Regulatory T Cells and Human Disease Annual Review of Immunology Vol. 38:541-566 (Volume publication date April 2020) First published as a Review in Advance on February 4, 2020 https://doi.org/10.1146/annurev-immunol-042718-04171 Regulatory T (T Reg) cells are essential for maintaining peripheral tolerance, preventing autoimmune diseases and limiting chronic inflammatory diseases. However, they also limit beneficial.. Foxp3-expressing CD4 + regulatory T (Treg) cells play key roles in the prevention of autoimmunity and the maintenance of immune homeostasis and represent a major barrier to the induction of robust antitumor immune responses. Thus, a clear understanding of the mechanisms coordinating Treg cell differentiation is crucial for understanding numerous facets of health and disease and for developing approaches to modulate Treg cells for clinical benefit. Here, we discuss current knowledge of the.
The FOXP3 + CD4 + regulatory T (T reg) cells located in non-lymphoid tissues differ in phenotype and function from their lymphoid organ counterparts. Tissue T reg cells have distinct.. Foxp3+CD4+regulatory T (Treg) cells are a subset of immune cells that function to regulate tissue inflammation. Skin is one of the largest organs and is home to a large proportion of the body's Treg cells. However, relative to other tissues (such as the spleen and gastrointestinal tract) the function of Treg cells in skin is less well defined Regulatory T cells (Tregs) are a specialized subpopulation of T cells that act to suppress immune response, thereby maintaining homeostasis and self-tolerance. It has been shown that Tregs are able to inhibit T cell proliferation and cytokine production and play a critical role in preventing autoimmunity. Different subsets with various functions of Treg cells exist. Tregs can be usually.
Regulatory T (Treg) cells are a developmentally and functionally distinct T cell subpopulation that is engaged in sustaining immunological self-tolerance and homeostasis. The transcription factor Foxp3 plays a key role in Treg cell development and function Regulatory T (Treg) cells: phenotype and function. Treg cells are a dynamic subset of CD4 + T lymphocytes that modulate physiological and pathological responses of the immune system . Tregs are categorized into two distinct subsets according to their site of development. Natural Tregs (nTregs) are generated in the thymus while induced Tregs (iTregs) develop from conventional, naive T cells in. The T helper type 2 (Th2) subsets are primarily involved in this disease process. Nevertheless, there is growing evidence in support of T cells with regulatory potential that operates in non-allergic individuals. These regulatory T cells occur naturally are called natural T regulatory cells (nTregs) and express the transcription factor Foxp3 Regulatory T cells (Tregs) characterized by the expression of the master transcription factor forkhead box protein p3 (Foxp3) suppress anticancer immunity, thereby hindering protective immunosurveillance of tumours and hampering effective antitumour immune responses in tumour-bearing hosts, constitute a current research hotspot in the field. However, Tregs are also essential for the maintenance of the immune tolerance of the body and share many molecular signalling pathways with. In this Review Series, Guest Editor Ciriaco A. Piccirillo has invited experts to contribute review articles on the recent progress in understanding the genetic basis of regulatory T cell functional development, their role in ensuring tolerance in health, the mechanisms underlying their dysfunction in diseased states and their use in cellular therapies for the treatment of a host inflammatory conditions in humans
