterogeneity and the development of protocols to generate custom-made DC will allow to improve DC vaccines. In particular, the use of antigen-pulsed moDCs may be replaced with more tailored DC such as cDC1, coupled with adjuvants, loaded with tumor-specific antigens, and equipped with receptors/ligands, using mRNA technology, to efficiently activate T cells once they are administered to patients. The choice of antigen is a critical step that depends on the patient's tumor characteristics (tissue of origin of tumor cells, DNA mutations/amplifications, RNA expression/translation, and immunopeptidome). For this purpose, it is important to consider not only neoepitopes derived from nonsynonymous DNA mutations but also peptides (in particular, MHC-associated peptides assessed by mass spectrometry) derived from unmutated aberrantly expressed genomic regions or noncanonical splicing, which may represent the majority of peptides presented by tumor cells.<sup>247-251</sup>

Regarding strategies to harness DC potential *in vivo*, we believe that future treatments will likely need to integrate several synergistic mechanisms highlighted in this review. These include tumor antigen specificity, DC-targeted delivery, the induction of ICD, and direct DC stimulation, as key components for an effective DC-driven antitumor response. In this context, ADC and bi-/tri-specific antibodies represent promising avenues to achieve such combinatorial effects.<sup>252</sup> Ideally, the next generation of drugs would be designed as multifunctional antibodies or molecular platforms capable of simultaneously engaging a tumor antigen, a DC receptor, and a DC-activating molecule while also delivering a cytotoxic payload to induce ICD or ICD-like cell death.

Finally, trained immunity, defined by epigenetic imprinting and metabolic rewiring of myeloid progenitors and innate immune cells, represents a powerful potential strategy to strengthen DC functions to prevent cancer emergence or recurrence.<sup>253,254</sup> This mechanism has been extensively described using BCG vaccination or other inflammatory stimuli, such as heat-killed *M. tuberculosis* or β-glucans.<sup>253,255</sup> Translating these insights into clinical practice will require further development and careful evaluation of potential risks such as autoimmunity.
<figure><img src="image_23.png" /></figure>

## Author contributions

All the authors conceptualized the review and schemes, reviewed the literature, contributed to discussion of the content, and reviewed and/or edited the manuscript before submission. L. Laoubi and E. Gobbini wrote the article and generated the figures.

## Disclosure statement

Elisa Gobbini: speaker bureau for Merck Sharp & Dohme, Bristol-Myers Squibb, Regeneron, Sanofi, and Janssen.
Spouse of an AstraZeneca employee. Other authors declare no conflicts of interest.

## ORCID

Léo Laoubi ID 0000-0001-9388-4826

Elisa Gobbini ID 0000-0002-0555-5836

Pierre Duplouye ID 0009-0009-4131-8166

Margaux Hubert ID 0000-0003-2584-6494

Christophe Caux ID 0000-0003-2438-833X

Nathalie Bendriss-Vermare ID 0000-0002-8771-3585

Aurélien Voissière ID 0000-0001-7811-3919

## Data availability statement

Data sharing is not applicable to this article, as no data were created or analyzed in this study.

## Funding

This work was supported by INSERM, CNRS, Centre Léon Bérard, INCA (PRTK number 2022-186), Fondation ARC pour la recherche sur le cancer (AAP Sign'IT 2023030006402), Ligue contre le Cancer (Nationale, Régionale Auvergne-Rhône-Alpes et Saône et-Loire, Comité de la Savoie), the Région Rhône-Alpes Auvergne, the LABEX DEVWeCAN (ANR-10-LABX-0061) of the University of Lyon, within the program "Investissements d'Avenir" organized by the French National Research Agency (ANR). Elisa Gobbini was supported by ESMO (any views, opinions, findings, conclusions, or recommendations expressed in this material are those of the authors and do not necessarily reflect those of ESMO) and ITMO INSERM.

## References

1. Waldman AD, Fritz JM, Lenardo MJ. A guide to cancer immunotherapy: from T cell basic science to clinical practice. Nat Rev Immunol. 2020;20:651-668. doi: 10.1038/s41577-020-0306-5.

2. Fitzsimmons TS, Singh N, Walker TDJ, Newton C, Evans DGR, Crosbie EJ, Ryan NAJ. Immune checkpoint inhibitors efficacy across solid cancers and the utility of PD-L1 as a biomarker of response: a systematic review and meta-analysis. Front Med. 2023;10:1192762. doi: 10.3389/fmed.2023.1192762.

3. Yan T, Yu L, Zhang J, Chen Y, Fu Y, Tang J, Liao D. Achilles' Heel of currently approved immune checkpoint inhibitors: immune related adverse events. Front Immunol. 2024;15:1292122. doi: 10.3389/fimmu.2024.1292122.

4. Iberg CA, Jones A, Hawiger D. Dendritic cells as inducers of peripheral tolerance. Trends Immunol. 2017;38:793-804. doi: 10.1016/j.it.2017.07.007.

5. Man SM, Jenkins BJ. Context-dependent functions of pattern recognition receptors in cancer. Nat Rev Cancer. 2022;22:397-413. doi: 10.1038/s41568-022-00462-5.

6. Bosteels V, Maréchal S, De Nolf C, Rennen S, Maelfait J, Tavernier SJ, Vetters J, Van De Velde E, Fayazpour F, Deswarte K, et al. LXR signaling controls homeostatic dendritic cell maturation. Sci Immunol. 2023;8:eadd3955. doi: 10.1126/sciimmunol.add3955.

7. Bosteels V, Janssens S. Striking a balance: new perspectives on homeostatic dendritic cell maturation. Nat Rev Immunol. 2024;25:1-16. doi: 10.1038/s41577-024-01079-5.

8. Heidkamp GF, Sander J, Lehmann CHK, Heger L, Eissing N, Baranska A, Lühr JJ, Hoffmann A, Reimer KC, Lux A, et al. Human lymphoid organ dendritic cell identity is predominantly dictated by ontogeny, not tissue microenvironment. Sci Immunol. 2016;1:eaai7677. doi: 10.1126/sciimmunol.aai7677.

9. Dudziak D, Kamphorst AO, Heidkamp GF, Buchholz VR, Trumpfheller C, Yamazaki S, Cheong C, Liu K, Lee H, Park CG, et al. Differential antigen processing by dendritic cell subsets in vivo. Science. 2007;315:107-111. doi: 10.1126/science.1136080.
<figure><img src="image_24.png" /></figure>

10. Grajales-Reyes GE, Iwata A, Albring J, Wu X, Tussiwand R, KC W, Kretzer NM, Briseño CG, Durai V, Bagadia P, et al. Batf3 maintains autoactivation of Irf8 for commitment of a CD8α + conventional DC clonogenic progenitor. Nat Immunol. 2015;16:708-717. doi: 10.1038/ni.3197.

11. Hambleton S, Salem S, Bustamante J, Bigley V, Boisson-Dupuis S, Azevedo J, Fortin A, Haniffa M, Ceron-Gutierrez L, Bacon CM, et al. IRF8 mutations and human dendritic-cell immunodeficiency. N Engl J Med. 2011;365:127-138. doi: 10.1056/NEJMoa1100066.

12. Poulin LF, Salio M, Griessinger E, Anjos-Afonso F, Craciun L, Chen J, Keller AM, Joffre O, Zelenay S, Nye E, et al. Characterization of human DNGR-1+ BDCA3+ leukocytes as putative equivalents of mouse CD8α+ dendritic cells. J Exp Med. 2010;207:1261-1271. doi: 10.1084/jem.20092618.

13. Ou F, Ferris ST, Kim S, Wu R, Anderson DA, Liu T, Jo S, Chen MY, Gillanders WE, Murphy TL. Enhanced in vitro type 1 conventional dendritic cell generation via the recruitment of hematopoietic stem cells and early progenitors by Kit ligand. Eur J Immunol. 2023;53:e2250201. doi: 10.1002/eji.202250201.

14. Kirkling ME, Cytlak U, Lau CM, Lewis KL, Resteu A, Khodadadi-Jamayran A, Siebel CW, Salmon H, Merad M, Tsirigos A, et al. Notch signaling facilitates in vitro generation of cross-presenting classical dendritic cells. Cell Rep. 2018;23:3658-3672.e6. doi: 10.1016/j.celrep.2018.05.068.

15. Lellahi SM, Azeem W, Hua Y, Gabriel B, Paulsen Rye K, Reikvam H, Kalland K. GM-CSF, Flt3-L and IL-4 affect viability and function of conventional dendritic cell types 1 and 2. Front Immunol. 2023;13. doi: 10.3389/fimmu.2022.1058963.

16. Heger L, Hatscher L, Liang C, Lehmann CHK, Amon L, Lühr JJ, Kaszubowski T, Nzirorera R, Schaft N, Dörrie J, et al. XCR1 expression distinguishes human conventional dendritic cell type 1 with full effector functions from their immediate precursors. Proc Natl Acad Sci. 2023;120:e2300343120. doi: 10.1073/pnas.2300343120.

17. Barclay AN, Van den Berg TK. The interaction between signal regulatory protein alpha (SIRPα) and CD47: structure, function, and therapeutic target. Annu Rev Immunol. 2014;32:25-50. doi: 10.1146/annurev-immunol-032713-120142.

18. Jaiswal S, Jamieson CH, Pang WW, Park CY, Chao MP, Majeti R, Traver D, van Rooijen N, Weissman IL. CD47 is upregulated on circulating hematopoietic stem cells and leukemia cells to avoid phagocytosis. Cell. 2009;138:271-285. doi: 10.1016/j.cell.2009.05.046.

19. Gilmour BC, Corthay A, Øynebråten I. High production of IL-12 by human dendritic cells stimulated with combinations of pattern-recognition receptor agonists. NPJ Vaccines. 2024;9:1-12.

20. Meiser P, Knolle MA, Hirschberger A, de Almeida GP, Bayerl F, Lacher S, Pedde A, Flommersfeld S, Hönninger J, Stark L, et al. A distinct stimulatory cDC1 subpopulation amplifies CD8+ T cell responses in tumors for protective anti-cancer immunity. Cancer Cell. 2023;41:1498-1515.e10. doi: 10.1016/j.ccell.2023.06.008.

21. Hubert M, Gobbini E, Couillault C, Manh TV, Doffin A, Berthet J, Rodriguez C, Ollion V, Kielbassa J, Sajous C, et al. IFN-III is selectively produced by cDC1 and predicts good clinical outcome in breast cancer. Sci Immunol. 2020;5:3942. doi: 10.1126/sciimmunol.aav3942.

22. Nguyen KB, Roerden M, Copeland CJ, Backlund CM, Klop-Packel NG, Remba T, Kim B, Singh NK, Birnbaum ME, Irvine DJ, et al. Decoupled neoantigen cross-presentation by dendritic cells limits anti-tumor immunity against tumors with heterogeneous neoantigen expression. eLife. 2023;12:e85263. doi: 10.7554/eLife.85263.

23. Caronni N, Piperno GM, Simoncello F, Romano O, Vodret S, Yanagihashi Y, Dress R, Dutertre C, Bugatti M, Bourdeley P, et al. TIM4 expression by dendritic cells mediates uptake of tumor-associated antigens and anti-tumor responses. Nat Commun. 2021;12:2237. doi: 10.1038/s41467-021-22535-z.

24. Spranger S, Dai D, Horton B, Gajewski TF. Tumor-residing Batf3 dendritic cells are required for effector T cell trafficking and adoptive T cell therapy. Cancer Cell. 2017;31:711-723.e4. doi: 10.1016/j.ccell.2017.04.003.

25. Böttcher JP, Bonavita E, Chakravarty P, Blees H, Cabeza-Cabrerizo M, Sammicheli S, Rogers NC, Sahai E, Zelenay S, Reis e Sousa C. NK cells stimulate recruitment of cDC1 into the tumor microenvironment promoting cancer immune control. Cell. 2018;172:1022-1037.e14. doi: 10.1016/j.cell.2018.01.004.

