Francisella tularensis is a highly infectious gram-negative coccobacillus that causes the zoonosis tularemia and is a Category A agent. The need for understanding the molecular basis for F. tularensis disease in order to combat possible threats is evident. A hallmark of tularemia is the ability of the bacterium to grow in mammalian hosts before the onset of a protective cell-mediated immune response. Mammalian hosts are endowed with numerous antimicrobial effector functions. Accordingly, F. tularensis has evolved mechanisms to subvert host defenses. It is very striking that this small bacterium can infect its host via a variety of different infection routes, each of which involves a different host tissue site with a vastly different microenvironment. Given that F. tularensis is so successful at infecting its host via multiple tissue sites, our hypothesis is that in addition to a core set of genes that are needed for general survival and growth in vivo, F. tularensis possess additional genes that are required in specific tissues or microniches. Thus, our overarching goal is to identify novel core and tissue-specific virulence factors in F. tularensis. In the first aim, we will identify tissue-specific (e.g. lung-, spleen, and skin-specific) F. tularensis virulence factors using our well-established microarray-based negative selection methodology following intranasal, intraperitoneal and intradermal routes of inoculation. In the second and third aims, we will validate the tissue-specificity of novel virulence factors and characterize the molecular mechanisms in our mouse models of infection and in vitro in tissue culture assays. This project is synergistic with the other Francisella project in the Program in that it will allow us to directly compare the results of genetic and proteomic analyses obtained by Dr. Marcus Horwitz's laboratory utilizing F. tularensis subsp. tularensis, the LVS and F. novicida with our in vivo negative selection results. Since we will be using the same transposon mutant library for our in vivo and in vitro assays, followed by our very rapid microarray-based detection method, we will identify novel Francisella factors that interact with host proteins in an extremely efficient manner.
There currently is not useful vaccine to prevent Francisella disease. We propose that F. tularensis, through the use of specific virulence factors, is tailoring the host innate immune responses in the infected tissues (e.g., lung, skin and spleen) to its advantage and that a better understanding of these molecular mechanisms will lead to the rational design of novel therapeutics that may be effective against other intracellular pathogens.
|Torres, Rodrigo; Lan, Benson; Latif, Yama et al. (2014) Structural snapshots along the reaction pathway of Yersinia pestis RipA, a putative butyryl-CoA transferase. Acta Crystallogr D Biol Crystallogr 70:1074-85|
|Houghton, Raymond L; Reed, Dana E; Hubbard, Mark A et al. (2014) Development of a prototype lateral flow immunoassay (LFI) for the rapid diagnosis of melioidosis. PLoS Negl Trop Dis 8:e2727|
|Strotmeier, Jasmin; Mahrhold, Stefan; Krez, Nadja et al. (2014) Identification of the synaptic vesicle glycoprotein 2 receptor binding site in botulinum neurotoxin A. FEBS Lett 588:1087-93|
|Koellhoffer, Jayne F; Dai, Zhou; Malashkevich, Vladimir N et al. (2014) Structural characterization of the glycoprotein GP2 core domain from the CAS virus, a novel arenavirus-like species. J Mol Biol 426:1452-68|
|Bennett, Shannon N; Gu, Se Hun; Kang, Hae Ji et al. (2014) Reconstructing the evolutionary origins and phylogeography of hantaviruses. Trends Microbiol 22:473-82|
|Burtnick, Mary N; Brett, Paul J; DeShazer, David (2014) Proteomic analysis of the Burkholderia pseudomallei type II secretome reveals hydrolytic enzymes, novel proteins, and the deubiquitinase TssM. Infect Immun 82:3214-26|
|Koskiniemi, Sanna; Garza-Sánchez, Fernando; Sandegren, Linus et al. (2014) Selection of orphan Rhs toxin expression in evolved Salmonella enterica serovar Typhimurium. PLoS Genet 10:e1004255|
|Sabouri, Amir H; Marcondes, Maria Cecilia Garibaldi; Flynn, Claudia et al. (2014) TLR signaling controls lethal encephalitis in WNV-infected brain. Brain Res 1574:84-95|
|Vigant, Frederic; Hollmann, Axel; Lee, Jihye et al. (2014) The rigid amphipathic fusion inhibitor dUY11 acts through photosensitization of viruses. J Virol 88:1849-53|
|Relman, David A (2014) "Inconvenient truths" in the pursuit of scientific knowledge and public health. J Infect Dis 209:170-2|
Showing the most recent 10 out of 317 publications