Si-Yi Chen Professor Department of Molecular Microbiology and Immunology Keck School of Medicine USC / Norris Comprehensive Cancer Center

Education:
M.D. 1983 Medicine - Second Military Medical Univ., Shanghai, China
Ph.D. 1988 Molecular Virology - Chinese Academy of Medical Science of China, Beijing

Postdoctoral Research Fellowship:
1989 - 1992 University of Alabama at Birmingham Postdoctoral
1992 - 1994 Dana Farber Cancer Institute, Harvard Medical School Postdoctoral

Started at USC: 2007

Research Topics: Immunology gene therapy

Research Description

• Regulation of innate and adaptive immunity. One of our research interests is to identify key negative regulators in control of antigen presentation by dendritic cells (DCs) and mechanistically investigate the roles of these regulators in control of innate and adaptive immunity. Our recent studies demonstrated that the negative regulator of cytokine signaling, suppressor of cytokine signaling 1 (SOCS1), plays a critical role in negative regulation of antigen presentation by DCs. Our studies further illustrate the importance of inhibiting these negative regulators for breaking self tolerance and inducing more effective antitumor immunity. We are also investigating the role of negative regulators of Toll-like receptors (TLRs)-mediated signaling in regulation of immunity and tolerance. Furthermore, we are exploring the role of these negative regulators in the differentiation and function of embryonic and tissue-specific stem cells.
• Immune and gene therapy against cancer. A main research interest of my laboratory is to create innovative technologies and approaches for the development of immunotherapies against cancer. Our ongoing studies focus on the development of tumor vaccines by combining the inhibition of SOCS1 or other antigen presentation attenuators (APA) and TLR stimulation. A tumor vaccine that co-expresses three components, an SOCS1-siRNA, tumor antigens, and a TLR agonist is being developed and tested in mouse models and primates, and is now seeking regulatory approval for clinical trials in cancer patients.
• Immune and gene therapy against HIV infection. Another research interest is to develop novel approaches for the prevention and treatment of HIV infection. For example, we developed an “Intrabody” (intracellular antibody) technology by designing and engineering antibodies for their expression inside a cell to intracellularly inactivate target proteins. We also developed an “Intrakine” approach to intracellularly inactivate the HIV co-receptors in T cells, leading to the blockade of HIV infection. These novel technologies provide powerful approaches for basic researches as well as for potentially therapeutic applications against HIV infection. In addition, we are currently working on the development of novel HIV vaccines by combining the inhibition of antigen presentation attenuators and promotion of antigen presentation of modified HIV antigens.