26. Michea P, Noël F, Zakine E, Czerwinska U, Sirven P, Abouzid O, Goudot C, Scholer-Dahirel A, Vincent-Salomon A, Reyal F, et al. Adjustment of dendritic cells to the breast-cancer microenvironment is subset specific. Nat Immunol. 2018;19:885-897. doi: 10.1038/s41590-018-0145-8.

27. Roberts EW, Broz ML, Binnewies M, Headley MB, Nelson AE, Wolf DM, Kaisho T, Bogunovic D, Bhardwaj N, Krummel MF. Critical role for CD103(+)/CD141(+) dendritic cells bearing CCR7 for tumor antigen trafficking and priming of T cell immunity in melanoma. Cancer Cell. 2016;30:324-336. doi: 10.1016/j.ccell.2016.06.003.

28. Salmon H, Idoyaga J, Rahman A, Leboeuf M, Remark R, Jordan S, Casanova-Acebes M, Khudoynazarova M, Agudo J, Tung N, et al. Expansion and activation of CD103(+) dendritic cell progenitors at the tumor site enhances tumor responses to therapeutic PD-L1 and BRAF inhibition. Immunity. 2016;44:924-938. doi: 10.1016/j.immuni.2016.03.012.

29. Ferris ST, Durai V, Wu R, Theisen DJ, Ward JP, Bern MD, Davidson JT, Bagadia P, Liu T, Briseño CG, et al. cDC1 prime and are licensed by CD4+ T cells to induce anti-tumour immunity. Nature. 2020;584:624-629. doi: 10.1038/s41586-020-2611-3.

30. Bayerl F, Meiser P, Donakonda S, Hirschberger A, Lacher SB, Pedde A, Hermann CD, Elewaut A, Knolle M, Ramsauer L, et al. Tumor-derived prostaglandin E2 programs cDC1 dysfunction to impair intratumoral orchestration of anti-cancer T cell responses. Immunity. 2023;56:1341-1358.e11. doi: 10.1016/j.immuni.2023.05.011.
<figure><img src="image_25.png" /></figure>

31. Kim S, Chen J, Jo S, Ou F, Ferris ST, Liu T, Ohara RA, Anderson DA, Wu R, Gillanders WE, et al. IL-6 selectively suppresses cDC1 specification via C/EBPβ. J Exp Med. 2023;220:e20221757. doi: 10.1084/jem.20221757.

32. Giampazolias E, Schulz O, Lim KHJ, Rogers NC, Chakravarty P, Srinivasan N, Gordon O, Cardoso A, Buck MD, Poirier EZ, et al. Secreted gelsolin inhibits DNGR-1-dependent cross-presentation and cancer immunity. Cell. 2021;184:4016-4031.e22. doi: 10.1016/j.cell.2021.05.021.

33. Wennerberg E, Spada S, Rudqvist N, Lhuillier C, Gruber S, Chen Q, Zhang F, Zhou XK, Gross SS, Formenti SC, et al. CD73 blockade promotes dendritic cell infiltration of irradiated tumors and tumor rejection. Cancer Immunol Res. 2020;8:465-478. doi: 10.1158/2326-6066.CIR-19-0449.

34. Kim N, Lee K, Hong Y, Cho JH, Choi JW, Suh Y, Ku BM, Eum HH, Joung J, Park W, et al. Single-cell RNA sequencing demonstrates the molecular and cellular reprogramming of metastatic lung adenocarcinoma. Nat Commun. 2020;11:2285. doi: 10.1038/s41467-020-16164-1.

35. Dutertre C-A, Becht E, Irac SE, Khalilnezhad A, Narang V, Ng PY, van den Hoogen LL, Leong JY, Lee B, Chevrier M, et al. Single-cell analysis of human mononuclear phagocytes reveals subset-defining markers and identifies circulating inflammatory dendritic cells. Immunity. 2019;51:573-589.e8. doi: 10.1016/j.immuni.2019.08.008.

36. Cheng S, Li Z, Gao R, Xing B, Yang Y, Qin S, Zhang L, Ouyang H, Du P, Jiang L, et al. A pan-cancer single-cell transcriptional atlas of tumor infiltrating myeloid cells. Cell. 2021;184:792-809.e23. doi: 10.1016/j.cell.2021.01.010.

37. Binnewies M, Mujal AM, Pollack JL, Combes AJ, Hardison EA, Barry KC, Tsui J, Ruhland MK, Kersten K, Abushawish MA, et al. Unleashing type-2 dendritic cells to drive protective antitumor CD4 + T cell immunity. Cell. 2019;177:556-571.e16. doi: 10.1016/j.cell.2019.02.005.

38. Ruhland MK, Roberts EW, Cai E, Mujal AM, Marchuk K, Beppler C, Nam D, Serwas NK, Binnewies M, Krummel MF. Visualizing synaptic transfer of tumor antigens among dendritic cells. Cancer Cell. 2020;37:786-799.e5. doi: 10.1016/j.ccell.2020.05.002.

39. Pirillo C, Al Khalidi S, Sims A, Devlin R, Zhao H, Pinto R, Jasim S, Shearer PA, Shergold AL, Donnelly H, et al. Co-transfer of antigen and contextual information harmonises peripheral and lymph node cDC activation. Sci Immunol. 2023;8:eadg8249. doi: 10.1126/sciimmunol.adg8249.

40. Duong E, Fessenden TB, Lutz E, Dinter T, Yim L, Blatt S, Bhutkar A, Wittrup KD, Spranger S. Type I interferon activates MHC class I-dressed CD11b+ conventional dendritic cells to promote protective anti-tumor CD8+ T cell immunity. Immunity. 2022;55:308-323.e9. doi: 10.1016/j.immuni.2021.10.020.

41. Zhang X, Artola-Boran M, Fallegger A, Arnold IC, Weber A, Reuter S, Taube C, Müller A. IRF4 expression is required for the immunoregulatory activity of conventional type 2 dendritic cells in settings of chronic bacterial infection and cancer. J Immunol Baltim. 2020;205:1933-1943.

42. Villani A-C, Satija R, Reynolds G, Sarkizova S, Shekhar K, Fletcher J, Griesbeck M, Butler A, Zheng S, Lazo S, et al. Single-cell RNA-seq reveals new types of human blood dendritic cells, monocytes, and progenitors. Science. 2017;356:283. doi: 10.1126/science.aah4573.

43. Bourdely P, Anselmi G, Vaivode K, Ramos RN, Missolo-Koussou Y, Hidalgo S, Tosselo J, Nuñez N, Richer W, Vincent-Salomon A, et al. Transcriptional and functional analysis of CD1c+ human dendritic cells identifies a CD163+ subset priming CD8+CD103+ T cells. Immunity. 2020;53:335-352.e8. doi: 10.1016/j.immuni.2020.06.002.

44. Subtil B, van der Hoorn IAE, Cuenca-Escalona J, Becker AMD, Alvarez-Begue M, Iyer KK, Janssen J, van Oorschot T, Poel D, Gorris MAJ, et al. cDC2 plasticity and acquisition of a DC3-like phenotype mediated by IL-6 and PGE2 in a patient-derived colorectal cancer organoids model. Eur J Immunol. 2024;54:e2350891. doi: 10.1002/eji.202350891.

45. Zilionis R, Engblom C, Pfirschke C, Savova V, Zemmour D, Saatcioglu HD, Krishnan I, Maroni G, Meyerovitz CV, Kerwin CM, et al. Single-cell transcriptomics of human and mouse lung cancers reveals conserved myeloid populations across individuals and species. Immunity. 2019;50:1317-1334.e10. doi: 10.1016/j.immuni.2019.03.009.

46. Leader AM, Grout JA, Maier BB, Nabet BY, Park MD, Tabachnikova A, Chang C, Walker L, Lansky A, Le Berichel J, et al. Single-cell analysis of human non-small cell lung cancer lesions refines tumor classification and patient stratification. Cancer Cell. 2021;39:1594-1609.e12. doi: 10.1016/j.ccell.2021.10.009.

47. Maier B, Leader AM, Chen ST, Tung N, Chang C, LeBerichel J, Chudnovskiy A, Maskey S, Walker L, Finnigan JP, et al. A conserved dendritic-cell regulatory program limits antitumour immunity. Nature. 2020;580:257-262. doi: 10.1038/s41586-020-2134-y.

48. Zhang Q, He Y, Luo N, Patel SJ, Han Y, Gao R, Modak M, Carotta S, Haslinger C, Kind D, et al. Landscape and dynamics of single immune cells in hepatocellular carcinoma. Cell. 2019;179:829-845.e20. doi: 10.1016/j.cell.2019.10.003.

49. Qian J, Olbrecht S, Boeckx B, Vos H, Laoui D, Etlioglu E, Wauters E, Pomella V, Verbandt S, Busschaert P, et al. A pan-cancer blueprint of the heterogeneous tumor microenvironment revealed by single-cell profiling. Cell Res. 2020;30:745-762. doi: 10.1038/s41422-020-0355-0.

50. Gerhard GM, Bill R, Messemaker M, Klein AM, Pittet MJ. Tumor-infiltrating dendritic cell states are conserved across solid human cancers. J Exp Med. 2021;218. doi: 10.1084/jem.20200264.

51. Zhang L, Li Z, Skrzypczynska KM, Fang Q, O'Brien SA, He Y, Wang L, Kim A, Gao R, Orf J, et al. Single-cell analyses inform mechanisms of myeloid-targeted therapies in colon cancer. Cell. 2020;181:442-459.e29. doi: 10.1016/j.cell.2020.03.048.
<figure><img src="image_26.png" /></figure>

52. Ohl L, Mohaupt M, Czeloth N, Hintzen G, Kiafard Z, Zwirner J, Blankenstein T, Henning G, Förster R. CCR7 governs skin dendritic cell migration under inflammatory and steady-state conditions. Immunity. 2004;21:279-288. doi: 10.1016/j.immuni.2004.06.014.

53. Saddawi-Konefka R, Msari RA, Tang S, Philips C, Sadat S, Clubb LM, Luna S, Fassardi S, Jones R, Pietryga IF, et al. The tumor-sentinel lymph node immuno-migratome reveals CCR7+ dendritic cells drive response to sequenced immunoradiotherapy. Nat Commun. 2025;16:6578. doi: 10.1038/s41467-025-61780-4.

54. Dudek AM, Martin S, Garg AD, Agostinis P. Immature, semi-mature, and fully mature dendritic cells: toward a DC-cancer cells interface that augments anticancer immunity. Front Immunol. 2013;4:438. doi: 10.3389/fimmu.2013.00438.

55. Chudnovskiy A, Castro TBR, Nakandakari-Higa S, Cui A, Lin C, Sade-Feldman M, Phillips BK, Pae J, Mesin L, Bortolatto J, et al. Proximity-dependent labeling identifies dendritic cells that drive the tumor-specific CD4 + T cell response. Sci Immunol. 2024;9:eadq8843. doi: 10.1126/sciimmunol.adq8843.

56. Maier B, Leader AM, Chen ST, Tung N, Chang C, LeBerichel J, Chudnovskiy A, Maskey S, Walker L, Finnigan JP, et al. A conserved dendritic-cell regulatory program limits antitumour immunity. Nature. 2020;580:257-262. doi: 10.1038/s41586-020-2134-y.

57. Lee CYC, Kennedy BC, Richoz N, Dean I, Tuong ZK, Gaspal F, Li Z, Willis C, Hasegawa T, Whiteside SK, et al. Tumour-retained activated CCR7+ dendritic cells are heterogeneous and regulate local anti-tumour cytolytic activity. Nat Commun. 2024;15:682. doi: 10.1038/s41467-024-44787-1.

