scholarly journals Normal T lymphocytes can express two different T cell receptor beta chains: implications for the mechanism of allelic exclusion.

1995 ◽  
Vol 181 (4) ◽  
pp. 1587-1591 ◽  
Author(s):  
E Padovan ◽  
C Giachino ◽  
M Cella ◽  
S Valitutti ◽  
O Acuto ◽  
...  

We have examined the extent of allelic exclusion at the T cell receptor (TCR) beta locus using monoclonal antibodies specific for V beta products. A small proportion (approximately 1%) of human peripheral blood T cells express two V beta as determined by flow cytometric analysis, isolation of representative clones, and sequencing of the corresponding V beta chains. Dual beta T cells are present in both the CD45R0+ and CD45R0- subset. These results indicate that dual beta expression is compatible with both central and peripheral selection. They also suggest that the substantial degree of TCR beta allelic exclusion is dependent only on asynchronous rearrangements at the beta locus, whereas the role of the pre-TCR is limited to signaling the presence of at least one functional beta protein.

1993 ◽  
Vol 178 (5) ◽  
pp. 1807-1811 ◽  
Author(s):  
W R Heath ◽  
J F Miller

CD8+ T cells taken directly from mice expressing a Kb-specific T cell receptor (TCR) transgene expressed the transgenic TCR in a bimodal profile as detected by flow cytometric analysis using a clonotype-specific monoclonal antibody. Those cells expressing the lower density of the transgenic TCR expressed the transgenic beta chain and two different alpha chains on their surface. One alpha chain was the product of the alpha transgene, whereas the other was derived by endogenous rearrangement. This report provides the first demonstration that T cells isolated directly from mice may express two different TCR clonotypes on their surface. The potential consequences of this finding for studies using TCR transgenic mice and for the induction of autoimmunity are discussed.


1991 ◽  
Vol 174 (4) ◽  
pp. 815-819 ◽  
Author(s):  
J P van Meerwijk ◽  
P Romagnoli ◽  
A Iglesias ◽  
H Bluethmann ◽  
M Steinmetz

In mice double transgenic for functionally rearranged T cell receptor (TCR) V beta 2 and V beta 8.2 genes we found that most T lymphocytes express both TCR beta chains simultaneously. These T cells show no abnormality in thymic selection in vivo and their TCRs are capable of transducing activation signals in vitro. These results indicate that multispecific T cells may appear in the periphery if allelic exclusion of TCR beta genes is not established at the level of gene rearrangement.


2021 ◽  
Vol 22 (5) ◽  
pp. 2713
Author(s):  
Sun-Hye Shin ◽  
Kyung-Ah Cho ◽  
Hee-Soo Yoon ◽  
So-Yeon Kim ◽  
Hee-Yeon Kim ◽  
...  

(1) Background: six mammalian ceramide synthases (CerS1–6) determine the acyl chain length of sphingolipids (SLs). Although ceramide levels are increased in murine allergic asthma models and in asthmatic patients, the precise role of SLs with specific chain lengths is still unclear. The role of CerS2, which mainly synthesizes C22–C24 ceramides, was investigated in immune responses elicited by airway inflammation using CerS2 null mice. (2) Methods: asthma was induced in wild type (WT) and CerS2 null mice with ovalbumin (OVA), and inflammatory cytokines and CD4 (cluster of differentiation 4)+ T helper (Th) cell profiles were analyzed. We also compared the functional capacity of CD4+ T cells isolated from WT and CerS2 null mice. (3) Results: CerS2 null mice exhibited milder symptoms and lower Th2 responses than WT mice after OVA exposure. CerS2 null CD4+ T cells showed impaired Th2 and increased Th17 responses with concomitant higher T cell receptor (TCR) signal strength after TCR stimulation. Notably, increased Th17 responses of CerS2 null CD4+ T cells appeared only in TCR-mediated, but not in TCR-independent, treatment. (4) Conclusions: altered Th2/Th17 immune response with higher TCR signal strength was observed in CerS2 null CD4+ T cells upon TCR stimulation. CerS2 and very-long chain SLs may be therapeutic targets for Th2-related diseases such as asthma.


