The microbiota as instructor and arbiter of immune responses in health and disease

Wednesday, February 22, 2017 | 3:00 to 4:00 p.m. ET

Dan R. Littman, M.D., Ph.D.

Investigator, Howard Hughes Medical Institute

Kimmel Professor of Molecular Immunology, Kimmel Professor of Molecular Immunology

NYU School of Medicine

Website

Summary

Dr. Littman’s laboratory applies molecular and genetics tools to study how T lymphocytes develop and participate in inflammation and how HIV interacts with the host innate immune system. Dr. Littman isolated the genes for the CD4 and CD8 co-receptors and determined how their expression is regulated and their signaling influences selection of helper and cytotoxic cells. His group discovered that the nuclear receptor RORt regulates differentiation of Th17 cells and lymphoid tissue inducer cells and that it can be targeted for autoimmune disease therapy. He and his colleagues identified a commensal gut bacterium that selectively induces Th17 cells and promotes autoimmunity in mice, which may be relevant for human diseases, e.g. rheumatoid arthritis, thought to be influenced by imbalanced microbiota. Dr. Littman’s group also characterized CD4 and CCR5 as receptors for HIV and showed how HIV evades host innate responses by failing to replicate in dendritic cells. His laboratory’s current focus is on elucidating the mechanisms that promote immune system homeostasis at mucosal surfaces and on characterizing the role of the microbiota in these processes.