58. Yin Y-X, Ling Y, Wei X, He C, Wang B, Hu C, Lin W, Nie R, Chen J, Zhou J, et al. Impact of mature tertiary lymphoid structures on prognosis and therapeutic response of Epstein-Barr virus-associated gastric cancer patients. Front Immunol. 2022;13. doi: 10.3389/fimmu.2022.973085.

59. Ling Y, Zhong J, Weng Z, Lin G, Liu C, Pan C, Yang H, Wei X, Xie X, Zhang H, et al. The prognostic value and molecular properties of tertiary lymphoid structures in oesophageal squamous cell carcinoma. Clin Transl Med. 2022;12:e1074. doi: 10.1002/ctm2.1074.

60. Rodrigues PF, Alberti-Servera L, Eremin A, Grajales-Reyes GE, Ivanek R, Tussiwand R. Distinct progenitor lineages contribute to the heterogeneity of plasmacytoid dendritic cells. Nat Immunol. 2018;19:711-722. doi: 10.1038/s41590-018-0136-9.

61. Manz MG. Plasmacytoid dendritic cells: origin matters. Nat Immunol. 2018;19:652-654. doi: 10.1038/s41590-018-0143-x.

62. Ziegler-Heitbrock L, Ohteki T, Ginhoux F, Shortman K, Spits H. Reclassifying plasmacytoid dendritic cells as innate lymphocytes. Nat Rev Immunol. 2023;23:1-2. doi: 10.1038/s41577-022-00806-0.

63. Reizis B, Idoyaga J, Dalod M, Barrat F, Naik S, Trinchieri G, Tussiwand R, Cella M, Colonna M. Reclassification of plasmacytoid dendritic cells as innate lymphocytes is premature. Nat Rev Immunol. 2023;23:336-337. doi: 10.1038/s41577-023-00864-y.

64. Ziegler-Heitbrock L, Ohteki T, Ginhoux F, Shortman K, Spits H. Reply to 'Reclassification of plasmacytoid dendritic cells as innate lymphocytes is premature'. Nat Rev Immunol. 2023;23:338-339. doi: 10.1038/s41577-023-00866-w.

65. Alcantara-Hernandez M, Alcántara-Hernández M, Leylek R, Wagar LE, Engleman EG, Keler T, Marinkovich MP, Davis MM, Nolan GP, Idoyaga J. High-dimensional phenotypic mapping of human dendritic cells reveals interindividual variation and tissue specialization. Immunity. 2017;47:1037-1050.e6. doi: 10.1016/j.immuni.2017.11.001.

66. Alculumbre SG, Saint-André V, Di Domizio J, Vargas P, Sirven P, Bost P, Maurin M, Maiuri P, Wery M, Roman MS, et al. Diversification of human plasmacytoid predendritic cells in response to a single stimulus. Nat Immunol. 2018;19:63-75. doi: 10.1038/s41590-017-0012-z.

67. van Dijk FAW, Warner van Dijk FA, Tong O, O'Neil TR, Bertram KM, Hu K, Baharlou H, Vine EE, Jenns K, Gosselink MP, et al. Characterising plasmacytoid and myeloid AXL+ SIGLEC-6+ dendritic cell functions and their interactions with HIV. PLOS Pathog. 2024;20:e1012351. doi: 10.1371/journal.ppat.1012351.

68. Oberkampf M, Guillerey C, Mouriès J, Rosenbaum P, Fayolle C, Bobard A, Savina A, Ogier-Denis E, Enninga J, Amigorena S, et al. Mitochondrial reactive oxygen species regulate the induction of CD8+ T cells by plasmacytoid dendritic cells. Nat Commun. 2018;9:2241. doi: 10.1038/s41467-018-04686-8.

69. Cella M, Jarrossay D, Facchetti F, Alebardi O, Nakajima H, Lanzavecchia A, Colonna M. Plasmacytoid monocytes migrate to inflamed lymph nodes and produce large amounts of type I interferon. Nat Med 1999;5:919-923. doi: 10.1038/11360.

70. Seth S, Oberdörfer L, Hyde R, Hoff K, Thies V, Worbs T, Schmitz S, Förster R. CCR7 essentially contributes to the homing of plasmacytoid dendritic cells to lymph nodes under steady-state as well as inflammatory conditions. J Immunol Baltim. 2011;186:3364-3372.

71. Bekeredjian-Ding I, Bekeredjian-Ding I, Schäfer M, Hartmann E, Pries R, Parcina M, Schneider P, Giese T, Endres S, Wollenberg B. Tumour-derived prostaglandin E and transforming growth factor-beta synergize to inhibit plasmacytoid dendritic cell-derived interferon-alpha. Immunology. 2009;128:439-450. doi: 10.1111/j.1365-2567.2009.03134.x.

72. Sisirak V, Vey N, Goutagny N, Renaudineau S, Malfroy M, Thys S, Treilleux I, Labidi-Galy SI, Bachelot T, Dezutter-Dambuyant C, et al. Breast cancer-derived transforming growth factor-β and tumor necrosis factor-α
<figure><img src="image_27.png" /></figure>

compromise interferon-α production by tumor-associated plasmacytoid dendritic cells. Int J Cancer. 2013;133:771-778. doi: 10.1002/ijc.28072.

73. Labidi-Galy SI, Sisirak V, Meeus P, Gobert M, Treilleux I, Bajard A, Combes J, Faget J, Mithieux F, Cassignol A, et al. Quantitative and functional alterations of plasmacytoid dendritic cells contribute to immune tolerance in ovarian cancer. Cancer Res. 2011;71:5423-5434. doi: 10.1158/0008-5472.CAN-11-0367.

74. Sisirak V, Faget J, Gobert M, Goutagny N, Vey N, Treilleux I, Renaudineau S, Poyet G, Labidi-Galy SI, Goddard-Leon S, et al. Impaired IFN-α production by plasmacytoid dendritic cells favors regulatory T-cell expansion that may contribute to breast cancer progression. Cancer Res. 2012;72:5188-5197. doi: 10.1158/0008-5472.CAN-11-3468.

75. Sosa Cuevas E, Bendriss-Vermare N, Mouret S, De Fraipont F, Charles J, Valladeau-Guilemond J, Chaperot L, Aspord C. Diversification of circulating and tumor-infiltrating plasmacytoid DCs towards the P3 (CD80+ PDL1-)-pDC subset negatively correlated with clinical outcomes in melanoma patients. Clin Transl Immunol. 2022;11:e1382. doi: 10.1002/cti2.1382.

76. Cytlak U, Resteu A, Pagan S, Green K, Milne P, Maisuria S, McDonald D, Hulme G, Filby A, Carpenter B, et al. Differential IRF8 transcription factor requirement defines two pathways of dendritic cell development in humans. Immunity. 2020;53:353-370.e8. doi: 10.1016/j.immuni.2020.07.003.

77. See P, Dutertre C, Chen J, Günther P, McGovern N, Irac SE, Gunawan M, Beyer M, Händler K, Duan K, et al. Mapping the human DC lineage through the integration of high-dimensional techniques. Science. 2017;356:eaaq3009. doi: 10.1126/science.aag3009.

78. Sulczewski FB, Maqueda-Alfaro RA, Alcántara-Hernández M, Perez OA, Saravanan S, Yun TJ, Seong D, Arroyo Hornero R, Raquer-McKay HM, Esteva E, et al. Transitional dendritic cells are distinct from conventional DC2 precursors and mediate proinflammatory antiviral responses. Nat Immunol 2023;24:1265-1280. doi: 10.1038/s41590-023-01545-7.

79. Audiger C, Tomei S, Naik SH. tDCs — a distinct subset with dual functional and developmental roles. Nat Immunol. 2023;24:1222-1223. doi: 10.1038/S41590-023-01565-3.

80. Rodrigues PF, Kouklas A, Cvijetic G, Bouladoux N, Mitrovic M, Desai JV, Lima-Junior DS, Lionakis MS, Belkaid Y, Ivanek R, et al. pDC-like cells are pre-DC2 and require KLF4 to control homeostatic CD4 T cells. Sci Immunol. 2023;8:eadd4132. doi: 10.1126/sciimmunol.add4132.

81. Wu X, Briseño CG, Durai V, Albring JC, Haldar M, Bagadia P, Kim K, Randolph GJ, Murphy TL. Mafb lineage tracing to distinguish macrophages from other immune lineages reveals dual identity of Langerhans cells. J Exp Med. 2016;213:2553-2565. doi: 10.1084/jem.20160600.

82. De Monte A, Olivieri CV, Vitale S, Bailleux S, Castillo L, Giordanengo V, Maryanski JL, Segura E, Doglio A. CD1c-related DCs that express CD207/langerin, but are distinguishable from Langerhans cells, are consistently present in human tonsils. Front Immunol. 2016;7:25.

83. Bigley V, McGovern N, Milne P, Dickinson R, Pagan S, Cookson S, Haniffa M, Collin M. Langerin-expressing dendritic cells in human tissues are related to CD1c + dendritic cells and distinct from Langerhans cells and CD141 high XCR1 + dendritic cells. J Leukoc Biol. 2015;97:627-634. doi: 10.1189/jlb.1HI0714-351R.

84. Seneschal J, Clark RAA, Gehad A, Baecher-Allan CMM, Kupper TSS. Human epidermal langerhans cells maintain immune homeostasis in skin by activating skin resident regulatory T cells. Immunity. 2012;36:873-884. doi: 10.1016/j.immuni.2012.03.018.

85. Romano E, Cotari JW, Barreira da Silva R, Betts BC, Chung DJ, Avogadri F, Fink MJ, St Angelo ET, Mehrara B, Heller G, et al. Human Langerhans cells use an IL-15R-α/IL-15/pSTAT5-dependent mechanism to break T-cell tolerance against the self-differentiation tumor antigen WT1. Blood. 2012;119:5182-5190. doi: 10.1182/blood-2011-09-382200.

86. Ratzinger G, Baggers J, de Cos MA, Yuan J, Dao T, Reagan JL, Münz C, Heller G, Young JW. Mature human langerhans cells derived from CD34+ hematopoietic progenitors stimulate greater cytolytic T lymphocyte activity in the absence of bioactive IL-12p70, by either single peptide presentation or cross-priming, than do dermal-interstitial or monocyte-derived dendritic cells1. J Immunol. 2004;173:2780-2791.

87. Banchereau J, Thompson-Snipes L, Zurawski S, Blanck J, Cao Y, Clayton S, Gorvel J, Klechevsky E. The differential production of cytokines by human Langerhans cells and dermal CD14(+) DCs controls CTL priming. Blood. 2012;119:5742-5749. doi: 10.1182/blood-2011-08-371245.

88. Klechevsky E, Morita R, Liu M, Cao Y, Coquery S, Thompson-Snipes L, Briere F, Chaussabel D, Zurawski G, Palucka AK, et al. Functional specializations of human epidermal langerhans cells and CD14+ dermal dendritic cells. Immunity. 2008;29:497-510. doi: 10.1016/j.immuni.2008.07.013.

89. Matsui K, Mori A, Ikeda R. Langerhans cell-like dendritic cells stimulated with an adjuvant direct the development of Th1 and Th2 cells in vivo. Clin Exp Immunol. 2015;182:101-107. doi: 10.1111/cei.12671.

90. Artyomov MN, Munk A, Gorvel L, Korenfeld D, Cella M, Tung T, Klechevsky E. Modular expression analysis reveals functional conservation between human Langerhans cells and mouse cross-priming dendritic cells. J Exp Med. 2015;212:743-757. doi: 10.1084/jem.20131675.

91. Saba Y, Aizenbud I, Matanes D, Koren N, Barel O, Zubeidat K, Capucha T, David E, Eli-Berchoer L, Stoitzner P, et al. Early antitumor activity of oral Langerhans cells is compromised by a carcinogen. Proc Natl Acad Sci. 2022;119:e2118424119. doi: 10.1073/pnas.2118424119.
<figure><img src="image_28.png" /></figure>

92. Gerlini G, Susini P, Sestini S, Brandani P, Giannotti V, Borgognoni L. Langerhans cells in sentinel lymph nodes from melanoma patients. Cancers. 2024;16:1890. doi: 10.3390/cancers16101890.