Regulatory T (T reg) cells are essential for maintaining peripheral tolerance, preventing autoimmune diseases and limiting chronic inflammatory diseases.However, they also limit beneficial responses by suppressing sterilizing immunity and limiting anti-tumour immunity. Given that T reg cells can have both beneficial and deleterious effects, there is considerable interest in determining their. CD4+Foxp3+ regulatory T-cells (Tregs) are a unique subset of helper T-cells, which regulate immune response and establish peripheral tolerance. Tregs not only maintain the tone and tenor of an immune response by dominant tolerance but, in recent years, have also been identified as key players in resolving tissue inflammation and as mediators of tissue healing was identiﬁed. These cells, termed regulatory T cells or Treg cells, were highly enriched in suppressor activity (13). Treg cells were able to prevent autoimmunity upon transfer into day-3 thymectomized mice and, in various other experimental models of autoimmunity, inhibit transplant rejection and thwart tumor immunity (reviewed in 14, 15). The presenc
Recently, the role of Foxp3+ regulatory T cells (Treg) in the establishment and maintenance of tolerance has been the focus of numerous studies. In this review, we briefly discuss the historical background leading to the identification of Foxp3+ Treg and give an overview of their role in controlling systemic and mucosal immune responses Alteration of regulatory T cells in type 1 diabetes mellitus: a comprehensive review. Tan T(1), Xiang Y, Chang C, Zhou Z. Author information: (1)Diabetes Center, The Second Xiangya Hospital, and Institute of Metabolism and Endocrinology, Key Laboratory of Diabetes Immunology, Ministry of Education, National Clinical Research Center for Metabolic Diseases, Central South University, 139 Renmin. review by regulatory agencies but not yet approved and thus is not discussed in this article. Both axi-cel and tisa-cel have demonstrated efﬁcacy and manageable toxicity proﬁles in separate single-arm clinical trials and in the real-world setting, providing patients with promising new treatment options for r/r DLBCL beyond conventional therapies [11-16]. Because these two CAR T-cell. . CD4+T cells are commonly divided into regulatory T (Treg) cells and conventional T helper (Th) cells. Th cells control adaptive immunity against pathogens and cancer by activating other effector immune cells. Treg cells are defined as CD4+T cells in charge of suppressing potentially deleterious activities of Th cells
Regulatory T (T reg) cells are essential for maintaining peripheral tolerance, preventing autoimmune diseases and limiting chronic inflammatory diseases. However, they also limit beneficial responses by suppressing sterilizing immunity and limiting anti-tumour immunity. Given that T Regulatory T cells (Tregs) play an indispensable role in maintaining immunological unresponsiveness to self-antigens and in suppressing excessive immune responses deleterious to the host. Tregs are produced in the thymus as a functionally mature subpopulation of T cells and can also be induced from naive T cells in the periphery. Recent research reveals the cellular and molecular basis of Treg development and function and implicates dysregulation of Tregs in immunological disease Regulatory T cells (Treg) play a crucial role in regulating the immune response to pathogens and peripheral tolerance, which controls the development of various autoimmune diseases [, , ]. However, their frequency and functional capacities in various autoimmune immune diseases are still controversial, and their exact roles and molecular mechanisms have not been fully defined. Since some controversies were caused in part due to different stages of diseases, different methods. Regulatory T (Treg) cells can utilize several different suppressive mechanisms falling into three broad categories: (1) cell-cell contact-mediated suppression, (2) the metabolic disruption of effector T (Teff) cells, and (3) the secretion of inhibitory cytokines. (1) Contact-mediated suppression dampens the immunostimulatory properties of dendritic cells (DC) and occurs via the engagement of Treg cell inhibitory receptors such as CTLA-4 and LAG-3 with CD80/86 and MHC molecules. Foxp3‐expressing regulatory T (Treg) cells, which are indispensable for preventing autoimmunity, also suppress effective tumor immunity. Treg cells abundantly infiltrate into tumor tissues, which is often associated with poor prognosis in cancer patients. Removal of Treg cells enhances anti‐tumor immune responses but may also elicit autoimmunity. A key issue in devising Treg‐targeting cancer immunotherapy is, therefore, how to specifically deplete Treg cells infiltrating.
