bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of structural changes of beta-mannosylceramide on activation of invariant natural killer T cells and stimulation of anti-tumor immunity
Authors: Yau Jessica , Robinson Sage , Compton Benjamin , Larsen David , Painter Gavin , Berzofsky Jay A. , Terabe Masaki 
Published: January 2023

Abstract
Invariant natural killer T cells (iNKT) are T cells that recognize a diverse repertoire of structurally distinct lipid antigens, instead of peptides, presented by the non-classical major histocompatibility complex molecule, CD1d. Agonists of iNKT cells that induce strong anti-tumor immunity in vivo include alpha-galactosylceramide (aGC) and beta-mannosylceramide (bMC). Previous studies have shown that altering the lipid structures of aGC resulted in different cytokine profiles and anti-tumor properties. In this study, we aimed to examine the effect of altering the lipid structure of bMC on cytokine profiles and anti-tumor activity. The ceramide structure of bMC was replaced with structures that had been reported to significantly alter the activity of aGC. We examined the analogues of bMC whose acyl chain was altered to a lyso, phenylfluoro, phenyl-O-phenylfluoro, or shorter unsaturated form (C20:2). Alpha-mannosylceramide (aMC) and lyso-alpha-mannosylceramide were also studied. An in vitro stimulation assay of two iNKT cell hybridomas, DN32.D3 and 24.8A, was used to determine whether the analogues can be recognized by TCRs of iNKT cells when presented by CD1d. aMC exhibited 8-fold less activity than bMC in the hybridoma assay. An in vivo CT26 lung metastasis model was used to measure the anti-tumor activity of the analogues. Surprisingly, the analogues, besides aMC, were not recognized by the iNKT hybridoma cell lines and appear to have little or no effect on tumor growth typically seen with aGC and bMC in the CT26 lung metastasis model. These results demonstrate significant differences between aGC and bMC in how the structural changes in the lipid portion affect the anti-tumor biological activity.
Expression of a neoantigen renders pancreas cancer transiently susceptible to immunotherapy
Authors: Burrack Adam L , Spartz Ellen , Raynor Jackson , Olson Margaret , Stromnes Ingunn 
Published: January 2023

Abstract
Immune checkpoint blockade has been largely ineffective for treating pancreatic ductal adenocarcinoma (PDA). Here, we develop a novel model of pancreatic cancer to investigate reasons for response and failure to immune checkpoint blockade in this lethal malignancy. Primary tumor epithelial cell clones from the genetically engineered KPC mouse model transduced to express a specific luciferase antigen, commonly used for bioluminescent in mice, rapidly establish tumors similar to parental cells after orthotopic implantation into syngeneic mice. Unexpectedly, αPD-L1 or αPD-1, which fail to elicit responses to luciferase- KPC parental cells, induce objective responses to luciferase+ KPC clones and prolong animal survival. We identify the immunodominant luciferase H- 2Db-restricted epitope and generate a fluorescently labeled peptide:MHC tetramer that specifically binds PDA-specific CD8 T cells. Up to 40% of tumor-infiltrating T cells bind this tetramer, yet most of these cells co-express PD-1 and Lag-3 and are dysfunctional. αPD-L1 enhances the systemic expansion of tetramer+ T cells and induced the accumulation of PD-1+ Ki67+ and Ki67- tetramer+ T cells in PDA. αPD-L1 significantly reduced the frequency of intra-tumoral tetramer+ T cells that expressed Lag-3 resulting in enhanced ex vivo peptide-specific cytokine production. However, tumors rapidly returned despite T cell infiltration and prolonged immunotherapy. Current efforts are underway to study the evolution of PDA-specific T cells and tumor clones using single cell technologies to inform clinical immunotherapy design.
The role of neutrophil extracellular traps in nonalcoholic steatohepatitis-associated hepatocellular carcinoma
Authors: Zhang Hongji , van der Windt Dirk J , Ren Jinghua , Tsung Allan , Huang Hai 
Published: January 2023

Abstract

Introduction
Nonalcoholic steatohepatitis (NASH) is a progressive form of nonalcoholic fatty liver disease characterized by steatosis, hepatocellular injury and chronic inflammation. Our recent findings showed that neutrophil forming neutrophil extracellular traps(NETs) in the NASH liver provide a pro-tumorigenic micro-environment. However, the mechanism has not been investigated. Here we sought that NASH induced-NETs suppress the development of anti-tumor immunity by promoting an immune-suppressive through Programmed eath-ligand 1 (PD-L1) signaling for HCC survival.