93. León B, López-Bravo M, Ardavín C. Monocyte-derived dendritic cells formed at the infection site control the induction of protective T helper 1 responses against Leishmania. Immunity. 2007;26:519–531. doi: 10.1016/j.immuni.2007.01.017.

94. Segura E, Touzot M, Bohineust A, Cappuccio A, Chiocchia G, Hosmalin A, Dalod M, Soumelis V, Amigorena S. Human inflammatory dendritic cells induce Th17 cell differentiation. Immunity. 2013;38:336–348. doi: 10.1016/j.immuni.2012.10.018.

95. Sheng J, Chen Q, Soncin I, Ng SL, Karjalainen K, Ruedl C. A discrete subset of monocyte-derived cells among typical conventional type 2 dendritic cells can efficiently cross-present. Cell Rep. 2017;21:1203–1214. doi: 10.1016/j.celrep.2017.10.024.

96. Ma Y, Mattarollo SR, Adjemian S, Yang H, Aymeric L, Hannani D, Portela Catani JP, Duret H, Teng MW, Kepp O, et al. CCL2/CCR2-dependent recruitment of functional antigen-presenting cells into tumors upon chemotherapy. Cancer Res. 2014;74:436–445. doi: 10.1158/0008-5472.CAN-13-1265.

97. Kuhn S, Yang J, Ronchese F. Monocyte-derived dendritic cells are essential for CD8+ T cell activation and antitumor responses after local immunotherapy. Front Immunol. 2015;6:584. doi: 10.3389/fimmu.2015.00584.

98. Laoui D, Keirsse J, Morales Y, Van Overmeire E, Geeraerts X, Elkrim Y, Kiss M, Bolli E, Lahmar Q, Sichien D, et al. The tumour microenvironment harbours ontogenically distinct dendritic cell populations with opposing effects on tumour immunity. Nat Commun. 2016;7:13720. doi: 10.1038/ncomms13720.

99. Lehmann CHK, Baranska A, Heidkamp GF, Heger L, Neubert K, Lühr JJ, Hoffmann A, Reimer KC, Brückner C, Beck S, et al. DC subset-specific induction of T cell responses upon antigen uptake via Fcγ receptors in vivo. J Exp Med. 2017;214:1509–1528. doi: 10.1084/jem.20160951.

100. Binnewies M, Mujal AM, Pollack JL, Combes AJ, Hardison EA, Barry KC, Tsui J, Ruhland MK, Kersten K, Abushawish MA, et al. Unleashing type-2 dendritic cells to drive protective antitumor CD4+ T cell immunity. Cell. 2019;177:556–571.e16. doi: 10.1016/j.cell.2019.02.005.

101. Zhang J-G, Czabotar PE, Policheni AN, Caminschi I, San Wan S, Kitsoulis S, Tullett KM, Robin AY, Brammananth R, van Delft MF, et al. The dendritic cell receptor Clec9A binds damaged cells via exposed actin filaments. Immunity. 2012;36:646–657. doi: 10.1016/j.immuni.2012.03.009.

102. Si Y, Wang Y, Tian Q, Pollard JM, Srivastava PK, Esser-Kahn AP, Collier JH, Sperling AI, Chong AS. Lung cDC1 and cDC2 dendritic cells priming naive CD8+ T cells in situ prior to migration to draining lymph nodes. Cell Rep. 2023;42:113299. doi: 10.1016/j.celrep.2023.113299.

103. Chudnovskiy A, Castro TBR, Nakandakari-Higa S, Cui A, Lin C, Sade-Feldman M, Phillips BK, Pae J, Mesin L, Bortolatto J, et al. Proximity-dependent labeling identifies dendritic cells that drive the tumor-specific CD4+ T cell response. Sci Immunol. 2024;9:eadq8843. doi: 10.1126/sciimmunol.adq8843.

104. Crozat K, Guiton R, Contreras V, Feuillet V, Dutertre C, Ventre E, Vu Manh T, Baranek T, Storset AK, Marvel J, et al. The XC chemokine receptor 1 is a conserved selective marker of mammalian cells homologous to mouse CD8alpha+ dendritic cells. J Exp Med. 2010;207:1283–1292. doi: 10.1084/jem.20100223.

105. Dorner BG, Zhou X, Opitz C, Mora A, Güttler S, Hutloff A, Mages HW, Ranke K, Schaefer M, Jack RS, et al. Selective expression of the chemokine receptor XCR1 on cross-presenting dendritic cells determines cooperation with CD8+ T cells. Immunity. 2009;31:823–833. doi: 10.1016/j.immuni.2009.08.027.

106. Böttcher JP, Bonavita E, Chakravarty P, Blees H, Cabeza-Cabrerizo M, Sammicheli S, Rogers NC, Sahai E, Zelenay S, Reis e Sousa C. NK cells stimulate recruitment of cDC1 into the tumor microenvironment promoting cancer immune control. Cell. 2018;172:1022–1037.e14. doi: 10.1016/j.cell.2018.01.004.

107. Chen JH, Nieman LT, Spurrell M, Jorgji V, Elmelech L, Richieri P, Xu KH, Madhu R, Parikh M, Zamora I, et al. Human lung cancer harbors spatially organized stem-immunity hubs associated with response to immunotherapy. Nat Immunol. 2024;25:644–658. doi: 10.1038/s41590-024-01792-2.

108. Cohen M, Giladi A, Barboy O, Hamon P, Li B, Zada M, Gurevich-Shapiro A, Beccaria CG, David E, Maier BB, et al. The interaction of CD4+ helper T cells with dendritic cells shapes the tumor microenvironment and immune checkpoint blockade response. Nat Cancer. 2022;3:303–317. doi: 10.1038/s43018-022-00338-5.

109. Di Pilato M, Kfuri-Rubens R, Pruessmann JN, Ozga AJ, Messemaker M, Cadilha BL, Sivakumar R, Cianciaruso C, Warner RD, Marangoni F, et al. CXCR6 positions cytotoxic T cells to receive critical survival signals in the tumor microenvironment. Cell. 2021;184:4512–4530.e22. doi: 10.1016/j.cell.2021.07.015.

110. Magen A, Hamon P, Fiaschi N, Soong BY, Park MD, Mattiuz R, Humblin E, Troncoso L, D'souza D, Dawson T, et al. Intratumoral dendritic cell–CD4+ T helper cell niches enable CD8+ T cell differentiation following PD-1 blockade in hepatocellular carcinoma. Nat Med. 2023;29:1389–1399. doi: 10.1038/s41591-023-02345-0.

111. Gobbini E, Hubert M, Doffin A, Eberhardt A, Hermet L, Li D, Duplouye P, Ghamry-Barrin S, Berthet J, Benboubker V, et al. The spatial organization of cDC1 with CD8+ T cells is critical for the response to immune checkpoint inhibitors in melanoma patients. Cancer Immunol Res. 2025;13:517–526. doi: 10.1158/2326-6066.CIR-24-0421.

112. Garris CS, Arlauckas SP, Kohler RH, Trefny MP, Garren S, Piot C, Engblom C, Pfirschke C, Siwicki M, Gungabeesoon J, et al. Successful anti-PD-1 cancer immunotherapy requires T cell-dendritic cell crosstalk involving the cytokines IFN-γ and IL-12. Immunity. 2018;49:1148–1161.e7. doi: 10.1016/j.immuni.2018.09.024.
<figure><img src="image_29.png" /></figure>

113. Espinosa-Carrasco G, Chiu E, Scrivo A, Zumbo P, Dave A, Betel D, Kang SW, Jang H, Hellmann MD, Burt BM, et al. Intratumoral immune triads are required for immunotherapy-mediated elimination of solid tumors. Cancer Cell. 2024;42:1202–1216.e8. doi: 10.1016/j.ccell.2024.05.025.

114. Lei X, Khatri I, de Wit T, de Rink I, Nieuwland M, Kerkhoven R, van Eenennaam H, Sun C, Garg AD, Borst J, et al. CD4+ helper T cells endow cDC1 with cancer-impeding functions in the human tumor micro-environment. Nat Commun. 2023;14:217. doi: 10.1038/s41467-022-35615-5.

115. Ridge JP, Di Rosa F, Matzinger P. A conditioned dendritic cell can be a temporal bridge between a CD4+ T- helper and a T-killer cell. Nature. 1998;393:474–478. doi: 10.1038/30989.

116. Bennett SR, Carbone FR, Karamalis F, Flavell RA, Miller JFAP, Heath WR. Help for cytotoxic-T-cell responses is mediated by CD40 signalling. Nature. 1998;393:478–480. doi: 10.1038/30996.

117. Schoenberger SP, Toes RE, van der Voort EI, Offringa R, Melief CJ. T-cell help for cytotoxic T lymphocytes is mediated by CD40-CD40L interactions. Nature. 1998;393:480–483. doi: 10.1038/31002.

118. Jang J-E, Hajdu CH, Liot C, Miller G, Dustin ML, Bar-Sagi D. Crosstalk between regulatory T cells and tumor-associated dendritic cells negates anti-tumor immunity in pancreatic cancer. Cell Rep. 2017;20:558–571. doi: 10.1016/j.celrep.2017.06.062.

119. Sultan H, Takeuchi Y, Ward JP, Sharma N, Liu T, Sukhov V, Firulyova M, Song Y, Ameh S, Brioschi S, et al. Neoantigen-specific cytotoxic Tr1 CD4 T cells suppress cancer immunotherapy. Nature. 2024;632:182–191. doi: 10.1038/s41586-024-07752-y.

120. You S, Li S, Zeng L, Song J, Ni H, Xiao X, Deng W, Lin W, Liang C, Zheng Y, et al. Lymphatic-localized Treg-mregDC crosstalk limits antigen trafficking and restrains anti-tumor immunity. Cancer Cell. 2024;42:1415–1433.e12. doi: 10.1016/j.ccell.2024.06.014.

121. Faget J, Bendriss-Vermare N, Gobert M, Durand I, Olive D, Biota C, Bachelot T, Treilleux I, Goddard-Leon S, Lavergne E, et al. ICOS-ligand expression on plasmacytoid dendritic cells supports breast cancer progression by promoting the accumulation of immunosuppressive CD4+ T Cells. Cancer Res. 2012;72:6130–6141. doi: 10.1158/0008-5472.CAN-12-2409.

122. Faget J, Sisirak V, Blay J, Caux C, Bendriss-Vermare N, Ménétrier-Caux C. ICOS is associated with poor prognosis in breast cancer as it promotes the amplification of immunosuppressive CD4+ T cells by plasma-cytoid dendritic cells. Oncoimmunology. 2013;2:e23185. doi: 10.4161/onci.23185.

123. Conrad C, Gregorio J, Wang Y, Ito T, Meller S, Hanabuchi S, Anderson S, Atkinson N, Ramirez PT, Liu Y, et al. Plasmacytoid dendritic cells promote immunosuppression in ovarian cancer via ICOS costimulation of Foxp3(+) T-regulatory cells. Cancer Res. 2012;72:5240–5249. doi: 10.1158/0008-5472.CAN-12-2271.

124. Wei S, Kryczek I, Zou L, Daniel B, Cheng P, Mottram P, Curiel T, Lange A. Plasmacytoid dendritic cells induce CD8+ regulatory T cells in human ovarian carcinoma. Cancer Res. 2005;65:5020–5026. doi: 10.1158/0008-5472.CAN-04-4043.

