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.

Public Health Relevance

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.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Specialized Center--Cooperative Agreements (U54)
Project #
5U54AI065359-08
Application #
8378813
Study Section
Special Emphasis Panel (ZAI1-DDS-M)
Project Start
Project End
Budget Start
2012-05-01
Budget End
2013-04-30
Support Year
8
Fiscal Year
2012
Total Cost
$266,785
Indirect Cost
$39,112
Name
University of California Irvine
Department
Type
DUNS #
046705849
City
Irvine
State
CA
Country
United States
Zip Code
92697
Hertz, Tomer; Beatty, P Robert; MacMillen, Zachary et al. (2017) Antibody Epitopes Identified in Critical Regions of Dengue Virus Nonstructural 1 Protein in Mouse Vaccination and Natural Human Infections. J Immunol 198:4025-4035
Marques, Adriana R; Yang, Xiuli; Smith, Alexis A et al. (2017) Citrate Anticoagulant Improves the Sensitivity of Borreliella (Borrelia) burgdorferi Plasma Culture. J Clin Microbiol 55:3297-3299
Parameswaran, Poornima; Wang, Chunling; Trivedi, Surbhi Bharat et al. (2017) Intrahost Selection Pressures Drive Rapid Dengue Virus Microevolution in Acute Human Infections. Cell Host Microbe 22:400-410.e5
Bortell, Nikki; Flynn, Claudia; Conti, Bruno et al. (2017) Osteopontin Impacts West Nile virus Pathogenesis and Resistance by Regulating Inflammasome Components and Cell Death in the Central Nervous System at Early Time Points. Mediators Inflamm 2017:7582437
Barbour, Alan G (2017) Infection resistance and tolerance in Peromyscus spp., natural reservoirs of microbes that are virulent for humans. Semin Cell Dev Biol 61:115-122
Nualnoi, Teerapat; Norris, Michael H; Tuanyok, Apichai et al. (2017) Development of Immunoassays for Burkholderia pseudomallei Typical and Atypical Lipopolysaccharide Strain Typing. Am J Trop Med Hyg 96:358-367
Nakajima, Rie; Escudero, Raquel; Molina, Douglas M et al. (2016) Towards Development of Improved Serodiagnostics for Tularemia by Use of Francisella tularensis Proteome Microarrays. J Clin Microbiol 54:1755-65
Zeltina, Antra; Bowden, Thomas A; Lee, Benhur (2016) Emerging Paramyxoviruses: Receptor Tropism and Zoonotic Potential. PLoS Pathog 12:e1005390
Ziegler, Christopher M; Eisenhauer, Philip; Bruce, Emily A et al. (2016) A novel phosphoserine motif in the LCMV matrix protein Z regulates the release of infectious virus and defective interfering particles. J Gen Virol 97:2084-9
Park, Arnold; Yun, Tatyana; Hill, Terence E et al. (2016) Optimized P2A for reporter gene insertion into Nipah virus results in efficient ribosomal skipping and wild-type lethality. J Gen Virol 97:839-43

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