bluuebunny/crossref_metadata_2025 huggingface dataset:
Paradoxical pro-tumor functions of dendritic cells on colorectal cancer
Authors: Huang Hsin-I , Hammer Gianna
Published: January 2023

The immune system’s ability to eradicate cancer requires coordination between innate and adaptive immune cells. No other cell type bridges innate and adaptive immunity better than the dendritic cell (DC). For this reason, DCs, specifically the Batf3-dependent DC subset, are thought to be key to anti-tumor immunity. Although the anti-tumor functions of Batf3-dependent DCs have been well described in skin cancer, whether these DCs have similar anti-tumor functions in other cancers is unknown. Here we investigated the roles of Batf3-dependent DCs in colon cancer and paradoxically found that these DCs actually promote colon tumorigenesis. Thus, in a spontaneous colorectal cancer mouse model, loss of Batf3-dependent DCs resulted in decreased colon tumor number. Although Batf3-dependent DCs are best known for expanding IFNγ-producing T cells, in colon tumors, we surprisingly found that Batf3-dependent DCs were required to expand tumor-infiltrating γδT cells producing IL-17. IL-17 is known to promote colon tumorigenesis and our findings pinpoint IL-17-producing γδT cells as a key source of IL-17 for tumor growth, and surprisingly describe a requirement for Batf3-dependent DCs to expand an IL-17-producing T cell population. In addition, we identified tumor-infiltrating Batf3-dependent DCs uniquely upregulate high levels of PD-L1as a second mode of action to promote colon cancer. PD-L1 upregulation and high PD-L1 expression on Batf3-dependent DCs was specific within the tumor microenvironment. Collectively, these paradoxical pro-tumorigenic functions of Batf3-dependent DCs suggest that these DCs are not universally anti-tumor and that targeted therapies that modulate Batf3-dependent DCs could benefit colon cancer patients.
The immune suppressive role of DC-derived IL-27 in hepatocellular carcinoma via the modulation of gut microbiota
Authors: Liu Haiyan , Liu Yonghao , Song Yuan
Published: January 2023

IL-27 can drive the expression of co-inhibitory receptors on T cells, such as PD-1, TIM-3 and podoplanin, which may inhibit T cell functions during chronic inflammation and tumor development. However, the role of IL-27 in regulating anti-tumor immunity is still controversial. Here, we identified a tumor-promoting role of DC-derived IL-27 in murine hepatocellular carcinoma models. IL-27-p28 conditional knockout (KO) in DCs had significantly reduced tumor growth compared with the wild type (WT) controls. The numbers of T cells and NK cells were increased in the tumor microenvironment and the productions of IFN-gamma and TNF-alpha in T cells and NK cells were also enhanced in IL-27 KO mice compared with the WT mice. Moreover, deficiency of IL-27 in DCs did not affect the expression of co-inhibitory receptors on T cells from naïve mice, but reduced the expression level of PD-1 on tumor infiltrating T cells. Interestingly, when WT mice received fecal microbiota transplant from IL-27 KO mice, the tumor growth was significantly reduced. Therefore, DC-derived IL-27 may regulate anti-tumor immune response through the modulation of gut microbiota. Furthermore, we discovered that the commensal bacteria, bifidobacterium and akkermansia, were increased in IL-27 deficient tumor-bearing mice compared with the WT controls. These two strains were found to be increased during anti-PD-L1 or anti-PD-1 antibody therapy and may promote anti-tumor immunity. Thus, our results demonstrated that DC-derived IL-27 could promote tumor growth by suppressing anti-tumor immune responses possibly through the modulation of gut microbiota.
Dendritic cells dysfunction in tumor-draining lymph nodes
Authors: Bandola-Simon Joanna Marta , Roche Paul A
Published: January 2023

An effective anti-tumor response requires activation of both CD4 helper T cells (through MHC class II) and CD8 cytotoxic T cells (through MHC class I). Activation of tumor-specific CD4 and CD8 T cells depends on tumor antigen presentation by DCs. However, it is known that the tumor microenvironment largely suppresses immune responses. The focus of our study is to characterize the functional status of DCs in tumor-draining lymph nodes and to identify the mechanisms that lead to defective MHC class II presentation of tumor antigens. We injected either B16-F10 melanoma or MB49 bladder cancer adenocarcinoma cells into the flank of mice and isolated DCs from both tumor-draining lymph node (TDLN) and non-draining lymph nodes (NDLN) as our model system. Cross-presentation of OVA to OVA-specific CD8 T cells was not suppressed in TDLN in comparison to the NDLN either in vivo and ex vivo. However, both in vivo and ex vivo CD4 T cell activation by DCs from TDLNs was defective. Subset analysis revealed that both migratory and resident CD8-positive and CD8-negative DCs in TDLN show a less mature phenotype as compared to their counterparts isolated from NDLN. Examination of antigen uptake and processing also showed defects in DCs in TDLN. RNA-seq revealed many differences in gene expression between both resident and migratory DCs isolated from TDLN and NDLN. Characterized phenotypical and functional differences, confirmed by gene expression studies, may explain the dysfunction of DCs in tumor-bearing mice. Further analysis should enable moving towards “correcting” DC defects that would allow proper CD4 T cell priming to provide help to anti-tumor CD8 T cells.
CDDO-Me Redirects Macrophage Activation
Authors: Santiesteban Gretel Maria Torres , Shabaneh Tamer , Bhandari Rajan , Liby Karen , Turk Mary Jo , Pioli Patricia
Published: January 2023

