All intracellular pathogens possess specialized strategies for invading their host cell, evading its defenses, and multiplying at the expense of its metabolism. The long term goal of the research described in this proposal is to understand the molecular basis of these events in a specific host-parasite system. To do this an extensive molecular genetic analysis has been undertaken of a facultative bacterial pathogen. Legionella pneumophila, the causative agent of legionnaire's disease and related respiratory ailments. This organism invades human macrophages and monocytes, evades their microbicidal systems, and grows exponentially within a specialized vacuole. These events are also observed with other intracellular pathogens. This system is ideally suited to molecular genetic analysis because L. pneumophila can be grown on bacterial culture media but grows exclusively intracellularly in tissue culture conditions. The products of genes required for monocyte killing (vir genes) will be identified. In some cases the nucleotide sequence of the vir genes will be determined. The structural gene for the major extracellular protein, a metalloprotease of broad specificity, (mep) will be sequenced and the regulation of mep expression will be studied using lac gene fusions. The conditions inside the monocytes during L. pneumophila infection will be probed with lac gene fusions to L. pneumophila """"""""indicator genes"""""""" that are regulated by a variety of factors including: amino acid availability, oxidative damage, metabolic stress, iron availability, and osmolarity. Finally genes that are induced or repressed during monocyte infection will be identified by comparing the activities of lac fusions during growth in bacteriologic media versus growth in monocytes.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI023549-08
Application #
3135851
Study Section
Bacteriology and Mycology Subcommittee 2 (BM)
Project Start
1986-06-01
Project End
1994-05-31
Budget Start
1993-06-01
Budget End
1994-05-31
Support Year
8
Fiscal Year
1993
Total Cost
Indirect Cost
Name
Columbia University (N.Y.)
Department
Type
Schools of Medicine
DUNS #
064931884
City
New York
State
NY
Country
United States
Zip Code
10027
Shi, Xingqi; Halder, Partho; Yavuz, Halenur et al. (2016) Direct targeting of membrane fusion by SNARE mimicry: Convergent evolution of Legionella effectors. Proc Natl Acad Sci U S A 113:8807-12
Burstein, David; Amaro, Francisco; Zusman, Tal et al. (2016) Genomic analysis of 38 Legionella species identifies large and diverse effector repertoires. Nat Genet 48:167-75
Amaro, Francisco; Wang, Wen; Gilbert, Jack A et al. (2015) Diverse protist grazers select for virulence-related traits in Legionella. ISME J 9:1607-18
Czy?, Daniel M; Potluri, Lakshmi-Prasad; Jain-Gupta, Neeta et al. (2014) Host-directed antimicrobial drugs with broad-spectrum efficacy against intracellular bacterial pathogens. MBio 5:e01534-14
Trigui, Hana; Dudyk, Paulina; Sum, Janet et al. (2013) Analysis of the transcriptome of Legionella pneumophila hfq mutant reveals a new mobile genetic element. Microbiology 159:1649-60
Faucher, Sebastien P; Shuman, Howard A (2013) Methods to study legionella transcriptome in vitro and in vivo. Methods Mol Biol 954:567-82
Amaro, Francisco; Gilbert, Jack A; Owens, Sarah et al. (2012) Whole-genome sequence of the human pathogen Legionella pneumophila serogroup 12 strain 570-CO-H. J Bacteriol 194:1613-4
Abdul-Sater, Ali A; Grajkowski, Andrzej; Erdjument-Bromage, Hediye et al. (2012) The overlapping host responses to bacterial cyclic dinucleotides. Microbes Infect 14:188-97
Franco, Irina Saraiva; Shohdy, Nadim; Shuman, Howard A (2012) The Legionella pneumophila effector VipA is an actin nucleator that alters host cell organelle trafficking. PLoS Pathog 8:e1002546
Levi, Assaf; Folcher, Marc; Jenal, Urs et al. (2011) Cyclic diguanylate signaling proteins control intracellular growth of Legionella pneumophila. MBio 2:e00316-10

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