scholarly journals Regulation of Intrinsic and Bystander T Follicular Helper Cell Differentiation and Autoimmunity by Tsc1

2021 ◽  
Vol 12 ◽  
Author(s):  
Shimeng Zhang ◽  
Lei Li ◽  
Danli Xie ◽  
Srija Reddy ◽  
John W. Sleasman ◽  
...  

T Follicular helper (Tfh) cells promote germinal center (GC) B cell responses to develop effective humoral immunity against pathogens. However, dysregulated Tfh cells can also trigger autoantibody production and the development of autoimmune diseases. We report here that Tsc1, a regulator for mTOR signaling, plays differential roles in Tfh cell/GC B cell responses in the steady state and in immune responses to antigen immunization. In the steady state, Tsc1 in T cells intrinsically suppresses spontaneous GC-Tfh cell differentiation and subsequent GC-B cell formation and autoantibody production. In immune responses to antigen immunization, Tsc1 in T cells is required for efficient GC-Tfh cell expansion, GC-B cell induction, and antigen-specific antibody responses, at least in part via promoting GC-Tfh cell mitochondrial integrity and survival. Interestingly, in mixed bone marrow chimeric mice reconstituted with both wild-type and T cell-specific Tsc1-deficient bone marrow cells, Tsc1 deficiency leads to enhanced GC-Tfh cell differentiation of wild-type CD4 T cells and increased accumulation of wild-type T regulatory cells and T follicular regulatory cells. Such bystander GC-Tfh cell differentiation suggests a potential mechanism that could trigger self-reactive GC-Tfh cell/GC responses and autoimmunity via neighboring GC-Tfh cells.

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Yuhong Chen ◽  
Mei Yu ◽  
Yongwei Zheng ◽  
Guoping Fu ◽  
Gang Xin ◽  
...  

Abstract Many autoimmune diseases are characterized by the production of autoantibodies. The current view is that CD4+ T follicular helper (Tfh) cells are the main subset regulating autoreactive B cells. Here we report a CXCR5+PD1+ Tfh subset of CD8+ T cells whose development and function are negatively modulated by Stat5. These CD8+ Tfh cells regulate the germinal center B cell response and control autoantibody production, as deficiency of Stat5 in CD8 T cells leads to an increase of CD8+ Tfh cells, resulting in the breakdown of B cell tolerance and concomitant autoantibody production. CD8+ Tfh cells share similar gene signatures with CD4+ Tfh, and require CD40L/CD40 and TCR/MHCI interactions to deliver help to B cells. Our study thus highlights the diversity of follicular T cell subsets that contribute to the breakdown of B-cell tolerance.


2021 ◽  
Vol 41 (1) ◽  
Author(s):  
He Hao ◽  
Shingo Nakayamada ◽  
Yoshiya Tanaka

AbstractT follicular helper cells participate in stimulating germinal center (GC) formation and supporting B cell differentiation and autoantibody production. However, T follicular regulatory (Tfr) cells suppress B cell activation. Since changes in the number and functions of Tfr cells lead to dysregulated GC reaction and autoantibody response, targeting Tfr cells may benefit the treatment of autoimmune diseases. Differentiation of Tfr cells is a multistage and multifactorial process with various positive and negative regulators. Therefore, understanding the signals regulating Tfr cell generation is crucial for the development of targeted therapies. In this review, we discuss recent studies that have elucidated the roles of Tfr cells in autoimmune diseases and investigated the modulators of Tfr cell differentiation. Additionally, potential immunotherapies targeting Tfr cells are highlighted.


2020 ◽  
Author(s):  
Can Cui ◽  
Jiawei Wang ◽  
Ping-Min Chen ◽  
Kelli A. Connolly ◽  
Martina Damo ◽  
...  

AbstractCD4+ T follicular helper (TFH) cells provide help to B cells, which is critical for germinal center (GC) formation, but the importance of TFH-B cell interactions in cancer is unclear. We found TFH cells correlated with GC B cells and with prolonged survival of lung adenocarcinoma (LUAD) patients. To investigate further, we developed an LUAD model, in which tumor cells expressed B-cell- and T-cell-recognized neoantigens. Interactions between tumor-specific TFH and GC B cells were necessary for tumor control, as were effector CD8+ T cells. The latter were reduced in the absence of T cell-B cell interactions or the IL-21 receptor. IL-21 was produced primarily by TFH cells, development of which required B cells. Moreover, development of tumor-specific TFH cell-responses was also reliant upon tumors that expressed B-cell-recognized neoantigens. Thus, tumor-neoantigens themselves can control the fate decisions of tumor-specific CD4+ T cells by facilitating interactions with tumor-specific B cells.Abstract Figure


2018 ◽  
Author(s):  
Rasheduzzaman Rashu ◽  
Taufiqur Rahman Bhuiyan ◽  
Mohammad Rubel Hoq ◽  
Lazina Hossain ◽  
Anik Paul ◽  
...  