Melanoma tumors are highly immunogenic, making them an attractive target for immunotherapy. However, many patients do not mount robust clinical responses to targeted therapies, which is attributable, at least in part, to suppression of immune responses by tumor-associated macrophages (TAMs) in the tumor microenvironment (TME). Using a human in vitro culture system, we now show that the synthetic triterpenoid CDDO-Me enhances immune activation by reprogramming macrophages from immuno-suppressive to immuno-stimulatory. CDDO-Me treatment inhibits surface marker expression of CD16 and CD163 and significantly reduces production of CCL2 and IL-6 in macrophages. These studies also demonstrate that CDDO-Me effects on TAM activation are enhanced when macrophages are tri-cultured with autologous activated T cells and BRAFV600Emutant cells. Because CDDO-Me dramatically attenuates secretion of CCL2, we hypothesize that CDDO-Me may enhance melanoma patient response to additional immunotherapies, including BRAF inhibition. Approximately 50% of advanced melanomas harbor activating BRAFV600Emutations, and BRAF inhibitors have consistently shown anti-tumor responses in patients with BRAFV600Emutant melanoma. However, the duration of the response has been limited due to the development of acquired resistance, which occurs because of myeloid recruitment driven by CCL2. Current studies are focused on assessing the efficacy of combination CDDO-Me/BRAF inhibition. Collectively, these studies suggest that the redirection of immuno-suppressive myeloid cell activation may provide both a direct means of inhibiting melanoma growth and may enhance the efficacy of additional targeted immunotherapies.
The effects of a CRISPR/Cas9 IL-6 knockout in 4T1 mammary carcinoma cells on myeloid-derived suppressor cells (MDSCs) and Th17/Th22 cells
Authors: Rase Viva Jeanne , Haughian James M , Pullen Nicholas A
Published: January 2023

The 4T1 mouse mammary carcinoma cell line is syngeneic to Balb/c mice and is an effective tumor model to study the interactions between the immune system and metastatic breast cancer. The pro-tumor effects that myeloid-derived suppressor cell (MDSC) populations have on CD8+ T cells and Tregs are well known, but comparably less attention has been directed at the relationship between MDSCs and Type III immune Th17/Th22 cells in breast cancer. MDSCs and Th17/Th22 cells have been linked in other inflammatory settings, so in this study, we investigated MDSC, Th17 and Th22 cell interactions in 4T1 tumors, and the role of tumor-derived IL-6 in these interactions. IL-6 plays a key role in the induction of MDSCs under pathological conditions, as well as fate determining in Th maturation. Thus, the removal of IL-6 from 4T1 tumors allowed us to better characterize the source of these interactions. Populations of Monocytic (M)-MDSCs (CD11b+Ly-6G−Ly-6Chi), Polymorphonuclear (PMN)-MDSCs (CD11b+Ly-6G+Ly-6Clow), Th17 (CD3+CD4+RORγt+IFN-γ−IL-17A+IL-22−) and Th22 (CD3+CD4+IFN-γ−RORγt−IL-17A−IL-22+) cells were identified in peripheral blood, spleen, tumor and bone marrow (BM) of mice bearing wild-type and IL-6 knockout 4T1 tumors. Finally, we isolated 4T1 induced MDSCs (CD11b+Gr-1+)and cocultured them with healthy donors to investigate Th17 and Th22 population expansion. Our findings provide further insight into the interactions among MDSCs, Th17 and Th22 cells in a murine cancer model, which may inform immunotherapy efficacy and outcomes in human breast cancer.
Myeloid derived suppressor cells promote ovarian cancer progression in a murine model of ovarian cancer
Authors: Rattan Ramandeep , Sakr Sharif , Dar Sajad , Buekars Thomas , Morris Robert , Munkarah Adnan , Giri Shailendra
Published: January 2023

Myeloid Derived Suppressor Cells (MDSCs) are a heterogeneous population of immature myeloid cells that create an immunosuppressive environment by inhibiting T-cell function. MDSCs also promote angiogenesis, tumor invasion, and metastasis. Increased MDSCs in epithelial ovarian cancer (EOC) are been associated with poor prognosis. The aim of our study was to investigate if MDSCs can influence EOC progression and if their depletion would improve immune response and restrict EOC growth. The intraperitoneal ID8 syngeneic mouse EOC model in B6 mice was used. ID8 tumor bearing mice exhibited significantly higher levels of MDSCs (CD11b+Gr1+) in bone marrow, blood, ascites and tumor compared to non-tumor control groups, including both sub-populations; granulocytic (CD11b+Ly6G+Ly6Clo) and monocytic (CD11b+Ly6G−Ly6Chi). Depleting MDSCs either by anti-Gr1 (Ly6G/Ly6C mAb) monoclonal antibody or gemcitabine treatment significantly slowed EOC progression, as reflected by decreased ascites and reduced tumor burden at the peritoneum, bowel, liver, spleen, and kidney. This was accompanied with an increased number of IFNγ-producing CD4 and CD8 T-cells. Adoptive transfer of MDSCs (Gr1hiLy6G+) enhanced ID8 tumor progression, further supporting their pathogenic role in EOC. Moreover, depletion of MDSCs enhanced the effects of anti-PD-1 immunotherapy in the ID8 EOC mouse model. Overall, we report here that depleting MDSCs improves the antitumor immune response, restricts EOC progression, and enhances tumor responsiveness to immunotherapy. Thus, targeting MDSCs is a potential therapeutic modality in EOC that may be beneficial in combination with other immunotherapies.
ST8Sia6 Overexpression Accelerates Tumor Growth, Alters Macrophage Polarization and the Immune Response
Authors: Friedman David J , Shapiro Michael , Rajcula Matthew , McCue Shaylene , Shapiro Virginia Smith
Published: January 2023

