# Primary cilia loss and cell cycle re-entry in Chlamydia-infected cells

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA-IRVINE · 2024 · $520,275

## Abstract

Project Summary/Abstract
 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.

## Key facts

- **NIH application ID:** 10875498
- **Project number:** 5R01AI153410-05
- **Recipient organization:** UNIVERSITY OF CALIFORNIA-IRVINE
- **Principal Investigator:** CHRISTINE SUETTERLIN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $520,275
- **Award type:** 5
- **Project period:** 2020-07-17 → 2026-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10875498

## Citation

> US National Institutes of Health, RePORTER application 10875498, Primary cilia loss and cell cycle re-entry in Chlamydia-infected cells (5R01AI153410-05). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10875498. Licensed CC0.

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