Xingxing Zang, Ph.D.

T lymphocytes play a central role in the initiation and regulation of the adaptive immune response to antigen, whether foreign or native. The outcome of T cell engagement of antigen is determined by both positive costimulation and negative coinhibition, generated mainly by the interaction between the B7 family and their receptor CD28 family. We have recently discovered the newest members of the T cell costimulatory/coinhibitory B7 family, and are using a variety of experimental approaches (gene knock-out mice, transgenic mice, monoclonal antibodies, etc) to understand how new B7 family members regulate T cell activation and tolerance. Current emphasis in the lab is placed in the following areas: 1) Functions of B7x and B7-H3 in T cell responses in vivo; 2) Cancer-associated B7x and B7-H3; 3) Roles of B7x, B7-H3, and PD-L1 in autoimmune diseases; 4) Relationship between B7x and B7-H3 and infection; 5) New members of the immunoglobulin superfamily; and 6) Translational medicine of T cell costimulation and coinhibition. Our goal is to elucidate the mechanisms by which costimulation and coinhibition regulate T cells in peripheral non-lymphoid organs, and to translate the lessons learned in these studies towards developing new therapeutic strategies for immune-mediated diseases such as cancer, autoimmune disorders, infectious diseases, and transplantation rejection.