Autoimmunity
Abstract
Multiple sclerosis is characterized by CNS infiltration of auto-reactive immune cells that drive both acute inflammatory demyelination and chronic progressive axonal and neuronal injury. Expanding evidence implicates CD8+ anti-neural T cells in the irreversible neurodegeneration that underlies progression in multiple sclerosis, yet therapies specifically targeting this cell population are limited. CD8+ T cells from patients with MS exhibit increased engagement of the pentose phosphate pathway. Pharmacologic inhibition of the pentose phosphate pathway reduced glycolysis, glucose uptake, NADPH production, ATP production, proliferation, and proinflammatory cytokine secretion in CD8+ T cells activated by ligation of CD3 and CD28. Pentose phosphate pathway inhibition also prevented CD8+ T cell-mediated antigen-specific neuronal injury in vitro and in both an adoptive transfer-based cuprizone model of demyelination and in mice with experimental autoimmune encephalomyelitis. Notably, transcriptional profiling of CNS-infiltrating CD8+ T cells in patients with MS indicated increased pentose phosphate pathway engagement, suggesting that this pathway is involved in CD8+ T cell-mediated injury of axons and neurons in the demyelinated CNS. Inhibiting the pentose phosphate pathway disrupts CD8+ T cell metabolic reprogramming and effector functions, suggesting that such inhibition may serve as a therapeutic strategy to prevent neurodegeneration in patients with progressive MS.
Authors
Ethan M. Grund, Benjamin D.S. Clarkson, Susanna Pucci, Maria S. Westphal, Carolina Muniz Partida, Sara A. Muhammad, Charles L. Howe
Abstract
The presence of B cells in tumors is correlated with favorable prognosis and efficient response to immunotherapy. While tumor-reactive antibodies have been detected in several cancer types, identifying antibodies that specifically target tumor-associated antigens remains a challenge. Here, we investigated the antibodies spontaneously elicited during breast and lung cancer that bind the cancer-associated antigen MET. We screened patients with lung (n = 25) and breast (n = 75) cancer and found that 13% had antibodies binding to both the recombinant ectodomain of MET, and the ligand binding part of MET, SEMA. MET binding in the breast cancer cohort was significantly correlated with hormone receptor–positive status. We further conducted immunoglobulin sequencing of peripheral MET-enriched B cells from 6 MET-reactive patients. The MET-enriched B cell repertoire was found to be polyclonal and prone to non-IgG1 subclass. Nine monoclonal antibodies were cloned and analyzed, and these exhibited MET binding, low thermostability, and high polyreactivity. Among these, antibodies 87B156 and 69B287 effectively bound to tumor cells and inhibited MET-expressing breast cancer cell lines. Overall, our data demonstrate that some patients with breast and lung cancer develop polyreactive antibodies that cross-react with MET. These autoantibodies have a potential contribution to immune responses against tumors.
Authors
Michal Navon, Noam Ben-Shalom, Maya Dadiani, Michael Mor, Ron Yefet, Michal Bakalenik-Gavry, Dana Chat, Nora Balint-Lahat, Iris Barshack, Ilan Tsarfaty, Einav Nili Gal-Yam, Natalia T. Freund
Abstract
Dysregulation of T follicular helper (Tfh) and T follicular regulatory (Tfr) cell homeostasis in germinal centers (GCs) can lead to antibody-mediated autoimmunity. While interleukin-1β (IL-1β) modulates the GC response via IL-1R1 and IL-1R2 receptors on follicular T cells in animal models, its role in humans remains unclear. We analyzed Tfh and Tfr phenotypes in human secondary lymphoid organs (tonsils, spleen, and mesenteric lymph nodes) using flow cytometry, single-cell transcriptomics, and in vitro culture, comparing findings with samples from autoimmune patients. We observed organ-specific Tfh/Tfr phenotypes according to activation status and IL-1 receptor expression. An excess of IL-1R1 over IL-1R2 expression promoted a unique activated Tfr subset with Treg and GC-Tfh features. IL-1β signaling via IL-1R1 enhanced follicular T-cell activation and Tfh-to-Tfr differentiation, while IL-1β inhibition upregulated IL-1R1, indicating a tightly regulated process. In autoimmune patients, high IL-1β and circulating Tfr levels correlated with increased autoantibody production, linking inflammation, IL-1β signaling, and Tfr/Tfh balance. Our findings highlight the critical role of IL-1β in follicular T-cell activation and suggest that targeting IL-1β signaling in Tfh and Tfr cells could be a promising strategy for treating antibody-mediated autoimmune diseases.
