Involvement of p21ras distinguishes positive and negative selection in thymocytes.
نویسندگان
چکیده
منابع مشابه
Positive and negative selection of thymocytes depends on Lck interaction with the CD4 and CD8 coreceptors.
Considerable evidence supports a role for the Src family protein tyrosine kinase Lck in regulating multiple aspects of thymocyte development. In this report, we establish that early events in T lymphopoiesis are restored to Lck-deficient mice by provision of a transgene encoding a version of Lck that cannot interact with the coreceptors CD4 and CD8. In addition, we demonstrate that later events...
متن کاملOrigin of the sharp boundary that discriminates positive and negative selection of thymocytes.
T lymphocytes play a key role in adaptive immunity and are activated by interactions of their T cell receptors (TCR) with peptides (p) derived from antigenic proteins bound to MHC gene products. The repertoire of T lymphocytes available in peripheral organs is tuned in the thymus. Immature T lymphocytes (thymocytes) interact with diverse endogenous peptides bound to MHC in the thymus. TCR expre...
متن کاملSelective role of NFATc3 in positive selection of thymocytes.
The four Ca(2+)-dependent NFATc proteins are both signal transducers and transcription factors that reside in the cytoplasm until dephosphorylation by calcineurin. Dephosphorylation exposes nuclear import sequences and sends NFATc proteins into the nucleus where they assemble with nuclear partners into NFAT transcription complexes. Recent genetic studies have indicated that calcineurin-NFAT sig...
متن کاملDouble-positive thymocytes resistant to antigen-MHC-induced negative selection lack active caspase.
Thymocytes bearing autoreactive TCR are eliminated from the organism by a process termed negative selection. The molecular basis of this deletion has been recently shown to be a consequence of TCR-triggered activation of a caspase by certain peptide-MHC ligands in the immature CD4+CD8+ double-positive (DP) thymocyte subpopulation. Of note, the numerically minor TCRhigh DP thymocyte subpopulatio...
متن کاملIntermediate steps in positive selection: differentiation of CD4+8int TCRint thymocytes into CD4-8+TCRhi thymocytes
The differentiation potential of putative intermediates between CD4+8+ thymocytes and mature T cells has been examined. Such intermediate populations were sorted, in parallel with CD4+8+ thymocytes, from three types of C57BL/6 mice: major histocompatibility complex (MHC) class II-deficient mice, mice transgenic for an alpha/beta T cell receptor (TCR) restricted by class I MHC and normal mice. T...
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ژورنال
عنوان ژورنال: The EMBO Journal
سال: 1995
ISSN: 0261-4189
DOI: 10.1002/j.1460-2075.1995.tb07001.x