T-cell targeted immunotherapy has resulted in novel treatments for multiple cancers and has been the primary focus in cancer immunotherapy. However, many patients still fail checkpoint therapies due to immune suppression mechanisms driven by cells, such as tolerogenic M2-like macrophages, which support tumor growth. ST8Sia6, a sialyltransferase, generates α2,8-linked disialic acids on O-linked glycoproteins. Cancer patients with high ST8Sia6 expression exhibit reduced survival as compared to patients with low expression, but the mechanism is unknown. We generated MC38 and B16–F10 murine cancer cell lines that overexpress ST8Sia6. Expression of ST8Sia6 accelerated flank tumor growth in both single and dual flank injection models as compared to parental tumors. In vivo, macrophage polarization was altered in ST8Sia6 expressing tumors. At day 7, tumor associated macrophages (TAMs) from ST8Sia6 negative MC38 tumors were primarily M1-like, while TAMs from ST8Sia6 expressing MC38 tumors were predominately M2-like. Tumor growth and M2-like polarization was dependent Siglec-E. Siglec-E present on innate cells bind α2,8-linked disialic acids generated by ST8Sia6 and suppress immune activation. Therefore, ST8Sia6 overexpressing tumors engage Siglec-E, suppressing the immune response and increasing tumor growth. ST8Sia6 overexpression in a spontaneous murine colon cancer model decreased survival from over 6 months to 2–3 months. Therefore, ST8Sia6 expression in tumors may promote tumor growth by promoting tolerogenic immune responses.
A mixed phenotype of tumor-associated macrophages and neutrophils is evident within hours of murine mammary carcinoma delivery
Authors: Kurt Robert A , Zhang Chenyu , Schwartz Jennifer , Lauricella Amanda , Adusei Matthew , DeBenedetto Matthew , Newsom-Stewart Catherine
Published: January 2023

Most of what we know about tumor associated macrophages (TAM) and tumor associated neutrophils (TAN) comes from analysis of these cells isolated from solid tumors, or the periphery of humans or mice with solid tumors. These studies have largely led to a model in which tumor progression over time creates an environment that leads to the generation of pro-tumor TAM and TAN. If this model is correct then one may expect TAM and TAN that arrive early at tumor sites to largely exhibit an anti-tumor phenotype. In order to address this hypothesis we used a gelatin sponge model to capture TAM and TAN well before a solid tumor was palpable. Not surprisingly, the immune response during the first 72 hours was predominated by Ly6G+ and F4/80+ cells. While TNF-a was the most predominant cytokine produced by these cells, TGF-b was also produced at appreciable levels, and TAM found at the site of the most immunogenic of the tumors exhibited a significant increase in anti-tumor (TNF-a) as well as immune suppressive (arginase, TGF-b) cytokines between 24 to 72 hours post tumor injection. In addition, while there were more ROS+ TAN at the tumor sites compared to control sites at 72 hours, the amount of ROS in the cells at the tumor sites was lower than the amount of ROS in the cells at the control sites. Finally, we looked at metabolism because increased oxidative phosphorylation has been correlated with an immune suppressive phenotype. We found that 72 hours after tumor delivery there was already a significant shift toward oxidative phosphorylation in the TAM. Collectively, these data support the contention that an immune suppressive environment is well underway at the early stages of tumor growth; before a tumor is even palpable.
Selective IL-2 receptor β (CD122) targeting improves αPD-L1 immunotherapy in a metastatic bladder cancer model
Authors: Reyes Ryan Michael , Zhang Deyi , Deng Yilun , Mukherjee Neelam , Ji Niannian , Gupta Harshita B , Svatek Robert S , Curiel Tyler J
Published: January 2023

αPD-L1 is an FDA-approved bladder cancer (BC) immunotherapy but is effective in ≤30% of cases. We tested conjugates of αIL-2 antibody + IL-2 (IL-2c) that block IL-2 from binding high-affinity IL-2Rα (CD25) for preferential IL-2Rβ(CD122) binding. CD25 and CD122 are preferred for IL-2 capture by regulatory T cells and anti-tumor effector T cells (Teff), respectively, allowing IL-2c to target Teff preferentially. Orthotopic, intravesical (in bladder) MB49 BC produces PD-L1+BC tumors in syngeneic BL6 mice. αPD-L1 or IL-2c treated intravesical, but not lung metastatic MB49 produced by intravenous injection. Still, in metastatic BC, αPD-L1 + IL-2c (combo) reduced lung metastases and extended survival. Preliminary data found combo treatment efficacy was better in lung versus bladder. In subcutaneous (SQ) B16 melanoma, combo was better than single agents, and increased CD8+CXCR5+TCF-1+Tim-3−PD-1+T stem cells (CXCR5+SC, see X. Zhang poster) vs. single agents. Neither αPD-L1 nor combo increased CXCR5+SC in MB49 in bladder or lung metastases, suggesting a novel treatment mechanism. To test the impact of tumor PD-L1 on treatment efficacy, we made PD-L1KOMB49, but it did not grow in bladder or SQ in wild type mice, but grew similar to control MB49 in immunodeficient NSG mice SQ, suggesting tumor PD-L1 microenvironment-specific effects. PD-L1KOB16 grew well SQ in wild type mice, excluding a PD-L1-specific defect. Thus, tumor PD-L1 differs in immune evasion in a tumor-dependent manner. Selective IL-2 targeting to CD122 improves αPD-L1 treatment of metastatic BC. Mechanisms differ from melanoma, which could be due to tumor, PD-L1, or microenvironment effects. We are assessing mechanisms and αPD-1 treatment effects (also FDA-approved for BC).
Enhanced antitumor effects by combining IL-12 gene electrotransfer with anti-PD1 in preclinical metastatic cancer model
Authors: Shi Guilan , Lundberg Cathryn , Scott Megan , Edelblute Chelsea , Heller Richard
Published: January 2023