AbstractVibrio choleraeO1 can cause life threatening diarrheal disease if left untreated. A long lasting immune response, producing 3-5 years of protection from subsequent, symptomatic disease following natural infection, is mediated by B cell mediated humoral immunity. T cells can play critical roles in inducing such immunity. However, the mechanism of T cell dependent B cell maturation and whether a key sub-population of T cells are involved is not well established in cholera. We hypothesized that a specific population of T cells, follicular helper T (Tfh) cells, are involved in B cell maturation following cholera; we used flow cytometry, culture and colorimetric assays to address this question. We found thatV. choleraeinfection induces significant increase in circulating Tfh cells expressing B cell maturation associated protein CD40L early in disease. The increased Tfh cells expressing CD40L recognize cholera toxin most prominently, with lessened responses to two antigens tested,V. choleraemembrane preparation (MP) andVibrio choleraecytolysin (VCC). We further showed that early induction of Tfh cells and CD40L was associated with later memory B cell responses to same antigens. Lastly, we demonstratedin vitrothat Tfh cells isolated after cholera can stimulate class switching of cocultured, isolated B cells from patients with cholera, leading to production of the more durable IgG antibody isotype. These studies were conducted on circulating Tfh cells; future studies will be directed at examining role of Tfh cells during cholera directly in the gut mucosa of biopsied samples, at the single cell level if feasible.


2021 ◽  
Vol 12 ◽  
Author(s):  
Sarah A. O’Brien ◽  
Minghua Zhu ◽  
Weiguo Zhang

Mice with a mutation at the LAT-PLCγ1 binding site (Y136) have a defect in thymocyte development due to dampened TCR signaling. CD4+ T cells that do reach the periphery are hyper-activated and skewed to Th2. Over time, these mice develop an autoimmune-like syndrome, characterize by overproduction of Th2 cytokines, T cell infiltration into various organs, and B cell activation, isotype switching, and autoantibody production. In this study, we examined IL4 production by CD4+ T cells in the LATY136F mice using the KN2 reporter mice, in which human CD2 expression marks T cells that are actively producing IL4 protein. We showed that these mice had spontaneous Tfh differentiation. Despite the fact that the majority of CD4+ T cells were skewed to Th2 and were GATA3+, only a small subset of them were actively secreting IL4. These T cells were Tfh cells that expressed BCL6 and were localized to B cell-rich germinal centers within the spleen. Interestingly, these Tfh cells expressed high levels of both BCL6 and GATA3. By using LAT conditional knockout mice that inducibly express only the LATY136F allele, we further showed that Tfh cell differentiation was likely the result of defective LAT-PLCγ1 signaling in the periphery. In addition, B cells were required for spontaneous development of Tfh cells and uncontrolled T cell expansion in these mice. Together, these results indicated a novel role for tonic LAT-PLCγ1 signaling in modulating Tfh cell differentiation during development of autoimmune syndrome.


2019 ◽  
Vol 216 (8) ◽  
pp. 1843-1856 ◽  
Author(s):  
Pablo F. Cañete ◽  
Rebecca A. Sweet ◽  
Paula Gonzalez-Figueroa ◽  
Ilenia Papa ◽  
Naganari Ohkura ◽  
...  

Mucosal lymphoid tissues such as human tonsil are colonized by bacteria and exposed to ingested and inhaled antigens, requiring tight regulation of immune responses. Antibody responses are regulated by follicular helper T (TFH) cells and FOXP3+ follicular regulatory T (TFR) cells. Here we describe a subset of human tonsillar follicular T cells identified by expression of TFH markers and CD25 that are the main source of follicular T (TF) cell–derived IL-10. Despite lack of FOXP3 expression, CD25+ TF cells resemble T reg cells in high CTLA4 expression, low IL-2 production, and their ability to repress T cell proliferation. CD25+ TF cell–derived IL-10 dampens induction of B cell class-switching to IgE. In children, circulating total IgE titers were inversely correlated with the frequencies of tonsil CD25+ TF cells and IL-10–producing TF cells but not with total T reg cells, TFR, or IL-10–producing T cells. Thus, CD25+ TF cells emerge as a subset with unique T and B cell regulatory activities that may help prevent atopy.


Immunity ◽  
2014 ◽  
Vol 41 (6) ◽  
pp. 1026-1039 ◽  
Author(s):  
Peter T. Sage ◽  
Alison M. Paterson ◽  
Scott B. Lovitch ◽  
Arlene H. Sharpe

2017 ◽  
Vol 131 (24) ◽  
pp. 2933-2945 ◽  
Author(s):  
Xinrui Wang ◽  
Yonggang Zhu ◽  
Manli Zhang ◽  
Jie Hou ◽  
Hongjuan Wang ◽  
...  