125. Barry KC, Hsu J, Broz ML, Cueto FJ, Binnewies M, Combes AJ, Nelson AE, Loo K, Kumar R, Rosenblum MD, et al. A natural killer-dendritic cell axis defines checkpoint therapy-responsive tumor microenvironments. Nat Med. 2018;24:1178–1191. doi: 10.1038/s41591-018-0085-8.

126. Holmes TD, Wilson EB, Black EVI, Benest AV, Vaz C, Tan B, Tanavde VM, Cook GP. Licensed human natural killer cells aid dendritic cell maturation via TNFSF14/LIGHT. Proc Natl Acad Sci U S A. 2014;111:5688–5696. doi: 10.1073/pnas.1411072112.

127. Bosch NC, Martin L, Voskens CJ, Berking C, Seliger B, Schuler G, Schaft N, Dörrie J. A chimeric IL-15/IL-15Ra molecule expressed on NFκB-activated dendritic cells supports their capability to activate natural killer Cells. Int J Mol Sci. 2021;22:10227. doi: 10.3390/ijms221910227.

128. Allen F, Bobanga ID, Rauhe P, Barkauskas D, Teich N, Tong C, Myers J, Huang AY. CCL3 augments tumor rejection and enhances CD8+ T cell infiltration through NK and CD103+ dendritic cell recruitment via IFNγ. Oncoimmunology. 2018;7:e1393598. doi: 10.1080/2162402X.2017.1393598.

129. Deauvieau F, Ollion V, Doffin A, Achard C, Fonteneau J, Verronese E, Durand I, Ghittoni R, Marvel J, Dezutter-Dambuyant C, et al. Human natural killer cells promote cross-presentation of tumor cell-derived antigens by dendritic cells. Int J Cancer. 2015;136:1085–1094. doi: 10.1002/ijc.29087.

130. Cazzetta V, Franzese S, Carenza C, Della Bella S, Mikulak J, Mavilio D. Natural killer-dendritic cell interactions in liver cancer: implications for immunotherapy. Cancers. 2021;13:2184. doi: 10.3390/cancers13092184.

131. Russick J, Joubert P, Gillard-Bocquet M, Torset C, Meylan M, Petitprez F, Dragon-Durey M, Marmier S, Varthaman A, Josseaume N, et al. Natural killer cells in the human lung tumor microenvironment display immune inhibitory functions. J Immunother Cancer. 2020;8:e001054. doi: 10.1136/jitc-2020-001054.

132. Park JH, Lee HK. Function of γδ T cells in tumor immunology and their application to cancer therapy. Exp Mol Med. 2021;53:318–327. doi: 10.1038/s12276-021-00576-0.

133. Girard P, Charles J, Cluzel C, Degeorges E, Manches O, Plumas J, De Fraipont F, Leccia M, Mouret S, Chaperot L, et al. The features of circulating and tumor-infiltrating γδ T cells in melanoma patients display critical perturbations with prognostic impact on clinical outcome. Oncoimmunology. 2019;8:1601483. doi: 10.1080/2162402X.2019.1601483.

134. Gentles AJ, Newman AM, Liu CL, Bratman SV, Feng W, Kim D, Nair VS, Xu Y, Khuong A, Hoang CD, et al. The prognostic landscape of genes and infiltrating immune cells across human cancers. Nat Med. 2015;21:938–945. doi: 10.1038/nm.3909.
<figure><img src="image_30.png" /></figure>

135. Scotet E, Nedellec S, Devilder M-C, Allain S, Bonneville M. Bridging innate and adaptive immunity through gammadelta T-dendritic cell crosstalk. Front Biosci J Virtual Libr. 2008;13:6872-6885. doi: 10.2741/3195.

136. Fiore F, Castella B, Nuschak B, Bertieri R, Mariani S, Bruno B, Pantaleoni F, Foglietta M, Boccadoro M, Massaia M. Enhanced ability of dendritic cells to stimulate innate and adaptive immunity on short-term incubation with zoledronic acid. Blood. 2007;110:921-927. doi: 10.1182/blood-2006-09-044321.

137. Devilder M-C, Maillet S, Bouyge-Moreau I, Donnadieu E, Bonneville M, Scotet E. Potentiation of antigen-stimulated V gamma 9V delta 2 T cell cytokine production by immature dendritic cells (DC) and reciprocal effect on DC maturation. J Immunol Baltim. 2006;176:1386-1393.

138. Kunzmann V, Kretzschmar E, Herrmann T, Wilhelm M. Polyinosinic-polycytidylic acid-mediated stimulation of human gammadelta T cells via CD11c dendritic cell-derived type I interferons. Immunology. 2004;112:369-377. doi: 10.1111/j.1365-2567.2004.01908.x.

139. Dunne MR, Madrigal-Estebas L, Tobin LM, Doherty DG. (E)-4-hydroxy-3-methyl-but-2 enyl pyrophosphate-stimulated Vgamma9Vdelta2 T cells possess T helper type 1-promoting adjuvant activity for human monocyte-derived dendritic cells. Cancer Immunol Immunother. 2010;59:1109-1120. doi: 10.1007/s00262-010-0839-8.

140. Devilder M-C, Allain S, Dousset C, Bonneville M, Scotet E. Early triggering of exclusive IFN-γ responses of human Vγ9Vδ2 T cells by TLR-activated myeloid and plasmacytoid dendritic cells. J Immunol. 2009;183:3625-3633. doi: 10.4049/jimmunol.0901571.

141. Girard P, Sosa Cuevas E, Ponsard B, Mouret S, Gil H, Col E, De Fraipont F, Sturm N, Charles J, Manches O, et al. Dysfunctional BTN3A together with deregulated immune checkpoints and type I/II IFN dictate defective interplay between pDCs and γδ T cells in melanoma patients, which impacts clinical outcomes. Clin Transl Immunol. 2021;10:e1329. doi: 10.1002/cti2.1329.

142. Marin-Acevedo JA, Dholaria B, Soyano AE, Knutson KL, Chumsri S, Lou Y. Next generation of immune checkpoint therapy in cancer: new developments and challenges. J Hematol Oncol. 2018;11:39. doi: 10.1186/s13045-018-0582-8.

143. Brewitz A, Eickhoff S, Dähling S, Quast T, Bedoui S, Kroczek RA, Kurts C, Garbi N, Barchet W, Iannacone M, et al. CD8+ T cells orchestrate pDC-XCR1+ dendritic cell spatial and functional cooperativity to optimize priming. Immunity. 2017;46:205-219. doi: 10.1016/j.immuni.2017.01.003.

144. Lou Y, Liu C, Kim GJ, Hwu P, Wang G. Plasmacytoid dendritic cells synergize with myeloid dendritic cells in the induction of antigen-specific antitumor immune responses. J Immunol. 2007;178:1534-1541. doi: 10.4049/jimmunol.178.3.1534.

145. Sakref C, Saby A, Rodriguez C, Ardin M, Moudombi L, Doffin A, Gobbini E, Voissiere A, Besson L, Laoubi L, et al. Type III interferon primes pDCs for TLR7 activation and antagonizes immune suppression mediated by TGF-β and PGE2. Nat Commun. 2025;16:3045. doi: 10.1038/s41467-025-58220-8.

146. Sanlorenzo M, Novoszel P, Vujic I, Gastaldi T, Hammer M, Fari O, De Sa Fernandes C, Landau AD, Göcen-Oguz BV, Holcmann M, et al. Systemic IFN-I combined with topical TLR7/8 agonists promotes distant tumor suppression by c-Jun-dependent IL-12 expression in dendritic cells. Nat Cancer. 2025;6:175-193. doi: 10.1038/s43018-024-00889-9.

147. Messmer D, Yang H, Telusma G, Knoll F, Li J, Tracey KJ, Chiorazzi N. High mobility group box protein 1: an endogenous signal for dendritic cell maturation and Th1 polarization. J Immunol. 2004;173:307-313. doi: 10.4049/jimmunol.173.1.307.

148. Lande R, Gregorio J, Facchinetti V, Chatterjee B, Wang Y, Homey B, Cao W, Su B, Nestle FO, Zal T, et al. Plasmacytoid dendritic cells sense self-DNA coupled with antimicrobial peptide. Nature. 2007;449:564-569. doi: 10.1038/nature06116.

149. Yang D, de la Rosa G, Tewary P, Oppenheim JJ. Alarmins link neutrophils and dendritic cells. Trends Immunol. 2009;30:531-537. doi: 10.1016/j.it.2009.07.004.

150. Badal D, Dayal D, Singh G, Sachdeva N. Role of DNA-LL37 complexes in the activation of plasmacytoid dendritic cells and monocytes in subjects with type 1 diabetes. Sci Rep. 2020;10:8896. doi: 10.1038/s41598-020-65851-y.

151. Jeong YS, Bae Y-S. Formyl peptide receptors in the mucosal immune system. Exp Mol Med. 2020;52:1694-1704. doi: 10.1038/s12276-020-00518-2.

152. Findlay EG, Currie AJ, Zhang A, Ovciarikova J, Young L, Stevens H, McHugh BJ, Canel M, Gray M, Milling SW, et al. Exposure to the antimicrobial peptide LL-37 produces dendritic cells optimized for immunotherapy. Oncoimmunology. 2019;8:1608106. doi: 10.1080/2162402X.2019.1608106.

153. Stakheev D, Taborska P, Kalkusova K, Bartunkova J, Smrz D. LL-37 as a powerful molecular tool for boosting the performance of ex vivo-produced human dendritic cells for cancer immunotherapy. Pharmaceutics. 2022;14:2747. doi: 10.3390/pharmaceutics14122747.

154. Odobasic D, Kitching AR, Yang Y, O'Sullivan KM, Muljadi RCM, Edgton KL, Tan DSY, Summers SA, Morand EF, Holdsworth SR. Neutrophil myeloperoxidase regulates T-cell-driven tissue inflammation in mice by inhibiting dendritic cell function. Blood. 2013;121:4195-4204. doi: 10.1182/blood-2012-09-456483.

155. van Gisbergen KP, Sanchez-Hernandez M., Geijtenbeek TB, van Kooyk Y. Neutrophils mediate immune modulation of dendritic cells through glycosylation-dependent interactions between Mac-1 and DC-SIGN. J Exp Med. 2005;201:1281.
<figure><img src="image_31.png" /></figure>

156. Bhattacharya P, Ismail N, Saxena A, Gannavaram S, Dey R, Oljuskin T, Akue A, Takeda K, Yu J, Karmakar S, et al. Neutrophil-dendritic cell interaction plays an important role in live attenuated Leishmania vaccine induced immunity. PLoS Negl Trop Dis. 2022;16:e0010224. doi: 10.1371/journal.pntd.0010224.

157. Tiburcio R, Melo LD, Nunes S, Barbosa ALA, de Oliveira EC, Suarez M, Borges VM, Tavares N, Brodskyn CI. DC-SIGN mediates the interaction between neutrophils and leishmania amazonensis-infected dendritic cells to promote DC maturation and parasite elimination. Front Immunol. 2021;12. doi: 10.3389/fimmu.2021.750648.

158. Lee AM, Laurent P, Nathan CF, Barrat FJ. Neutrophil-plasmacytoid dendritic cell interaction leads to production of type I IFN in response to *Mycobacterium tuberculosis*. Eur J Immunol. 2024;54:2350666. doi: 10.1002/eji.202350666.

159. Caldeira PC, Vieira ÉLM, Sousa AA, Teixeira AL, Aguiar MCF. Immunophenotype of neutrophils in oral squamous cell carcinoma patients. J Oral Pathol Med Off Publ Int Assoc Oral Pathol Am Acad Oral Pathol. 2017;46:703-709.

160. Ruffell B, Chang-Strachan D, Chan V, Rosenbusch A, Ho CM, Pryer N, Daniel D, Hwang ES, Rugo HS, Coussens LM. Macrophage IL-10 blocks CD8+ T cell-dependent responses to chemotherapy by suppressing IL-12 expression in intratumoral dendritic cells. Cancer Cell. 2014;26:623-637. doi: 10.1016/j.ccell.2014.09.006.