Disease pathogenesis is mainly driven by type 1 and type 17 cytokine‐producing cells which, in healthy individuals, are modulated by regulatory T cells (Tregs). Tregs play a fundamental role in immune homeostasis and contribute to the prevention of autoimmune disease by suppressing immune responses Regulatory T cells (Tregs) play a pivotal role in the homeostasis of the immune system and in the modulation of the immune response. Tregs have emerged as key players in the development and maintenance of peripheral immune tolerance. Broadly speaking, CD4+ T cells possessing the ability to suppress immune responses can be divided into two types: naturally occurring (nTreg) and inducible (iTreg. Regulatory T cells play an important role in the downregulation of immune responses in infectious diseases, tumor immunology, and autoimmunity (reviewed in 36). Natural regulatory T cells can turn off effector T cell responses mostly by a direct contact-mediated mechanism but can also act through suppressive cytokines Lymphocyte activation gene−3 (LAG-3) is a cell surface molecule expressed on activated T cells, NK and B cells, and functions as an immune regulatory protein. It is a homolog for CD4+, which allows for binding to major histocompatibility complex II (MHC II) on DC populations ( 78 )
CD8 + regulatory T cells (CD8 Tregs), which possess impor-tant immunosuppressive functions, are able to effectively block the overreacting immune response and maintain the body's immune homeostasis. In recent years, studies have identified a small set of special CD8+ Tregs that can recognize major histocompatibility complex class Ib molecules, mor Adaptive Foxp3 + CD4 + regulatory T (iTreg) cells develop outside the thymus under subimmunogenic antigen presentation, during chronic inflammation, and during normal homeostasis of the gut. iTreg cells are essential in mucosal immune tolerance and in the control of severe chronic allergic inflammation, and most likely are one of the main barriers to the eradication of tumors , and they play key roles for maintaining immune system in homeostasis Principal cells of the immune system that drive the immunopathological processes are T cells, especially of T H 1 and T H 17 subsets. However, in recent years, it was disclosed that regulatory T cells took part in, too. Subsequently, there was endeavour to develop ways how to re-establish their physiological functions. In this review, we. As the name suggests regulatory T cells (also called Tregs) are T cells which have a role in regulating or suppressing other cells in the immune system. Tregs control the immune response to self and foreign particles (antigens) and help prevent autoimmune disease. Tregs produced by a normal thymus are termed 'natural'
IDO‑mediated catabolic products, which are additionally termed ʻkynureninesʼ, exerts important immunosuppressive functions primarily via regulating T effector cell anergy and inducing the proliferation of T regulatory cells. This endogenous tolerogenic pathway has a critical effect on mediating the magnitude of immune responses under various stress conditions, including tumor, infection and transplantation. The present review evaluates the recent progress in elucidating how catabolism of. REVIEW ARTICLE Targeting regulatory T cells in tumors Chang Liu1, Creg J. Workman1 and Dario A. A. Vignali1,2 1 Department of Immunology, University of Pittsburgh, Pittsburgh, PA, USA 2 Tumor Microenvironment Center, University of Pittsburgh Cancer Institute, Pittsburgh, PA, US Regulatory T (Treg) cells maintain immune homeostasis by suppressing excessive immune responses. Treg cells induce tolerance against self- and foreign antigens, thus preventing autoimmunity, allergy, graft rejection, and fetus rejection during pregnancy. However, Treg cells also infiltrate into tumors and inhibit antitumor immune responses, thus inhibiting anticancer therapy Review Regulatory T cells in rheumatoid arthritis Jan Leipe1, Alla Skapenko1, Peter E Liy2 and Hendrik Schulze-Koops1,2 1Nikolaus Fiebiger Center for Molecular Medicine, University of Erlangen-Nuremberg, Erlangen, Germany 2National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA Corresponding author: Hendrik Schulze-Koops.
CD4+CD25+ regulatory T cells (Tregs) are a class of CD4+ T cells with immunosuppressive functions that play a critical role in maintaining immune homeostasis. However, in certain disease settings, Tregs demonstrate plastic differentiation, and the stability of these Tregs, which is characterized by the stable expression or protective epigenetic modifications of the transcription factor Foxp3. CD regulatory T cells (Tregs) suppress a variety of nor mal physiological and pathological immune responses via several pathways, such as inhibitory cytokine secretion, direct cytolysis induction, and antigen-presenting cell functional modulation. FoxP +CD CD Tregs are involved in a variety of central nervous system diseases and injuries, including axonalinjury,neurodegenerativediseases. REVIEW | 01 April 2015. Genetically modified T cells in cancer therapy: opportunities and challenges Michaela Sharpe, Michaela Sharpe Cell Therapy Catapult, 12th Floor Tower Wing, Guy's Hospital, Great Maze Pond, London, SE1 9RT, UK. Search for other works by this author on: This site. PubMed. Google Scholar. Natalie Mount. Natalie Mount * Cell Therapy Catapult, 12th Floor Tower Wing, Guy.