Authors
Romain Vaineau, Raphaël Jeger-Madiot, Samir Ali-Moussa, Laura Prudhomme, Hippolyte Debarnot, Nicolas Coatnoan, Johanna Dubois, Marie Binvignat, Hélène Vantomme, Bruno Gouritin, Gwladys Fourcade, Paul Engeroff, Aude Belbézier, Romain Luscan, Françoise Denoyelle, Roberta Lorenzon, Claire Ribet, Michelle Rosenzwajg, Bertrand Bellier, David Klatzmann, Nicolas Tchitchek, Stéphanie Graff-Dubois
Abstract
Epstein-Barr virus (EBV) infection precedes multiple sclerosis (MS) onset and plays a poorly understood etiologic role. To investigate possible viral pathogenesis, we analyzed single-cell expression in peripheral B cells from people with early MS collected longitudinally during the Immune Tolerance Network (ITN) STAyCIS Trial. Expression profiles were compared to scRNA-seq from in vitro EBV models, autoimmune disorders, chronic infectious diseases, and healthy controls. Analyses focused on CD19+/CD20+/CD21lo/CD11c+/T-bet+ atypical B cells (ABCs). ABCs were significantly enriched in early MS PBMCs versus healthy controls by scRNA-seq and flow cytometry, establishing ABC expansion as a clinical feature. EBV-associated ABC expression including CXCR3, PD-L1, and PD-L2 was enriched in early MS; however, direct EBV infection of ABCs was not detected. Early MS ABCs exhibited significantly upregulated inflammatory cytokine mRNAs (CXCL8, IL18, VEGFA). Further de novo EBV-infected B cells secreted IL-8 and VEGF. MS activity stratification revealed rare distinctive inflammatory ABCs significantly underrepresented in individuals with no evidence of activity long-term (LTNA) versus people with additional RRMS activity at the primary endpoint. Moreover, CXCR3+ ABCs increased after baseline diagnosis and were significantly enriched in people with disease exacerbation during the study. Thus, ABC expansion and inflammatory responses correlate to early MS activity, possibly as a bystander response to EBV.
Authors
Elliott D. SoRelle, Ellora Haukenfrers, Gillian Q. Horn, Vaibhav Jain, James Giarraputo, Karen Abramson, Emily Hocke, Laura A. Cooney, Kristina M. Harris, Scott S. Zamvil, Simon G. Gregory, Micah A. Luftig
Abstract
Lupus nephritis (LN) constitutes the most common organ-threatening manifestation of systemic lupus erythematosus (SLE), with the pathological proliferation of mesangial cells (MCs) recognized as a critical factor in its pathogenesis and progression. Self-DNA-containing immune complex (DNA-IC) represents a prime pathogenic factor in SLE, yet its pathological impact on MCs remains unclear. In the present study, we elucidated the mechanism underlying the excessive proliferation of MCs following the recognition of DNA-IC in LN patients. Here, we pinpointed that the excessive proliferation of MCs was attributed to an anomalous transition from the G1 to the S phase of the cell cycle in LN patients. Mechanically, the dysfunction of P27 protein resulted in the aberrant G1-S phase transition, and the phenomenon was closely related to the ubiquitin-mediated degradation of its key transcription factor, PBX1. This degradation was regulated by lactylation of PBX1 in the site of Lys40 residue. The elevated lactylation level of PBX1 protein arisen from the up-regulation of glycolysis levels induced by DNA-IC. Accordingly, targeting lactate production in MCs of LN patients effectively alleviated renal inflammation and fibrosis progression in LN patients. Elevated lactate results in PBX1 lactylation, leading to MCs excessive proliferation and thus serving as a promising therapeutic target for LN.
