scholarly journals Piezo1 channels restrain regulatory T cells but are dispensable for effector CD4+ T cell responses

2021 ◽  
Vol 7 (28) ◽  
pp. eabg5859
Author(s):  
Amit Jairaman ◽  
Shivashankar Othy ◽  
Joseph L. Dynes ◽  
Andriy V. Yeromin ◽  
Angel Zavala ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Bacterial Infections ◽  
Transforming Growth Factor ◽  
Cell Function ◽  
Inflammatory Responses ◽  
Transforming Growth Factor Β ◽  
T Helper 1 ◽  
Cell Functions ◽  
Mechanosensitive Ion Channel

T lymphocytes encounter complex mechanical cues during an immune response. The mechanosensitive ion channel, Piezo1, drives inflammatory responses to bacterial infections, wound healing, and cancer; however, its role in helper T cell function remains unclear. In an animal model for multiple sclerosis, experimental autoimmune encephalomyelitis (EAE), we found that mice with genetic deletion of Piezo1 in T cells showed diminished disease severity. Unexpectedly, Piezo1 was not essential for lymph node homing, interstitial motility, Ca2+ signaling, T cell proliferation, or differentiation into proinflammatory T helper 1 (TH1) and TH17 subsets. However, Piezo1 deletion in T cells resulted in enhanced transforming growth factor–β (TGFβ) signaling and an expanded pool of regulatory T (Treg) cells. Moreover, mice with deletion of Piezo1 specifically in Treg cells showed significant attenuation of EAE. Our results indicate that Piezo1 selectively restrains Treg cells, without influencing activation events or effector T cell functions.

scholarly journals Tumor-derived TGF-β inhibits mitochondrial respiration to suppress IFN-γ production by human CD4+ T cells

2019 ◽  
Vol 12 (599) ◽  
pp. eaav3334 ◽  
Author(s):  
Sarah Dimeloe ◽  
Patrick Gubser ◽  
Jordan Loeliger ◽  
Corina Frick ◽  
Leyla Develioglu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Atp Synthase ◽  
Transforming Growth Factor ◽  
Cell Function ◽  
Nuclear Translocation ◽  
Cell Metabolism ◽  
Transforming Growth Factor Β ◽  
Smad Proteins ◽  
Ifn Γ

Transforming growth factor–β (TGF-β) is produced by tumors, and increased amounts of this cytokine in the tumor microenvironment and serum are associated with poor patient survival. TGF-β–mediated suppression of antitumor T cell responses contributes to tumor growth and survival. However, TGF-β also has tumor-suppressive activity; thus, dissecting cell type–specific molecular effects may inform therapeutic strategies targeting this cytokine. Here, using human peripheral and tumor-associated lymphocytes, we investigated how tumor-derived TGF-β suppresses a key antitumor function of CD4+ T cells, interferon-γ (IFN-γ) production. Suppression required the expression and phosphorylation of Smad proteins in the TGF-β signaling pathway, but not their nuclear translocation, and depended on oxygen availability, suggesting a metabolic basis for these effects. Smad proteins were detected in the mitochondria of CD4+ T cells, where they were phosphorylated upon treatment with TGF-β. Phosphorylated Smad proteins were also detected in the mitochondria of isolated tumor-associated lymphocytes. TGF-β substantially impaired the ATP-coupled respiration of CD4+ T cells and specifically inhibited mitochondrial complex V (ATP synthase) activity. Last, inhibition of ATP synthase alone was sufficient to impair IFN-γ production by CD4+ T cells. These results, which have implications for human antitumor immunity, suggest that TGF-β targets T cell metabolism directly, thus diminishing T cell function through metabolic paralysis.

scholarly journals CD40/CD40L contributes to hypercholesterolemia-induced microvascular inflammation

