Currently we are working on two newly identified genes:

Th-POK (T-helper-inducing POZ/Kruppel factor): T lymphocytes, further divided into two major subpopulations, CD4 helper and CD8 cytotoxic T cells, play a crucial role in control microbial infections and cancer development. Th-POK is a transcriptional factor, which we cloned from HD (CD4 helper deficiency) mutant mouse line. Th-POK functions as a master gene in determining the CD4 vs. CD8 T cell lineage choice. A point mutation in Th-POK gene results in all mature T cells becoming CD8 cells, while over-expression of this factor leads totally lack of CD8 T cells. We are looking for the up-stream regulator(s) and down-stream target(s) of Th-POK. In addition, aberrant expression of Th-POK causes lymphoma. We are studying the underlying mechanisms towards tumor genesis.

CIIEM (MHC Class II Expression Modifier): Antigen presenting cells (APC) capture, process, and present non-self antigens (from microorganisms or tumor cells) to T lymphocytes to initiate a specific immune response. MHC Class II proteins are expressed on cell surface of the professional APC (B cells, dendritic cells, and macrophages). Human T cells also express MHC Class II products and present antigens. In many cases, T cells can present self-antigens and are implicated in autoimmune diseases. Using bioinformatics, a putative novel gene CIIEM, was identified. We hypothesize that CIIEM can inhibit the expression of MHC Class II genes in mouse T cells. Cloning the full length of CIIEM cDNA and investigating its biological function are in progress.

Xiao He, MD, PhD