Research

Bobby Cherayil, MD
Associate Professor of Pediatrics

Phone: 617-726-4170
Fax: 617-726-4172
Email: cherayil@helix.mgh.harvard.ed

Curriculum Vita

Fellow: Ying Fu, PhD, MD

Research in my laboratory is broadly directed at elucidating the molecular details of mammalian innate immunity, particularly in the gastrointestinal tract. We use a combination of in vitro and in vivo approaches to analyze the host factors that influence the response to infection with Salmonella typhimurium, an important agent of acute gastroenteritis in humans. In one series of experiments, we are attempting to elucidate the effects of altered iron metabolism on macrophage function in salmonellosis. In collaboration with Dr. Marianne Wessling-Resnick’s group at the Harvard School of Public Health, we have shown that changes in expression of the iron transporter ferroportin have a significant impact on the intracellular survival and growth of Salmonella. These studies have also revealed a novel role for intracellular iron in the regulation of inflammatory cytokine biosynthesis at the level of mRNA translation. Our findings have important implications for the understanding of host-pathogen interactions in conditions such as hemochromatosis and also suggest that modulation of intracellular iron levels may represent a novel approach to controlling the inflammatory response.

A second series of experiments is directed at clarifying the role of the immunoregultory enzyme indoleamine 2,3-dioxygenase (IDO) in intestinal immunity. In collaboration with Dr. Allan Walker’s laboratory, we showed that the expression of IDO in the gut is developmentally regulated in response to signals from the commensal microflora and interferon gamma. We have also found, in collaboration with Dr. Hai Ning Shi, that lack of IDO alters the intestinal inflammatory response to infection with enteric pathogens such as Salmonella and Citrobacter rodentium. We are currently attempting to clarify the mechanisms that regulate IDO expression in the gut and determine how exactly IDO influences intestinal inflammation.

In addition to my laboratory research, I have been actively involved in teaching immunology to medical students. Every year for the last 6 years, I have been a tutor in HST175, a clinically-oriented, introductory course in cellular and molecular immunology offered to first year medical students, as well as some graduate students, enrolled in the Harvard-MIT Health Science and Technology program. As a tutor in this course, I lead a group of about 15 students in patient-based discussions of basic issues in immunology, a format that allows me to make effective use of both my clinical and laboratory experience.