Review Article Regulatory T Cells: Molecular Actions on Effector Cells in Immune Regulation AsielArce-Sillas, 1 DianaDenisseÁlvarez-Luquín, 1 BeatrizTamaya-Domínguez, 1 SandraGomez-Fuentes, 1 AbelTrejo-García, 1 MarleneMelo-Salas, 1 GracielaCárdenas, 1 JuanRodríguez-Ramírez, 1 andLauraAdalid-Peralta 1,2 Instituto Nacional de Neurolog ´ a y Neurocirug ´ a,M ´exico, DF, Mexic Regulatory T-cells (Tregs) are key players in successful pregnancy and their deficiencies are implicated in pregnancy complications such as preeclampsia (PE), but the results are inconsistent among studies. This study aims to compile an overview of the studies about the associations of Tregs and PE risk and to provide recommendations for future research. A sensitive search of three databases. Review Article The Role of MicroRNAs in Regulatory T Cells Chao Liu,1 Nannan Li,2 and Guijian Liu 1 1Clinical Laboratory, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, China 2Feiyan Biotechnology Company Limited, Beijing, China Correspondence should be addressed to Guijian Liu; firstname.lastname@example.org
Review and cite REGULATORY T CELL protocol, troubleshooting and other methodology information | Contact experts in REGULATORY T CELL to get answer Review Article Tryptophan Metabolism, Regulatory T Cells, and Inflammatory Bowel Disease: A Mini Review Xueyan Ding ,1,2,3 Peng Bin,1,2,3 Wenwen Wu,1,2,3 Yajie Chang,1,2,3 and Guoqiang Zhu 1,2,3 1College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China 2Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Chin
Regulatory T cells (Tregs) play a pivotal role in the homeostasis of the immune system and in the modulation of the immune response. Tregs have emerged as key players in the development and maintenance of peripheral immune tolerance.Broadly speaking, CD4+ T cells possessing the ability to suppress immune responses can be divided into two types naturally occurring (nTreg) and inducible (iTreg. T-regulatory cells (Tregs), formerly known as T suppressor cells, are a T cell subset with direct roles in both autoimmunity and responses to pathogens. Tregs decrease inflammation via the secretion of immunosuppressive cytokines (IL-10, TGF-b) and also through direct suppression of inflammatory effector T cells (such as Th1 and Th17 cells). Tregs control and likely prevent autoimmune diseases. known as regulatory T cells, which are induced in the periphery in an antigen-specific fashion [3,4]. The present review will discuss the various types of regulatory T cells, as well as the. Review Article Statins as Modulators of Regulatory T-Cell Biology DavidA.Forero-PeñaandFredyR.S.Gutierrez Grupo de Investigaci ´on en Ciencias Biom ´edicas, Facultad de Medicina, Universidad Antonio Nari no, Bogot a, Colombia´ Correspondence should be addressed to Fredy R. S. Gutierrez; email@example.com
Review The role of CD4+FoxP3+ regulatory T cells in the immunopathogenesis of COVID-19: implications for treatment Yifei Wang †, Jingbin Zheng , Md Sahidul Islam, Yang Yang, Yuanjia Hu and Xin Chen State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Med ical Sciences, University of Macau, Macau SAR 999078, China † These authors have contributed equally to. Since its rediscovery in the mid-1990s, FOXP3 + regulatory T cells (Tregs) have climbed the rank to become commander-in-chief of the immune system. They possess diverse power and ability to orchestrate the immune system in time of inflammation and infection as well as in time of harmony and homeostasis. To be the commander-in-chief, they must be equipped with both offensive and defensive.
