scholarly journals The transcriptional repressor HIC1 regulates intestinal immune homeostasis

2016 ◽  
Author(s):  
Kyle Burrows ◽  
Frann Antignano ◽  
Michael Bramhall ◽  
Alistair Chenery ◽  
Sebastian Scheer ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Vitamin A ◽  
Molecular Mechanisms ◽  
Cell Function ◽  
Immune Cell ◽  
Intestinal Inflammation ◽  
Critical Role ◽  
Central Component ◽  
Food Antigens

ABSTRACTThe intestine is a unique immune environment that must respond to infectious organisms but remain tolerant to commensal microbes and food antigens. However, the molecular mechanisms that regulate immune cell function in the intestine remain unclear. Here we identify the POK/ZBTB family transcription factor Hypermethylated in cancer 1 (HIC1, ZBTB29) as a central component of immunity and inflammation in the intestine. HIC1 is specifically expressed in immune cells in the intestinal lamina propria (LP) in the steady state and mice with a T cell-specific deletion of HIC1 have reduced numbers of T cells in the LP. HIC1 expression is regulated by the Vitamin A metabolite retinoic acid, as mice raised on a Vitamin A-deficient diet lack HIC1-positive cells in the intestine. HIC1-deficient T cells overproduce IL-17A in vitro and in vivo, and fail to induce intestinal inflammation, identifying a critical role for HIC1 in the regulation of T cell function in the intestinal microenvironment under both homeostatic and inflammatory conditions.

scholarly journals Deubiquitinating enzyme CYLD negatively regulates the ubiquitin-dependent kinase Tak1 and prevents abnormal T cell responses

2007 ◽  
Vol 204 (6) ◽  
pp. 1475-1485 ◽  
Author(s):  
William W. Reiley ◽  
Wei Jin ◽  
Andrew Joon Lee ◽  
Ato Wright ◽  
Xuefeng Wu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Transforming Growth Factor ◽  
Cell Function ◽  
Intestinal Inflammation ◽  
Critical Role ◽  
Deubiquitinating Enzyme ◽  
Iκb Kinase

The deubiquitinating enzyme CYLD has recently been implicated in the regulation of signal transduction, but its physiological function and mechanism of action are still elusive. In this study, we show that CYLD plays a pivotal role in regulating T cell activation and homeostasis. T cells derived from Cyld knockout mice display a hyperresponsive phenotype and mediate the spontaneous development of intestinal inflammation. Interestingly, CYLD targets a ubiquitin-dependent kinase, transforming growth factor–β-activated kinase 1 (Tak1), and inhibits its ubiquitination and autoactivation. Cyld-deficient T cells exhibit constitutively active Tak1 and its downstream kinases c-Jun N-terminal kinase and IκB kinase β. These results emphasize a critical role for CYLD in preventing spontaneous activation of the Tak1 axis of T cell signaling and, thereby, maintaining normal T cell function.

scholarly journals Induction of T Cell Senescence by Cytokine Induced Bystander Activation

2021 ◽  
Vol 2 ◽  
Author(s):  
Attiya A. Abbas ◽  
Arne N. Akbar
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Immune Cell ◽  
Critical Role ◽  
The Elderly ◽  
Cell Receptor ◽  
Antigen Specificity ◽  
Tcr Signaling ◽  
Bystander Activation

As people around the world continue to live longer, maintaining a good quality of life is of increasing importance. The COVID-19 pandemic revealed that the elderly are disproportionally vulnerable to infectious diseases and Immunosenescence plays a critical role in that. An ageing immune system influences the conventional activity of T cells which are at the forefront of eliminating harmful foreign antigens. With ageing, unconventional end-stage T cells, that exhibit a senescent phenotype, amass. These senescent T cells deviate from T cell receptor (TCR) signaling toward natural killer (NK) activity. The transition toward innate immune cell function from these adaptor T cells impacts antigen specificity, contributing to increased susceptibility of infection in the elderly. The mechanism by which senescent T cells arise remains largely unclear however in this review we investigate the part that bystander activation plays in driving the change in function of T cells with age. Cytokine-induced bystander activation may offer a plausible explanation for the induction of NK-like activity and senescence in T cells. Further understanding of these specific NK-like senescent T cells allows us to identify the benefits and detriments of these cells in health and disease which can be utilized or regulated, respectively. This review discusses the dynamic of senescent T cells in adopting NK-like T cells and the implications that has in an infectious disease context, predominately in the elderly.