2009 ◽  
Vol 296 (3) ◽  
pp. H689-H697 ◽  
Author(s):  
Karen Y. Stokes ◽  
LeShanna Calahan ◽  
Candiss M. Hamric ◽  
Janice M. Russell ◽  
D. Neil Granger
Keyword(s):  
Oxidative Stress ◽  
T Cells ◽  
T Cell ◽  
Blood Cell ◽  
Cell Function ◽  
Inflammatory Responses ◽  
Microvascular Dysfunction ◽  
Cd40 Ligand ◽  
Scid Mice ◽  
Endothelial Cell Function

Hypercholesterolemia is associated with phenotypic changes in endothelial cell function that lead to a proinflammatory and prothrombogenic state in different segments of the microvasculature. CD40 ligand (CD40L) and its receptor CD40 are ubiquitously expressed and mediate inflammatory responses and platelet activation. The objective of this study was to determine whether CD40/CD40L, in particular T-cell CD40L, contributes to microvascular dysfunction induced by hypercholesterolemia. Intravital microscopy was used to quantify blood cell adhesion in cremasteric postcapillary venules, endothelium-dependent vasodilation responses in arterioles, and microvascular oxidative stress in wild-type (WT) C57BL/6, CD40-deficient (−/−), CD40L−/−, or severe combined immune deficient (SCID) mice placed on a normal (ND) or high-cholesterol (HC) diet for 2 wk. WT-HC mice exhibited an exaggerated leukocyte and platelet recruitment in venules and impaired vasodilation responses in arterioles compared with ND counterparts. A deficiency of CD40, CD40L, or lymphocytes attenuated these responses to HC. The HC phenotype was rescued in CD40L−/− and SCID mice by a transfer of WT T cells. Bone marrow chimeras revealed roles for both vascular- and blood cell-derived CD40 and CD40L in the HC-induced vascular responses. Hypercholesterolemia induced an oxidative stress in both arterioles and venules of WT mice, which was abrogated by either CD40 or CD40L deficiency. The transfer of WT T cells into CD40L−/− mice restored the oxidative stress. These results implicate CD40/CD40L interactions between circulating cells and the vascular wall in both the arteriolar and venular dysfunction elicited by hypercholesterolemia and identify T-cell-associated CD40L as a key mediator of these responses.

scholarly journals Characterizing T Cells in SCID Patients Presenting with Reactive or Residual T Lymphocytes

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Atar Lev ◽  
Amos J. Simon ◽  
Luba Trakhtenbrot ◽  
Itamar Goldstein ◽  
Meital Nagar ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Cell Function ◽  
Severe Combined Immunodeficiency ◽  
Cell Activity ◽  
Mhc Ii ◽  
Cell Functions ◽  
Circulating T Cells

Introduction. Patients with severe combined immunodeficiency (SCID) may present with residual circulating T cells. While all cells are functionally deficient, resulting in high susceptibility to infections, only some of these cells are causing autoimmune symptoms.Methods. Here we compared T-cell functions including the number of circulating CD3+T cells,in vitroresponses to mitogens, T-cell receptor (TCR) repertoire, TCR excision circles (TREC) levels, and regulatory T cells (Tregs) enumeration in several immunodeficinecy subtypes, clinically presenting with nonreactive residual cells (MHC-II deficiency) or reactive cells. The latter includes patients with autoreactive clonal expanded T cell and patients with alloreactive transplacentally maternal T cells.Results. MHC-II deficient patients had slightly reduced T-cell function, normal TRECs, TCR repertoires, and normal Tregs enumeration. In contrast, patients with reactive T cells exhibited poor T-cell differentiation and activity. While the autoreactive cells displayed significantly reduced Tregs numbers, the alloreactive transplacentally acquired maternal lymphocytes had high functional Tregs.Conclusion. SCID patients presenting with circulating T cells show different patterns of T-cell activity and regulatory T cells enumeration that dictates the immunodeficient and autoimmune manifestations. We suggest that a high-tolerance capacity of the alloreactive transplacentally acquired maternal lymphocytes represents a toleration advantage, yet still associated with severe immunodeficiency.