2001 ◽  
Vol 194 (10) ◽  
pp. 1473-1483 ◽  
Author(s):  
Isabel Ferrero ◽  
Anne Wilson ◽  
Friedrich Beermann ◽  
Werner Held ◽  
H. Robson MacDonald

A particular feature of γδ T cell biology is that cells expressing T cell receptor (TCR) using specific Vγ/Vδ segments are localized in distinct epithelial sites, e.g., in mouse epidermis nearly all γδ T cells express Vγ3/Vδ1. These cells, referred to as dendritic epidermal T cells (DETC) originate from fetal Vγ3+ thymocytes. The role of γδ TCR specificity in DETC's migration/localization to the skin has remained controversial. To address this issue we have generated transgenic (Tg) mice expressing a TCR δ chain (Vδ6.3-Dδ1-Dδ2-Jδ1-Cδ), which can pair with Vγ3 in fetal thymocytes but is not normally expressed by DETC. In wild-type (wt) Vδ6.3Tg mice DETC were present and virtually all of them express Vδ6.3. However, DETC were absent in TCR-δ−/− Vδ6.3Tg mice, despite the fact that Vδ6.3Tg γδ T cells were present in normal numbers in other lymphoid and nonlymphoid tissues. In wt Vδ6.3Tg mice, a high proportion of in-frame Vδ1 transcripts were found in DETC, suggesting that the expression of an endogenous TCR-δ (most probably Vδ1) was required for the development of Vδ6.3+ epidermal γδ T cells. Collectively our data demonstrate that TCR specificity is essential for the development of γδ T cells in the epidermis. Moreover, they show that the TCR-δ locus is not allelically excluded.


1994 ◽  
Vol 102 (6) ◽  
pp. 856-860 ◽  
Author(s):  
Miroslaw Kuchnio ◽  
Edward A. Sausville ◽  
Elaine S. Jaffe ◽  
Timothy Greiner ◽  
Francine M. Foss ◽  
...  

1996 ◽  
Vol 183 (3) ◽  
pp. 1277-1282 ◽  
Author(s):  
T Ohteki ◽  
H R MacDonald

The liver of C57BL/6 mice contains a major subset of CD4+8- and CD4-8- T cell receptor (TCR)-alpha/beta+ cells expressing the polymorphic natural killer NK1.1 surface marker. Liver NK1.1+TCR-alpha/beta+ (NK1+ T) cells require interaction with beta2-microglobulin-associated, major histocompatibility complex I-like molecules on hematopoietic cells for their development and have a TCR repertoire that is highly skewed to Vbeta8.2, Vbeta7, and Vbeta2. We show here that congenic C57BL/6.Vbeta(a) mice, which lack Vbeta8- expressing T cells owing to a genomic deletion at the Vbeta locus, maintain normal levels of liver NK1+ T cells owing to a dramatic increase in the proportion of cells expressing Vbeta7 and Vbeta2 (but not other Vbetas). Moreover, in C57BL/6 congenic TCR-V Vbeta3 and -Vbeta8.1 transgenic mice (which in theory should not express other Vbeta, owing to allelic exclusion at the TCR-beta locus), endogenous TCR-Vbeta8.2, Vbeta7, and Vbeta2 (but not other Vbetas) are frequently expressed on liver NK1+T cells but absent on lymph node T cells. Finally, when endogenous V beta expression is prevented in TCR-Vbeta3 and Vbeta8.1 transgenic mice (by introduction of a null allele at the C beta locus), the development of liver NK1+T cells is totally abrogated. Collectively, our data indicate that liver NK1+T cells have a stringent requirement for expression of TCR-Vbeta8.2, Vbeta7, or Vbeta2 for their development.


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