Plague is an acute infection caused by Yersinia pestis, a Gram-negative, facultative intracellular bacterium that infects and survives in macrophages. Growing evidence suggests that intracellular growth is important for mammalian colonization by Y. pestis. Upon entry into macrophages, Y. pestis remains in a membrane-bound compartment called the Yersinia-containing vacuole (YCV), but it is not killed by the macrophage. Furthermore, the bacterium actively inhibits acidification of the YCV. We hypothesize that Y. pestis interacts with specific host factors in order to alter YCV maturation and acidification. While bacterial factors important for intracellular survival have been identifie, the molecular mechanisms used by the bacterium to survive within macrophages have not been defined. To identify these factors/pathways, we have built a novel Y. pestis bioreporter to monitor Y. pestis survival in macrophages. Using this bioreporter, we have developed an inhibitory RNA-based assay to specifically identify host factors that alter Y. pestis intracellular survival. With this assay we will perform a genome wide screen to identify host factors/pathways required for Y. pestis survival in macrophages (Aim 1). Using a combination of in silico and microscopy analysis, we will also specifically identify host factors identified in our screen that alter phagosome maturation to the benefit of Y. pestis (Aim 2). These studies will be the first to target the host cell to understand the mechanisms used by Y. pestis to survive in host cells.

Public Health Relevance

Yersinia pestis is the causative agent of plague, an acute human disease and potential bioweapon. The work proposed here will identify host targets required by Y. pestis to infect cells of the innate immune system. Understanding the interactions between Y. pestis and the host immune system will allow us to design new vaccine and therapeutic approaches to combat plague infections.

Agency
National Institute of Health (NIH)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21AI097608-02
Application #
8666710
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Mukhopadhyay, Suman
Project Start
Project End
Budget Start
Budget End
Support Year
2
Fiscal Year
2014
Total Cost
Indirect Cost
Name
University of Louisville
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
City
Louisville
State
KY
Country
United States
Zip Code
40202