scholarly journals Neuropilin-1: a checkpoint target with unique implications for cancer immunology and immunotherapy

2020 ◽  
Vol 8 (2) ◽  
pp. e000967 ◽  
Author(s):  
Christopher A Chuckran ◽  
Chang Liu ◽  
Tullia C Bruno ◽  
Creg J Workman ◽  
Dario AA Vignali
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Modulation ◽  
Cell Function ◽  
Inflammatory Responses ◽  
Checkpoint Inhibitors ◽  
Objective Response ◽  
Standard Of Care ◽  
Peripheral Tolerance ◽  
Neuropilin 1

Checkpoint blockade immunotherapy established a new paradigm in cancer treatment: for certain patients curative treatment requires immune reinvigoration. Despite this monumental advance, only 20%–30% of patients achieve an objective response to standard of care immunotherapy, necessitating the consideration of alternative targets. Optimal strategies will not only stimulate CD8+ T cells, but concomitantly modulate immunosuppressive cells in the tumor microenvironment (TME), most notably regulatory T cells (Treg cells). In this context, the immunoregulatory receptor Neuropilin-1 (NRP1) is garnering renewed attention as it reinforces intratumoral Treg cell function amidst inflammation in the TME. Loss of NRP1 on Treg cells in mouse models restores antitumor immunity without sacrificing peripheral tolerance. Enrichment of NRP1+ Treg cells is observed in patients across multiple malignancies with cancer, both intratumorally and in peripheral sites. Thus, targeting NRP1 may safely undermine intratumoral Treg cell fitness, permitting enhanced inflammatory responses with existing immunotherapies. Furthermore, NRP1 has been recently found to modulate tumor-specific CD8+ T cell responses. Emerging data suggest that NRP1 restricts CD8+ T cell reinvigoration in response to checkpoint inhibitors, and more importantly, acts as a barrier to the long-term durability of CD8+ T cell-mediated tumor immunosurveillance. These novel and distinct regulatory mechanisms present an exciting therapeutic opportunity. This review will discuss the growing literature on NRP1-mediated immune modulation which provides a strong rationale for categorizing NRP1 as both a key checkpoint in the TME as well as an immunotherapeutic target with promise either alone or in combination with current standard of care therapeutic regimens.

scholarly journals P12.05 Evaluating the compatibility of tumor treating electric fields with key antitumoral immune functions

2019 ◽  
Vol 21 (Supplement_3) ◽  
pp. iii60-iii60
Author(s):  
G Diamant ◽  
H Simchony ◽  
T Shiloach ◽  
A Globerson-Levin ◽  
L Gasri Plotnitsky ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Function ◽  
Rational Approach ◽  
Immune Functions ◽  
Color Flow ◽  
Cell Functions ◽  
Car T Cells ◽  
Car T

