TY - JOUR
T1 - Selective association between MHC class I-restricted T cell receptors, CD8, and activated tyrosine kinases on thymocytes undergoing positive selection
AU - Carrera, A. C.
AU - Wee, S. B.
AU - Roberts, T. M.
AU - Pardoll, D. M.
PY - 1992
Y1 - 1992
N2 - Developing T cells undergo distinct selection processes that determine the TCR repertoire. Positive selection involves the differentiation of immature thymocytes capable of recognizing antigens complexed with self-MHC molecules to mature T cells. Besides the central role of TCR engagement by MHC in triggering selection; the interaction of CD8 and CD4 with MHC class I and class II, respectively; is thought to be important in regulating the selection process. To study potential mechanisms involved in positive selection of CD8+ cells, we have analyzed mice expressing a unique transgenic TCR. The transgenic receptor recognizes the HY male Ag in the context of the MHC class I molecule, H2-Db. We describe that CD8 and the TCR are selectively associated in thymocytes of mice expressing the restricting MHC, but not in thymocytes of mice expressing a nonrestricting MHC, pp56(lck) and pp59(fyn), the tyrosine kinases associated with CD8 and TCR, respectively, were found to be present in this complex in an activated form. No comparable TCR-CD4 complex formation was found in thymuses undergoing positive selection to CD8+ cells. The formation of a multimolecular complex between CD8 and TCR, in which pp56(lck) and pp59(fyn) are activated, may initiate specific signaling programs involved in the maturation of CD8+ cells.
AB - Developing T cells undergo distinct selection processes that determine the TCR repertoire. Positive selection involves the differentiation of immature thymocytes capable of recognizing antigens complexed with self-MHC molecules to mature T cells. Besides the central role of TCR engagement by MHC in triggering selection; the interaction of CD8 and CD4 with MHC class I and class II, respectively; is thought to be important in regulating the selection process. To study potential mechanisms involved in positive selection of CD8+ cells, we have analyzed mice expressing a unique transgenic TCR. The transgenic receptor recognizes the HY male Ag in the context of the MHC class I molecule, H2-Db. We describe that CD8 and the TCR are selectively associated in thymocytes of mice expressing the restricting MHC, but not in thymocytes of mice expressing a nonrestricting MHC, pp56(lck) and pp59(fyn), the tyrosine kinases associated with CD8 and TCR, respectively, were found to be present in this complex in an activated form. No comparable TCR-CD4 complex formation was found in thymuses undergoing positive selection to CD8+ cells. The formation of a multimolecular complex between CD8 and TCR, in which pp56(lck) and pp59(fyn) are activated, may initiate specific signaling programs involved in the maturation of CD8+ cells.
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M3 - Article
C2 - 1431093
AN - SCOPUS:0026467243
SN - 0022-1767
VL - 149
SP - 3142
EP - 3149
JO - Journal of Immunology
JF - Journal of Immunology
IS - 10
ER -