scholarly journals Influence of T cell receptor V alpha expression on Mlsa superantigen-specific T cell responses.

1992 ◽  
Vol 175 (5) ◽  
pp. 1405-1408 ◽  
Author(s):  
M S Vacchio ◽  
O Kanagawa ◽  
K Tomonari ◽  
R J Hodes

Recognition of conventional foreign antigen by T cells is determined by the expression of multiple variable regions of both alpha and beta chains of the T cell receptor (TCR) alpha/beta heterodimer. In contrast, there exists a class of antigens that appears to interact with the TCR alpha/beta heterodimer through the variable region on the beta chain (V beta), independent of other TCR components, a property that has led to their designation as superantigens. The goal of the present study was to analyze V alpha use in V beta 6+ T cells responsive to the superantigen, Mlaa. Results indicate that while deletion of T cells expressing V beta 6 in Mlsa-expressing mice is essentially complete and therefore appears to occur regardless of V alpha usage, in vitro Mlsa stimulation of T cells from Mlsa-negative mice results in significant skewing of V alpha use among responding V beta 6+ T cells. This indicates that V alpha expression influences recognition of the superantigen, Mlsa by mature peripheral T cells.

Blood ◽  
1992 ◽  
Vol 79 (11) ◽  
pp. 2965-2972 ◽  
Author(s):  
Y Kusunoki ◽  
Y Hirai ◽  
S Kyoizumi ◽  
M Akiyama

Abstract Rare T lymphocytes bearing CD3 surface antigen and T-cell receptor (TCR) alpha and beta chains, but lacking both CD4 and CD8 antigens, viz, TCR alpha beta+CD4–8- cells, appear at a frequency of 0.1% to 2% in peripheral blood TCR alpha beta+ cells of normal donors. Here we report two unusual cases, found among 100 healthy individuals studied, who showed an abnormally elevated frequency of these T cells, ie, 5% to 10% and 14% to 19%. Southern blot analyses of the TCR alpha beta+CD4–8- clones all showed the identical rearrangement patterns for each individual, demonstrating that these are derivatives of a single T cell. The same rearrangement patterns were also observed for the freshly isolated lymphocytes of TCR alpha beta+CD4-CD8- fraction, which excludes the possible bias in the processes of in vitro cloning. These TCR alpha beta+CD4–8- T cells were found to express other mature T-cell markers such as CD2, CD3, and CD5 antigens, as well as natural killer (NK) cell markers (CD11b, CD16, CD56, and CD57 antigens) for both individuals. Further, although lectin-dependent or redirected antibody- dependent cell-mediated cytotoxicities were observed for both freshly sorted lymphocytes of TCR alpha beta+CD4–8- fraction and in vitro established clones, NK-like activity was not detected.


1998 ◽  
Vol 188 (8) ◽  
pp. 1465-1471 ◽  
Author(s):  
Barry P. Sleckman ◽  
Bernard Khor ◽  
Robert Monroe ◽  
Frederick W. Alt

The generation of a productive “in-frame” T cell receptor β (TCR β), immunoglobulin (Ig) heavy (H) or Ig light (L) chain variable region gene can result in the cessation of rearrangement of the alternate allele, a process referred to as allelic exclusion. This process ensures that most αβ T cells express a single TCR β chain and most B cells express single IgH and IgL chains. Assembly of TCR α and TCR γ chain variable region genes exhibit allelic inclusion and αβ and γδ T cells can express two TCR α or TCR γ chains, respectively. However, it was not known whether assembly of TCR δ variable regions genes is regulated in the context of allelic exclusion. To address this issue, we have analyzed TCR δ rearrangements in a panel of mouse splenic γδ T cell hybridomas. We find that, similar to TCR α and γ variable region genes, assembly of TCR δ variable region genes exhibits properties of allelic inclusion. These findings are discussed in the context of γδ T cell development and regulation of rearrangement of TCR δ genes.