scholarly journals CD4+ regulatory T cells require CTLA-4 for the maintenance of systemic tolerance

2009 ◽  
Vol 206 (2) ◽  
pp. 421-434 ◽  
Author(s):  
Randall H. Friedline ◽  
David S. Brown ◽  
Hai Nguyen ◽  
Hardy Kornfeld ◽  
JinHee Lee ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Cell Function ◽  
Cytotoxic T Lymphocyte ◽  
Critical Role ◽  
Lymphoproliferative Disease ◽  
In Trans ◽  
And Function

Cytotoxic T lymphocyte antigen-4 (CTLA-4) plays a critical role in negatively regulating T cell responses and has also been implicated in the development and function of natural FOXP3+ regulatory T cells. CTLA-4–deficient mice develop fatal, early onset lymphoproliferative disease. However, chimeric mice containing both CTLA-4–deficient and –sufficient bone marrow (BM)–derived cells do not develop disease, indicating that CTLA-4 can act in trans to maintain T cell self-tolerance. Using genetically mixed blastocyst and BM chimaeras as well as in vivo T cell transfer systems, we demonstrate that in vivo regulation of Ctla4−/− T cells in trans by CTLA-4–sufficient T cells is a reversible process that requires the persistent presence of FOXP3+ regulatory T cells with a diverse TCR repertoire. Based on gene expression studies, the regulatory T cells do not appear to act directly on T cells, suggesting they may instead modulate the stimulatory activities of antigen-presenting cells. These results demonstrate that CTLA-4 is absolutely required for FOXP3+ regulatory T cell function in vivo.

scholarly journals T-cell lineage commitment and cytokine responses of thymic progenitors

Blood ◽  
1995 ◽  
Vol 86 (5) ◽  
pp. 1850-1860 ◽  
Author(s):  
TA Moore ◽  
A Zlotnik
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Cultured Cells ◽  
Critical Role ◽  
Cell Lineage ◽  
Lineage Commitment ◽  
Organ Cultures ◽  
Cell Commitment

The earliest steps of intrathymic differentiation recently have been elucidated. It has been reported that both CD4lo (CD44+ CD25- c-kit+ CD3- CD4lo CD8-) and pro-T cells (CD44+ CD25+ c-kit+ CD3- CD4- CD8-, representing the next step in maturation) exhibit germline T-cell receptor beta and gamma loci, suggesting that neither population is exclusively committed to the T-cell lineage. Several groups have shown that CD4lo cells retain the capacity to generate multiple lymphoid lineages in vivo; however, the lineage commitment status of pro-T cells is unknown. To determine when T-cell lineage commitment occurs, we examined the ability of sorted CD4lo and pro-T cells to generate lymphoid lineage cells in vivo or in fetal thymic organ cultures (FTOCs). When intravenously injected into scid mice, CD4lo cells generated both T and B cells, whereas the progeny of pro-T cells contained T cells exclusively. Fetal thymic organ cultures repopulated with CD4lo cells contained both T and natural killer (NK) cells, whereas cultures repopulated with pro-T cells contained T cells almost exclusively. These observations strongly suggest that T-cell lineage commitment occurs during the transition of CD4lo to pro-T cells. Because it is likely that the thymic microenvironment plays a critical role in T-cell commitment, we compared the responses of CD4lo and pro-T cells to various cytokine combinations in vitro, as well as the ability of the cultured cells to repopulate organ cultures. Cytokine combinations that maintained T-cell repopulation potential for both CD4lo and pro-T cells were found. CD4lo cells proliferated best in response to the combination containing interleukin-1 (IL-1), IL-3, IL- 6, IL-7, and stem cell factor (SCF). Unlike CD4lo cells, pro-T cells were much more dependent upon IL-7 for proliferation and FTOC repopulation. However, combinations of cytokines lacking IL-7 were found that maintained the T-cell repopulating potential of pro-T cells, suggesting that, whereas this cytokine is clearly very important for normal pro-T cell function, it is not an absolute necessity during early T-cell expansion and differentiation.