The survival and expansion of effector cytotoxic T lymphocytes (CTLs) during an immunological response are critical for the successful elimination of cancer cells. Among the factors that regulate the immune response, interleukin-12 (IL-12), is known to stimulate growth and survival of T cells. Major differences exist between these lymphokines in their capacity to act on various T-cell types such as CD4+ or CD8+ and effector versus memory T lymphocytes. PD1 expression can have a negative effect on effector or memory T-cell populations causing anergy or cell death. Limited information is available regarding the function of combining IL-12 gene electrotransfer (GET) with anti-PD1 in preclinical metastatic cancer models. Here, we report that IL-12 (GET) induced expansion of effector CD8 CTLs. Combining IL-12 GET with anti-PD1 i.p. injection resulted in long-term survival of CD8+PD1− T cells. Most significantly, the effector cytolytic activity of CTLs were expanded and maintained for up to 60 days, indicating that these cells do not differentiate into a memory functional phenotype. In a two site metastatic model, B16F10 melanoma cells expressing luciferase were injected via intraperitoneal route and B16.F10 cells (no luciferase) were injected subcutaneously. Results on day 60 using an In Vivo Imaging System (IVIS) illuminated a lower flux signal in intraperitoneal metastases. Simultaneously, the primary subcutaneous tumors completely regressed in 80% of these mice. The expression of CD44+ CD62L− increased with time, which was detected on CD8 CTLs, suggesting that the memory response was still active at 120 days. The present findings have practical implications for the combination of IL-12 gene electrotransfer with anti-PD1.
Isoform specific anti-TGFβ therapy enhances antitumor efficacy in mouse models of cancer
Authors: Budhu Sadna , Gupta Aditi , Giese Rachel , van Snick Jacques , Uyttenhove Catherine , Ritter Gerd , Wolchok Jedd D , Merghoub Taha
Published: January 2023

TGFβ is a pleotropic cytokine, which has emerged as a potential target in cancer treatment due to its dual role in tumorigenesis and homeostasis. There are three isoforms of TGFβ (TGFβ1, TGFβ2 and TGFβ3), which are secreted by immune and nonimmune cells as an inactive latent complex. Depending on the local context and players, TGFβ can adopt opposing roles in carcinogensis and in modulating the immune system. However, the expression of TGFβ isoforms within the tumor microenvironment and isoform specific inhibition remains to be investigated. The main source of TGFβ isoforms in the tumor microenvironment of B16 melanoma are infiltrating immune cells, with TGFβ1 and TGFβ3 being highly expressed on myeloid and dendritic cells. The CD45− population from B16 tumors demonstrated a lower expression of both TGFβ isoforms. Compared to untreated control animals, anti-TGFβ3 therapy resulted in the greatest delay in B16 tumor growth, followed by anti-TGFβ1 therapy and pan-TGFβ blockade. However, none of the therapies resulted in improved overall survival. Similar results were achieved in a 4T1 breast model. T cell functional assays demonstrated that anti-TGFβ3 resulted in CD8+ T cells with greater cytolytic ability as they showed higher granzyme B expression and killing against B16 cells when plated ex-vivo. Anti-TGFβ1 treatment resulted in greater interferon-γ production by CD8+ T cells, suggesting an increase in antigen-specificity. Isoform specific TGFβ inhibition in combination with immune checkpoint blockade demonstrated improved tumor control and survival. This provides rationale for the use of anti-TGFβ therapy in stroma poor tumors, such as melanoma, and for its potential to enhance the effectiveness of existing therapies.
Induction of Antigen-Specific Immune Suppression Using Biodegradable Nanoparticles Containing Antigen and Dexamethasone
Authors: Kim Sang-Hyun , Moon Jun-Hyeok , Jeong Seong-Un , Lee Chong-Kil
Published: January 2023

Dexamethasone (Dex) is known to reduce inflammation and autoimmunity by modulating dendritic cell (DC) function, maturation, and differentiation. Nanoparticles (NPs) prepared using biodegradable and biocompatible poly(lactic-co-glycolic acid) (PLGA) can be used to target-delivery vehicles to DCs. In the present study, PLGA nanoparticles containing ovalbumin (OVA) and Dex (NP[OVA+Dex]) were prepared by W1/O/W2 double emulsion solvent evaporation method, and evaluated their antigen-specific immune tolerizing effects. DCs treated with NP[OVA+Dex] were decreased in the expression of MHC class II (I-Ab) and co-stimulatory molecules (CD80 and CD86), and increased in the proportion of CD86−PD-L1+ cell population. DCs treated with NP[OVA+Dex] were reduced in the production of pro-inflammatory cytokine, such as IL-1β, IL-6, IL-12p40 and TNF-α, whereas the production of immunosurpressive cytokine IL-10 was enhanced. Treatment of DCs with NP[OVA+Dex] were diminished in MHC class II-restricted OVA presentation and allogenic T cell stimulatory capacity. NP[OVA+Dex]-treated DCs induced CD4+CD25+FoxP3+ regulatory T cell differentiation from CD4+CD25− T cells isolated from normal, or OT-II mice. Mice injected i.v., or i.g. with NP[OVA+Dex] were suppressed in both inducing OVA-specific CTL responses and producing OVA-specific IgG. The present study demonstrates that NPs encapsulated with antigen and Dex are useful tools in inducing antigen-specific immune tolerance.
IL-17A control CNS inflammatory disease by regulating Treg cells through modulation of gut microbiota in HLA class-II transgenic mice model of multiple sclerosis (MS)
Authors: Shahi Shailesh K , Freedman Samantha N , Murra Alexandra C , Zarei Kasra , Guseva Natalya V , Corley Katherine Gibson , Bossler Aaron , Karandikar Nitin J , Mangalam Ashutosh K
Published: January 2023

