Disulfide‐linked surface molecules of monoclonal antigen‐specific suppressor T cells: evidence for T cell receptor structures

摘要

AbstractBy two‐dimensional polyacrylamide gel electrophoresis analysis under nonreducing/reducing conditions, five proteins with interchain disulfide bridges are revealed on the surface of the suppressor T cell lymphoma line LH8‐105 obtained by radiation leukemia virus‐induced transformation of hen egg‐white lysozyme‐specific suppressor T lymphocytes. Two disulfide‐linked surface proteins expressed by LH8‐105 cells have been positively identified by immunoprecipitation with specific antisera. The major labeled membrane protein of LH8‐105 cells is the murine leukemiavirus envglycoprotein gp70. The second disulfide‐linked molecule identified on LH8‐105 cells has a molecular mass of 84 kDa under nonreducing conditions and 42 kDa after reduction, and is immunoprecipitated by an antiserum which recognizes the T cell receptor for antigen. A disulfide‐linked molecule of a similar molecular mass is also immunoprecipitated from surface‐labeled LH8‐105 cells by a rabbit antiserum directed against a synthetic peptide predicted from the nucleotide sequence of a cDNA clone encoding the β chain constant region of a helper T cell hybridoma. Therefore, a dimeric structure comparable to the T cell receptor expressed by cytotoxic and helper T cells is present on the cell surface of these monoclonal antigens