scholarly journals TRPM2 Is Not Required for T-Cell Activation and Differentiation

2022 ◽  
Vol 12 ◽  
Author(s):  
Niels C. Lory ◽  
Mikolaj Nawrocki ◽  
Martina Corazza ◽  
Joanna Schmid ◽  
Valéa Schumacher ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Transient Receptor Potential ◽  
Cell Function ◽  
Intestinal Inflammation ◽  
Activation Markers

Antigen recognition by the T-cell receptor induces a cytosolic Ca2+ signal that is crucial for T-cell function. The Ca2+ channel TRPM2 (transient receptor potential cation channel subfamily M member 2) has been shown to facilitate influx of extracellular Ca2+ through the plasma membrane of T cells. Therefore, it was suggested that TRPM2 is involved in T-cell activation and differentiation. However, these results are largely derived from in vitro studies using T-cell lines and non-physiologic means of TRPM2 activation. Thus, the relevance of TRPM2-mediated Ca2+ signaling in T cells remains unclear. Here, we use TRPM2-deficient mice to investigate the function of TRPM2 in T-cell activation and differentiation. In response to TCR stimulation in vitro, Trpm2-/- and WT CD4+ and CD8+ T cells similarly upregulated the early activation markers NUR77, IRF4, and CD69. We also observed regular proliferation of Trpm2-/- CD8+ T cells and unimpaired differentiation of CD4+ T cells into Th1, Th17, and Treg cells under specific polarizing conditions. In vivo, Trpm2-/- and WT CD8+ T cells showed equal specific responses to Listeria monocytogenes after infection of WT and Trpm2-/- mice and after transfer of WT and Trpm2-/- CD8+ T cells into infected recipients. CD4+ T-cell responses were investigated in the model of anti-CD3 mAb-induced intestinal inflammation, which allows analysis of Th1, Th17, Treg, and Tr1-cell differentiation. Here again, we detected similar responses of WT and Trpm2-/- CD4+ T cells. In conclusion, our results argue against a major function of TRPM2 in T-cell activation and differentiation.

scholarly journals 641 Spatially organized multicellular immune hubs in MMRd and MMRp colorectal cancer

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A670-A670
Author(s):  
Jonathan Chen ◽  
Karin Pelka ◽  
Matan Hofree ◽  
Marios Giannakis ◽  
Genevieve Boland ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Mismatch Repair ◽  
Molecular Mechanisms ◽  
Immune Cell ◽  
Single Cells ◽  
Large Set ◽  
Colon Tissue