1993 ◽  
Vol 177 (2) ◽  
pp. 541-546 ◽  
Author(s):  
J H Park ◽  
R Mitnacht ◽  
N Torres-Nagel ◽  
T Hünig

The role of interleukin (IL)2 in intrathymic T cell development is highly controversial, and nothing is known about IL-2R expression on thymocytes of the T cell receptor (TCR) alpha/beta lineage undergoing TCR-driven differentiation events. We analyze here IL-2R alpha and beta mRNA expression in an in vitro system where newly generated rat CD4,8 double positive (DP) thymocytes respond to TCR ligation plus IL-2 (but not to either stimulus alone) with rapid differentiation to functional CD8 single positive T cells (Hünig, T., and R. Mitnacht. 1991. J. Exp. Med. 173:561). TCR ligation induced expression of IL-2R beta (but not alpha) chain mRNA in DP thymocytes. Addition of IL-2 then lead to functional maturation and expression of the IL-2R alpha chain. To investigate if the CD8 T cells generated via this IL-2R beta-driven pathway in vitro correspond to the bulk of CD8 T cells seeding peripheral lymphoid organs in vivo, we compared their phenotype to that of lymph node CD8 T cells. Surprisingly, analysis of CD8 cell surface expression using a novel anti-CD8 monoclonal antibody specific for the alpha/beta heterodimeric isoform, and of CD8 alpha and beta chain mRNA revealed that T cells generated by TCR ligation plus IL-2 resemble thymus-independent rather than thymus-derived CD8 cells in that they express CD8 alpha without beta chains. These findings demonstrate that TCR crosslinking induces functional IL-2R on immature DP rat thymocytes. In addition, they show that at least in vitro, CD8 alpha/alpha T cells are generated from TCR-stimulated DP thymocytes (which express the CD8 alpha/beta in the heterodimeric isoform) along an IL-2-driven pathway of T cell differentiation.


Blood ◽  
1992 ◽  
Vol 79 (11) ◽  
pp. 2965-2972 ◽  
Author(s):  
Y Kusunoki ◽  
Y Hirai ◽  
S Kyoizumi ◽  
M Akiyama

Rare T lymphocytes bearing CD3 surface antigen and T-cell receptor (TCR) alpha and beta chains, but lacking both CD4 and CD8 antigens, viz, TCR alpha beta+CD4–8- cells, appear at a frequency of 0.1% to 2% in peripheral blood TCR alpha beta+ cells of normal donors. Here we report two unusual cases, found among 100 healthy individuals studied, who showed an abnormally elevated frequency of these T cells, ie, 5% to 10% and 14% to 19%. Southern blot analyses of the TCR alpha beta+CD4–8- clones all showed the identical rearrangement patterns for each individual, demonstrating that these are derivatives of a single T cell. The same rearrangement patterns were also observed for the freshly isolated lymphocytes of TCR alpha beta+CD4-CD8- fraction, which excludes the possible bias in the processes of in vitro cloning. These TCR alpha beta+CD4–8- T cells were found to express other mature T-cell markers such as CD2, CD3, and CD5 antigens, as well as natural killer (NK) cell markers (CD11b, CD16, CD56, and CD57 antigens) for both individuals. Further, although lectin-dependent or redirected antibody- dependent cell-mediated cytotoxicities were observed for both freshly sorted lymphocytes of TCR alpha beta+CD4–8- fraction and in vitro established clones, NK-like activity was not detected.


1993 ◽  
Vol 178 (6) ◽  
pp. 2107-2113 ◽  
Author(s):  
A J da Silva ◽  
O Janssen ◽  
C E Rudd

Intracellular signaling from the T cell receptor (TCR)zeta/CD3 complex is likely to be mediated by associated protein tyrosine kinases such as p59fyn(T), ZAP-70, and the CD4:p56lck and CD8:p56lck coreceptors. The nature of the signaling cascade initiated by these kinases, their specificities, and downstream targets remain to be elucidated. The TCR-zeta/CD3:p59fyn(T) complex has previously been noted to coprecipitate a 120/130-kD doublet (p120/130). This intracellular protein of unknown identity associates directly with p59fyn(T) within the receptor complex. In this study, we have shown that this interaction with p120/130 is specifically mediated by the SH2 domain (not the fyn-SH3 domain) of p59fyn(T). Further, based on the results of in vitro kinase assays, p120/130 appears to be preferentially associated with p59fyn(T) in T cells, and not with p56lck. Antibody reprecipitation studies identified p120/130 as a previously described 130-kD substrate of pp60v-src whose function and structure is unknown. TCR-zeta/CD3 induced activation of T cells augmented the tyrosine phosphorylation of p120/130 in vivo as detected by antibody and GST:fyn-SH2 fusion proteins. p120/130 represents the first identified p59fyn(T):SH2 binding substrate in T cells, and as such is likely to play a key role in the early events of T cell activation.


