查看文章

The antigen receptor on human T lymphocytes consists of two variable immunoglobulin-like glycoproteins, α and β, which occur in association with three invariable T3 membrane proteins^1–3. In humans two of these proteins, T3-γ and T3-δ, are glycoproteins of relative molecular mass (M_r) 25,000 (25K) and 20,000 (20K), respectively, while the third, T3-ε, is a 20K non-glycosylated protein^4–6. On the surface of murine T cells, a non-glycosylated protein dimer composed of 17K subunits (T3-ζ) is found associated with the T-cell receptor α and β chains and the three T3-like polypeptide chains^7,8. It is generally accepted that major histocompatibility complex-restricted antigen recognition is a function of the α–β heterodimer. This has led to the postulation that the proteins of the T3 complex are involved in the signal transduction that immediately follows antigen recognition via the antigen receptor⁹. Events believed to be …