John Leong, MD, PhD


Edith Rieva and Hyman S. Trilling Professor of Molecular Biology & Microbiology



BA, Biology, Brown University
MD, PhD, Molecular Biology, Brown University
Postdoctoral Training, Tufts University School of Medicine


Campus: Boston
Office: Arnold 511E
Laboratory: Arnold 511

Contact Information

Office Phone: 617-636-0488
Lab Phone: 617-636-0906
E-mail   Send an e-mail


Research Web Site  Lab Research Page
Recent Publications  Abstract in PubMed

Graduate Programs

Immunology, Molecular Microbiology


Research Synopsis

In causing disease, bacterial pathogens establish an infectious niche and generate damage within the mammalian host. We investigate three bacterial pathogens to understand the host-microbe interactions that promote colonization and disease, and then, during resolution of infection, mediate microbial clearance. Enterohemorrhagic Escherichia coli O157:H7 is a food-borne intestinal pathogen that that injects into intestinal epithelial cells proteins that stimulate actin polymerization directly beneath bound bacteria. We are studying the action of these proteins to understand how interactions between these bacteria and the intestinal epithelium promote colonization and disease, as well as to gain insight into fundamental mechanisms of actin assembly in mammalian cells. Streptococcus pneumoniae, an important cause of lung infection, and pathogenic spirochetes, such as the Lyme disease spirochete Borrelia burgdorferi, each can establish a localized infection but are also capable of spreading throughout the host. We investigate the microbe-host cell interactions that promote tissue invasion and systemic spread, as well as the components of the host immune response that contribute to immune protection and bacterial clearance.


Lab Members

Walter Adams, Postdoctoral Scholar Send an e-mail  Lab Research Page
Elsa Bou Ghanem, Research Associate Send an e-mail  Lab Research Page
Basma Joma, PhD Student in Immunology Send an e-mail  Lab Research Page
Nick Lee, Research Technician Send an e-mail 
Loranne Magoun, Laboratory Manager Send an e-mail  Lab Research Page
Charmaine Nganje, PREP Scholar Send an e-mail  Lab Research Page
Marcia Osburne, Senior Research Associate Send an e-mail Lab Research Page
Michael Pereira, PhD Student in Molecular Microbiology Send an e-mail  Lab Research Page
Xi Qian, Postdoctoral Scholar  Send an e-mail Lab Research Page
Sara Roggensack, PhD Student in Molecular Microbiology Send an e-mail  Lab Research Page
Beau Wager, Postdoctoral Scholar  Send an e-mail Lab Research Page

Apply to the Sackler School


The priority application deadlines are as follows:

December 1: Basic Science Division PhD Programs

February 15: Building Diversity in Biomedical Sciences

March 31: Post-Baccalaureate Research Program

May 1: Clinical & Translational Science, MS in Pharmacology & Drug Development

June 15: Online Certificate in Fundamentals of Clinical Care Research