bluuebunny/crossref_metadata_2025 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

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

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

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.

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

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

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

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

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

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

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

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

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

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

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.
Pregnancy and lactation interfere with the response of autoimmunity to modulation of gut microbiota
Authors: Mu Qinghui , Cabana-Puig Xavier , Swartwout Brianna , Abdelhamid Leila , Cecere Thomas E , Wang Haifeng , Reilly Christopher M , Luo Xin M
Published: January 2023

Dysbiosis of gut microbiota exists in the pathogenesis of many autoimmune diseases, including lupus. Currently, women with lupus are recommended to avoid pregnancy, as lupus patients who experienced pregnancy usually had more severe disease flares. However, the possible role of gut microbiota in the link between pregnancy and exacerbation of lupus remains to be explored. In the present study, in the classical lupus mouse model MRL/lpr, we compared the structures of gut microbiota in pregnant and lactating individuals vs. age-matched naïve mice. Consistent with studies on non-lupus mice, both pregnancy and lactation significantly changed the composition and diversity of gut microbiota. Strikingly, modulation of gut microbiota using the same strategy resulted in different disease outcomes in experienced (which had undergone pregnancy and lactation) vs. control (naïve) MRL/lpr females: while vancomycin treatment attenuated lupus in naïve mice, it even exacerbated lupus in experienced mice. L. animalis flourished in the gut upon vancomycin treatment, and direct administration of the bacteria recapitulated the differential effects of vancomycin in experienced vs. control mice. A pregnancy-related enzyme, DHNA, was significantly inhibited by L. animalis; however, this inhibition was only apparent in experienced mice, which explained, at least partially, the lack of beneficial response to vancomycin in these mice. The differential production of IL-10 and IFNγ in experienced vs. control mice further explained why the disease phenotypes varied between the two types of mice bearing the same treatment. These results suggest that pregnancy and lactation interfere with the response of autoimmunity to modulation of gut microbiota.
Microbial exposure and autoimmunity in the etiopathogenesis of Sarcoidosis
Authors: Allushi Bujana , Bagavant Harini , Papinska Joanna , Montgomery Courtney G , Deshmukh Umesh S
Published: January 2023

Sarcoidosis is an enigmatic inflammatory disease affecting multiple organs such as the lungs, lymph nodes, brain, heart, and skin. It is characterized by the occurrence of multiple non-caseating granulomas comprised of macrophages, giant cells, and CD4 T cells. Although genetic and environmental factors increase the risk for sarcoidosis, the etiology remains unknown. Recent studies have shown that HLA-DR3+ sarcoidosis patients harbor CD4+ T cells reactive with a vimentin peptide 424–443. However, whether autoimmunity is a cause or consequence of the disease is not known.

This study was undertaken to investigate the mechanisms responsible for activation of vimentin reactive T cells and determine their pathogenic role in sarcoidosis. For this purpose, we immunized the NOD-DR3 mice with the vimentin peptide 424–443 and induced a robust T cell response against the peptide. Fine epitope mapping using T cell hybridomas reactive with the peptide showed that both N-terminal and C-terminal amino acids were critical for T cell activation. Homology searches of microbial protein database identified a 100% homologous sequence in a protein from Klebsiella pneumoniae. Immunization of mice with this peptide, followed by intravenous transfer of peptide-coupled agarose beads induced granulomatous lesions in the lungs. Immunohistochemical analysis of these lesions showed the presence of CD4+ T cells, macrophages, and an upregulated MHC-II expression.

