scholarly journals Cytotoxic T Lymphocyte Antigen 4 Is Induced in the Thymus upon In Vivo Activation and Its Blockade Prevents Anti-CD3–mediated Depletion of  Thymocytes

1998 ◽  
Vol 188 (7) ◽  
pp. 1239-1246 ◽  
Author(s):  
Corrado M. Cilio ◽  
Michael R. Daws ◽  
Anna Malashicheva ◽  
Charles L. Sentman ◽  
Dan Holmberg
Keyword(s):  
T Cell ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Tyrosine Phosphatase ◽  
Costimulatory Molecule ◽  
Sh2 Domain ◽  
Double Positive ◽  
Cell Repertoire ◽  
Lymphocyte Antigen

The development of a normal T cell repertoire in the thymus is dependent on the interplay between signals mediating cell survival (positive selection) and cell death (negative selection or death by neglect). Although the CD28 costimulatory molecule has been implicated in this process, it has been difficult to establish a role for the other major costimulatory molecule, cytotoxic T lymphocyte antigen (CTLA)-4. Here we report that in vivo stimulation through the T cell receptor (TCR)–CD3 complex induces expression of CTLA-4 in thymocytes and leads to the association of CTLA-4 with the SH2 domain–containing phosphatase (SHP)-2 tyrosine phosphatase. Moreover, intrathymic CTLA-4 blockade dramatically inhibits anti-CD3–mediated depletion of CD4+CD8+ double positive immature thymocytes. Similarly, anti-CD3–mediated depletion of CD4+CD8+ double positive cells in fetal thymic organ cultures could also be inhibited by anti–CTLA-4 antibodies. Thus, our data provide evidence for a role of CTLA-4 in thymic selection and suggest a novel mechanism contributing to the regulation of TCR-mediated selection of T cell repertoires.

scholarly journals Immunologic Self-Tolerance Maintained by Cd25+Cd4+Regulatory T Cells Constitutively Expressing Cytotoxic T Lymphocyte–Associated Antigen 4

2000 ◽  
Vol 192 (2) ◽  
pp. 303-310 ◽  
Author(s):  
Takeshi Takahashi ◽  
Tomoyuki Tagami ◽  
Sayuri Yamazaki ◽  
Toshimitsu Uede ◽  
Jun Shimizu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
T Lymphocyte ◽  
Cd4 T Cells ◽  
Cytotoxic T Lymphocyte ◽  
Costimulatory Molecule ◽  
Self Tolerance

This report shows that cytotoxic T lymphocyte–associated antigen 4 (CTLA-4) plays a key role in T cell–mediated dominant immunologic self-tolerance. In vivo blockade of CTLA-4 for a limited period in normal mice leads to spontaneous development of chronic organ-specific autoimmune diseases, which are immunopathologically similar to human counterparts. In normal naive mice, CTLA-4 is constitutively expressed on CD25+CD4+ T cells, which constitute 5–10% of peripheral CD4+ T cells. When the CD25+CD4+ T cells are stimulated via the T cell receptor in vitro, they potently suppress antigen-specific and polyclonal activation and proliferation of other T cells, including CTLA-4–deficient T cells, and blockade of CTLA-4 abrogates the suppression. CD28-deficient CD25+CD4+ T cells can also suppress normal T cells, indicating that CD28 is dispensable for activation of the regulatory T cells. Thus, the CD25+CD4+ regulatory T cell population engaged in dominant self-tolerance may require CTLA-4 but not CD28 as a costimulatory molecule for its functional activation. Furthermore, interference with this role of CTLA-4 suffices to elicit autoimmune disease in otherwise normal animals, presumably through affecting CD25+CD4+ T cell–mediated control of self-reactive T cells. This unique function of CTLA-4 could be exploited to potentiate T cell–mediated immunoregulation, and thereby to induce immunologic tolerance or to control autoimmunity.

scholarly journals Modulation of Susceptibility to HIV-1 Infection by the Cytotoxic T Lymphocyte Antigen 4 Costimulatory Molecule