Methods
NASH-HCC mice were created by exposing C57BL/6 mice to streptozotocinand(STZ) and high fat diet. NET blockade was achieved with injection of DNase1, or by using PAD4 KO mice.

Results
There is increased neutrophil infiltration in the liver in the NASH-HCC mice and a concomitant decline in CD4+ and CD8+ T cells. Cit-H3, a specific NET marker persists in the liver through 20 weeks when HCC growth was visible. NETs blockade suppressed tumor growth. PD-L1 expression and PD-1, CTLA-4, LAG-3, TIM-3, the hallmarks of T cell exhaustion are all remarkably increased in CD8+ T cells from NASH-HCC liver compared with control and blocking NETs reduced their expressions. Furthermore, PD-L1 is expressed in the structure of NETs and neutrophils by exposure to stimuli which induce NET formation. The viability of CD4+ and CD8+ T cells isolated from spleen with the stimulation of pure NETs decreased.

Summary
The present results indicate that NASH induced NETs are critical to the inflammation driven carcinogenesis of NASH-HCC by promoting PD-1/PD-L-1 inhibitory signals, and demonstrate the therapeutic potential of disrupting NETs for the prevention of NASH-associated HCC.
Inhibition of effective anti-tumor immunity by macrophage Bcl6
Authors: Desai Nidhi Nitin , ZHU BIBO , Son YoungMin , Sun Jie 
Published: January 2023

Abstract
The role of Bcl6 expression in different immune compartments in regulating anti-tumor immunity is relatively unknown. Previous studies have linked Bcl6 expression in PBMC with poor prognosis in non-small cell lung cancer. We found that high expression of Bcl6 in tumor predicts survival in gastric and ovarian cancers. Using cell type specific conditional knockouts, we were able to investigate the contribution of Bcl6 expression in different lineages in modulating immune response to subcutaneously implanted B16-ova melanoma tumors. Myeloid deficiency of Bcl6 results in decreased tumor growth and metastasis. This is accompanied by enrichment of antigen specific T cells within the tumor. These tumor infiltrating T cells show an increased expression of exhausted markers such as PD-1, Lag-3 and Tim-3. Tumor associated innate cells also upregulate PD-L1. Furthermore, the TILs display an enhanced effector profile measured by robust production of granzyme B, interferon gamma and CCL3 on ex vivo stimulation. This is accompanied by increase in poly-functional CD8 T cells. Our result suggests that Bcl6 expression in the monocyte/macrophage lineage dampens the development of effective anti-tumor immunity and augments immunosuppressive tumor microenvironment. We will elucidate the exact underlying mechanisms and evaluate the translational potential of Bcl6 inhibitors in conjunction with immune checkpoint blockade in the future.
The IRE1-XBP1 axis controls the tumorigenic properties of macrophages Jeffrey J. Rodvold, Alyssa Batista, Alyssa Lew, Takao Iwawaki, Gonzalo Almanza, and Maurizio Zanetti. Moores Cancer Center, UCSD, La Jolla, CA 92093-0815
Authors: Zanetti Maurizio 
Published: January 2023

Abstract
Macrophages are major facilitators of tumorigenicity in mice and humans. However, a general unifying mechanism for how macrophages insert themselves into the tumorigenic process is still missing. We hypothesized that the dysregulation of macrophages could originate from an unbalanced unfolded protein response (UPR). Indeed, the transcriptional profile of tumor-infiltrating CD11b+Gr1− macrophages in experimentally induced (B16.F10) or spontaneously-arising (APC) tumors in mice, shows that they express features of a generalized UPR with concomitant upregulation of IL-23 and Arginase1 relative to spleen and bone marrow myeloid cells. This defines a mixed pro-inflammatory/immune suppressive phenotype (IIS) also described in human cancers. These effects were largely attenuated in B16.F10 tumors grown in TLR4 −/− mice except for the upregulation of Arg1. Using IRE-1 (4μ8c) and PERK (GSK2656157) specific small molecule inhibitors we also determined that macrophages with the UPR/IIS phenotype undergo an IRE1-dependent upregulation of PD-L1. Under similar experimental conditions the ablation of either Ern1 (IRE1) or Xbp1 in macrophages also prevented the upregulation of PD-L1. Finally, the survival of mice implanted with B16.F10 tumor cells was significantly prolonged in mice with Ern1−/− macrophages over that in fl/fl control mice. A prolonged survival in mice with Xbp1−/− macrophages was not significant. These results demonstrate the central role of the IRE1-XBP1 axis in the pro-inflammatory/immune suppressive characteristics of intratumoral macrophages, and their tumor promoting effects overall. They also point to the benefit of modulating the IRE1- XBP1 axis in the tumor microenvironment.
Tumor-derived retinoic acid promotes immune suppression in sarcoma
Authors: Devalaraja Samir , To Tsun , Folkert Ian , Li Minghong , Tada Yuma , Haldar Malay 
Published: January 2023

