Genhong Cheng, PhD

 Professor, Department of Microbiology, Immunology and Molecular Genetics, David Geffen School of Medicine at UCLA

The central goal of Dr. Cheng's laboratory is to understand the similarity and difference in host immune responses to different types of bacterial and viral infections, the balance between immune and inflammatory responses, the crosstalk between host immune and metabolic systems. In order to achieve the goals of his program, Dr. Cheng studies signal transduction and gene expression through the TNF receptor, Toll-like receptor (TLR), and Nod families during the process of innate and adaptive immune responses.  Interestingly, most members in TNF receptor, TLR and Nod families use the TRAF family proteins as their adapters for activating similar signal transduction pathways such as NF-kB, JNK, p38, ERK and PI3K. Dr. Cheng and his colleagues have recently identified several gene programs specific for antiviral or antibacterial responses. In some cases, the researchers found that host responses to bacterial infection and viral infection may even be opposite. For example, type I interferon, an essential antiviral cytokine, might play a harmful role in host defense against certain bacterial infection. Dr Cheng is also interested in understanding the mechanisms of chemoresistance and developing novel strategies to improve cancer treatment. He has recently demonstrated that the MEKK1-dependent signal transduction pathway is essential for cell apoptosis in response to microtubule or actin disruption and found that many chemotherapy agents commonly used in clinic, which suppose to kill tumor cells, can actually activate alternative cell survival pathways (such as the NF-kB-dependent up-regulation of Bcl-x and Bfl-1 genes) to protect tumor cells. Blocking the NF-kB-dependent up-regulation of Bcl-x and Bfl-1 genes can greatly reduce chemoresistance and sensitize chemotherapy-mediated apoptosis.  Dr. Cheng has established a comprehensive program using biochemical and microarray analysis, cell-based assays, as well as animal models to determine the role and the specificity of individual receptors, signaling pathways and their targeting molecules in immune and inflammatory responses to bacterial and viral infections.