Structural biology of T cell immunity
The central issue of T cell immunity is that a T cell receptor recognizes a cognate antigenic peptide presented by a MHC molecule on antigen-presenting cell surface. The interaction is aided by co-receptors CD4 and CD8 in helper T cell (class II) and cytotoxic T cell (class I), respectively. We have been working out structures of T cell receptor (TCR) and its complex with antigenic peptides bound to MHC molecule in both class I and II systems. We have also worked out the structures of co-receptors CD8 and CD4 in complex with classic or non-classic MHC molecules. We have provided the structural basis for cellular immune recognition. We have currently been interested in exploring the mechanism of T cell immunity in the host control of HIV-1 infection. To unravel how some patients’ own immune system can prevent the HIV-1 infection from developing into AIDS will provide a lesson for vaccine design. We are also working on the development aspect of T cell receptors, aiming to decode how ligands in thymus direct T cell receptor develop.