Follicular T Cells are Clonally and Transcriptionally Distinct in B Cell-Driven Autoimmune Disease
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ABSTRACT: To better understand the role of follicular T cells in autoantibody-mediated disease, we performed single cell RNA and T cell receptor (TCR) sequencing of follicular T cells in a mouse model of autoantibody-mediated disease. This repository provides paired transcriptomes and unbiased TCRab repertoires from sorted CD4+CXCR5+PD1+ follicular T cells at single cell resolution. Our analysis revealed that a minority of clonotypes are preferentially shared amongst autoimmune follicular T cells, and clonotypic expansion is associated with differential gene signatures in autoimmune disease. These data provide insight into the phenotypic differences of follicular T cells in B cell-driven autoimmune disease versus foreign immunization.
Project description:Many autoimmune diseases are characterized by the production of autoantibodies. The current view is that CD4+ Tfh cells are the main subset regulating autoreactive B cells. Here, we discover a novel CXCR5+PD1+ Tfh subset of CD8+ T cells whose development and function are negatively regulated by Stat5. These CD8+ Tfh cells regulate the GC B cell response and control autoantibody production. Deficiency of Stat5 in CD8+ T cells leads to an increase of CD8+ Tfh cells, resulting in the breakdown of B cell tolerance and autoantibody production. CD8+ Tfh cells share similar gene signatures with CD4+ Tfh cells and require CD40L/CD40 and TCR/MHCI interactions to deliver help to B cells. Our study highlights the diversity of follicular T cell subsets that contribute to the breakdown of B-cell tolerance
Project description:Many autoimmune diseases are characterized by the production of autoantibodies. The current view is that CD4+ Tfh cells are the main subset regulating autoreactive B cells. Here, we discover a distinct novel CXCR5+PD1+ Tfh subset of CD8+ T cells whose development and function are negatively regulated by Stat5. These CD8+ Tfh cells regulate the GC B cell response and control autoantibody production. Deficiency of Stat5 in CD8+ T cells leads to an increase of CD8+ Tfh cells, resulting in the breakdown of B cell tolerance and autoantibody production. CD8+ Tfh share similar gene signatures with CD4+ Tfh and require CD40L/CD40 and TCR/MHCI interactions to deliver help to B cells. Our study highlights the diversity of follicular T cell subsets that contribute to the breakdown of B-cell tolerance
Project description:Follicular CXCR5+ PD-1+ CD8 T cells (CD8 Tfc) arise in multiple models of systemic autoimmunity yet their functional contribution to disease remains in debate. Here we define the follicular localization and functional interactions of CD8 Tfc with B cells during autoimmune disease. The absence of functional T regulatory cells in autoimmunity allows for CD8 Tfc development that then expands with lymphoproliferation. CD8 Tfc are identifiable within the lymph nodes and spleen during systemic autoimmunity, but not during tissue-restricted autoimmune disease. Autoimmune CD8 Tfc cells are polyfunctional, producing helper cytokines IL-21, IL-4, and IFNγ while maintaining cytolytic proteins CD107a, granzyme B, and TNF. During autoimmune disease, IL-2-KO CD8 T cells infiltrate the B cell follicle and germinal center, including the dark zone, to induce AID in vitro in naïve B cells via IL-4 secretion. CD8 Tfc represent a unique CD8 T cell population with a diverse effector cytokine repertoire that can contribute to pathogenic autoimmune B cell response.
Project description:Autoimmune T follicular helper (Tfh) cells have different properties from B6/J nonautoimmune tfh cells. To compare differences in Tfh cells due to ongoing SLE disease, spontaneous splenic Tfh (CD4+CXCR5+PD-1+) were cell sorted from a pre-enriched population of negatively isolated total CD4 cells by autoMACS. New zealand derived triple congenic lupus strain was compared with B6/J. RNA was immediately extracted with no culturing or treatment of cells.