Regulatory T cells in autoimmune endocrine diseases F. Susan Wong1 and Colin M. Dayan2 1Department of Cellular and Molecular Medicine, University of Bristol, Bristol BS8 1TD, UK 2Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol BS1 3NY, UK Regulatory T cells (Tregs) play a vital role in maintainin role of regulatory T cells in immune homeostasis, with defects in number and suppressive function of regulatory T cells seen in patients with Crohn's disease. We review the function of regulatory T cells and the pathways by which they exert immune tolerance in the intestinal mucosa. We explore the principles and challenges o CD4 + regulatory T cells (T regs) Here, we will review the current understanding of T reg-mediated immune suppressive mechanisms in cancer, the involvement of T regs in cancer immune therapy, and future therapeutic strategies targeting T regs. Natural and induced T regs. T regs are separated into natural/thymic and peripherally induced T regs on the basis of the sites in which they are. T-regulatory cells (Tregs) are found infiltrating tumors in a vast array of tumor types, and tumor-infiltrating Tregs are often associated with a poor clinical outcome. Tregs are potent immunosuppressive cells of the immune system that promote progression of cancer through their ability to limit antitumor immunity and promote angiogenesis
plastic process. Inducible Treg cell populations in-clude: T regulatory 1 (Tr1) cells, which secrete IL‑10; T helper 3 (Th3) cells, which secrete TGF-β, and con-verted Foxp3+ Treg cells [1-3]. This review is focused on the induction of CD4+ Tregs, mostly by Foxp3+ expression, and on their suppressor activities durin Regulatory T-cells are arguably the most versatile immuno- suppressive cells and work like immunological sentinels across various tissues. Both in mice and men, loss of these cells essen- tially results in breakdown of tolerance and multi-organ autoim- munity Abstract. Regulatory T (T reg) cells expressing forkhead box P3 (Foxp3) arise during thymic selection among thymocytes with modestly self-reactive T cell receptors.In vitro studies suggest Foxp3 can also be induced among peripheral CD4 + T cells in a cytokine dependent manner. T reg cells of thymic or peripheral origin may serve different functions in vivo, but both populations are. Alterations in the levels of circulating cytokines during the progression of SIRS have been well established. However, only a small number of studies have demonstrated the responses of lymphocytes during HS, and no studies have investigated immune‑regulatory cells, such as regulatory T cells (Tregs) by the discovery of regulatory T cell epitopes, which suggests that immunogenicity testing must now take regulatory T cells into consideration. In this review, we address the application of computational tools for preclinical immunogenicity assessment, the implication of the discovery of regulatory T cell epitopes, an
Regulatory Tools Used for CAR T Therapy Approval. FDA designation programs that have been used in the approval of CAR T therapy products include: priority review, breakthrough therapy, orphan drug, accelerated approval, and regenerative medicine advanced therapy (RMAT). These regulatory tools can significantly reduce the time to approval and marketing of a CAR T therapy drug This study assessed in detail the influence of four different human proteins on the activation of CD4+ and CD8+ T lymphocytes and on the formation of regulatory T cells. Human whole-blood samples were incubated with four different human proteins. The effects of these proteins on the downstream immune-system response, on the expression of extracellular activation markers on and intracellular cytokines in T lymphocytes, and on the number of regulatory T cells (T-reg cells) were. Among the multiple T cell subsets with suppressive function, the regulatory T cells (Tregs), defined by the expression of CD4, the IL‐2 receptor α chain (CD25), and the transcription factor FOXP3, have emerged as having a central role in maintaining immune‐tolerance to autoantigens. Tregs are equipped with an array of mechanisms of suppression, including the modulation of antigen. Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract resulting from the homeostasis imbalance of intestinal microenvironment, immune dysfunction, environmental and genetic factors, and so on. This disease is associated with multiple immune cells including regulatory T cells (Tregs). Tregs are a subset of T cells regulating the function of various. Regulatory T Cells: A Review of the Empirical Evidence and Clinical Applications Luigi Cari , Francesca De Rosa , Giuseppe Nocentini * and Carlo Riccardi Section of Pharmacology, Department of Medicine, University of Perugia, Perugia I-06129, Italy; firstname.lastname@example.org (L.C.); email@example.com (F.D.R.); firstname.lastname@example.org (C.R.
This Review summarizes our current knowledge of regulatory T cells, illustrates the ongoing regulatory T-cell-based clinical trials, analyses the strengths and pitfalls of this new therapeutic.. 3. Regulatory T cells. Regulatory cells (Tregs) play a critical role in the establishment and maintenance of immune homeostasis as well as in the limitation of chronic inflammatory responses directed against pathogens and environmental factors [8-10]. This cell-mediated suppression is considered a vital mechanism of negative regulation of immunomediated inflammation, and plays a prominent role in autoimmunity and auto-inflammatory disorders, allergies, acute and chronic. Regulatory T cells not only show a direct self-tolerance effect, but also secrete various substances such as cytokines, growth factors to affect other immune cells. 44 - 46 Cytokines are a category of signaling molecules that regulate immunity, inflammation and hematopoiesis. 47, 48 The cytokine array was performed to identify cytokines contained in Treg cells CM regulatory T cells are involved in the mechanism of oral tolerance but a clear distinction of their contribution in the induction and stabilization of local and systemic tolerance remains to be determined. Review Trends in Immunology Vol.29 No.11 533. PP-derived cells, when intestinal and spleen cells are monitored after feeding Ag . Accordingly, mice lacking PP were shown to be more. REVIEW. Regulatory T cells: a potential target in cancer immunotherapy. Kohei Shitara. Department of Gastroenterology and Gastrointestinal Oncology, National Cancer Center Hospital East, Chiba, Japan . Search for more papers by this author. Hiroyoshi Nishikawa. Corresponding Author. email@example.com; Division of Cancer Immunology, Research Institute/EPOC, National Cancer Center, Tokyo.