Despite extensive studies on IL-17A in MS and its animal model EAE, the role of IL-17 in disease development and maintenance is unclear. We have previously established proteolipid protein-(PLP)91–110 induce EAE model in HLA-DR3 transgenic mice. In the present study, we investigated the role of IL-17A in disease development and severity utilizing HLA-DR3 transgenic mice lacking IL-17A (IL-17A−/−). We observed that HLA-DR3.IL17A−/− mice develop milder EAE than HLA-DR3 mice suggesting that IL17 is redundant for the development of EAE but might be required for the disease severity. Milder disease in HLA-DR3.IL17A−/− mice were due to an increase in CD4+CD25+FoxP3+ Treg frequency and suppressive function of Treg cells. Depletion of Tregs using anti-CD25 neutralizing antibody abrogated milder disease phenotype in HLA-DR3.IL17A−/− mice. As gut microbiota play an important role in the generation of Treg cells, we asked whether an absence of IL17A altered gut microbiota towards Treg promoting bacteria. Our 16s rRNA analysis of gut microbiota confirmed that IL-17 deficient mice had distinct gut microbiota than IL-17 sufficient mice with an increased abundance of Treg promoting bacteria such as Lactobacillus and Clostridia. Fecal transplantation studies are underway to confirm the role of Treg promoting gut bacteria. We next investigated whether IL-17F and GM-CSF can compensate for the absence of IL-17A. Interestingly blockage of both IL-17F and GM-CSF led to increased disease severity suggesting a protective role for IL-17F and GM-CSF. Thus our study suggests that there is a bidirectional link between the gut microbiota and IL-17A and the inverse relationship between IL-17A and Tregs might determine the susceptibility vs protection from EAE.
B cells, bugs, bowels, and bones: Bruton’s tyrosine kinase deficiency alters gut B lymphocyte populations and IgA recognition of commensal bacteria in autoimmune arthritis
Authors: Bonami Rachel , Thurman Christina , Nyhoff Lindsay , Barron Bridgette , Kendall Peggy L.
Published: January 2023

IgA is the most abundantly produced isotype, much of which is secreted into the gut lumen. IgA interacts with bacteria, but the dialogue between intestinal B lymphocytes, their antibody products, and commensals is incompletely understood. Elimination of bacteria prevents spontaneous arthritis in the K/BxN model of rheumatoid arthritis, as does disrupted B cell receptor signaling via Bruton’s tyrosine kinase (Btk) deficiency. We hypothesized that altered B cell signaling impacts commensal bacteria recognition. We find that germinal center B cells and IgA class-switched cells are dramatically reduced by Btk deficiency in the in Peyer’s patches of K/BxN mice. Plasmablast and plasma cell numbers are not reduced by Btk deficiency in the small intestine lamina propria; however, the frequency of IgA-coated bacteria is decreased, and the IgA-coated community is shifted. Parabacteroides distasonis is reduced in Btk−/y mice. P. distasonis infection enhances autoimmune arthritis development in antibiotic-treated mice that are otherwise protected, suggesting this commensal plays an inciting role in disease development. In contrast, P. distasonis was protective in prior studies of a multiple sclerosis model. These data show impaired B cell receptor signaling alters the dynamic interplay between B lymphocytes and commensal microbes to impact autoimmune arthritis development. BTK inhibitors are used to treat lymphoma and clinical trials investigating their efficacy in several autoimmune diseases, including rheumatoid arthritis, are ongoing. Our work suggests that the impact of such regimens on the delicate balance between commensal bacteria and adaptive immunity should be considered in the specific autoimmune context.
Discovery of Autoantibodies Associated with Psoriatic Arthritis
Authors: Wu Tianfu , Yuan Yulin , Tyring Stephen K
Published: January 2023

Objective

The autoimmune etiology in psoriasis is not very clear, we aim to identify autoantigens and autoantibodies in psoriasis, which may shed light on the molecular and cellular basis of the pathogenesis of psoriasis and psoriatic arthritis.

Methods

In this study, we developed an autoantigen array system harboring a variety of antigens including typical autoantigens in rheumatic diseases as well as skin antigens, inflammatory mediators and putative autoantigens in psoriasis. Sera from psoriasis patients (N = 73) were used to interrogate antigens on the array. Individual ELISA was also used in validation studies.

Results

We found several serum autoantibodies were elevated in psoriasis patients compared to healthy controls; particularly, IgG autoantibodies against two novel antigens, LL37 and ADAMTSL5, were significantly increased in the psoriasis patients compared to healthy controls. Importantly, serum levels of IgG autoantibodies against LL37 and ADAMTSL5 were correlated with Psoriasis Area and Severity Index (PASI), and reflected disease progression in longitudinally collected samples from psoriasis patients. Importantly, we found both anti-ADAMTSL5 and anti-LL-37 autoantibodies were significantly elevated in psoriatic arthritis (PsA) compared to Non-PsA, suggesting that these molecules may be involved in the pathogenesis of psoriatic arthritis.

Conclusion

Our findings suggest that these autoantibodies may be useful biomarkers and indicative of therapeutic targets of psoriasis and psoriatic arthritis.
Type I IFN and IL-4R define B cell checkpoint defects in systemic lupus erythematosus
Authors: Mountz John D , Liu Shanrun , Wu Qi , Yang PingAr , Essman W. Alex , Ojo Oluwagbemiga A , Luo Bao , Gao Min , Chen Jake Y , Sanz Ignacio , Chatham W. Winn , Hsu Hui-Chen
Published: January 2023