BackgroundImmune responses to cancer are highly variable, with DNA mismatch repair-deficient (MMRd) tumors exhibiting more anti-tumor immunity than mismatch repair-proficient (MMRp) tumors. Almost all tumors are infiltrated with immune cells, but the types of immune responses and their effects on tumor growth, metastasis and death, vary greatly between different cancers and individual tumors. Which of the numerous cell subsets in a tumor contribute to the response, how their interactions are regulated, and how they are spatially organized within tumors remains poorly understood.MethodsTo understand the rules governing these varied responses, we transcriptionally profiled 371,223 single cells from colorectal tumors and adjacent normal tissues of 28 MMRp and 34 MMRd treatment-naive patients. We developed a systematic approach to discover cell types, their underlying gene programs, and cellular communities based on single cell RNA-seq (scRNAseq) profiles and applied it to study the distinguishing features of human MMRd and MMRp colorectal cancer. Cellular communities discovered from this analysis were spatially mapped in tissue sections using multiplex RNA in situ hybridization microscopy.ResultsTo understand the basis for differential immune responses in CRC, we first determined and compared the immune cell composition of MMRd and MMRp CRC and normal colon tissue, finding dramatic remodeling between tumor and normal tissue and between MMRd and MMRp tumors, particularly within the myeloid, T cell, and stromal compartments. Among the clusters enriched in MMRd tumors were activated CXCL13+ CD8 T cells. Importantly, gene program co-variation analysis revealed multicellular networks. We discovered a myeloid cell-attracting hub at the tumor-luminal interface associated with tissue damage, and an MMRd-enriched immune hub within the tumor, with activated IFNG+ and CXCL13+ T cells together with malignant and myeloid cells expressing T-cell-attracting chemokines (figure 1).ConclusionsOur study provides a rich dataset of cellular states, gene programs and their transformations in tumors across a relatively large cohort of patients with colorectal cancer. Our predictions of several multicellular hubs based on co-variation of gene expression programs, and subsequent spatial localization of two major immune-malignant hubs, organizes a large set of cell states and programs into a smaller number of coordinated networks of cells and processes. Understanding the molecular mechanisms underlying these hubs, and studying their temporal and spatial regulation upon treatment will be critical for advancing cancer therapy.Ethics ApprovalThis study was approved by the DF-HCC institutional review board (protocols 03-189 and 02-240).Abstract 641 Figure 1A coordinated network of CXCL13+ T cells with myeloid and malignant cells expressing ISGs. Image shows a portion of formalin-fixed paraffin-embedded tissue from an MMRd CRC specimen stained with multiplex RNA ISH / IF for PanCK-IF, CD3E-ISH, CXCL10/CXCL11-ISH, CXCL13-ISH, and IFNG-ISH. Note IFNG+ and CXCL13+ cells in proximity to cells expressing the chemokines CXCL10/CXCL11

scholarly journals Dynamics of TCR repertoire and T cell function in COVID-19 convalescent individuals

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Lingjie Luo ◽  
Wenhua Liang ◽  
Jianfeng Pang ◽  
Gang Xu ◽  
Yingying Chen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Critical Role ◽  
World Health ◽  
Cell Repertoire ◽  
Metabolic Functions ◽  
Tcr Repertoire ◽  
Discharged Patients ◽  
Health Organization

AbstractSARS-CoV-2 outbreak has been declared by World Health Organization as a worldwide pandemic. However, there are many unknowns about the antigen-specific T-cell-mediated immune responses to SARS-CoV-2 infection. Here, we present both single-cell TCR-seq and RNA-seq to analyze the dynamics of TCR repertoire and immune metabolic functions of blood T cells collected from recently discharged COVID-19 patients. We found that while the diversity of TCR repertoire was increased in discharged patients, it returned to basal level ~1 week after becoming virus-free. The dynamics of T cell repertoire correlated with a profound shift of gene signatures from antiviral response to metabolism adaptation. We also demonstrated that the top expanded T cell clones (~10% of total T cells) display the key anti-viral features in CD8+ T cells, confirming a critical role of antigen-specific T cells in fighting against SARS-CoV-2. Our work provides a basis for further analysis of adaptive immunity in COVID-19 patients, and also has implications in developing a T-cell-based vaccine for SARS-CoV-2.

Nitric oxide plays a critical role in suppression of T-cell proliferation by mesenchymal stem cells

Blood ◽  
2006 ◽  
Vol 109 (1) ◽  
pp. 228-234 ◽  
Author(s):  
Kazuya Sato ◽  
Katsutoshi Ozaki ◽  
Iekuni Oh ◽  
Akiko Meguro ◽  
Keiko Hatanaka ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Stem Cells ◽  
Cell Proliferation ◽  
T Cells ◽  
Mesenchymal Stem Cells ◽  
T Cell ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Specific Inhibitor ◽  
T Cell Proliferation