1999 ◽  
Vol 191 (11) ◽  
pp. 1987-1998 ◽  
Author(s):  
James L. Riley ◽  
Katia Schlienger ◽  
Patrick J. Blair ◽  
Beatriz Carreno ◽  
Nancy Craighead ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocyte ◽  
Cd4 T Cells ◽  
Cytotoxic T Lymphocyte ◽  
Costimulatory Molecule ◽  
Lymphocyte Antigen ◽  
Viral Spread ◽  
Hiv 1

CD4 T cells activated in vitro by anti-CD3/28–coated beads are resistant to infection by CC chemokine receptor 5 (CCR5)-dependent HIV-1 isolates. In vivo, antigen-presenting cells (APCs) activate CD4 T cells in part by signaling through the T cell receptor and CD28, yet cells stimulated in this manner are susceptible to HIV-1 infection. We show that cytotoxic T lymphocyte antigen 4 (CTLA-4) engagement counteracts the CD28 antiviral effects, and that the ratio of CTLA-4 to CD28 engagement determines the susceptibility of HIV-1 infection. Furthermore, unopposed CTLA-4 signaling provided by CD28 blockade promotes vigorous HIV-1 replication, despite minimal T cell proliferation. Finally, CTLA-4 antibodies decrease the susceptibility of antigen-activated CD4 T cells to HIV, suggesting a potential approach to prevent or limit viral spread in HIV-1–infected individuals.

Carrier-reactive hapten-specific cytotoxic T lymphocyte clones originate from a highly preselected T cell repertoire: implications for chemical-induced self-reactivity

1995 ◽  
Vol 25 (10) ◽  
pp. 2788-2796 ◽  
Author(s):  
Stefan Martin ◽  
Helga Ruh ◽  
Sabine Hebbelmann ◽  
Ulrike Pflugfelder ◽  
Barbara Rüde ◽  
...  
Keyword(s):  
T Cell ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
T Cell Repertoire ◽  
Cell Repertoire

scholarly journals T cell receptor genes in a series of class I major histocompatibility complex-restricted cytotoxic T lymphocyte clones specific for a Plasmodium berghei nonapeptide: implications for T cell allelic exclusion and antigen-specific repertoire.

1991 ◽  
Vol 174 (6) ◽  
pp. 1371-1383 ◽  
Author(s):  
J L Casanova ◽  
P Romero ◽  
C Widmann ◽  
P Kourilsky ◽  
J L Maryanski
Keyword(s):  
Major Histocompatibility Complex ◽  
T Cell ◽  
T Lymphocyte ◽  
Plasmodium Berghei ◽  
Cytotoxic T Lymphocyte ◽  
Class I ◽  
Allelic Exclusion ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Histocompatibility Complex

We report here the first extensive study of a T cell repertoire for a class I major histocompatibility complex (MHC)-restricted cytotoxic T lymphocyte (CTL) response. We have found that the T cell receptors (TCRs) carried by 28 H-2Kd-restricted CTL clones specific for a single Plasmodium berghei circumsporozoite nonapeptide are highly diverse in terms of V alpha, J alpha, and J beta segments and aminoacid composition of the junctional regions. However, despite this extensive diversity, a high proportion of the TCRs contain the same V beta segment. These results are in contrast to most previously reported T cell responses towards class II MHC-peptide complexes, where the TCR repertoires appeared to be much more limited. In our study, the finding of a dominant V beta in the midst of otherwise highly diverse TCRs suggests the importance of the V beta segment in shaping the T cell repertoire specific for a given MHC-peptide complex. As an additional finding, we observed that nearly all clones have rearranged both TCR alpha loci. Moreover, as many as one-third of the CTL clones that we analyzed apparently display two productive alpha rearrangements. This argues against a regulated model of sequential recombination at the alpha locus and consequently raises the question of whether allelic exclusion of the TCR alpha chain is achieved at all.