Abstract
Sarcoma is a rare but heterogeneous collection of fatal malignancies that arise from mesenchymal tissue such as fat, muscle, cartilage, etc. Recent efforts to utilize immunotherapies such as immune checkpoint blockade in sarcoma have demonstrated efficacy only in a small percentage of patients, underscoring the importance of elucidating additional immune evasion mechanisms. Immunosuppressive tumor associated macrophages (TAMs) are abundant in the solid tumor microenvironment (TME) and pose a major barrier to effective anti-tumor immunity. Though circulating monocytes are a major reservoir for TAMs, how the TME governs intratumoral monocyte differentiation is poorly understood. In multiple types of mouse and human sarcoma, we found that the TME induced tumor cells to produce high levels of the tissue metabolite retinoic acid (RA). RA promoted intratumoral monocytes to differentiate into immunosuppressive TAMs and inhibited monocyte differentiation into dendritic cells. Sarcomas genetically modified to produce limited RA harbored a more stimulatory myeloid compartment and enhanced T cell dependent anti-tumor immunity. Notably, RA inhibition demonstrated robust synergy with immune checkpoint blockade therapy. Together, our findings suggest that RA is a local tissue metabolite that promotes myeloid-mediated immune suppression in sarcoma.
Low dose radiotherapy promotes immune-mediated anti-tumor responses
Authors: Barsoumian Hampartsoum B , Younes Ahmed I , Ramapriyan Rishab , Caetano Mauricio S , Schoenhals Jonathan E , Menon Hari , Cushman Taylor R , Cadena Alexandra , Li Ailin , Cortez Maria Angelica , Welsh James W 
Published: January 2023

Abstract
In an immune competent host, immune surveillance maintains the guards against abnormal cell growth, therefore establishing the need for tumors to evade immunity to grow. Tumors tend to mask themselves with an inhibitory stroma, rich with T regulatory cells, Myeloid-derived suppressor cells, Cancer associated fibroblasts, and pro-tumor M2 macrophages. Despite current advances with checkpoint inhibitors and cell-based therapies, the majority of cancer patients remain refractory to treatment due to the presence of the stroma and the inability of effector cells to penetrate. Radiotherapy (XRT) has been traditionally used to control tumors locally. More recently, we developed the RadScopal technique that combines high dose XRT (H-XRT) to release antigens and prime T-cells with low dose XRT (L-XRT) to overcome the stroma, favor the polarization of M1 macrophages, reduce TGF-β levels, and enhance NK cell infiltration. In the 129Sv/Ev murine model of bilaterally transplanted tumors, RadScopal treatment significantly improved the outcomes of anti-CTLA-4 and anti-PD1 checkpoint inhibitors and controlled the growth of primary as well as distal secondary tumors treated with L-XRT. The RadScopal efficacy was nulled when using nude mice lacking effector adaptive immunity. Moreover, specific immune-cell depletion studies highlighted the importance of CD4+ T-cells and NK cells to carry out the anti-tumor functions. Our radio-immunotherapeutic approach was operative in other models such as Lewis Lung Carcinoma, where L-XRT retarded the growth of secondary tumors. In conclusion, L-XRT significantly augmented checkpoint blockers with potential future application to cell therapies (CAR-T and TCR) to extend the benefits to more patients.
Ibrutinib, but not acalabrutinib, inhibits anti-lymphoma T cell and NK cell function
Authors: Hammerich Linda , Svensson-Arvelund Judit , Covey Todd , Brody Joshua 
Published: January 2023

