Lalita Ramakrishnan, M.B.B.S., Ph.D.

Lalita Ramakrishnan, M.B.B.S., Ph.D.

Professor, Microbiology and Adjunct Professor, Immunology

Dr. Ramakrishnan received her M.B.B.S. in Vadodara, India in 1983 and her Ph.D. in Immunology at Tufts University, Boston in 1990. Prior to joining the University of Washington in 2001, she did a medical residency at the Tufts-New England Medical Center in Boston, an infectious diseases fellowship at the University of California San Francisco and a post doctoral fellowship at Stanford University. Her research is funded by the National Institutes of Health, and she is the recipient of the NIH Director's Pioneer Award.

Contact Info

Department of Microbiology
University of Washington  
Office K-443C, HSC, Box 357242
1959 NE Pacific Street
Seattle WA 98195
Phone: 206-616-4286
Fax: 206-616-1575

Research Areas

  • Adaptive Immune Responses
    Developmental Immunology
    Infectious Diseases
    Innate Immunity
    Molecular Immunology



Lalita Ramakrishnan

We are interested in understanding the pathogenesis of tuberculosis and the basis of vastly different susceptibilities to this disease. Tuberculosis infection results in the formation of granulomas, complex immune structures that are composed of differentiated macrophages, lymphocytes and other immune cells. However, bacteria can persist within granulomas despite the development of antigen-specific immunity. To understand the mechanistic basis of mycobacterial persistence, the mechanisms of granuloma formation and its role in tuberculosis, we have developed the zebra fish as model to study immunity to tuberculosis. Zebra fish are naturally susceptible to tuberculosis caused by Mycobacterium marinum, a close genetic relative of M. tuberculosis, the agent of human tuberculosis. We exploit the optical transparency and genetic tractability of the zebra fish to monitor the infection process in real-time and modulate it using genetically defined host and bacterial mutants. We have employed both forward and reverse genetics to understand the basis of host resistance and susceptibility to TB. Our research is shedding light on TB pathogenesis as well as fundamental mechanisms of immune cell chemotaxis, adhesion and aggregation as well as immune regulation. Findings made in the zebra fish have been borne out in human populations and are informing new strategies for intervention.

1. Adams KN, Takaki K, Connolly LE, Wiedenhoft H, Winglee K, Humbert O, Edelstein PH, Cosma CL, Ramakrishnan L.  Drug tolerance in replicating mycobacteria mediated by a macrophage-induced efflux mechanism.  Cell. 2011 Apr 1;145(1):39-53. Epub 2011 Mar 3. Erratum in: Cell. 2011 Apr 1;145(1):159.  PMID:21376383 

2. Tobin DM, Vary JC Jr, Ray JP, Walsh GS, Dunstan SJ, Bang ND, Hagge DA, Khadge S, King MC, Hawn TR, Moens CB, Ramakrishnan L. The lta4h locus modulates susceptibility to mycobacterial infection in zebra fish and humans. Cell. 2010 Mar 5;140(5):717-30. PMID:20211140

M.B.B.S., Medicine, Vadodara Medical College, India
Ph.D., Immunology, Tufts University

Graduate Students
Russell Berg,
CJ Cambier,
Morwan Osman,
Sachi Seilie,
Steven Levitte,

Postdoctoral Fellows
Rafael Hernandez,
Cressida Madigan,
Francisco Roca,
John Szumowski,
Antonio Pagan,
William Conrad,

Laboratory Staff
James Cameron,
Christine Cosma,
Tiffany Pecor,
Kevin Takaki,