Authors
Enzhuo Liu, Chenghua Weng, Chenchu Yan, Xingchen Zhu, Xinyue Li, Mengdi Liu, Zhenke Wen, Zhichun Liu
Abstract
Autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) are autoimmune liver diseases with strong female predominance. They are caused by T cell–mediated injury of hepatic parenchymal cells, but the mechanisms underlying this sex bias are unknown. Here, we investigated whether testosterone contributes to T cell activation in women with PBC. Compared with sex- and age-matched healthy controls (n = 23), cisgender (cis) women with PBC (n = 24) demonstrated decreased testosterone serum levels and proinflammatory CD4+ T cell profile in peripheral blood. Testosterone suppressed the expression of TNF and IFN-γ by human CD4+ T cells in vitro. In trans men receiving gender-affirming hormone therapy (GAHT) (n = 25), testosterone affected CD4+ T cell function by inhibiting Th1 and Th17 differentiation and by supporting the differentiation into regulatory Treg. Mechanistically, we provide evidence for a direct effect of testosterone on T cells using mice with T cell–specific deletion of the cytosolic androgen receptor. Supporting a role for testosterone in autoimmune liver disease, we observed an improved disease course and profound changes in T cell states in a trans man with AIH/primary sclerosing cholangitis (PSC) variant syndrome receiving GAHT. We here report a direct effect of testosterone on CD4+ T cells that may contribute to future personalized treatment strategies.
Authors
Lara Henze, Nico Will, Dakyung Lee, Victor Haas, Christian Casar, Jasper Meyer, Stephanie Stein, Franziska Mangler, Silja Steinmann, Tobias Poch, Jenny Krause, Johannes Fuss, Johanna Schröder, Alexandra E. Kulle, Paul-Martin Holterhus, Stefan Bonn, Marcus Altfeld, Samuel Huber, Ansgar W. Lohse, Dorothee Schwinge, Christoph Schramm
Abstract
Fibroblasts are central to pathogenesis of systemic sclerosis (SSc). However, studies of conventional explant fibroblast cultures incompletely reflect disease biology and treatment response. We isolated a second non-migratory “resident” population of fibroblasts from skin biopsies after outgrowth of explant “migratory” cells. These non-motile resident fibroblasts were compared with migratory cells from the same biopsy, using functional studies, bulk and scRNAseq, and localised in situ by multichannel immunofluorescence. Migratory and resident fibroblast populations in SSc showed distinct pro-fibrotic characteristics and gene expression for pathogenic pathways differing by stage and autoantibody subgroup. TGFβ signalling was highly active in migratory fibroblasts in early stage dcSSc. Conversely, resident fibroblasts had less upregulated TGFβ signalling, especially in late dcSSc. Increased chemokine expression was a hallmark of resident fibroblasts at all stages. In vitro studies confirmed differential response to TGFβ1 and CCL2 between migratory and resident cells. We suggest that migratory fibroblasts are especially important in early skin disease whereas non-migratory fibroblasts may have a regulatory role and contribute more to fibrosis in later stage disease. Thus, we have identified a pathogenic fibroblast population in SSc, not isolated by conventional explant culture, that could play an important role in fibrosis and be targeted therapeutically.
Authors
Kristina E.N. Clark, Shiwen Xu, Moustafa Attar, Voon H. Ong, Christopher D. Buckley, Christopher P. Denton
Abstract
Lipid metabolism is closely linked with antitumor immunity and autoimmune disorders. However, the precise role of lipid metabolism in uveitis pathogenesis is not clear. In our study, we analyzed the single-cell RNA-Seq (scRNA-Seq) data from cervical draining lymph nodes (CDLNs) of mice with experimental autoimmune uveitis (EAU), revealing an increased abundance of fatty acids in Th17 cells. Subsequent scRNA-Seq analysis identified the upregulation of DGAT1 expression in EAU and its marked reduction under various immunosuppressive agents. Suppression of DGAT1 prevented the conversion of fatty acids into neutral lipid droplets, resulting in the accumulation of lipid peroxidation and subsequent reduction in the proportion of Th17 cells. Inhibiting lipid peroxidation by Ferrostatin-1 effectively restored Th17 cell numbers that were decreased by DGAT1 inhibitor. Moreover, we validated the upregulation of DGAT1 in CD4+ T cells from patients with Vogt-Koyanagi-Harada (VKH) disease, a human uveitis. Inhibiting DGAT1 induced lipid peroxidation in human CD4+ T cells and reduced the proportion of Th17 cells. Collectively, our study focused on elucidating the regulatory mechanisms underlying Th17 cell survival and proposed that targeting DGAT1 may hold promise as a therapeutic approach for uveitis.