The development of pathogenic autoantibody producing B cells is normally limited at the early transitional (Tr) stage and a later T-dependent developmental checkpoint. The precise molecular mechanisms underlying defective autoreactive B cell deletion/anergy at each checkpoint have been difficult to define. We utilized a combined single-cell B cell transcriptome and high dimensional flow cytometry analysis approach for a parallel understanding of B-cell developmental checkpoint defects at multiple stages in SLE. We found that while high levels of B-cell endogenous interferon-β (IFNβ) is an important risk factor for autoantibody positive African American (AA) SLE patients, low expression of IL-4R was a risk factor of both AA and European-Americans (EA) patients for development of pathogenic autoantibodies. The molecular signature of autoreactive B cells that escape deletion at the Tr stage include type I IFN stimulated genes (ISGs), including IRF7, ISG15, ISG20, MX1, and STAT1. The molecular signature of autoreactive B cells that escape the second T-dependent checkpoint, include low expression of IL4R and the transcriptional repressor BACH2, and high levels of TBX21, ITGAX, FCRL5 and IFI30. Interestingly, in vitro culture stimulation confirmed that the presence of IL-4 signaling significantly suppressed the development of pathogenic CD21−CD27−IgD−CD11c+T-bet+ double negative 2 (DN2) B cells in SLE. These results suggest that B-cell checkpoint defects can be used to stratify SLE patients according to high type I IFN or low IL-4R and their response signatures. These immune phenotype and transcriptome signatures offer the potential to predict therapy responses to type I IFN blockade or other therapies.
Increased immune surveillance of neuron-restricted antigen during demyelination leads to axon loss perpetrated by CD8+ T cells
Authors: Clarkson Ben D.S. , Grund Ethan M , Mirchia Kanish , Standiford Miranda M , Howe Charles L
Published: January 2023

Clonally expanded CD8+ T cells outnumber their CD4+ counterparts in MS lesions yet their role in disease pathogenesis and the relevant target antigen(s) remain unknown. We posited that CNS CD8+ T cells are specific for neuronal antigen and may participate in axon or neuron injury in multiple sclerosis—thereby contributing to cumulative disability. Here we show using neuron-specific translational profiling that demyelination is sufficient to drive neuronal expression of MHC class I genes as well as antigen processing genes. We further demonstrate that neuron-targeted neoantigen (ovalbumin) is sampled by peripheral immune cells even in the absence of demyelination—as assessed by neuroantigen-specific (OTI) CD8+ T cell activation in cervical lymph nodes. However, OTI T cell retention in the healthy CNS was not observed. In contrast, cuprizone diet induced demyelination drives increased OTI T cell proliferation as well as accumulation of these cells to the CNS, leading to elimination of ovalbumin+ neurons. CNS recruited OT1 cells were found to be juxtaposed next to degenerating ovalbumin+ neurons and axons. These findings support a role for autoreactive CD8+ T cells in the axonal injury that underlies progression in multiple sclerosis. Future studies are aimed at identifying patients with pathogenic anti-axonal CD8+ T cells who may be responsive to targeted immunotherapy.
The role of CB1 in experimental autoimmune encephalomyelitis (EAE)
Authors: Nichols James Matthew , Kaplan Barbara
Published: January 2023

It is well known that cannabinoid receptors have critical roles in immune homeostasis. This includes the CB1 receptor, which is encoded on by the Cnr1 gene. Previous work by others using the EAE model in ABH Cnr1−/− mice showed that while disease severity and onset were similar between wild type (WT) and Cnr1−/− mice, recovery from a relapse was better in WT mice suggesting a level of neuroprotection mediated by the CB1 receptor. In this study, we used the active EAE model in Cnr1−/− and WT C57BL/6 littermates to determine the importance of the CB1 receptor in disease progression by examining both the peripheral and neural immune response. We found clinical disease to be more severe in Cnr1−/− mice as compared to WT mice, which corresponded with significant increases of IFNγ from supernatants of restimulated splenocytes as determined by ELISA. Our results also showed that IL17A was modestly higher in the serum and culture supernatants of the Cnr1−/− mice as compared to WT mice, and histologic analysis of spinal sections showed modestly higher levels of neuroinflammation in Cnr1−/− mice as compared to WT mice. This suggests that CB1 receptors may have an immunoregulatory effect in the peripheral immune response of EAE, which combined with the neuroprotective effect via CB1 found in the other study, ultimately leads to less severe clinical disease in WT mice.
Pulmonary involvement in a mouse model of Sjögren’s syndrome induced by activation of the STING pathway
Authors: Papinska Joanna Aleksandra , Gmyrek Grzegorz , Srinivasan R. Sathish , Deshmukh Umesh , Bagavant Harini
Published: January 2023

Sjögren’s Syndrome (SS) is a chronic autoimmune disorder characterized by an increased type 1 interferon gene signature, autoantibody production, and salivary gland inflammation. Engagement of Stimulator of interferon genes (STING) induces type 1 interferon production. Gain of function mutations in TMEM173, encoding STING, results in a severe vasculopathy affecting the skin and lungs. We have previously reported that activation of the STING pathway in mice, using a STING agonist DMXAA, causes an SS-like disease characterized by sialoadenitis and salivary gland dysfunction. Considering that lungs are affected in 9–20% of SS patients, this study was undertaken to investigate lung involvement in DMXAA treated mice.

Female C57BL/6 mice injected with DMXAA rapidly upregulated expression of IFNβ, IFNγ, and Mx1 in the lungs at 4 hours. This was followed by an increase in type 1 innate lymphoid cells on day 8. Histopathologic analysis showed the presence of peri-bronchial inflammatory infiltrates on day 35, which persisted until day 57. The lung inflammation was associated with an increased expression of multiple pro-inflammatory genes including CCl20, CXCl10, CXCl9, and IL17α. In addition, there was an increased frequency of lymphatic endothelial cells, suggestive of lymphangiogenesis. Although STING expression was seen in bronchial epithelium and alveolar cells in the lung, bone marrow chimeras between STING KO and wild type mice suggest that STING expression in myeloid cells was critical for lung inflammation.