161. Dammeijer F, Lievense LA, Kaijen-Lambers ME, van Nimwegen M, Bezemer K, Hegmans JP, van Hall T, Hendriks RW, Aerts JG. Depletion of tumor-associated macrophages with a CSF-1R kinase inhibitor enhances antitumor immunity and survival induced by DC immunotherapy. Cancer Immunol Res. 2017;5:535-546. doi: 10.1158/2326-6066.CIR-16-0309.

162. Mierzejewska J, Węgierek-Ciura K, Rossowska J, Szczygiel A, Anger-Góra N, Szermer-Olearnik B, Geneja M, Pajtasz-Piasecka E. The beneficial effect of IL-12 and IL-18 transduced dendritic cells stimulated with tumor antigens on generation of an antitumor response in a mouse colon carcinoma model. J Immunol Res. 2022;2022:7508928.

163. Yang X, Deng Y, Ye Y, Meng J, Su M, Wei W, Qin Y, Zhang H, Tian Y, Liao Z, et al. Macrophage-derived itaconate suppresses dendritic cell function to promote acquired resistance to Anti-PD-1 immunotherapy. Cancer Res. 2025;85:1842-1856. doi: 10.1158/0008-5472.CAN-24-2982.

164. Danelli L, Frossi B, Gri G, Mion F, Guarnotta C, Bongiovanni L, Tripodo C, Mariuzzi L, Marzinotto S, Rigoni A, et al. Mast cells boost myeloid-derived suppressor cell activity and contribute to the development of tumor-favoring microenvironment. Cancer Immunol Res. 2015;3:85-95. doi: 10.1158/2326-6066.CIR-14-0102.

165. Jachetti E, Cancila V, Rigoni A, Bongiovanni L, Cappetti B, Belmonte B, Enriquez C, Casalini P, Ostano P, Frossi B, et al. Cross-talk between myeloid-derived suppressor cells and mast cells mediates tumor-specific immunosuppression in prostate cancer. Cancer Immunol Res. 2018;6:552-565. doi: 10.1158/2326-6066.CIR-17-0385.

166. Janssens S, Rennen S, Agostinis P. Decoding immunogenic cell death from a dendritic cell perspective. Immunol Rev. 2024;321:350-370. doi: 10.1111/imr.13301.

167. Galluzzi L, Guilbaud E, Schmidt D, Kroemer G, Marincola FM. Targeting immunogenic cell stress and death for cancer therapy. Nat Rev Drug Discov. 2024;23:445-460. doi: 10.1038/s41573-024-00920-9.

168. Forveille S, Leduc M, Sauvat A, Kroemer G, Kepp O. Datopotamab deruxtecan induces hallmarks of immunogenic cell death. Cell Stress. 2025;9:194-200. doi: 10.15698/cst2025.08.311.

169. Obeid M, Tesniere A, Ghiringhelli F, Fimia GM, Apetoh L, Perfettini J, Castedo M, Mignot G, Panaretakis T, Casares N, et al. Calreticulin exposure dictates the immunogenicity of cancer cell death. Nat Med. 2007;13:54-61. doi: 10.1038/nm1523.

170. Aymeric L, Apetoh L, Ghiringhelli F, Tesniere A, Martins I, Kroemer G, Smyth MJ, Zitvogel L. Tumor cell death and ATP release prime dendritic cells and efficient anticancer immunity. Cancer Res. 2010;70:855-858. doi: 10.1158/0008-5472.CAN-09-3566.

171. Moriya T, Kitagawa K, Hayakawa Y, Hemmi H, Kaisho T, Ueha S, Ikebuchi R, Yasuda I, Nakanishi Y, Honda T, et al. Immunogenic tumor cell death promotes dendritic cell migration and inhibits tumor growth via enhanced T cell immunity. iScience. 2021;24:102424. doi: 10.1016/j.isci.2021.102424.

172. Li T, Cheng H, Yuan H, Xu Q, Shu C, Zhang Y, Tan J, Rui Y. Antitumor activity of cGAMP via stimulation of cGAS-cGAMP-STING-IRF3 mediated innate immune response. Sci Rep. 2016;6:19049. doi: 10.1038/srep19049.

173. Fucikova J, Kepp O, Kasikova L, Petroni G, Yamazaki T, Liu P, Zhao L, Spisek R, Kroemer G, Galluzzi L. Detection of immunogenic cell death and its relevance for cancer therapy. Cell Death Dis. 2020;11:1013. doi: 10.1038/s41419-020-03221-2.

174. Efimova I, Catanzaro E, Van der Meeren L, Turubanova VD, Hammad H, Mishchenko TA, Vedunova MV, Fimognari C, Bachert C, Coppieters F, et al. Vaccination with early ferroptotic cancer cells induces efficient antitumor immunity. J Immunother Cancer. 2020;8:e001369. doi: 10.1136/jitc-2020-001369.

175. Wiernicki B, Maschalidi S, Pinney J, Adjemian S, Vanden Berghe T, Ravichandran KS, Vandenabeele P. Cancer cells dying from ferroptosis impede dendritic cell-mediated anti-tumor immunity. Nat Commun. 2022;13:3676. doi: 10.1038/s41467-022-31218-2.

176. Jaime-Sanchez P, Uranga-Murillo I, Aguilo N, Khouili SC, Arias MA, Sancho D, Pardo J. Cell death induced by cytotoxic CD8+ T cells is immunogenic and primes caspase-3-dependent spread immunity against endogenous tumor antigens. J Immunother Cancer. 2020;8:e000528. doi: 10.1136/jitc-2020-000528.
<figure><img src="image_32.png" /></figure>

177. Minute L, Teijeira A, Sanchez-Paulete AR, Ochoa MC, Alvarez M, Otano I, Etxeberria I, Bolaños E, Azpilikueta A, Garasa S, et al. Cellular cytotoxicity is a form of immunogenic cell death. *J Immunother Cancer*. 2020;8:e000325. doi: 10.1136/jitc-2019-000325.

178. Keogh E, Fikes J, Southwood S, Celis E, Chesnut R, Sette A. Identification of new epitopes from four different tumor-associated antigens: recognition of naturally processed epitopes correlates with HLA-A*0201-binding affinity. *J Immunol Baltim*. 2001;167:787-796.

179. Besse B, Felip E, Garcia Campelo R, Cobo M, Mascaux C, Madroszyk A, Cappuzzo F, Hilgers W, Romano G, Denis F, et al. Randomized open-label controlled study of cancer vaccine OSE2101 versus chemotherapy in HLA-A2-positive patients with advanced non-small-cell lung cancer with resistance to immunotherapy: ATA-LANTE-1. *Ann of Oncol*. 2023;34:920-933. doi: 10.1016/j.annonc.2023.07.006.

180. Kruit WHJ, Suciu S, Dreno B, Mortier L, Robert C, Chiarion-Sileni V, Maio M, Testori A, Dorval T, Grob J, et al. Selection of immunostimulant AS15 for active immunization with MAGE-A3 protein: results of a randomized phase II study of the European organisation for research and treatment of cancer melanoma group in metastatic melanoma. *J Clin. 2013;31:2413-2420. doi: 10.1200/JCO.2012.43.7111.*

181. Vansteenkiste J, Zielinski M, Linder A, Dahabreh J, Gonzalez EE, Malinowski W, Lopez-Brea M, Vanakesa T, Jassem J, Kalofonos H, et al. Adjuvant MAGE-A3 immunotherapy in resected non-small-cell lung cancer: phase II randomized study results. *J Clin. 2013;31:2396-2403. doi: 10.1200/JCO.2012.43.7103.*

182. Dreno B, Thompson JF, Smithers BM, Santinami M, Jouary T, Gutzmer R, Levchenko E, Rutkowski P, Grob J, Korovin S, et al. MAGE-A3 immunotherapeutic as adjuvant therapy for patients with resected, MAGE-A3-positive, stage III melanoma (DERMA): a double-blind, randomised, placebo-controlled, phase 3 trial. *Lancet Oncol*. 2018;19:916-929. doi: 10.1016/S1470-2045(18)30254-7.

183. Sahin U, Muik A, Derhovanessian E, Vogler I, Kranz LM, Vormehr M, Baum A, Pascal K, Quandt J, Maurus D, et al. COVID-19 vaccine BNT162b1 elicits human antibody and TH1 T cell responses. *Nature*. 2020;586:594-599. doi: 10.1038/s41586-020-2814-7.

184. Sahin U, Oehm P, Derhovanessian E, Jabulowsky RA, Vormehr M, Gold M, Maurus D, Schwarck-Kokarakis D, Kuhn AN, Omokoko T, et al. An RNA vaccine drives immunity in checkpoint-inhibitor-treated melanoma. *Nature*. 2020;585:107-112. doi: 10.1038/s41586-020-2537-9.

185. Weber JS, Carlino MS, Khattak A, Meniawy T, Ansstas G, Taylor MH, Kim KB, McKean M, Long GV, Sullivan RJ, et al. Individualised neoantigen therapy mRNA-4157 (V940) plus pembrolizumab versus pembrolizumab monotherapy in resected melanoma (KEYNOTE-942): a randomised, phase 2b study. *Lancet*. 2024;403:632-644. doi: 10.1016/S0140-6736(23)02268-7.

186. Lee JM, Spicer J, Nair S, Khattak A, Brown M, Meehan RS, Shariati nM, Deng X, Samkari A, Chaft JE. The phase 3 INTerpath-002 study design: Individualized neoantigen therapy (INT) V940 (mRNA-4157) plus pembrolizumab vs placebo plus pembrolizumab for resected early-stage non-small-cell lung cancer (NSCLC). *J Clin Oncol*. 2024;42:TPS8116-TPS8116. doi: 10.1200/JCO.2024.42.16_suppl.TPS8116.

187. Weber JS, Luke JJ, Carlino MS, Khattak MA, Meehan RS, Brown M, Zhang J, Krepler C, Duic JP, Long GV. INTerpath-001: Pembrolizumab with V940 (mRNA-4157) versus pembrolizumab with placebo for adjuvant treatment of high-risk stage II-IV melanoma. *J Clin Oncol*. 2024;42:TPS9616-TPS9616. doi: 10.1200/JCO.2024.42.16_suppl.TPS9616.

188. Botelho NK, Tschumi BO, Hubbell JA, Swartz MA, Donda A, Romero P. Combination of synthetic long peptides and XCL1 fusion proteins results in superior tumor control. *Front Immunol*. 2019;10:294. doi: 10.3389/fimmu.2019.00294.

189. Masterman K-A, Haigh OL, Tullett KM, Leal-Rojas IM, Walpole C, Pearson FE, Cebon J, Schmidt C, O'Brien L, Rosendahl N, et al. Human CLEC9A antibodies deliver NY-ESO-1 antigen to CD141+ dendritic cells to activate naïve and memory NY-ESO-1-specific CD8+ T cells. *J Immunother Cancer*. 2020;8:e000691. doi: 10.1136/jitc-2020-000691.

190. Bhardwaj N, Friedlander PA, Pavlick AC, Ernstoff MS, Gastman BR, Hanks BA, Curti BD, Albertini MR, Luke JJ, Blazquez AB, et al. Flt3 ligand augments immune responses to anti-DEC-205-NY-ESO-1 vaccine through expansion of dendritic cell subsets. *Nat Cancer*. 2020;1:1204-1217. doi: 10.1038/s43018-020-00143-y.

191. Kantoff PW, Higano CS, Shore ND, Berger ER, Small EJ, Penson DF, Redfern CH, Ferrari AC, Dreicer R, Sims RB, et al. Sipuleucel-T immunotherapy for castration-resistant prostate cancer. *N Engl J Med*. 2010;363:411-422. doi: 10.1056/NEJMoa1001294.