Authors
Tianfu Wang, Runping Duan, Zhaohuai Li, Bowen Zhang, Qi Jiang, Loujing Jiang, Jianjie Lv, Wenru Su, Lei Feng
Abstract
Using transcriptomic profiling at single-cell resolution, we investigated cell-intrinsic and cell-extrinsic signatures associated with pathogenesis and inflammation-driven fibrosis in both adult and pediatric patients with localized scleroderma (LS). We performed single-cell RNA-Seq on adult and pediatric patients with LS and healthy controls. We then analyzed the single-cell RNA-Seq data using an interpretable factor analysis machine learning framework, significant latent factor interaction discovery and exploration (SLIDE), which moves beyond predictive biomarkers to infer latent factors underlying LS pathophysiology. SLIDE is a recently developed latent factor regression-based framework that comes with rigorous statistical guarantees regarding identifiability of the latent factors, corresponding inference, and FDR control. We found distinct differences in the characteristics and complexity in the molecular signatures between adult and pediatric LS. SLIDE identified cell type–specific determinants of LS associated with age and severity and revealed insights into signaling mechanisms shared between LS and systemic sclerosis (SSc), as well as differences in onset of the disease in the pediatric compared with adult population. Our analyses recapitulate known drivers of LS pathology and identify cellular signaling modules that stratify LS subtypes and define a shared signaling axis with SSc.
Authors
Aaron BI Rosen, Anwesha Sanyal, Theresa Hutchins, Giffin Werner, Jacob S. Berkowitz, Tracy Tabib, Robert Lafyatis, Heidi Jacobe, Jishnu Das, Kathryn S. Torok
Abstract
Managing immune-related adverse events (irAEs) caused by cancer immunotherapy is essential for developing effective and safer therapies. However, cellular mechanism(s) underlying organ toxicity during anti-PD-(L)1 therapy remain unclear. Here, we investigated the effect of chronological aging on anti-PD-(L)1 therapy-induced irAE-like lung toxicity, utilizing tumor-bearing aged mice. Anti-PD-(L)1 therapy facilitated ectopic infiltration of T and B cells, and antibody deposition in lung of aged but not young mice. Adoptive transfer of aged lung-derived CD4 T cells into TCR-deficient mice revealed that both pathogenic CD4 T cells and aged host environment were necessary for the irAE-inducible responses. Single-cell transcriptomics of lung-infiltrating cells in aged mice demonstrated that anti-PD-(L)1 therapy elicited ICOS+CD4 T-cell activation. Disruption of ICOS-ICOSL interaction attenuated germinal center B-cell differentiation and subsequent lung damage, which were overcome by local administration of IL-21 in the lung of anti-PD-1 therapy-treated aged mice. Therefore, ICOS+CD4 T cells elicited under aged environment exacerbated aberrant immune responses and the subsequent lung dysfunction. Consistent with the findings from mouse model, ICOS up-regulation in CD4 T cells was associated with later irAE incidence in patients with cancer. These finding will help development of useful strategies for irAE management in cancer patients, many of whom are elderly.
Authors
Mari Yokoi, Kosaku Murakami, Tomonori Yaguchi, Kenji Chamoto, Hiroaki Ozasa, Hironori Yoshida, Mirei Shirakashi, Katsuhiro Ito, Yoshihiro Komohara, Yukio Fujiwara, Hiromu Yano, Tatsuya Ogimoto, Daiki Hira, Tomohiro Terada, Toyohiro Hirai, Hirotake Tsukamoto
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