Abstract
Chronic Lymphocytic Leukemia (CLL) is the predominant hematologic malignancy in the U.S. BTK inhibitors (BTKi) demonstrate prolonged survival compared to standard chemotherapy, but they also show notable toxicity, including increased risk for infections. While BTKi have shown both immunosuppressive and -stimulatory effects, the overall effect on T cells (TC), including tumor-reactive TC, is not well understood. Because non-BTK TEC-family and homologous kinases have critical roles in immune cells, we tested whether differentially specific BTKi have differing immunomodulatory effects. We treated mice with ibrutinib or acalabrutinib in vivo and analyzed their immune cell repertoire. Mass cytometry revealed that acalabrutinib, but not ibrutinib, increased the number of NK cells and myeloid cells in spleens and tumors of A20-lymphoma bearing mice, while both BTKi increased TC numbers in A20 tumors. Ibrutinib inhibited the activation of CD8 TC and NK cells isolated from BTKi-treated mice and their ability to lyse tumor cells ex vivo, while acalabrutinib improved CD8 TC-mediated cytolysis. A20 tumor growth was not influenced by BTKi in vivo, but ibrutinib inhibited the ability of transferred, antigen-specific TC to induce tumor regression. To translate our findings, we tested the effect of BTKi on immunogenicity of primary human CLL/MCL cells and their ability to stimulate TC. Ibrutinib inhibited upregulation of activation markers on tumor cells to a higher extent than acalabrutinib. Similarly, only ibrutinib inhibited autologous TC activation after co-culture with tumor cells and superantigen. In conclusion, ibrutinib, but not acalabrutinib inhibits the activation and function of anti-tumor T and NK cells in vivo and in vitro.
DeepTM IL-15 Primed T cells Avoid Toxicity and Synergize with PD-L1 Blockade to Overcome Checkpoint Resistance in Cancer
Authors: Sauer Karsten , Geretti Elena , Liang Xiaoyan , Lyons Jesse , Bardwell Philip , Caruso Santina , Hewes Becker , Fitzgerald Jonathan , Andresen Thomas 
Published: January 2023

Abstract
Interleukin-15 (IL-15) is an attractive asset for cancer immunotherapy which activates and expands CD8+ T cells and NK cells but not immunosuppressive Treg cells. IL-15 can also promote protective T cell memory. However, IL-15 systemic administration is limited by toxicities, and IL-15 efficacy can be dampened by PD-1 checkpoint upregulation on T cells. To overcome IL-15 toxicities by focusing its activity on the tumor microenvironment, we have developed DeepTM IL-15, a multimer of crosslinked IL-15/IL-15 Rα/Fc heterodimers. In DeepTM IL-15 Primed T cells, DeepTM IL-15 is surface anchored to tumor reactive T cells prior to adoptive cell transfer (ACT) into tumor-bearing hosts. Here, we show that DeepTM IL-15 coating enables autocrine activation and expansion of the engrafted but not host T cells, protects mice from tumor re-challenge, and limits IL-15 systemic exposure and toxicities. We further show that PD-L1 blockade synergizes with DeepTM IL-15 coated T cell ACT to eradicate checkpoint-resistant tumors in mice. Based on these data, Torque is currently initiating a Phase I clinical study of TRQ15-01 (DeepTM IL-15 Primed multi-targeted human T cells) and planning a combination arm with checkpoint blockade in solid tumors.
The non-classical MHC-II molecule H2-O (DO) is required for efficient recovery from influenza A infection
Authors: Stern Lawrence , Jurewicz Mollie M 
Published: January 2023

Abstract
H2-O (DO) is a non-classical MHC-II protein thought to regulate antigen presentation through inhibition of the catalytic peptide exchange factor H2-M (DM). H2-O−/− (DO-KO) mice have reduced diversity in the MHC-II peptide repertoire presented by peripheral and thymic antigen-presenting cells, as well as Treg populations with altered TCR repertoire and function. Absence of DO expression has been reported to result in increased neutralizing antibody titers, but a protective role for DO in an infectious disease model has not been reported. To determine whether lack of DO affects susceptibility to viral infection, we inoculated DO-KO and WT mice with a sublethal dose of influenza A (PR8). DO-KO mice exhibited a marked delay in recovery from weight loss after primary infection but not following rechallenge. Viral titers were not found to be significantly different between WT and DO-KO mice. After infection, DO-KO mice had reduced cellularity in spleen and draining lymph nodes, and reduced CD4 T cell responses across a variety of epitopes. Surprisingly, epitope-specific CD8 responses also were reduced, as were the numbers of NK and mast cells in lung after infection. These results demonstrate a role for DO in protection from influenza A infection in mice.
Epitope mapping of Mycobacterium tuberculosis proteins using a non-human primate model of infection
Authors: Grant Nicole L , Balgeman Alexis J , Ellis Amy L , O'Connor Shelby L , Scanga Charles A , Flynn JoAnne L 
Published: January 2023

