People

Eric G. Pamer, M.D. Eric G. Pamer received his M.D. from Case Western Reserve University Medical School and completed clinical training in internal medicine and infectious diseases at University of California San Diego (UCSD) Medical Center. He was a postdoctoral fellow with Charles E. Davis at UCSD, with Maggie So at Scripps Research Institute, and with Michael Bevan at the University of Washington before he moved to Yale University. In 2000, he moved his laboratory to Memorial Sloan-Kettering Cancer Center (MSKCC) in New York, where he has been chief of infectious diseases and, more recently, head of the Division of Subspecialty Medicine. Pamer initially studied T cell responses to Listeria monocytogenes infection, demonstrating the efficiency of antigen presentation and the impact of antigen presentation and inflammation on T cell response magnitudes. Upon moving to MSKCC, he extended his research to inflammatory monocytes. In a series of studies, Pamer demonstrated that inflammatory monocytes differentiate into TNF and iNOS producing dendritic cells in response to L. monocytogenes. He demonstrated that CCR2 chemokine receptors drive monocyte emigration from bone marrow but not, as previously assumed, immigration into infected tissues. Pamer showed that bone marrow mesenchymal cells have hair-trigger responses to TLR-ligands and produce CCL2, driving monocytes into the bloodstream. He demonstrated that monocytes transport fungal spores and Mycobacterium tuberculosis from the lung to mediastinal lymph nodes and, during Mtb infection, transfer antigen to dendritic cells to prime CD4 T cells in lymph nodes. Because infections caused by highly antibiotic-resistant pathogens are a growing problem, Pamer has focused on Vancomycin-resistant Enterococcus (VRE) and Clostridium difficile infections and the defensive roles of mucosal immunity and the microbiota. A seminal study demonstrating that antibiotics reduce intestinal immune defenses and facilitate VRE infection was followed by discovery of commensal bacterial species that enhance antimicrobial defenses. Pamer focused on patients undergoing bone marrow transplantation and discovered dramatic microbiota diversity losses following transplantation. He also demonstrated that diversity loss is associated with increased mortality. Pamer’s work has led to the first randomized clinical trial to determine the feasibility and benefit of reintroducing a patient’s own intestinal microbiota following bone marrow transplantation.