Biochemical Evidence for the Presence of a Single CD3δ and CD3γ Chain in the Surface T Cell Receptor/CD3 Complex

Qinghua Pan, Ananta S. Gollapudi, Vibhuti P. Dave
2004 Journal of Biological Chemistry  
The T cell antigen receptor (TCR) consists of an ␣␤ heterodimer and associated invariant CD3␥, ␦, ⑀, and chains (TCR/CD3 complex). The general stoichiometry of the receptor complex, which is believed to be one molecule each of TCR␣, TCR␤, CD3␥, and CD3␦ and two molecules each of CD3⑀ and CD3, is not clearly understood. Although it has been shown that there are two chains of CD3⑀ and CD3, the stoichiometry of CD3␥ or CD3␦ chains in the surface antigen receptor complex has not been determined. In
more » ... been determined. In the present study, transgenic mice expressing an altered form of mouse CD3␦ and CD3␥ were employed to show that the surface TCR complexes contain one molecule each of CD3␦ and CD3␥. Thymocytes from wild type and CD3 chain transgenic mice on the appropriate knockout background were surface-biotinylated and immunoprecipitated using a specific antibody. The immunoprecipitates were resolved in two dimensions under nonreducing/reducing conditions to determine the stoichiometry of CD3␦ and CD3␥ in the surface antigen receptor complex. Our data clearly show the presence of one molecule each of CD3␦ and CD3␥ in the surface TCR/CD3 complex.
doi:10.1074/jbc.m406145200 pmid:15459203 fatcat:6beozjkrwnbg3i3uegwbyzm7zm