Linking the behavior of individual host cells to their transcriptional signatures in tuberculosis Tuberculosis is an infectious disease of enormous proportions with no effective vaccine and the emergence of extensively drug resistant strains. Major holes in our understanding of its pathogenesis present roadblocks to new therapeutic and preventive interventions. My laboratory has developed zebrafish infection by Mycobacterium marinum as a powerful surrogate model for exploring tuberculosis pathogenesis. The transparency of zebrafish larvae allows real-time examination of cellular movements and behaviors in unprecedented detail. We have made surprising discoveries about central aspects of tuberculosis pathogenesis, in particular regarding the organized aggregate of immune cells called the granuloma. This hallmark structure was long thought to be a key host protective element. However, detailed kinetic monitoring of granuloma formation revealed that granulomas are converted by mycobacteria into tools for expansion and dissemination. Phagocytes are recruited to the nascent granuloma, where they phagocytose the contents of dying infected cells. A subset of newly infected cells leaves the granuloma to disseminate infection to new foci. Here I propose to systematically link the behaviors of immune cells to their expression profiles to gain insight into the molecular blueprint of the host processes that promote pathogenesis. I propose to use laser capture microdissection techniques combined with multiple fluorescent bacterial and host reporters to isolate cells engaged in distinct movements, i.e. migrating towards newly infecting bacteria, returning to tissues from peripheral infection sites, migrating to forming granulomas, and departing granulomas. The gene expression profiles of these cells will then be deciphered using single cell gene expression techniques. We will then perturb these molecular signatures with genetic techniques to determine their impact on infe

National Institute of Health (NIH)
National Institute of Mental Health (NIMH)
NIH Director’s Pioneer Award (NDPA) (DP1)
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Special Emphasis Panel (ZGM1-NDPA-B (01))
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Beckel-Mitchener, Andrea C
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University of Washington
Schools of Medicine
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Cambier, C J; Takaki, Kevin K; Larson, Ryan P et al. (2014) Mycobacteria manipulate macrophage recruitment through coordinated use of membrane lipids. Nature 505:218-22
Ramakrishnan, Lalita (2013) Looking within the zebrafish to understand the tuberculous granuloma. Adv Exp Med Biol 783:251-66
Tobin, David M; Roca, Francisco J; Ray, John P et al. (2013) An enzyme that inactivates the inflammatory mediator leukotriene b4 restricts mycobacterial infection. PLoS One 8:e67828
Takaki, Kevin; Davis, J Muse; Winglee, Kathryn et al. (2013) Evaluation of the pathogenesis and treatment of Mycobacterium marinum infection in zebrafish. Nat Protoc 8:1114-24
Szumowski, John D; Adams, Kristin N; Edelstein, Paul H et al. (2013) Antimicrobial efflux pumps and Mycobacterium tuberculosis drug tolerance: evolutionary considerations. Curr Top Microbiol Immunol 374:81-108
Tobin, David M; Ramakrishnan, Lalita (2013) TB: the Yin and Yang of lipid mediators. Curr Opin Pharmacol 13:641-5
Berg, Russell D; Ramakrishnan, Lalita (2012) Insights into tuberculosis from the zebrafish model. Trends Mol Med 18:689-90
Ramakrishnan, Lalita (2012) Revisiting the role of the granuloma in tuberculosis. Nat Rev Immunol 12:352-66
Takaki, Kevin; Cosma, Christine L; Troll, Mark A et al. (2012) An in vivo platform for rapid high-throughput antitubercular drug discovery. Cell Rep 2:175-84
Tobin, David M; Roca, Francisco J; Oh, Sungwhan F et al. (2012) Host genotype-specific therapies can optimize the inflammatory response to mycobacterial infections. Cell 148:434-46

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