In summary, our data demonstrate for the first time that autoimmunity is involved in the pathogenesis of sarcoidosis. Furthermore, the demonstration of molecular mimicry between a lung infecting microbe and vimentin might explain the role of microbial exposures as a risk factor for sarcoidosis.
Interactions between the host genome and the gut microbiome determine susceptibility to CNS autoimmune disease
Authors: Montgomery Theresa L , Fang Qian , Künster Axel , Busch Hauke , Teuscher Cory , Krementsov Dimitry
Published: January 2023

Multiple sclerosis (MS) is a chronic autoimmune central nervous system (CNS) disease and the leading cause of non-traumatic neurological disability in young adults. The etiology of MS is multifactorial and polygenic, with 30% of risk genetic and 70% environmental. Recent studies identified an imbalance in the human gut microbiome within MS patients, including depletion of the Lactobacillus genus. Animal models support a causal role of the gut microbiome in MS, though the mechanisms remain unclear.

Here, we leverage natural genetic variation in wild-derived PWD/PhJ (PWD) mice as compared to classic C57BL/6J (B6) mice, modeling human genetic diversity to identify host genome and gut microbiome interactions governing disease susceptibility. In a model of MS, experimental autoimmune encephalomyelitis (EAE), 27 consomic strains carrying PWD chromosomes on the B6 background demonstrated that PWD-derived loci exhibit bidirectional and sex-specific effects on disease severity. 16S rRNA gene sequencing of the gut microbiome in consomic and parental strains identified strain-specific profiles and metabolic functions associated with differential susceptibility to EAE. Functionally, manipulation of the gut microbiome by co-housing or transplantation, demonstrated direct host genotype-dependent effects of the microbiome on EAE susceptibility, with transfer of signature Lactobacillus species associated with changes in circulating indole metabolites and altered EAE severity. These studies reveal the presence of complex bidirectional interactions between the host genome and gut microbiome that modulate susceptibility to CNS autoimmunity, and identify specific microbiome constituents as potential therapeutic candidates.
Periodontal disease: from infection to autoimmunity
Authors: Garzon Hernan Santiago , Suarez Lina
Published: January 2023

Five decades of publications have been necessary to document the relationship between immune response and tissue injury in periodontitis. Multiple mechanisms have been implicated in the progression of tissue damage, including the controversial mechanisms of autoimmunity. The aim of this paper is the development of the theories that considered periodontal disease as an autoimmune entity with a historical narrative and descriptive view. Diverse theories have been referenced involving the innate and acquired immunity: generation of anti-neutrophil cytoplasmic antibodies (ANCA), Th17 cell function and IL-17, auto-antibodies to collagen and epithelial components of the periodontium, the role of NK cells T lymphocytes and T CD5, development of molecular mimicry, among others. In conclusion, it’s still difficult to classify periodontal disease as an stabilshed autoimmune disease, because its multifactorial nature makes it difficult to understand. However, the evidence is clear and comprehensive showing related autoimmune mechanisms, which could eventually explain the progression and its relation to systemic events such as cardiovascular disease and atherosclerosis.
Abnormal B cell development in an SLE patient suffering from immunothrombocytopenia
Authors: CHOI YOUN SOO , KIM JOOHYUNG
Published: January 2023

Follicular helper T (Tfh) cells are effector CD4 T cells which help B cells form germinal center reactions for memory B cells and long-lived plasma cells. Abnormal Tfh differentiation and function is highly associated with development and disease progression of SLE. B cell and CD4 T cell compartments were analyzed in the spleen, which was removed from one of outpatients in SNU hospital, who suffer from SLE with severe immunothrombocytopenia. PD1+CXCR5+ Tfh cells were hardly found in the spleen, where little germinal center (GC) B cells exist. B cell frequency in the peripheral blood of the patient was significantly low (~0.1%), which led us to speculate that B cell development is impaired in the patient. To reveal mutation(s) of genes responsible for B cell development defect, B cells and non-B cells isolated from splenocytes of the patient, and from peripheral blood mononuclear cells of the patient’s daughter, who does not exhibit clinical symptoms, were subject to whole exome sequencing (WES) analysis. Our initial screen failed to locate mutations in genes, including BTK and IKAROS, which are able to develop primary B cell deficient conditions, indicating that B cell development could be regulated by function of novel gene(s). We were able to find mutations in genes, whose products were reported to function in signaling pathways downstream of B cell surface receptors, during mitotic division, and so on. Our future study includes (i) to examine whether gene(s) of interest are expressed during B cell development in humans and mice, and (ii) to analyze whether shRNA mediated knockdown or CRISPR/Cas9-sgRNA mediated deletion of genes, which are expressed by developing B cells in both humans and mice, could give rise to B cell development defect in mice.
The Glycosylation and Glycoprotein Signature of Immunoglobulins in Patients with Autoimmune Liver Diseases
Authors: Zhang Weici , Zhou Xing , Muchena John , Shuai Zongwen , Sun Ying , Yang Guo-Xiang , Liu Chung Heng , Dhaliwal Sandeep , Invernizzi Pietro , Bowlus Christopher , Leung Patrick S.C. , Lebrilla Carlito , Gershwin M Eric
Published: January 2023