Abstract The molecular mechanisms by which mesenchymal stem cells (MSCs) suppress T-cell proliferation are poorly understood, and whether a soluble factor plays a major role remains controversial. Here we demonstrate that the T-cell–receptor complex is not a target for the suppression, suggesting that downstream signals mediate the suppression. We found that Stat5 phosphorylation in T cells is suppressed in the presence of MSCs and that nitric oxide (NO) is involved in the suppression of Stat5 phosphorylation and T-cell proliferation. The induction of inducible NO synthase (NOS) was readily detected in MSCs but not T cells, and a specific inhibitor of NOS reversed the suppression of Stat5 phosphorylation and T-cell proliferation. This production of NO in the presence of MSCs was mediated by CD4 or CD8 T cells but not by CD19 B cells. Furthermore, inhibitors of prostaglandin synthase or NOS restored the proliferation of T cells, whereas an inhibitor of indoleamine 2,3-dioxygenase and a transforming growth factor–β–neutralizing antibody had no effect. Finally, MSCs from inducible NOS−/− mice had a reduced ability to suppress T-cell proliferation. Taken together, these results suggest that NO produced by MSCs is one of the major mediators of T-cell suppression by MSCs.

Ligation of CD137 receptor prevents and reverses established anergy of CD8+ cytolytic T lymphocytes in vivo

Blood ◽  
2004 ◽  
Vol 103 (1) ◽  
pp. 177-184 ◽  
Author(s):  
Ryan A. Wilcox ◽  
Koji Tamada ◽  
Dallas B. Flies ◽  
Gefeng Zhu ◽  
Andrei I. Chapoval ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Molecular Mechanisms ◽  
Transplant Rejection ◽  
Critical Role ◽  
Tumor Necrosis Factor Receptor ◽  
T Cell Anergy ◽  
Cell Anergy ◽  
Induced Tolerance

Abstract T-cell anergy is a tolerance mechanism defined as a hyporesponsive status of antigen-specific T cells upon prior antigen encounter and is believed to play a critical role in the evasion of tumor immunity and the amelioration of allogeneic transplant rejection. Molecular mechanisms in controlling T-cell anergy are less known. We show here that administration of an agonistic monoclonal antibody (mAb) to CD137, a member of the tumor necrosis factor receptor superfamily, prevents the induction of CD8+ cytolytic T-lymphocyte (CTL) anergy by soluble antigens. More importantly, CD137 mAb restores the functions of established anergic CTLs upon reencountering their cognate antigen. As a result, infusion of CD137 mAb inhibits progressive tumor growth that is caused by soluble tumor antigen-induced tolerance in a P815R model. CD137 mAb also restores proliferation and effector functions of anergic alloreactive 2C T cells in a bone marrow transplantation model. Our results indicate that ligation of CD137 receptor delivers a regulatory signal for T-cell anergy and implicate manipulation of the CD137 pathway as a new approach to break T-cell tolerance.

scholarly journals Tumors induce de novo steroid biosynthesis in T cells to evade immunity

2018 ◽  
Author(s):  
Bidesh Mahata ◽  
Jhuma Pramanik ◽  
Louise van der Weyden ◽  
Krzysztof Polanski ◽  
Gozde Kar ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Tumor Immunity ◽  
Cell Function ◽  
Immune Cell ◽  
De Novo ◽  
Steroid Biosynthesis ◽  
Genetic Ablation ◽  
Tumor Immunosuppression

ABSTRACTTumors subvert immune cell function to evade immune responses, yet the complex mechanisms driving immune evasion remain poorly understood. Here we show that tumors induce de novo steroidogenesis in T lymphocytes to evade anti-tumor immunity. Using a novel transgenic steroidogenesis-reporter mouse line we identify and characterize de novo steroidogenic immune cells. Genetic ablation of T cell steroidogenesis restricts primary tumor growth and metastatic dissemination in mouse models. Steroidogenic T cells dysregulate anti-tumor immunity, and inhibition of the steroidogenesis pathway was sufficient to restore anti-tumor immunity. This study demonstrates T cell de novo steroidogenesis as a mechanism of anti-tumor immunosuppression and a potential druggable target.

Sign in / Sign up

Export Citation Format

Share Document