Sarcoidosis-like syndrome and lymphadenopathy due to checkpoint inhibitors

2016 ◽  
Vol 23 (8) ◽  
pp. 620-624 ◽  
Author(s):  
Belal Firwana ◽  
Rahul Ravilla ◽  
Mihir Raval ◽  
Laura Hutchins ◽  
Fade Mahmoud
Keyword(s):  
Cell Death ◽  
Adverse Event ◽  
T Cell ◽  
Metastatic Melanoma ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Checkpoint Inhibitors ◽  
Stage Iv ◽  
Stage Iii ◽  
Lymphocyte Antigen

Immunotherapy with checkpoint inhibitors has revolutionized the management of metastatic melanoma. These checkpoints, namely the cytotoxic T lymphocyte antigen 4 and the programmed T cell death 1 receptor, possess an inhibitory effect on the T cell function. Pharmacologic inhibition of cytotoxic T lymphocyte antigen 4 with ipilimumab and programmed T cell death 1 with either pembrolizumab or nivolumab has resulted in long-term sustained responses among patients with metastatic melanoma. The adverse events of these medications are predominantly immune related. Sarcoidosis-like syndrome/lymphadenopathy represents a challenging adverse event to the oncologist as it can be mistaken for progressive disease. Hence, awareness of such adverse event and obtaining a biopsy of the enlarged lymph nodes will confirm the diagnosis and avoid the unnecessary change of current therapies for those with stage IV disease or adding new ones for those with stage III disease. We report three cases of immunotherapy-related sarcoidosis-like syndrome/lymphadenopathy; two cases occurred during adjuvant ipilimumab for stage III surgically resected melanoma and one case during pemprolizumab for stage IV metastatic melanoma.

scholarly journals Cytotoxic T Lymphocyte Antigen 4 (CTLA4) Blockade Accelerates the Acute Rejection of Cardiac Allografts in CD28-deficient Mice: CTLA4 Can Function Independently of CD28

1998 ◽  
Vol 188 (1) ◽  
pp. 199-204 ◽  
Author(s):  
Hua Lin ◽  
Jeffrey C. Rathmell ◽  
Gary S. Gray ◽  
Craig B. Thompson ◽  
Jeffrey M. Leiden ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
T Lymphocyte ◽  
Graft Rejection ◽  
Allograft Rejection ◽  
Cell Activation ◽  
Cytotoxic T Lymphocyte ◽  
Wild Type ◽  
Lymphocyte Antigen ◽  
Deficient Mice

Cytotoxic T lymphocyte antigen 4 (CTLA4) appears to negatively regulate T cell activation. One mechanism by which CTLA4 might antagonize T cell function is through inhibition of CD28 signaling by competing for their shared ligands B7-1 and B7-2. In addition, CTLA4 ligation could initiate a signaling cascade that inhibits T cell activation. To address whether CTLA4 could inhibit immune responses in the absence of CD28, rejection of heart allografts was studied in CD28-deficient mice. H-2q hearts were transplanted into allogeneic wild-type or CD28-deficient mice (H-2b). Graft rejection was delayed in CD28-deficient compared with wild-type mice. Treatment of wild-type recipients with CTLA4-immunoglobulin (Ig), or with anti–B7-1 plus anti–B7-2 mAbs significantly prolonged allograft survival. In contrast, treatment of CD28-deficient mice with CTLA4-Ig, anti–B7-1 plus anti–B7-2 mAbs, or a blocking anti-CTLA4 mAb induced acceleration of allograft rejection. This increased rate of graft rejection was associated with more severe mononuclear cell infiltration and enhanced levels of IFN-γ and IL-6 transcripts in donor hearts of untreated wild-type and CTLA4-Ig– or anti-CTLA4 mAb–treated CD28-deficient mice. Thus, the negative regulatory role of CTLA4 extends beyond its potential ability to prevent CD28 activation through ligand competition. Even in the absence of CD28, CTLA4 plays an inhibitory role in the regulation of allograft rejection.

scholarly journals Ligation of Cytotoxic T Lymphocyte Antigen-4 to T Cell Receptor Inhibits T Cell Activation and Directs Differentiation into Foxp3+Regulatory T Cells

2012 ◽  
Vol 287 (14) ◽  
pp. 11098-11107 ◽  
Author(s):  
Jozsef Karman ◽  
Ji-Lei Jiang ◽  
Nathan Gumlaw ◽  
Hongmei Zhao ◽  
Juanita Campos-Rivera ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
T Cell Receptor ◽  
T Cell Activation ◽  
T Lymphocyte ◽  
Cell Activation ◽  
Cytotoxic T Lymphocyte ◽  
Cell Receptor ◽  
Lymphocyte Antigen
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