Glycosylation of antibodies, particularly in the Fc domain, critically modulate the ability of antibodies to bind to FcRs, maintaining immune quiescence and marshaling appropriate immune response to achieve a finely orchestrated immune response. Alterations in the glycosylation profile of immunoglobulin (Ig) have been implicated in various autoimmune conditions, which may arise prior to symptoms and have been considered diagnostic for autoimmune disease. We applied QqQ mass spectroscopy with subsequent multiple reaction monitoring (MRM) to elucidate the overall profile, composition and linkage of the sugar residues of plasma IgG, IgM and IgA glycans in 225 serum samples from healthy donors (HD; n=50), PBC (n=100) and PSC (n=75) with or without IBD, using an Agilent 6490 triple quadruple (QqQ) mass spectrometer. Our data demonstrate that most of IgA 1 and 2 glycopeptides significantly distinguish PBC from PSC, which are associated with lower level of Bi anterary glycoforms and elevated HexNac containing glycoforms in PBC samples as compared to both controls and PSC. HexNac terminated IgG1 glycoforms are enriched in both PBC and PSC. The levels of IgM glycopeptide, IgM_439_5200, IgM_439_6200 and J chain distinguish among three categories of samples. Most importantly, a distinct pattern of glycoforms exists in PSC patients with IBD. Neu5Ac terminated IgA and IgM are enriched, while the galactosylated forms are lower in PSC with IBD. Ig glycosylation pattern can be a novel serological marker to distinguish between PBC and PSC. This novel technology highlights the importance of glycan biology in the immune response and as a potential mechanism in the loss of tolerance and/or a disease specific chronic signal of inflammation.
Salivary IgA as biomarker of disease activity in Systemic Lupus Erythematosus
Authors: Romero Sandra , Sánchez-Salguero Erick Saúl , Torres-Ruiz Jiram José , Núñez-Álvarez Carlos , Santos-Argumedo Leopoldo , Chacón-Salinas Rommel , Gómez-Martín Diana , Maravillas-Montero José Luis
Published: January 2023

Immunoglobulin A (IgA) is the main antibody isotype present in the body fluids such as tears, intestinal mucous, colostrum and saliva. There are two subtypes of IgA in humans: IgA1 mainly present in blood and IgA2, the preferentially expressed mucosal antibody. In clinical practice, immunoglobulins are typically measured in venous or capillary blood; however, alternative samples including saliva are now being considered given its non-invasive and easy collection nature.

Since IgA deficiency could be frequently detected in patients with autoimmune diseases, we decided to evaluate the levels of both IgA subtypes in serum and saliva of systemic lupus erythematosus (SLE) patients. Specific IgA1 and IgA2 levels were measured by a light chain capture-based ELISA in a cohort of 32 patients with SLE that were compared with antibody levels of healthy volunteers.

Surprisingly, our results indicated that in saliva of SLE patients, both IgA subtypes were significantly elevated; however, serum IgA1 levels were decreased when compared with control subjects. Interestingly, we also found that salivary IgA levels, most specifically IgA1, positively correlate with the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) values as well with the amount of serum anti-nucleosomes and anti-dsDNA IgG autoantibodies. Strikingly, we also were able to detect the presence of salivary anti-nucleosome IgA antibodies in SLE patients, a feature that was not previously reported elsewhere.