Abstract BACKGROUND TTFields has the ability to induce immunogenic cell death (ICD). As immunotherapy and TTFields have different mechanisms of action (MOA), combining these therapies is a rational approach. Contrarily, TTFields may interfere with immune functions critical for effective T cell function. MATERIAL AND METHODS We cultured T cells from healthy donors’ peripheral blood or from viably dissociated glioblastoma samples under normal or TTFields conditions, with or without superantigen-stimulation. In order to assess T cell responses we used eight-color flow cytometry by monitoring select pivotal antitumoral functions: proliferation (CFSE), IFNγ secretion, cytotoxic degranulation (CD107a), activation/exhaustion (PD1) and viability. Evaluation of direct cytotoxicity was done by using chimeric antigen receptor (CAR) T cells. RESULTS TTFields did not change T cell activation rates for all evaluated functions with the exception of reduced proliferation - in line with TTFields’ MOA. TTFields substantially reduced the viability of activated proliferating T cells, moderately affected activated nonproliferating T cells and had almost no effect on the viability of non-activated cells. Polyfunctionality analysis of T-cells, associated with effective antitumoral responses, demonstrated that under TTFields, the activated non-proliferating T cells retained polyfunctional capabilities. PD1-expressing TILs, a subset containing most of the tumor antigen-specific TILs, exhibited unaltered viability and functionality under TTFields. CAR T-cells, which utilize the same killing machinery as unmodified T cells, exhibited unaltered cytotoxic capability under TTFields. Immunohistochemical evaluation of GBM samples before TTFields treatment and after recurrence showed that some patients had accommodated large increases in their CD8 and CD4 counts. RNA-Seq performed on GBM samples from 6 standardly-treated and 6 TTFields-treated patients before treatment and after recurrence. The data shows differential increases in TTFields-treated patients to controls, in the expression of immune genes associated with favorable prognosis (e.g. t-bet, NKG2D, ICOS-L, CD70) and concurrent decreases in genes associated with poor prognosis (e.g. IL4, TSLP, various complement genes). CONCLUSION The preclinical data showed that all antitumoral T cell functions examined, but proliferation, were unhindered by TTFields. The clinical data showed that TTFields may shift treated tumors to a state more conducive of antitumoral immune responses. Our findings support the further preclinical and clinical investigation into combining TTFields with immunotherapy.

scholarly journals TNF-α Regulates Mast Cell Functions by Inhibiting Cell Degranulation

2017 ◽  
Vol 44 (2) ◽  
pp. 751-762 ◽  
Author(s):  
Yuwei Gao ◽  
Baixue Xu ◽  
Peng Zhang ◽  
Yanlong He ◽  
Xin Liang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mast Cells ◽  
Cd4 T Cells ◽  
Cell Function ◽  
Mapk Signaling ◽  
Cell Functions ◽  
Tnf Α ◽  
Ifn Γ ◽  
Stimulation Of

Background/Aims: The aim of this study was to investigate the involvement of inducible co-stimulatory ligand (ICOSL) expression in stimulation of mast cells (MCs) by TNF-α and the ability of TNF-α stimulation of MCs to influence CD4+ T cell differentiation and function. The mechanisms underlying TNF-α stimulation of MCs were also explored. Methods: Mast cells and CD4+ T cells were prepared from C57BL/6 mice (aged 6–8 weeks). ICOSL expression by MCs was measured by real-time PCR and flow cytometry, and levels of IL-4, IL-10 and IFN-γ were measured by ELISA. Results: ICOSL expression by MCs was increased by TNF-α stimulation, and resulted in interaction with CD4+ T cells. The IL-4 and IL-10 levels in the co-culture system increased, while IFN-γ levels decreased. Furthermore, CD4+CD25+Foxp3+ T cell proliferation was induced by co-culture with TNF-α-stimulated MCs. The mechanism by which TNF-α stimulated MCs was dependent on the activation of the MAPK signaling pathway. Conclusion: TNF-α upregulated the expression of ICOSL on mast cells via a mechanism that is dependent on MAPK phosphorylation. TNF-α-treated MCs promoted the differentiation of regulatory T cells and induced a shift in cytokine expression from a Th1 to a Th2 profile by up-regulation ICOSL expression and inhibition of MC degranulation. Our study reveals a novel mechanism by which mast cells regulate T cell function.

scholarly journals Differential CD147 Functional Epitopes on Distinct Leukocyte Subsets

2021 ◽  
Vol 12 ◽  
Author(s):  
Supansa Pata ◽  
Sirirat Surinkaew ◽  
Nuchjira Takheaw ◽  
Witida Laopajon ◽  
Kantinan Chuensirikulchai ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Function ◽  
Inflammatory Diseases ◽  
Cell Contact ◽  
Cell Functions ◽  
Tnf Α ◽  
Ifn Γ