Our results show that systemic activation of the STING pathway might play an essential role in lung inflammation in SS patients.
The metabolic modulator metformin affects the activation and survival of murine dendritic cell subsets
Authors: Gallucci Stefania , Chakhtoura Marita , Lee Michael H , Qiu Connie C
Published: January 2023

Unique immunometabolic pathways control the ability of dendritic cell subsets to activate, and metabolic modulators are proposed as therapeutic candidates in cancer and autoimmunity, although their effects on specific immune cells are not fully known. The metabolic inhibitor metformin, the first-choice oral treatment for type II diabetes, has many effects on immunometabolism, including the inhibition of complex I of oxidative phosphorylation. Metformin was shown to decrease the severity of autoimmunity in murine models by inhibiting the activation of T cells. Moreover, it can diminish tumor growth through affecting the polarization of tumor-infiltrating macrophages. Here, we determined the effects of metformin on three subsets of dendritic cells that are proposed to have different energy requirements for activation. Upon TLR stimulation, we found that metformin does not affect the activation of the inflammatory GM-CSF-dependent dendritic cells (iDCs) or the Flt3-L-dependent conventional dendritic cells (cDCs), which rely on an immuno-metabolic shift to glycolysis to fully activate and express costimulatory molecules and pro-inflammatory cytokines, but it decreased cDC survival at resting state. In contrast, we found that metformin inhibited the activation of plasmacytoid dendritic cells (pDCs), which requires both an increase in oxidative phosphorylation and glycolysis for activation. Our studies provide a new layer of complexity in the potential of metformin as treatment in autoimmunity and cancer by showing that this drug can inhibit the activation of pDCs and also eliminate resting cDCs, therefore altering in opposite directions the impact of these innate cell subsets on the immune response.
Beta cells activate islet resident macrophages in a culture bioassay
Authors: Zaman Mohammad Mahabub-Uz , Zakharov Pavel
Published: January 2023

The pancreatic islets of all species contain a small number of resident macrophages. Transcriptional profiles of such islet macrophages indicate that they are in an activated state in steady state conditions expressing high MHC-II, TNFα, and IL-1β. However the reason for this activation is still unknown. To understand the molecular mechanism how the islet environment affects the biology of its resident macrophages we have developed a culture system that reproduces the beta cell: macrophage interaction taking place in islets. Our protocol involves culturing beta cells or insulinomas with bone marrow precursors in CSF-1 conditioned media for seven days. During the period of co-culture the insulinoma cells begin to bud off the plate and cluster with the developing macrophages forming a pseudo-islet structure. Two photon microscopic analysis of the organoids showed the presence of macrophages in the cluster closely attached to beta cells. Macrophages in the organoid capture insulin granules and express high level of MHC-II and PDL1. Microarray analysis shows upregulation of inflammatory genes of the NFκB pathway and a tight correlation with gene signature of bone marrow macrophages stimulated with LPS. The macrophage differentiation and activation is specific for insulinomas and does not take place with other immortalized cell lines; it requires cell contact between β cells and macrophage precursors: it does not take place with already differentiated macrophages. In sum, the beta cell:macrophage symbiosis can be generated in vitro by co-culturing beta cells and bone marrow precursors. We are currently investigating the mechanism how beta cells modulate the activation profile of macrophages using this in vitro co-culture system.
Pancreatic beta cells are constantly interacting with the immune system
Authors: Wan Xiaoxiao , Zinselmeyer Bernd , Zakharov Pavel , Vomund Anthony N , Lichti Cheryl F , Unanue Emil R
Published: January 2023

We have been examining how beta cells communicate their antigens to the innate immune system, in the context of the diabetic autoimmunity. Beta cells release peptides derived from the insulin granules intermittently into the blood following challenges with glucose. Most of the peptides derive from crinosomes, degradative vesicles that result from the fusion of insulin granules with lysosomes. Such a process is required in order to maintain homeostasis in the beta cells. A vast majority of the peptides in crinosomes derive from insulin and contain many epitopes responsible for activation of CD4 T cells. This process of the release of the peptides takes place normally in all mouse strains as well as in human beta cells; it is independent of the autoimmune status. In the NOD strain with its diabetic propensity genetic background the peptides released from crinosomes can be found bound to antigen presenting cells in all lymph nodes, resulting in interactions with T cells. We have documented that CD4 T cells to insulin peptides interact with the released peptides leading to their partial activation. Aside from peptide release, beta cells also communicate locally in the islets with the resident macrophages. We find that beta cells intimately interact with the macrophages, resulting in direct passage of the vesicles and their antigenic products. These resident macrophages are therefore strong presenting cells and are responsible for the entrance of the insulin-reactive CD4 T cells into islets. In brief, an endocrine organ like the pancreatic islet is constantly challenging the immune system by making autoantigens available.
Weighted Gene Correlation Network Analysis of Ovarian Cancer Driven by CXCL13- CXCR5 Interactions
Authors: Carey Kaylin , Griffen Tiara L , Young Corey D , Dill Courtney D. , Lillard James W
Published: January 2023