According to our results, IgA characterization in saliva could be used as a pre-diagnostic or follow-up clinical tool in SLE with easier, faster and safer to manipulate than blood samples.
Age-associated B cells in early drug-naive rheumatoid arthritis patients
Authors: VIDAL-PEDROLA GEMMA VIDAL , Cameron James , Pratt Arthur , Mellor Andrew , Scheel-Toellner Dagmar , Isaacs John , Anderson Amy
Published: January 2023

Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterised by joint inflammation. Studies in mice and patients suffering from autoimmune diseases described a novel subset of B cells named age-associated B cells (ABCs). Moreover, a subset of synovial fluid B cells with a similar phenotype and FcRL4 expression contributes to RA pathogenesis.

Newly diagnosed patients were recruited from the Newcastle Early Arthritis Clinic. B cell subsets in blood were phenotyped using flow cytometry. NanoString Immunlogy Panel was used to asses gene expression from sorted ABCs, naïve, memory and CD5+ B cells from RA patients, age-matched healthy controls and disease controls.

Our work showed that there are no significant differences in the frequency of ABCs between RA patients, and disease and healthy controls. Our results also show that ABCs resemble the memory B cell phenotype regarding class-switch immunoglobulins expression. Interestingly, the FcRL4+, the Ki67+ and the T-bet expressing B cells were enriched in the ABC population. ABCs expressed high levels of HLA-DR and co-stimulatory molecules, as well as the activation marker, CD69. Gene expression analysis showed a specific gene signature for the ABCs when compared to the other B cells. KEGG analysis results showed that differentially expressed genes were enriched in the antigen presentation and the cytokine-cytokine receptor interaction pathways. Moreover, 13 genes were overexpressed in ABCs from the RA patients compared to the other control groups.

This data supports the idea that ABCs have a pathogenic role in RA, potentially via T cell stimulation and migration to sites of inflammation. However, further characterisation of this subset and functional studies are needed.
MIF and MIF2 have distinct but synergistic roles in CIA pathogenesis
Authors: Doherty Edward H , Tilstam Pathricia Veronica , Bucala Richard
Published: January 2023

Rheumatoid arthritis (RA) is a relapsing autoimmune disease with progressive joint destruction. High expression alleles of the cytokine macrophage migration inhibitory factor (MIF) are associated with severe erosive RA. MIF and MIF family member D-dopachrome tautomerase (MIF2) signal through the receptor CD74. Previously we reported on the presence of CD74 expressing effector memory T cells in the collagen-induced arthritis (CIA) mouse model and identified CD74+ T cells in human RA synovium fluid. We studied MIF and MIF2 signaling on CD74+ T cells and inflammatory CD74high MΦ in the CIA model. We observed infiltration of CD74+ T cells (1.7 fold increase, p<0.001) and inflammatory CD74high MΦ (2 fold increase, p<0.001) in the joints of WT mice on day 28 post CIA induction. CD74+ T cell infiltration into paws positively correlated with CIA disease score (r=0.731, p=0.003). CD74+ T cells and CD74high MΦ failed to expand or infiltrate in the paws of Mif−/− mice in CIA. Interestingly, CIA induction in Mif2−/− mice expand CD74+ T cells in lymph nodes (0.5 fold increase, p=0.024), but fail to expand in other secondary lymphoid organs or infiltrate joints. Macrophage precursor Gr1high CD74+ monocytes expand in the spleen (3 fold, p<0.001) and blood (1 fold, p<0.001) of Mif2−/− mice, no change in CD74high MΦ levels is observed. The MIF inhibitor MIF098 ameliorates joint inflammation but did not inhibit the expansion or joint infiltration of CD74+ T cells (2 fold, p<0.001), Gr1high CD74+ monocytes, and CD74high MΦ (0.7 fold, p<0.01). Our findings provide evidence for a pathogenic role of novel MIF responsive CD74+ T cell in RA and suggest separate but crucial roles for both MIF and MIF2 in the development and localization for CD74+ T cells and CD74high MΦ in CIA.
STING-mediated chronic activation of ER stress through disrupting calcium homeostasis primes T cells for cell death
Authors: Wu Jianjun , Yan Nan
Published: January 2023