CD147, a member of the immunoglobulin (Ig) superfamily, is widely expressed in several cell types. CD147 molecules have multiple cellular functions, such as migration, adhesion, invasion, energy metabolism and T cell activation. In particular, recent studies have demonstrated the potential application of CD147 as an effective therapeutic target for cancer, as well as autoimmune and inflammatory diseases. In this study, we elucidated the functional epitopes on CD147 extracellular domains in T cell regulation using specific monoclonal antibodies (mAbs). Upon T cell activation, the anti-CD147 domain 1 mAbs M6-1E9 and M6-1D4 and the anti-CD147 domain 2 mAb MEM-M6/6 significantly reduced surface expression of CD69 and CD25 and T cell proliferation. To investigate whether functional epitopes of CD147 are differentially expressed on distinct leukocyte subsets, PBMCs, monocyte-depleted PBMCs and purified T cells were activated in the presence of anti-CD147 mAbs. The mAb M6-1E9 inhibited T cell functions via activation of CD147 on monocytes with obligatory cell-cell contact. Engagement of the CD147 epitope by the M6-1E9 mAb downregulated CD80 and CD86 expression on monocytes and IL-2, TNF-α, IFN-γ and IL-17 production in T cells. In contrast, the mAb M6-1D4 inhibited T cell function via activation of CD147 on T cells by downregulating IL-2, TNF-α and IFN-γ. Herein, we demonstrated that certain epitopes of CD147, expressed on both monocytes and T cells, are involved in the regulation of T cell activation.

scholarly journals Elevated coinhibitory molecule TIGIT mediates T cell exhaustion in septic patients

2021 ◽  
Author(s):  
Yini Sun ◽  
Renyu Ding ◽  
Yukun Chang ◽  
Jiuming Li ◽  
Xiaochun Ma
Keyword(s):  
T Cells ◽  
T Cell ◽  
Crucial Role ◽  
Cell Function ◽  
Inflammatory Responses ◽  
Ex Vivo ◽  
Healthy Controls ◽  
T Cell Exhaustion ◽  
Cell Exhaustion

Abstract Background: Sepsis-induced T cell exhaustion that is characterized by upregulated coinhibitory molecules and decreased cytokines release plays a crucial role in the immunosuppression during sepsis. Although PD-1 has shown a promising target to interfere with T cells dysfunction, the role of other coinhibitory receptors in sepsis remains largely elusive. Recently, it has been demonstrated that the coinhibitory molecule TIGIT more reliably identified exhausted T cells than PD-1. The aim of the study was to identify the expression of TIGIT on lymphocytes and the crucial role of TIGIT in modulating T cell function in septic patients. Methods: Twenty-five patients with sepsis and seventeen healthy controls were prospectively enrolled. Peripheral blood was obtained from septic patients within 24 hours after diagnosis of sepsis, as were healthy controls. TIGIT and other coinhibitory/costimulatory molecules expression on lymphocyte subsets was quantitated by flow cytometry. The relationship between TIGIT expression and clinical parameters was simultaneously evaluated. The function T cell from septic patients was assayed via stimulated cytokine secretion. Ex vivo functional assays were also conducted.Results: In the early stage of sepsis, patients exhibited higher levels of TIGIT on T cells relative to healthy donors, especially in the septic shock patients. Elevated frequencies of TIGIT + T cells positively correlated with the severity of organ failure and inflammatory responses in septic patients. TIGIT + T cells expressed higher levels of PD-1 and lower CD226. Further, elevated expression of TIGIT inhibited the release of cytokines including TNF, IFN-γ and IL-2 by CD4 + and CD8 + T cells. Strikingly, ex vivo blockade of TIGIT using anti-TIGIT antibody restored the frequencies of cytokine-producing T cells. Conclusions: These data illustrate TIGIT as a novel marker of exhausted T cells and suggest TIGIT may be a novel immunotherapeutic target during sepsis.

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