Abstract
Mycobacterium tuberculosis, the causative agent of tuberculosis, is the leading cause of death by a single infectious agent worldwide. Many studies have focused on the necessity of T cells in combating tuberculosis, particularly at the primary site of infection in the lungs, the granuloma. In spite of their importance in TB disease, very low frequencies of T cells in the granuloma produce cytokine. Our objective is to determine the number and function of Mtb specific T cells in tissues and the periphery using tetramers. We have developed non-human primate (NHP) models of Mtb infection which recapitulate human infection, however, both humans and many NHPs have high MHC variability making studies aimed at understanding the role of specific T cells at the site of infection difficult. For this study, we used a Mauritian cynomolgus macaque (MCM) model, due to their limited MHC variability, to map epitopes of Mtb proteins Rv1196 and Rv0125. Using homozygous animals we found that both proteins elicit peak peripheral IFNγ responses early post infection. We mapped epitopes using pooled or individual peptides in IFNγ Elispots and determined the peak binding regions. We tested allele restriction using RM3 cells expressing major M1 alleles. These data can be used to design tetramers which are vital in determining the number and functionality of antigen specific T cells in the periphery, LN, and lung granulomas of infected MCMs. Understanding the number and function of these Mtb specific T cells following infection will provide a deeper understanding of the role T cells play in pathology and bacterial containment.
Cell surface MHC-I molecules in dendritic cells undergo fast recycling but do not replenish the Rab11+Arf6+ juxtanuclear compartment to support cross-presentation
Authors: Van Endert Peter M , Montealegre Sebastian , Abramova Anastasia , de Kanter Anne-Floor 
Published: January 2023

Abstract
Cross-presentation of internalized antigens by MHC class I molecules (MHC-I) plays a critical role in priming of cytotoxic T cells recognizing pathogens and tumors. It is thought that peptides derived from cross-presented antigens can be loaded on MHC I in the endoplasmic reticulum as well as in endocytic or phagocytic compartments of murine dendritic cells (DCs). However, the origin of MHC I in the latter compartments is poorly understood. Recently MHC-I molecules trafficking through a juxtanuclear Rab11+ recycling compartment have been suggested to be recruited for cross-presentation of phagocytosed antigens. We have critically examined the existence of MHC I recycling and the role of Arf6, described to regulate recycling in non-professional antigen presenting cells, in DCs. We confirm MHC I accumulation in a juxtanuclear Rab11+ compartment and localize Arf6 to this compartment. DC MHC I molecules undergo fast recycling, however, both fully conformed and “open” internalized MHC I fail to enter a putative slow recycling pathway to the Rab11+Arf6+ compartment. Arf6 knockdown increases cell surface class density and reduces degradation of internalized “open” MHC I molecules. Moreover, it compromises cross-presentation of antigen internalized via Fc receptors but not other antigens. In conclusion, we demonstrate for the first time fast recycling of MHC I in mouse DCs but find that recycling is not required for general cross-presentation. We propose that Rab11 and Rab22, previously reported to be required for cross-presentation, mediate delivery of MHC I from the juxtanuclear compartment to phagosomes/endosomes. However, the origin of the MHC I molecules in this compartment remains to be determined.
Measuring the molecular mechanisms of tumor antigen cross-presentation in dendritic cells and macrophages
Authors: Muntjewerff Elke M. , Bianchi Frans , Maassen Sjors , van den Bogaart Geert 
Published: January 2023

Abstract

Objective
Antigen cross-presentation is essential for initiation of an adaptive immune response against cancer and pathogens. During this process, dendritic cells (DCs) present peptides derived from ingested antigens in their major histocompatibility complex class I protein (MHC-I) to cytotoxic CD8+T cells. As a result, these CD8+T cells become activated, enabling them to eliminate infected or malignant cells in the human body. Aim of this study is to develop a quantitative method to measure cross-presentation of NY-ESO1, a tumor-specific antigen expressed by several cancer types.

Methods
DCs were activated and loaded with NY-ESO1-based antigen. To measure cross-priming, DCs were co-cultured with primary naive CD8+T cells. These T cells were transfected with mRNA coding for a specific T cell receptor recognizing an NY-ESO-1-derived epitope. After incubation, the activation of the cytotoxic T cells was measured with ELISA and flow cytometry. In addition, we followed the dynamics of bio-orthogonally tagged NY-ESO1 peptides over time for direct visualization of antigen cross-presentation in dendritic cells and Peripheral Blood Mononuclear Cells (PBMC’s).

Results
Cross-presentation of bio-orthogonal tagged NY-ESO1 could be followed over time in dendritic cells and PBMC's. Interestingly, in our PBMC screen, not only CD1c dendritic cells but also macrophages are highly able to cross-present ingested peptides.

Conclusion
This novel method allows to measure presentation of tumor antigens on MHC-I in DCs and primary cells of human blood. Since cross-presentation is crucial for elimination of virus-infected and malignant cells by the immune system, this knowledge could contribute to improvement of DC-based immune therapies.