described in the present review. Regulatory T cells in mouse models of lupus Natural Tregs have protective effects in lupus-prone mice (Table 1). In the lupus-prone New Zealand mixed 2328 mice, 3-day thymectomy results in an early-onset, fatal glomerulo-nephritis in females. The nephritis, however, largely regresse Contributed by Shimon Sakaguchi, March 31, 2020 (sent for review December 26, 2019; reviewed by Ryo Abe and Benoit L. Salomon) Foxp3-expressingregulatory T cells (Tregs) canbegeneratedin vitro by antigenic stimulation of conventional T cells (Tconvs) in the pres-ence of TGF-β and IL-2. However, unlike Foxp3+ naturally occurrin T cell, there has been a renewal of interest in the area of active T cell-mediated suppression (11, 12). The suppression of immunity by the naturally occurring CD4+CD25+ regulatory T cells (CD4 Treg) has been suggested in many different animal models and in human studies (13). In addition to CD4 Treg, regulatory CD8 T cells (CD8 Treg) have also bee The role of regulatory T cells in cancer immunology Theresa L Whiteside University of Pittsburgh Cancer Institute, Pittsburgh, PA, US Abstract: Regulatory T cells (Treg) are generally considered to be significant contributors to tumor escape from the host immune system. Emerging evidence suggests, however, that in some human cancers, Treg are necessary to control chronic inflammation, prevent.
This Review summarizes our current knowledge of regulatory T cells, illustrates the ongoing regulatory T-cell-based clinical trials, analyses the strengths and pitfalls of this new therapeutic approach, and highlights the future perspectives. ASJC Scopus subject area Regulatory T-cells (Tregs) comprise a group of either thymically derived or peripherally induced suppressor CD4+ cells involved in the control of effector T-cells against both self- and foreign-antigens. They are found increased in tumor tissues and are thought to be involved in pathogenesis of cancer by providing tumors with a mechanism to evade immune detection and destruction. Despite the. Immunity Review The Biology of T Regulatory Type 1 Cells and Their Therapeutic Application in Immune-Mediated Diseases Maria Grazia Roncarolo,1 ,2 * Silvia Gregori,3.
Abstract: Regulatory T cells (Tregs) are important members of the immune system regulating the host responses to infection and neoplasms. Tregs prevent autoimmune disorders by protecting the host-cells from an immune response, related to the peripheral tolerance. However, tumor cells use Tregs as a shield to protect themselves against anti. T reg cells suppress antigen-presenting cells (APCs) by depleting immune stimulating cytokines, producing immunosuppressive cytokines and constitutively expressing CTLA-4. CTLA-4 molecules bind to CD80 and CD86 with a higher affinity than CD28 and act as competitive inhibitors of CD28 in APCs. The purpose of this review is to summarize state-of-the-art understanding of the molecular mechanisms underlining CTLA-4 immune regulation and the correlation of the ICI response with CTLA-4 expression.
Regulatory T cells (Tregs) are critical modulators of immune homeostasis. Tregs maintain peripheral tolerance to self-antigens, thereby preventing autoimmune disease. Furthermore, Tregs suppress excessive immune responses deleterious to the host. Recent research has deepened our understanding of how Tregs function at the ocular surface. This manuscript describes the classification, the. In addition, multiple immune cells like macrophages, dendritic cells (DCs), and lymphoid cells play important roles in the development of IBD, and the turbulence in the differentiation and function of certain T lymphocytes [e.g., regulatory T cells (Tregs)] could contribute to the pathogenesis of IBD [6, 7]. Hence, the thorough understanding of precise regulation of Tregs may be helpful to. The T cell repertoire in a healthy adult is shaped by thymic selection (positive and negative), where naive CD4 + and CD8 + T cells can then interact, and be primed, with foreign antigen in the secondary lymphoid tissues. Antigen engagement via the T cell receptor (TCR) then shapes the repertoire of antigen-specific T cells and most likely the.