192. Borges F, Laureano RS, Vanmeerbeek I, Sprooten J, Demeulenaere O, Govaerts J, Kinget L, Saraswat S, Beuselinck B, De Vleeschouwer S, et al. Trial watch: anticancer vaccination with dendritic cells. *Oncoimmunology*. 2024;13:2412876. doi: 10.1080/2162402X.2024.2412876.

193. Liau LM, Ashkan K, Brem S, Campian JL, Trusheim JE, Iwamoto FM, Tran DD, Ansstas G, Cobbs CS, Heth JA, et al. Association of autologous tumor lysate-loaded dendritic cell vaccination with extension of survival among patients with newly diagnosed and recurrent glioblastoma. *JAMA Oncol*. 2023;9:112-121. doi: 10.1001/jamaoncol.2022.5370.

194. Graciotti M, Kandalaft LE. Vaccines for cancer prevention: exploring opportunities and navigating challenges. *Nat Rev Drug Discov*. 2024;24:1-17. doi: 10.1038/s41573-024-01081-5.
<figure><img src="image_33.png" /></figure>

195. Kongsted P, Borch TH, Ellebaek E, Iversen TZ, Andersen R, Met Ø, Hansen M, Lindberg H, Sengeløv L, Svane IM. Dendritic cell vaccination in combination with docetaxel for patients with metastatic castration-resistant prostate cancer: a randomized phase II study. Cytotherapy. 2017;19:500-513. doi: 10.1016/j.jcyt.2017.01.007.

196. Tryggestad AMA, Axcrona K, Bigalke I, Brennhovd B, Inderberg EM, Hønnåshagen TK, Skoge LJ, Solum G, Sæboe-Larssen S, Josefsen D, et al. Long-term first-in-man phase I/II study of an adjuvant dendritic cell vaccine in patients with high-risk prostate cancer after radical prostatectomy. Prostate. 2022;82:245-253. doi: 10.1002/pros.24267.

197. Wilgenhof S, Corthals J, Heirman C, van Baren N, Lucas S, Kvistborg P, Thielemans K, Neyns B. Phase II Study of autologous monocyte-derived mRNA electroporated dendritic cells (TriMixDC-MEL) plus ipilimumab in patients with pretreated advanced melanoma. J Clin Oncol. 2016;34:1330-1338. doi: 10.1200/JCO.2015.63.4121.

198. De Keersmaecker B, Claerhout S, Carrasco J, Bar I, Corthals J, Wilgenhof S, Neyns B, Thielemans K. TriMix and tumor antigen mRNA electroporated dendritic cell vaccination plus ipilimumab: link between T-cell activation and clinical responses in advanced melanoma. J Immunother Cancer. 2020;8:e000329. doi: 10.1136/jitc-2019-000329.

199. Höltl L, Ramoner R, Zelle-Rieser C, Gander H, Putz T, Papesh C, Nussbaumer W, Falkensammer C, Bartsch G, Thurnher M. Allogeneic dendritic cell vaccination against metastatic renal cell carcinoma with or without cyclophosphamide. Cancer Immunol Immunother. 2005;54:663-670.

200. Tamir A, Basagila E, Kagahzian A, Jiao L, Jensen S, Nicholls J, Tate P, Stamp G, Farzaneh F, Harrison P, et al. Induction of tumor-specific T-cell responses by vaccination with tumor lysate-loaded dendritic cells in colorectal cancer patients with carcinoembryonic-antigen positive tumors. Cancer Immunol Immunother. 2007;56:2003-2016. doi: 10.1007/s00262-007-0299-y.

201. Trefzer U, Herberth G, Wohlan K, Milling A, Thiemann M, Sharav T, Sparbier K, Sterry W, Walden P. Tumour-dendritic hybrid cell vaccination for the treatment of patients with malignant melanoma: immunological effects and clinical results. Vaccine. 2005;23:2367-2373. doi: 10.1016/j.vaccine.2005.01.081.

202. de Gruijl TD, van den Eertwegh AJM, Pinedo HM, Scheper RJ. Whole-cell cancer vaccination: from autologous to allogeneic tumor- and dendritic cell-based vaccines. Cancer Immunol Immunother. 2008;57:1569-1577. doi: 10.1007/s00262-008-0536-z.

203. Lepski G, Bergami-Santos PC, Pinho MP, Chauca-Torres NE, Evangelista GCM, Teixeira SF, Flatow E, de Oliveira JV, Fogolin C, Peres N, et al. Adjuvant vaccination with allogenic dendritic cells significantly prolongs overall survival in high-grade gliomas: results of a phase II trial. Cancers. 2023;15:1239. doi: 10.3390/cancers15041239.

204. Anguille S, Smits EL, Lion E, van Tendeloo VF, Berneman ZN. Clinical use of dendritic cells for cancer therapy. Lancet Oncol. 2014;15:e257-267. doi: 10.1016/S1470-2045(13)70585-0.

205. Draube A, Klein-González N, Mattheus S, Brillant C, Hellmich M, Engert A, von Bergwelt-Baildon M, Bernhard EJ. Dendritic cell based tumor vaccination in prostate and renal cell cancer: a systematic review and meta-analysis. PLoS One. 2011;6:e18801. doi: 10.1371/journal.pone.0018801.

206. Ferris ST, Ohara RA, Ou F, Wu R, Huang X, Kim S, Chen J, Liu T-T, Schreiber RD, Murphy TL, et al. cDC1 vaccines drive tumor rejection by direct presentation independently of host cDC1. Cancer Immunol Res. 2022;10:920-931.

207. Tel J, Aarntzen EH, Baba T, Schreibelt G, Schulte BM, Benitez-Ribas D, Boerman OC, Croockewit S, Oyen WJ, van Rossum M, et al. Natural human plasmacytoid dendritic cells induce antigen-specific T-cell responses in melanoma patients. Cancer Res. 2013;73:1063-1075. doi: 10.1158/0008-5472.CAN-12-2583.

208. Schreibelt G, Bol KF, Westdorp H, Wimmers F, Aarntzen EH, Duiveman-de Boer T, van de Rakt MW, Scharenborg NM, de Boer AJ, Pots JM, et al. Effective clinical responses in metastatic melanoma patients after vaccination with primary myeloid dendritic cells. Clin Cancer Res. 2016;22:2155-2166. doi: 10.1158/1078-0432.CCR-15-2205.

209. Charles J, Chaperot L, Hannani D, Bruder Costa J, Templier I, Trabelsi S, Gil H, Moisan A, Persoons V, Hegelhofer H, et al. An innovative plasmacytoid dendritic cell line-based cancer vaccine primes and expands antitumor T-cells in melanoma patients in a first-in-human trial. Oncoimmunology. 2020;9:1738812. doi: 10.1080/2162402X.2020.1738812.

210. Bol KF, Schreibelt G, Bloemendal M, van Willigen WW, Hins-de Bree S, de Goede AL, de Boer AJ, Bos KJH, Duiveman-de Boer T, Olde Nordkamp MAM, et al. Adjuvant dendritic cell therapy in stage IIIB/C melanoma: the MIND-DC randomized phase III trial. Nat Commun. 2024;15:1632. doi: 10.1038/s41467-024-45358-0.

211. Schwarze JK, Tijtgat J, Awada G, Cras L, Vasaturo A, Bagnall C, Forsyth R, Dufait I, Tuyaerts S, Van Riet I, et al. Intratumoral administration of CD1c (BDCA-1)+ and CD141 (BDCA-3)+ myeloid dendritic cells in combination with talimogene laherparepvec in immune checkpoint blockade refractory advanced melanoma patients: a phase I clinical trial. J Immunother Cancer. 2022;10:e005141. doi: 10.1136/jitc-2022-005141.

212. Qdaisat S, Wummer B, Stover BD, Zhang D, McGuiness J, Weidert F, Chardon-Robles J, Grippin A, DeVries A, Zhao C, et al. Sensitization of tumours to immunotherapy by boosting early type-I interferon responses enables epitope spreading. Nat Biomed Eng. 2025;9:1-16. doi: 10.1038/s41551-025-01380-1.

213. Weiss SA, Sznol M, Shaheen M, Berciano-Guerrero M, Couselo EM, Rodríguez-Abreu D, Boni V, Schuchter LM, Gonzalez-Cao M, Arance A, et al. A phase II trial of the CD40 agonistic antibody sotigalimab (APX005M)
<figure><img src="image_34.png" /></figure>

in combination with nivolumab in subjects with metastatic melanoma with confirmed disease progression on anti-PD-1 therapy. Clin Cancer. 2024;30:74-81. doi: 10.1158/1078-0432.CCR-23-0475.

214. Padrón LJ, Maurer DM, O'Hara MH, O'Reilly EM, Wolff RA, Wainberg ZA, Ko AH, Fisher G, Rahma O, Lyman JP, et al. Sotigalimab and/or nivolumab with chemotherapy in first-line metastatic pancreatic cancer: clinical and immunologic analyses from the randomized phase 2 PRINCE trial. Nat Med. 2022;28:1167-1177.

215. Salomon R, Rotem H, Katzenelenbogen Y, Weiner A, Cohen Saban N, Feferman T, Amit I, Dahan R. Bispecific antibodies increase the therapeutic window of CD40 agonists through selective dendritic cell targeting. Nat Cancer. 2022;3:287-302. doi: 10.1038/s43018-022-00329-6.

216. Zhu B, Chen P, Aminu M, Li J, Fujimoto J, Tian Y, Hong L, Hu X, Vokes N, Moreira AL, et al. Spatial and multiomics analysis of human and mouse lung adenocarcinoma precursors reveals TIM-3 as a putative target for precancer interception. Cancer Cell. 2025;43:1125-1140.e10. doi: 10.1016/j.ccell.2025.04.003.

217. de Mingo Pulido Á, Gardner A, Hiebler S, Soliman H, Rugo HS, Krummel MF, Coussens LM, Ruffell B. TIM-3 regulates CD103+ dendritic cell function and response to chemotherapy in breast cancer. Cancer Cell. 2018;33:60-74.e6. doi: 10.1016/j.ccell.2017.11.019.

218. Tang H, Liang Y, Anders RA, Taube JM, Qiu X, Mulgaonkar A, Liu X, Harrington SM, Guo J, Xin Y, et al. PD-L1 on host cells is essential for PD-L1 blockade-mediated tumor regression. J Clin Investig. 2018;128:580-588. doi: 10.1172/JCI96061.

219. Van Lint S, Van Parys A, Van Den Eeckhout B, Vandamme N, Plaisance S, Verhee A, Catteeuw D, Rogge E, De Geest J, Vanderroost N, et al. A bispecific Clec9A-PD-L1 targeted type I interferon profoundly reshapes the tumor microenvironment towards an antitumor state. Mol Cancer. 2023;22:191. doi: 10.1186/s12943-023-01908-6.

220. Fan X, Ye M, Xue B, Ke Y, Wong CK, Xie Y. Human dendritic cells engineered to secrete interleukin-18 activate MAGE-A3-specific cytotoxic T lymphocytes in vitro. Immunol Investig. 2012;41:469-483. doi: 10.3109/08820139.2012.664225.

221. Ghasemi A, Martinez-Usatorre A, Li L, Hicham M, Guichard A, Marcone R, Fournier N, Torchia B, Martinez Bedoya D, Davanture S, et al. Cytokine-armed dendritic cell progenitors for antigen-agnostic cancer immunotherapy. Nat Cancer. 2024;5:240-261. doi: 10.1038/s43018-023-00668-y.

222. Giovanelli P, Sandoval TA, Cubillos-Ruiz JR. Dendritic cell metabolism and function in tumors. Trends Immunol. 2019;40:699-718. doi: 10.1016/j.it.2019.06.004.