Ovarian Cancer (OvCa) is a disease that affects postmenopausal women, with high-grade serous ovarian carcinoma being the most common and lethal type. Many patients are asymptomatic in the early stages of OvCa, thus going undetected, leading to higher patient mortality rates. Identifying biomarkers involved in ovarian cancer progression could enhance current therapeutic outcomes. Our laboratory was the first to show that CXCL13- CXCR5 signaling mediates prostate, breast and lung cancer cell growth, migration, invasion, and survival. We provided evidence that these chemokines are highly elevated in OvCa cell lines and clinical samples. These previous findings provided the rationale to support the hypothesis CXCL13-CXCR5 signaling promotes OvCa progression, metastasis and survival. In this study, we analyzed transcriptome data to determine possible molecular mechanisms and CXCL13-CXCR5 signaling pathways controlling OvCa progression. Weighted Gene Network Co-expression (WGCNA) analysis and Ingenuity Pathway Analysis were used to identify gene coexpression networks correlated with aggressive OvCa clinical phenotypes. CXCR5 was found to be co-expressed with several genes such as RB1, PIK3C3, GNAI1, LTB TNFRSF11B which are known to facilitate OvCa progression and tertiary lymphoid structure formation. Upon further analysis, we found that these gene expressions closely correlated with age at diagnosis and patient relapse. Our study suggests an important role of CXCL13-CXCR5 signaling and reveals an important set of co-expressed epigengenes involved in OvCa relapse.
IL-27-dependent STAT1 activation is enhanced in CD4 T cells from HIV infected patients
Authors: Cheng Jie , Kumar Jai , Kumar Princy , Catalfamo Marta
Published: January 2023

In patients with HIV infection, reconstitution of the CD4 T cell pool after initiation of combination antiretroviral therapy (cART) is a slow process and depends on CD4 T cell counts prior to therapy. This suggests that the CD4 T cell pool is under homeostatic pressure compared to the CD8 T cell pool which is expanded. We have previously shown that lymphopenia and IL-7 increase expression of the Signal Transducer and Activator of Transcriptions 1, 2 and 3 (STAT1, 2 and 3) leading to an enhanced response to Type I IFNs and contributing to the immune activation of CD4 T cells. A recent report has shown that IL-27, a member of the IL-12 family of cytokines, inhibits HIV replication in monocytes and monocyte-derived dendritic cells. IL-27 signals through the JAK/STAT and MAPK pathways. Since IL-27 activates STAT1 and STAT3, we hypothesized that IL-7-dependent modulation of STATs expression can influence the response to IL-27 in T cells from HIV patients. We tested whether the γc-cytokines IL-2, IL-7, IL-15 have an effect on STATs expression and their impact on IL-27 signaling in T cells from healthy controls. We found that in addition to IL-7, IL-2 and IL-15 significantly increased expression of STAT1 and STAT3 in CD4 and CD8 T cells and led to an enhanced STAT1 and STAT3 activation upon IL-27 in vitro stimulation. We also found that compared to healthy controls, CD4 T cells from HIV infected patients had a significantly increased STAT1 expression and showed enhanced STAT1 activation upon in vitro stimulation with IL-27. This effect was not observed in CD8 T cells. These data suggest that IL-2, IL-7 and IL-15 modulate IL-27 signaling. In the context of HIV infection, the enhanced IL-27-dependent STAT1 activation may impact CD4 T cell activation and function.
The tumor necrosis factor superfamily member RANKL suppresses effector cytokine production in group 3 innate lymphoid cells
Authors: Bando Jennifer , Gilfillan Susan , Song Christina , McDonald Keely G , Huang Stanley C-C , Newberry Rodney D , Kobayashi Yasuhiro , Allan David , Carlyle James R , Cella Marina , Colonna Marco
Published: January 2023

While signals that activate group 3 innate lymphoid cells (ILC3s) have been described, the factors that negatively regulate these cells are less well understood. Here we found that the tumor necrosis factor (TNF) superfamily member receptor activator of nuclear factor kB ligand (RANKL) suppressed ILC3 activity in the intestine. Deletion of RANKL in ILC3s and T cells increased C-C motif chemokine receptor 6 (CCR6)+ ILC3 abundance and enhanced production of interleukin-17A (IL-17A) and IL-22 in response to IL-23 and during infection with the enteric murine pathogen Citrobacter rodentium. Additionally, CCR6+ ILC3s produced higher amounts of the master transcriptional regulator RORγt at steady state in the absence of RANKL. RANKL-mediated suppression was independent of T cells, and instead occurred via interactions between CCR6+ ILC3s that expressed both RANKL and its receptor, RANK. Thus, RANK-RANKL interactions between ILC3s regulate ILC3 abundance and activation, suggesting that cell clustering may control ILC3 activity.
IL-6 overexpression triggers inflammation through its only relevant receptor IL-6R
Authors: Mufazalov Ilgiz , Brandfald Michaela , Schelmbauer Carsten , Andruszewski David , Tang Yilang , Masri Joumana , Karbach Susanne , Eich Christina , Wunderlich Thomas , Korn Thomas , Bluestone Jeffrey , Waisman Ari
Published: January 2023

IL-6 is a pleiotropic cytokine that regulates development and function of variety immune cells. Here we used a novel mouse strain in which IL-6 can be overexpressed in a Cre-dependent manner and show that mice with CD11c-Cre mediated IL-6 overexpression succumb from systemic inflammation. High levels of IL-6 perturbed B and T cell development in primary lymphoid organs, bone marrow and thymus. Interestingly, IL-6-triggered inflammation promoted expansion of both Th17 and Treg cells, two cell types known for their reciprocal developmental requirements. However, the most dramatic increase was noted for myeloid cells, mostly neutrophils, which invaded spleen, thymus and blood of mice with IL-6 overexpression. Observed systemic inflammation ultimately led to mice mortality within 11 weeks of age. Mechanistically, IL-6 mediates its biological functions strictly through binding to IL-6R alpha chain followed by recruitment of the signal transducer gp130. Previously, an alternative pathway was suggested in which IL-6 can utilize CD5 to signal via gp130. However, when IL-6R was deleted in mice with IL-6 overexpression these mice were completely protected from IL-6- triggered pathology and fully phenocopied IL-6R deficient mice. In fact, IL-6R deficiency prevented downstream activation of STAT3 in response to IL-6. Together, our data suggest that IL-6R is the only biological relevant receptor for IL-6 in mice.