B-cell immunity participates in the pathogenesis of ulcerative colitis (UC). The immune balance between follicular regulatory T (TFR) cells and follicular helper T (TFH) cells is important in regulating B-cell responses. However, the alteration of TFR/TFH balance in UC remains unclear. Peripheral blood from 25 UC patients and 15 healthy controls was examined for the frequencies of circulating TFR, TFH, and regulatory T (Treg) cells by flow cytometry. Levels of serum cytokines were measured using cytometric bead array (CBA). Disease activity was evaluated by the Mayo Clinic Score. Compared with controls, UC patients exhibited significant reductions in circulating Foxp3+CXCR5+ TFR cells, the subset interleukin (IL)-10+Foxp3+CXCR5+ cells, and Treg cells, but significant expansions in Foxp3−CXCR5+ TFH cells and IL-21+Foxp3−CXCR5+ cells. UC patients also had reduced levels of serum IL-10 and elevated levels of serum IL-21. The values of Mayo Clinic Score, C-reactive protein (CRP), or erythrocyte sedimentation rate (ESR) in UC patients were negatively correlated with circulating TFR cells, serum IL-10 level, and TFR/TFH ratio, while positively correlated with circulating TFH cells and serum IL-21 level. Alterations in circulating TFR and TFH cells shift the balance from immune tolerance to immune responsive state, contributing to dysregulated B-cell immunity and the pathogenesis of UC.


2017 ◽  
Vol 114 (31) ◽  
pp. E6400-E6409 ◽  
Author(s):  
James Badger Wing ◽  
Yohko Kitagawa ◽  
Michela Locci ◽  
Hannah Hume ◽  
Christopher Tay ◽  
...  

T-follicular helper (Tfh) cells differentiate through a multistep process, culminating in germinal center (GC) localized GC-Tfh cells that provide support to GC-B cells. T-follicular regulatory (Tfr) cells have critical roles in the control of Tfh cells and GC formation. Although Tfh-cell differentiation is inhibited by IL-2, regulatory T (Treg) cell differentiation and survival depend on it. Here, we describe a CD25− subpopulation within both murine and human PD1+CXCR5+Foxp3+ Tfr cells. It is preferentially located in the GC and can be clearly differentiated from CD25+ non–GC-Tfr, Tfh, and effector Treg (eTreg) cells by the expression of a wide range of molecules. In comparison to CD25+ Tfr and eTreg cells, CD25− Tfr cells partially down-regulate IL-2–dependent canonical Treg features, but retain suppressive function, while simultaneously up-regulating genes associated with Tfh and GC-Tfh cells. We suggest that, similar to Tfh cells, Tfr cells follow a differentiation pathway generating a mature GC-localized subpopulation, CD25− Tfr cells.


2021 ◽  
Vol 12 ◽  
Author(s):  
Tingting Ding ◽  
Rui Su ◽  
Ruihe Wu ◽  
Hongwei Xue ◽  
Yanyan Wang ◽  
...  

Balance of Tfh/Tfr cell is critically important for the maintenance of immune tolerance, as evidenced by the fact that T follicular helper (Tfh) cells are central to the autoantibodies generation through providing necessary help for germinal center (GC) B cells, whereas T follicular regulatory (Tfr) cells significantly inhibit autoimmune inflammation process through restraining Tfh cell responses. However, signals underlying the regulation of Tfh and Tfr cells are largely undefined. Regulatory B cells (Bregs) is a heterogeneous subpopulation of B cells with immunosuppressive function. Considerable advances have been made in their functions to produce anti‐inflammatory cytokines and to regulate Th17, Th1, and Treg cells in autoimmune diseases. The recent identification of their correlations with dysregulated Tfr/Tfh cells and autoantibody production makes Bregs an important checkpoint in GC response. Bregs exert profound impacts on the differentiation, function, and distribution of Tfh and Tfr cells in the immune microenvironment. Thus, unraveling mechanistic information on Tfh-Breg and Tfr-Breg interactions will inspire novel implications for the establishment of homeostasis and prevention of autoantibodies in diverse diseases. This review summarizes the dysregulation of Tfh/Tfr cells in autoimmune diseases with a focus on the emerging role of Bregs in regulating the balance between Tfh and Tfr cells. The previously unsuspected crosstalk between Bregs and Tfh/Tfr cells will be beneficial to understand the cellular mechanisms of autoantibody production and evoke a revolution in immunotherapy for autoimmune diseases.


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