223. Everts B, Amiel E, Huang SC, Smith AM, Chang C, Lam WY, Redmann V, Freitas TC, Blagih J, van der Windt GJW, et al. TLR-driven early glycolytic reprogramming via the kinases TBK1-IKKε supports the anabolic demands of dendritic cell activation. Nat Immunol. 2014;15:323-332. doi: 10.1038/ni.2833.

224. Yin X, Zeng W, Wu B, Wang L, Tian H, Jiang Y, Clay R, Wei X, Qin Y, Zhang F, et al. PPARα inhibition overcomes tumor-derived exosomal lipid-induced dendritic cell dysfunction. Cell Rep. 2020;33:108278. doi: 10.1016/j.celrep.2020.108278.

225. Brombacher EC, Patente TA, van der Ham AJ, Moll TJ, Otto F, Verheijen FW, Zaal EA, de Ru AH, Tjokrodirijo RT, Berkers CR, et al. AMPK activation induces RALDH+ tolerogenic dendritic cells by rewiring glucose and lipid metabolism. J Cell Biol. 2024;223:e202401024. doi: 10.1083/jcb.202401024.

226. Wculek SK, Khouili SC, Priego E, Heras-Murillo I, Sancho D. Metabolic control of dendritic cell functions: digesting information. Front Immunol. 2019;10:775.

227. Liu X, Yu P, Xu Y, Wang Y, Chen J, Tang F, Hu Z, Zhou J, Qiu W, Ye Y, et al. Metformin induces tolerogenicity of dendritic cells by promoting metabolic reprogramming. Cell Mol Life Sci. 2023;80:283. doi: 10.1007/s00018-023-04932-3.

228. Chen Y, Wang L, Chen N, Tang G. Metformin induces tumor immunogenic cell death in ovarian cancer by activating AMPK pathway. Transl Oncol. 2024;47:102052. doi: 10.1016/j.tranon.2024.102052.

229. Hua Y, Zheng Y, Yao Y, Jia R, Ge S, Zhuang A. Metformin and cancer hallmarks: shedding new lights on therapeutic repurposing. J Transl Med. 2023;21:403. doi: 10.1186/s12967-023-04263-8.

230. Saito T, Takayama T, Osaki T, Nagai S, Suzuki T, Sato M, Kuwano H, Tahara H. Combined mobilization and stimulation of tumor-infiltrating dendritic cells and natural killer cells with Flt3 ligand and IL-18 in vivo induces systemic antitumor immunity. Cancer Sci. 2008;99:2028-2036. doi: 10.1111/j.1349-7006.2008.00907.x.

231. Yamano T, Kaneda Y, Huang S, Hiramatsu SH, Hoon DSB. Enhancement of immunity by a DNA melanoma vaccine against TRP2 with CCL21 as an adjuvant. Mol Ther. 2006;13:194-202. doi: 10.1016/j.ymthe.2005.05.018.

232. Gray JE, Chiappori A, Williams CC, Tanvetyanon T, Haura EB, Creelan BC, Kim J, Boyle TA, Pinder-Schenck M, Khalil F, et al. A phase I/randomized phase II study of GM.CD40L vaccine in combination with CCL21 in patients with advanced lung adenocarcinoma. Cancer Immunol Immunother. 2018;67:1853-1862. doi: 10.1007/s00262-018-2236-7.

233. Yang S-C, Hillinger S, Riedl K, Zhang L, Zhu L, Huang M, Atianzar K, Kuo BY, Gardner B, Batra RK, et al. Intratumoral administration of dendritic cells overexpressing CCL21 generates systemic antitumor responses and confers tumor immunity. Clin Cancer. 2004;10:2891-2901. doi: 10.1158/1078-0432.CCR-03-0380.

234. Lee JM, Garon E, Goldman JW, Salehi-Rad R, Baratelli FE, Schaue D, Wang G, Rosen F, Yanagawa J, Walser TC, et al. Phase I trial of intratumoral injection of CCL21 gene-modified dendritic cells in lung cancer elicits tumor-specific immune responses and CD8+ T-cell infiltration. Clin Cancer. 2017;23:4556-4568. doi: 10.1158/1078-0432.CCR-16-2821.
<figure><img src="image_35.png" /></figure>

235. Oh MS, Dumitras C, Salehi-Rad R, Tran LM, Krysan K, Lim RJ, Jing Z, Tappuni S, Lisberg A, Garon EB, et al. Characteristics of a CCL21 gene-modified dendritic cell vaccine utilized for a clinical trial in non-small cell lung cancer. Mol Cancer Ther. 2025;24:286-298. doi: 10.1158/1535-7163.MCT-24-0435.

236. Shapir Itai Y, Barboy O, Salomon R, Bercovich A, Xie K, Winter E, Shami T, Porat Z, Erez N, Tanay A, et al. Bispecific dendritic-T cell engager potentiates anti-tumor immunity. Cell. 2024;187:375-389.e18. doi: 10.1016/j.cell.2023.12.011.

237. Ascic E, Åkerström F, Sreekumar Nair M, Rosa A, Kurochkin I, Zimmermannova O, Catena X, Rotankova N, Veser C, Rudnik M, et al. In vivo dendritic cell reprogramming for cancer immunotherapy. Science. 2024;386:eadn9083. doi: 10.1126/science.adn9083.

238. Hubert M, Gobbini E, Bendriss-Vermare N, Caux C, Valladeau-Guilemond J. Human tumor-infiltrating dendritic cells: from in situ visualization to high-dimensional analyses. Cancers. 2019;11:1082. doi: 10.3390/cancers11081082.

239. Lin J-R, Chen Y, Campton D, Cooper J, Coy S, Yapp C, Tefft JB, McCarty E, Ligon KL, Rodig SJ, et al. High-plex immunofluorescence imaging and traditional histology of the same tissue section for discovering image-based biomarkers. Nat Cancer. 2023;4:1036-1052. doi: 10.1038/s43018-023-00576-1.

240. Black S, Phillips D, Hickey JW, Kennedy-Darling J, Venkataraaman VG, Samusik N, Goltsev Y, Schürch CM, Nolan GP. CODEX multiplexed tissue imaging with DNA-conjugated antibodies. Nat Protoc. 2021;16:3802-3835. doi: 10.1038/s41596-021-00556-8.

241. Giesen C, Wang HAO, Schapiro D, Zivanovic N, Jacobs A, Hattendorf B, Schüffler PJ, Grolimund D, Buhmann JM, Brandt S, et al. Highly multiplexed imaging of tumor tissues with subcellular resolution by mass cytometry. Nat Methods. 2014;11:417-422. doi: 10.1038/nmeth.2869.

242. Scheuermann S, Kristmann B, Engelmann F, Nuernbergk A, Koloseus M, Abed T, Solass W, Seitz CM. Unveiling spatial complexity in solid tumor immune microenvironments through multiplexed imaging. Front Immunol. 2024;15. doi: 10.3389/fimmu.2024.1383932.

243. Wang Y, Liu B, Zhao G, Lee Y, Buzdin A, Mu X, Chen H, Li X. Spatial transcriptomics: technologies, applications and experimental considerations. Genomics. 2023;115:110671. doi: 10.1016/j.ygeno.2023.110671.

244. Mund A, Coscia F, Kriston A, Hollandi R, Kovács F, Brunner A, Migh E, Schweizer L, Santos A, Bzorek M, et al. Deep visual proteomics defines single-cell identity and heterogeneity. Nat Biotechnol. 2022;40:1231-1240. doi: 10.1038/s41587-022-01302-5.

245. Stanton SE, Castle PE, Finn OJ, Sei S, Emens LA. Advances and challenges in cancer immunoprevention and immune interception. J Immunother Cancer. 2024;12:e007815. doi: 10.1136/jitc-2023-007815.

246. Mazzilli SA, Rahal Z, Rouhani MJ, Janes SM, Kadara H, Dubinett SM, Spira AE. Translating premalignant biology to accelerate non-small-cell lung cancer interception. Nat Rev Cancer. 2025;25:379-392. doi: 10.1038/s41568-025-00791-1.

247. Kina E, Larouche J-D, Thibault P, Perreault C. The cryptic immunopeptidome in health and disease. Trends Genet. 2025;41:162-169. doi: 10.1016/j.tig.2024.09.003.

248. Ely ZA, Kulstad ZJ, Gunaydin G, Addepalli S, Verzani EK, Casarrubios M, Clauser KR, Wang X, Lippincott IE, Louvet C, et al. Pancreatic cancer-restricted cryptic antigens are targets for T cell recognition. Science. 2025;388:eadk3487. doi: 10.1126/science.adk3487.

249. Bonté P-E, Metoikidou C, Heurtebise-Chretien S, Arribas YA, Sutra Del Galy A, Ye M, Niborski LL, Zueva E, Piaggio E, Seguin-Givelet A, et al. Selective control of transposable element expression during T cell exhaustion and anti-PD-1 treatment. Sci Immunol. 2023;8. doi: 10.1126/sciimmunol.adf8838.

250. Merlotti A, Sadacca B, Arribas YA, Ngoma M, Burbage M, Goudot C, Houy A, Rocañín-Arjó A, Lalanne A, Seguin-Givelet A, et al. Noncanonical splicing junctions between exons and transposable elements represent a source of immunogenic recurrent neo-antigens in patients with lung cancer. Sci Immunol. 2023;8:eabm6359. doi: 10.1126/sciimmunol.abm6359.

251. Apavaloaei A, Zhao Q, Hesnard L, Cahuzac M, Durette C, Larouche J, Hardy M, Vincent K, Brochu S, Laverdure J, et al. Tumor antigens preferentially derive from unmutated genomic sequences in melanoma and non-small cell lung cancer. Nat Cancer. 2025;6:1419-1437. doi: 10.1038/s43018-025-00979-2.

252. Tapia-Galisteo A, Compte M, Álvarez-Vallina L, Sanz L. When three is not a crowd: trispecific antibodies for enhanced cancer immunotherapy. Theranostics. 2023;13:1028-1041. doi: 10.7150/thno.81494.

253. Sui Y, Berzofsky JA. Trained immunity inducers in cancer immunotherapy. Front Immunol. 2024;15:1427443. doi: 10.3389/fimmu.2024.1427443.

254. Tepale-Segura A, Gajón JA, Muñoz-Cruz S, Castro-Escamilla O, Bonifaz LC. The cholera toxin B subunit induces trained immunity in dendritic cells and promotes CD8 T cell antitumor immunity. Front Immunol. 2024;15:1362289. doi: 10.3389/fimmu.2024.1362289.

255. Kalafati L, Kourtzelis I, Schulte-Schrepping J, Li X, Hatzioannou A, Grinenko T, Hagag E, Sinha A, Has C, Dietz S, et al. Innate immune training of granulopoiesis promotes anti-tumor activity. Cell. 2020;183:771-785.e12. doi: 10.1016/j.cell.2020.09.058.

256. Brown CC, Gudjonson H, Pritykin Y, Deep D, Lavallée V, Mendoza A, Fromme R, Mazutis L, Ariyan C, Leslie C, et al. Transcriptional basis of mouse and human dendritic cell heterogeneity. Cell. 2019;179:846-863.e24. doi: 10.1016/j.cell.2019.09.035.
<figure><img src="image_36.png" /></figure>

257. Bosteels C, Neyt K, Vanheerswynghels M, van Helden MJ, Sichien D, Debeuf N, De Prijck S, Vandamme N, Martens L, Saeys Y, et al. Inflammatory type 2 cDCs acquire features of cDC1s and macrophages to orchestrate immunity to respiratory virus infection. Immunity. 2020;52:1039-1056.e9. doi: 10.1016/j.immuni.2020.04.005.

258. Chow MT, Ozga AJ, Servis RL, Frederick DT, Lo JA, Fisher DE, Freeman GJ, Boland GM, Luster AD. Intratumoral activity of the CXCR3 chemokine system is required for the efficacy of anti-PD-1 therapy. Immunity. 2019;50:1498-1512.e5. doi: 10.1016/j.immuni.2019.04.010.