2002 ◽  
Vol 196 (4) ◽  
pp. 481-492 ◽  
Author(s):  
Kristin V. Tarbell ◽  
Mark Lee ◽  
Erik Ranheim ◽  
Cheng Chi Chao ◽  
Maija Sanna ◽  
...  

Glutamic acid decarboxylase (GAD)65 is an early and important antigen in both human diabetes mellitus and the nonobese diabetic (NOD) mouse. However, the exact role of GAD65-specific T cells in diabetes pathogenesis is unclear. T cell responses to GAD65 occur early in diabetes pathogenesis, yet only one GAD65-specific T cell clone of many identified can transfer diabetes. We have generated transgenic mice on the NOD background expressing a T cell receptor (TCR)-specific for peptide epitope 286–300 (p286) of GAD65. These mice have GAD65-specific CD4+ T cells, as shown by staining with an I-Ag7(p286) tetramer reagent. Lymphocytes from these TCR transgenic mice proliferate and make interferon γ, interleukin (IL)-2, tumor necrosis factor (TNF)-α, and IL-10 when stimulated in vitro with GAD65 peptide 286–300, yet these TCR transgenic animals do not spontaneously develop diabetes, and insulitis is virtually undetectable. Furthermore, in vitro activated CD4 T cells from GAD 286 TCR transgenic mice express higher levels of CTL-associated antigen (CTLA)-4 than nontransgenic littermates. CD4+ T cells, or p286-tetramer+CD4+ Tcells, from GAD65 286–300-specific TCR transgenic mice delay diabetes induced in NOD.scid mice by diabetic NOD spleen cells. This data suggests that GAD65 peptide 286–300-specific T cells have disease protective capacity and are not pathogenic.


1992 ◽  
Vol 175 (4) ◽  
pp. 907-915 ◽  
Author(s):  
S Yoshino ◽  
L G Cleland

The effects of treatment with a monoclonal antibody (R73 mAb) against T cell receptor alpha/beta (TCR-alpha/beta) on both established adjuvant arthritis (EAA) and established collagen-induced arthritis (ECIA) in rats have been investigated. Rats were treated with R73 mAb when arthritis reached a peak. Treatment with the anti-TCR-alpha/beta mAb markedly suppressed EAA, whereas ECIA was not affected by the mAb treatment. Histologically, R73 mAb-treated rats with EAA showed mild hyperplasia of synovial tissues, sparse infiltration of inflammatory cells, and minimal erosion of cartilage, whereas arthritic rats treated with PBS and an irrelevant control mAb against Giardia had marked hyperplasia of synovium with pannus, massive inflammatory cell infiltrate, and severe destruction of cartilage and subchondral bone. R73 mAb-treated rats with ECIA exhibited pronounced formation of pannus containing many inflammatory cells and marked cartilage and subchondral damage similar to those in arthritic rats that received the control treatments. Treatment with R73 mAb depleted markedly alpha/beta+ T cells in both peripheral blood and synovial tissues of rats with EAA and ECIA. R73 mAb treatment was associated with marked reduction in arthritogen-specific delayed-type hypersensitivity responses in both EAA and ECIA. The titers of antibodies against type II collagen produced in rats with ECIA were not affected by the mAb. Thus, alpha/beta+ T cells appear to have a central role in EAA, but not in chronic ECIA.


2001 ◽  
Vol 16 (4) ◽  
pp. 423-429 ◽  
Author(s):  
Alexandre Corthay ◽  
Kutty Selva Nandakumar ◽  
Rikard Holmdahl

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