Consequences of intrathymic TCR engagement by partial agonist on selection events and peripheral T cell activation program

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Item Type:	Article
Title:	Consequences of intrathymic TCR engagement by partial agonist on selection events and peripheral T cell activation program
Creators Name:	Auphan, N., Simon, A.K., Asnagli, H., Phillips, R.J., Rincon, M., Ghosh, S., Flavell, R.A. and Schmitt-Verhulst, A.M.
Abstract:	Functions elicited from mature T cells depend on the nature of the Ag. Thus, an agonist induces a larger set of cytokine responses than a partial agonist. Additionally, Ags present in the thymus influence both the selection of TCRs generated by gene rearrangement and the potential functional program of developing thymocytes. This can be approached by analysing the development of T cells in mice expressing the same transgenic TCR (tgTCR) under different conditions of intrathymic selection. H-2Kbm8 was found to act as a partial agonist for CD8+ T cells expressing a tgTCR specific for the H-2Kb alloantigen. Intrathymic exposure to full or to partial agonist affected the development of thymocytes at different stages, consistent with the respective CD8-independent and -dependent characteristic of the tgTCR/Ag interaction. The presence of the partial agonist led to the accumulation of a major population of thymocytes (tgTCR(high) CD4- CD8(low)) originating from TCR engagement at the immature single-positive CD8(low) stage as evidenced by: 1) results from reaggregated thymic organ culture in the presence of H-2(k/bm8) thymic stromal cells; 2) the absence of CD4+ thymocytes, the development of which depends on rearrangements of endogenous TCR alpha genes; and 3) the identification of the CD8(low) thymocytes as cycling cells. Peripheral CD8(low) T cells selected in an H-2(k/bm8) thymus expressed a partial functional program in response to H-2Kb, akin to the response of CD8(high) T cells to a partial agonist. The analysis of the molecular bases for partial reactivity revealed a correlation with inefficient AP-1, but efficient NF-kappaB transactivation.
Keywords:	CD8 Antigens, Cell Differentiation, Cell Movement, H-2 Antigens, Hematopoietic Stem Cells, Lymphocyte Activation, Inbred C57BL Mice, Inbred CBA Mice, Transgenic Mice, T-Cell Antigen Receptors, T-Lymphocytes, Transcription Factor AP-1, Animals, Mice
Source:	Journal of Immunology
ISSN:	0022-1767
Publisher:	American Association of Immunologists
Volume:	160
Number:	10
Page Range:	4810-21
Date:	15 May 1998
Official Publication:	https://doi.org/10.4049/jimmunol.160.10.4810
PubMed:	View item in PubMed

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