Structural comparison of alpha/beta and gamma/delta T cell receptor-CD3 complexes reveals identical subunit interactions but distinct cross-linking patterns of T cell receptor chains.
Here we compare the subunit interactions within the alpha/beta and gamma/delta T cell receptor-CD3 (TcR-CD3) complexes. By using different detergent solubilization protocols, subunit interactions can be defined within such cell surface receptor complexes. It was found that in both TcR-CD3 complexes analogous subunit interactions can be defined: CD3 gamma and CD3 delta each form a stable complex with separate CD3 epsilon chains. Both the TcR gamma/delta and TcR alpha/beta form stable receptor complexes with these CD3 gamma/epsilon and CD3 delta/epsilon subunit. A zeta homodimer is present in these TcR-CD3 complexes. However, biochemical cross-linking results in a covalent bond between the CD3 gamma chain and the TcR beta chain in alpha/beta TcR-CD3 complexes and between the CD3 gamma chain and the TcR delta in gamma/delta TcR-CD3 complexes. This latter observation was independent of the type of TcR gamma/delta studied (e.g. disulfide or non-disulfide linked). These cross-linking results either indicate that the TcR beta and delta chains are each others structural homolog or that in TcR-CD3 complexes both TcR chains (alpha and beta, gamma and delta) are spatially closely associated with the CD3 gamma chain. The identical subunit interactions in the alpha/beta and gamma/delta TcR-CD3 complexes indicate no large structural differences between these receptor complexes but rather suggest a striking conservation of crucial interaction between subunits in the TcR-CD3 complexes.
Van Neerven
J
J
Department of Immunohematology and Bloodbank, University Hospital Leiden, The Netherlands.
Coligan
J E
JE
Koning
F
F
D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000737:chemistry* / Q000276:immunology; D017252:CD3 Complex; D004072:Digitonin / Q000494:pharmacology; D006801:Humans; D017830:Octoxynol; D011092:Polyethylene Glycols / Q000494:pharmacology; D011233:Precipitin Tests; D011817:Rabbits; D011948:Receptors, Antigen, T-Cell / Q000737:chemistry* / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D013601:T-Lymphocytes / Q000276:immunology
D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta; D016692:Receptors, Antigen, T-Cell, gamma-delta; D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40; D004072:Digitonin