Transition from TCR-beta dimer to TCR-alpha beta-expressing cells by introduction of an alpha-chain in an immature thymocyte cell line.
The molecular basis for the surface expression of TCR-beta chain in the absence of association with TCR-alpha, -gamma, or -delta chain by an immature thymocyte cell line was investigated. The TCR-beta chain expressed by this cell line was not encoded by any unique DNA sequence, nor was it inserted into the membrane via a glycosyl-phosphatidylinositol linkage. Transfection of two other beta-chains derived from mature T cell clones resulted in the surface expression of dimers of the transfected beta-chains in both cases. Immunoprecipitation of the beta-dimer-CD3 complex demonstrated that the association of the beta-dimer with the CD3 complex, especially the CD3 zeta chain, was so weak that they dissociated under the detergent conditions in which the TCR-CD3 complex of mature T cells is kept intact. Transfection of TCR-alpha chain resulted in the expression of a TCR-alpha beta-CD3 complex and the disappearance of beta-dimers. In accordance with the changes in TCR complex components, the association between TCR-alpha beta and CD3 complex became stable and the cells transduced signals more efficiently. The results demonstrate that the expression of TCR-beta as part of an incomplete TCR-CD3 complex is developmentally regulated and the expression of TCR-alpha chain results in normal configuration and function of TCR complex.
Kuwabara
I
I
Division of Molecular Genetics, Chiba University School of Medicine, Japan.
Ohno
H
H
Punt
J A
JA
Hashimoto
Y
Y
Saito
T
T
D000818:Animals; D001483:Base Sequence; D017252:CD3 Complex / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D015332:Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; D017261:Glycosylphosphatidylinositols / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D011487:Protein Conformation; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D014162:Transfection
D017252:CD3 Complex; D017931:DNA Primers; D018076:DNA, Complementary; D017261:Glycosylphosphatidylinositols; D016693:Receptors, Antigen, T-Cell, alpha-beta