Project description:Follicular CD8+ T cells (fCD8) mediate surveillance in lymph node (LN) germinal centers against lymphotropic infections and cancers, but precise mechanisms by which these cells mediate immune control remain incompletely resolved. To address this, we investigated functionality, clonotypic compartmentalization, spatial localization, phenotypic characteristics, and transcriptional profiles of LN-resident virus-specific CD8+ T cells in persons who control HIV without medications. Antigen-induced proliferative and cytolytic potential consistently distinguished spontaneous controllers from noncontrollers. T cell receptor analysis revealed complete clonotypic overlap between peripheral and LN-resident HIV-specific CD8+ T cells. Transcriptional analysis of LN CD8+ T cells revealed gene signatures of inflammatory chemotaxis and antigen-induced effector function. In HIV controllers, the cytotoxic effectors perforin and granzyme B were elevated among virus-specific CXCR5+ fCD8s proximate to foci of HIV RNA within germinal centers. These results provide evidence consistent with cytolytic control of lymphotropic infection supported by inflammatory recruitment, antigen-specific proliferation, and cytotoxicity of fCD8s.
Project description:IgD-CD27- “double negative” (DN) B cells are known to be expanded in the blood in many disease contexts and the IgD-CD27-CXCR5-CD11c+ DN2 B cell subset has been most widely studied in autoimmune diseases. In addition to DN2 B cells, a distinct IgD-CD27-CXCR5-CD11c- DN3 B cell subset accumulates in the blood both in IgG4-related disease, an autoimmune disease in which inflammation and fibrosis can be reversed by B cell depletion, and in severe COVID-19. DN3 B cells, but not DN2 B cells, prominently accumulate in the blood and end-organs of IgG4-related disease.
Project description:CD4+CXCR5+Foxp3+ T follicular regulatory (TFR) cells control the germinal center responses. Like follicular helper T-cells, they express high levels of Nuclear Factor of Activated T-cells c1, predominantly its short isoform NFATc1/αA. Ablation of NFATc1 in Tregs prevents upregulation of CXCR5 and migration of TFR cells into B-cell follicles. By contrast, constitutive active NFATc1/αA defines the surface density of CXCR5, whose level determines how deep a TFR migrates into the GC and how effectively it controls antibody production. NFATc1/αA is necessary to overcome TFR-expressed B lymphocyte-induced maturation protein (Blimp-1), which can directly repress Cxcr5. Blimp-1 then reinforces the recruitment of NFATc1 to Cxcr5 by protein-protein interaction and by those means cooperates with NFATc1 for Cxcr5 transactivation. On the contrary, Blimp-1 is necessary to counterbalance NFATc1/αA, which strengthens the follicular development of Tregs, but bears the inherent risk of causing an ex-Treg phenotype.
Project description:Lupus susceptibility results from the combined effects of numerous genetic loci, but the contribution of these loci to disease pathogenesis has been difficult to study due to the large cellular heterogeneity of the autoimmune immune response. We performed single cell RNA, B cell receptor (BCR), and T cell receptor (TCR) sequencing of splenocytes from mice with multiple polymorphic lupus susceptibility loci. We not only observed lymphocyte and myeloid expansion, but also characterized changes in subset frequencies and gene expression, such as decreased CD8 and marginal zone B cells and increased Fcrl5 and Cd5l expressing macrophages. Clonotypic analyses revealed expansion of B and CD4 clones, and TCR repertoires from lupus prone mice were distinguishable by algorithmic specificity prediction and unsupervised machine learning classification. Myeloid differential gene expression, metabolism, and altered ligand-receptor interaction were associated with decreased antigen presentation. This dataset provides novel mechanistic insight into the pathophysiology of a spontaneous model of lupus, highlighting potential therapeutic targets for autoantibody mediated disease.
Project description:Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by autoantibody production and immune complex deposition. Previous evidence showed abnormal accumulation of B cells in the thymus of lupus-prone mice, but the role of this population remains undefined. We analyzed the distribution, function, and properties of thymic B cells in the BWF1 murine model of SLE. We found that B cells proliferate and cluster in germinal center-like structures along with autoantibody-secreting cells in the thymus of diseased-BWF1 mice. These thymic B cells induced the differentiation of follicular helper T cells (TFH). Our data suggest that the accumulation of B cells in the thymus of BWF1 mice results in the formation of germinal center-like structures and the expansion of TFH cells, which may favor the differentiation of autoreactive plasma cells. Therefore, the thymus emerges as a niche supporting the maintenance of the pathogenic humoral response in the development of murine SLE.