STING is a central protein for innate immune response to a wide range of microbial pathogens. Gain-of-function STING mutations cause systemic inflammation, lung disease and T cell cytopenia in humans and in mice, although the mechanism of disease is not known. Here, we found that SAVI mutation N154S induces chronic activation of ER stress and unfolded protein response (UPR), leading to spontaneous T cell death by apoptosis in the StingN153S/+ mouse and in human T cells. Mechanistically, we found that N154S severely disrupts calcium homeostasis in T cells, thus intrinsically primes T cells to become hyper-responsive to T cell receptor (TCR) signaling-induced ER stress and the UPR, leading to cell death. This intrinsic priming effect is mediated through a novel region of STING protein that we name ‘the UPR motif’, which is distinct from known domains required for interferon signaling. Point mutations that disrupt the UPR motif rescue N154S-mediated calcium dysregulation and ER stress, and blocks T cell death. Pharmacological inhibition of ER stress also prevented T cell death in vitro and in vivo. Furthermore, restoring only the CD8+ T cells rescued splenomegaly, hypercytokinmia and perivascular lung inflammation in the StingN153S/+ mouse. Collectively, our data uncovers a critical IFN-independent function of STING that regulates calcium homeostasis, ER stress and T cell survival.
Antigen-presenting cells from naive mice constitutively present the T cell epitope of SERCA2a and induce inflammatory cytokine production in antigen-specific T cells
Authors: Reddy Jay , Arumugam Rajkumar , Yalaka Bharathi , Massilamany Chandirasegaran , Ali Shihabudeen , Riethoven Jean-Jack , Sun Xinghui
Published: January 2023

We recently reported that sarcoplasmic/endoplasmic reticulum (SR) calcium-ATPase2a (SERCA2a) 971–990 induces atrial myocarditis by generating autoreactive T cells in A/J mice. However, it was unknown as to how the antigen-sensitized T cells could recognize SERCA2a 971–990, since SERCA2a-expression is confined to SR. Here, we present evidence that antigen-presenting cells (APCs) from naïve animals constitutively present SERCA2a 971–990 and stimulate T cells antigen-specifically. By using major histocompatibility complex (MHC) class IIdextramers for SERCA2a 971–990, we created a panel of antigen-specific T cell hybridomas and demonstrated that splenocytes from naïve A/J mice stimulated the hybridoma cells without exogenous supplementation of SERCA2a 971–990, and such an effect was pronounced with unirradiated cells as compared to irradiated cells. We recapitulated this phenomenon by using SERCA2a 971–990-specific, primary T cells, and the T cell responses were verified to be MHC-restricted. While T cells exposed to mononuclear cells obtained from heart and liver responded similar to splenocytes, endothelial cells (ECs) generated from the corresponding organs displayed opposing effects in that the T cell responses were suppressed with the heart-ECs, but not from liver. Finally, SERCA2a 971–990-reactive T cells exposed to APCs were found to produce inflammatory cytokines namely, interferon-γ, granulocyte macrophage colony stimulating factor and interleukin-17. Our data suggest that the constitutive expression of SERCA2a 971–990 by APCs can trigger pathogenic responses under the conditions of autoimmunity that may have implications on endothelial dysfunction.
Intestinal Interleukin (IL)-22RA1 signaling regulates the reciprocal control of IL-22 and onset of high fat diet-induced metabolic disorders
Authors: Gaudino Stephen , Huang Huakang , Jean-Pierre Makheni , Beaupre Michael , Lin Xun , Kumar Pawan
Published: January 2023

Impaired signaling by IL-22 has been shown to accelerate high fat diet (HFD)-induced obesity. However, it is not known if IL-22 signaling in the intestine regulates HFD-induced metabolic disorders.

