Yersinia pestis is a facultative intracellular pathogen that causes the disease known as plague. Growing evidence indicates that intracellular growth in macrophages is important for Y. pestis virulence. Upon phagocytosis, Y. pestis alters the maturation of the phagosome to generate a protective compartment within the cell known as the Yersinia containing vacuole (YCV). Key steps in the generation of the YCV include inhibition of YCV acidification, expansion into a spacious vacuole, and acquisition of the autophagic markers. However, the mechanisms used by the bacterium to subvert the normal phagosome maturation process and generate the YCV have not been defined. Recently we have identified a subset of host Rab GTPases that are required for Y. pestis to survive within macrophages. Because Rab proteins are key mediators of vesicular trafficking, phagosome maturation, and autophagy, we hypothesize that these GTPases are required by Y. pestis to subvert phagosome maturation and generate the YCV, thus protecting the bacterium from macrophage clearance. As Rab proteins mediate many aspects of vesicular trafficking through direct interactions with specific organelles and recruitment of effector proteins, in Aim 1 we will determine if Rab GTPase required for Y. pestis intracellular survival are specifically recruited to the YCV.
In Aim 2, we will determine the contribution of individual Rab proteins on the biogenesis of the YCV. These studies will be the first to define the contribution of host Rab GTPases to the formation of the YCV. Ultimately, understanding the YCV biogenesis process will enable us to identify Y. pestis pathogenicity factors that contribute to intracellular survival.

Public Health Relevance

Yersinia pestis is the causative agent of plague, an acute human disease and potential bioweapon. The work proposed here will define the role of host Rab GTPases in biogenesis of an intracellular niche which protects Y. pestis from macrophage killing. Understanding the interactions between Y. pestis and macrophages will provide a broader understanding of Y. pestis pathogenesis which may impact the design of new vaccine and therapeutic approaches to combat plague infections.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AI119557-02
Application #
9233902
Study Section
Special Emphasis Panel (ZRG1-IDM-B (80)S)
Program Officer
Mukhopadhyay, Suman
Project Start
2016-03-01
Project End
2018-02-28
Budget Start
2017-03-01
Budget End
2018-02-28
Support Year
2
Fiscal Year
2017
Total Cost
$188,418
Indirect Cost
$63,418
Name
University of Louisville
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
057588857
City
Louisville
State
KY
Country
United States
Zip Code
40208
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VanCleave, Tiva T; Pulsifer, Amanda R; Connor, Michael G et al. (2017) Impact of Gentamicin Concentration and Exposure Time on Intracellular Yersinia pestis. Front Cell Infect Microbiol 7:505
Bobrov, Alexander G; Kirillina, Olga; Fosso, Marina Y et al. (2017) Zinc transporters YbtX and ZnuABC are required for the virulence of Yersinia pestis in bubonic and pneumonic plague in mice. Metallomics 9:757-772