scholarly journals Functional Reprogramming of the Primary Immune Response by T Cell Receptor Antagonism

2004 ◽  
Vol 200 (11) ◽  
pp. 1371-1382 ◽  
Author(s):  
Dipica Haribhai ◽  
Brandon Edwards ◽  
Mary L. Williams ◽  
Calvin B. Williams

The T cell receptor must translate modest, quantitative differences in ligand binding kinetics into the qualitatively distinct signals used to determine cell fate. Here, we use mice that express an endogenous T cell receptor (TCR) antagonist and an adoptive transfer system to examine the influence of TCR signal quality on the development of effector function. We show that activation of antigen-specific T cells in the presence of an antagonist results in a functional reprogramming of the primary immune response, marked by altered T cell homing, a failure to develop effector function, and ultimately clonal elimination by apoptosis. Importantly, antagonism does not block cell division, implying that the signals promoting clonal expansion and effector differentiation are distinct.

2020 ◽  
Vol 38 (10) ◽  
pp. 1194-1202 ◽  
Author(s):  
Huang Huang ◽  
Chunlin Wang ◽  
Florian Rubelt ◽  
Thomas J. Scriba ◽  
Mark M. Davis

mBio ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Jennifer D. Helble ◽  
Rodrigo J. Gonzalez ◽  
Ulrich H. von Andrian ◽  
Michael N. Starnbach

ABSTRACT While there is no effective vaccine against Chlamydia trachomatis infection, previous work has demonstrated the importance of C. trachomatis-specific CD4+ T cells (NR1 T cells) in pathogen clearance. Specifically, NR1 T cells have been shown to be protective in mice, and this protection depends on the host’s ability to sense the cytokine gamma interferon (IFN-γ). However, it is unclear what role NR1 production or sensing of IFN-γ plays in T cell homing to the genital tract or T cell-mediated protection against C. trachomatis. Using two-photon microscopy and flow cytometry, we found that naive wild-type (WT), IFN-γ−/−, and IFN-γR−/− NR1 T cells specifically home to sections in the genital tract that contain C. trachomatis. We also determined that protection against infection requires production of IFN-γ from either NR1 T cells or endogenous cells, further highlighting the importance of IFN-γ in clearing C. trachomatis infection. IMPORTANCE Chlamydia trachomatis is an important mucosal pathogen that is the leading cause of sexually transmitted bacterial infections in the United States. Despite this, there is no vaccine currently available. In order to develop such a vaccine, it is necessary to understand the components of the immune response that can lead to protection against this pathogen. It is well known that antigen-specific CD4+ T cells are critical for Chlamydia clearance, but the contexts in which they are protective or not protective are unknown. Here, we aimed to characterize the importance of gamma interferon production and sensing by T cells and the effects on the immune response to C. trachomatis. Our work here helps to define the contexts in which antigen-specific T cells can be protective, which is critical to our ability to design an effective and protective vaccine against C. trachomatis.


2006 ◽  
Vol 84 (2) ◽  
pp. 135-141 ◽  
Author(s):  
Xiaoyin Zhang ◽  
Liu Hong ◽  
W Y Chan ◽  
Taidong Qiao ◽  
Baojun Chen ◽  
...  

MG7-Ag is a human gastric-carcinoma-associated antigen with a high specificity. So far it is remained unclear whether MG7-Ag is correlated with the in vivo cellular immune response of patients with gastric cancer. In this study, we detected the expression of the T cell receptor (TCR) repertoire of T cell subpopulations and cytokines in tumor-infiltrating lymphocytes (TIL), peripheral blood lymphocytes (PBL), and residue benign mucosal lymphocytes (NML) of patients with gastric cancer using semiquantitative RT-PCR. Our data showed that the expanded clones in CD8+ NML and TIL and CD4+ NML and PBL in MG7-Ag-positive patients were significantly fewer than those of MG7-Ag-negative patients (p = 0.0360; p = 0.0026; p = 0.0065 p = 0.0109, respectively). The levels of IL-8 in CD8+ TIL and TNF in CD4+ TIL from the MG7-Ag-positive group were significantly higher than those from the MG7-Ag-negative group (p = 0.0302; p = 0.0177, respectively). Taken together, the results demonstrated a weaker T cell immune response and more proinflammatory cytokine secretion in MG7-Ag-positive patients with gastric cancer than in MG7-Ag-negative ones. This likely contributes to the poor prognosis in MG7-Ag-positive gastric-cancer patients.Key words: gastric carcinoma, tumor-associated antigen, T cell receptor repertoire, cytokine, RT-PCR.


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