More than 1.7 million cases of Chlamydia trachomatis infections are reported to the CDC each year, making it the most commonly reported infectious disease in the country. C. trachomatis causes an intracellular infection, and we have discovered that this bacterium causes two effects on an infected host cell that have not been previously described: 1) loss of the primary cilium, which is a solitary surface projection on most differentiated cells in the body; 2) re-entry of a quiescent host cell into the cell cycle. These novel host-pathogen interactions may have been missed because the conventional Chlamydia cell culture infection model uses cycling cells that lack primary cilia.
In Aim 1, we will determine if Chlamydia infection causes loss of the primary cilium by inducing cilia disassembly through the AurA regulatory pathway of the host cell.
In Aim 2, we will investigate how Chlamydia causes cell cycle re-entry and will determine if the infection involves and dysregulates known cellular regulators of cell cycle re-entry and progression.
In Aim 3, we will study if and how Chlamydia-induced primary cilia loss and cell cycle re-entry promote the chlamydial infection. We will also investigate if these two host-pathogen interaction are functionally linked or independent from each other. Successful completion of these studies will define two novel host-pathogen interactions: no microbe is known to cause primary cilia loss, and only viruses, but not bacteria, have been shown to cause quiescent host cells to re-enter the cell cycle. Interventions to prevent Chlamydia-induced primary cilia loss and cell cycle re-entry may lead to a novel therapeutic strategy against Chlamydia infections.

Public Health Relevance

Chlamydia is a major cause of sexually transmitted infections in the U.S., and more cases of chlamydial genital infections are reported to the CDC than any other infectious disease. This project will investigate two new effects of Chlamydia on a differentiated host cell: primary cilia loss and cell cycle re-entry. The project will study the mechanisms by which Chlamydia infection induces these effects on its host cell and will test if these two host-pathogen interactions are functionally linked. Interventions to prevent Chlamydia-induced primary cilia loss and cell cycle re-entry may lead to a novel therapeutic strategy against Chlamydia infections.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI153410-01
Application #
10033880
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Vincent, Leah Rebecca
Project Start
2020-07-17
Project End
2025-06-30
Budget Start
2020-07-17
Budget End
2021-06-30
Support Year
1
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of California Irvine
Department
Anatomy/Cell Biology
Type
Schools of Arts and Sciences
DUNS #
046705849
City
Irvine
State
CA
Country
United States
Zip Code
92617