Targeting myeloid cells to increase efficacy of immunotherapy against brain tumors.

PROJECT SUMMARY The proposed research career development program seeks to investigate the mechanism by which myeloid cells in brain tumors become immunosuppressive, preventing the immune system from controlling the tumor even in the presence of immunotherapy designed to activate it. The candidate is currently a Research Fellow in the Department of Pathology of the Massachusetts General Hospital. The proposal incorporates specific technical skills that will be required for the project including training in immune biology and advanced immune assay techniques. The structured career development plan includes training and mentorship in laboratory management, scientific leadership, research communications, grant writing, and other critical career skills. These technical and career skills will be acquired under the guidance of Dr. Bradley Bernstein, who will serve as primary mentor and has a history of trainees that obtain group leader positions in academia, as well as a Research Advisory Committee of word-class scientists including Drs. Mario Suva, John Iafrate, and Nir Hacohen. Through this comprehensive program, the candidate will acquire a unique set of clinical and research skills that will enable him to transition to an independent physician scientist faculty position with a lab focused on basic mechanisms and therapeutic opportunities in brain cancer epigenetics and immunology. The research strategy will investigate immunosuppressive tumor-associated myeloid cells in brain tumors – where they come from, the epigenetic mechanism by which they become immunosuppressive, and how to potentially transform them. Transforming or selectively killing myeloid cells that express immunosuppressive programs offers great opportunity to sensitize brain tumors to immunotherapy. However, it remains unknown if these myeloid cells come from circulating monocytes or endogenous microglia, or what make them immunosuppressive, significantly hindering the design of rational clinical strategies to target these cells in brain tumors. The aims of this proposal are to: (1) Determine the origin of immunosuppressive myeloid cell states in brain tumors, (2) identify the epigenetic regulatory factors that maintain the immunosuppressive cell program, (3) discover perturbations that eliminate or transform immunosuppressive myeloid cells. Overall, these studies will provide valuable data needed to develop targeted therapies against immunosuppressive myeloid cells and increase the efficacy of immunotherapy for brain cancer patients.