To test this, intestinal epithelial-specific IL-22RA1 knockout mice – Il22RA1fl/fl;Villin cre+ (IL-22RA1ΔIEC) and control Il22RA1fl/fl;Villin cre- (IL-22RA1fl/fl) mice – were generated. When placed on HFD for 16 weeks, IL- 22RA1ΔIEC and IL-22RA1fl/fl mice display commensal dysbiosis, reduced antimicrobial peptide expression, and dysregulated IL-22 responses. No difference in weight gain was observed between these mice over the 16-week period. Interestingly, IL-22RA1ΔIEC mice displayed decreased glucose tolerance when compared to controls. Upon antibiotic treatment, differences in glucose tolerance between these mice were not observed. Furthermore, this difference in glucose tolerance was not due to histopathology changes in white adipose tissue (WAT) or liver tissue. In IL-22RA1ΔIEC mice, we observed that expression of genes related to β-oxidation (Acox1) were increased in the WAT, and liver tissues displayed decreased expression of β-oxidation (Pparα) and glycolysis (G6PC) genes. These changes were not observed in Il22−/− mice or liver-specific IL-22RA1 knockout mice which suggests IL-22 may drive the expression of critical metabolic genes in the WAT and liver. We found exacerbated IL-22 response in HFD-fed IL-22RA1ΔIEC mice. Indeed, injection of IL-22RA1ΔIEC mice with anti-IL-22 decreased glucose tolerance when compared to IL-22RA1ΔIEC mice injected with an isotype control.

Collectively, our data suggest that IL-22 signaling in the intestinal epithelium is important for regulating HFD-induced metabolic disorder.
Multivariate Transcriptome Analysis of CXCR5-CXCL13 signaling in Unmutated and Mutated CLL
Authors: Griffen Tiara L , Young Corey , Dill Courtney D. , Carey Kaylin , Adebayo Olayinka , Nunez Sha'kayla , Lillard James W
Published: January 2023

Chronic Lymphocytic Leukemia (CLL) is characterized by the appearance of mature-appearing B cells in the blood, bone marrow, and lymph nodes, but the molecular pathogenesis of CLL is incompletely known. Chemokines and their receptors contribute to the progression of several malignancies. CXCR5 and CXCL13 are produced by cells in the CLL microenvironments, which promote disease progression. There is a gap in understanding the molecular mechanisms involved in CXCL13-CXCR5 interactions during CLL. Together, this provided the rationale to test the hypothesis CXCR5-CXCL13 signaling contributes to the growth, metastasis, and survival of CLL. The role of CXCR5, CXCL13, and associated genes was investigated by conducting Weighted Gene Network Co-expression (WGCNA) and upstream regulator, canonical pathway, and gene interaction analyses of International Cancer Genome Consortium (ICGC) transcriptomes with quantitative and qualitative clinical traits identified in CLL patients (n=203). The WGCNA-designated blue module, co-expression network, contained CXCL13 and 2088 other genes, which significantly correlated (R2=0.31, p= 3e–05) with IGHV-unmutated CLL status. This network included CXCL13-CXCR5 driven genes, e.g., SYK, ATM, JAK1, STAT1, LTB, LTB4R, MAPK, PLC, PIK3, and WNT genes, which mediate survival, stemness, and metastasis of CLL. CXCR5 was found in the WCGNA grey module, which included other CLL-driver genes, e.g., IGHV, MYC, and ZAP-70. This module was significantly associated with stage A, relapse, and IGHV-mutatedCLL cases. Among the top canonical pathways of the grey module were BCR- and PIK3/Akt-signaling. Taken together, our data suggest clinical significance of the CXCL13-CXCR5 pathway in CLL progression.