# Host-pathogen interactions controlling Chlamydia developmental cycle

> **NIH NIH R01** · UNIVERSITY OF VIRGINIA · 2021 · $479,721

## Abstract

SUMMARY
Chlamydia trachomatis is the leading cause of sexually transmitted infections of bacterial origin. No vaccine is
available. Infections are often asymptomatic, leading to long-term damage of the reproductive organs and
deleterious effects on human health ranging from pelvic inflammatory disease to infertility. Pathogenesis is linked
to a host inflammatory response triggered by the invasion of the genital tract epithelium with this obligate
intracellular pathogen. A hallmark and critical aspect of Chlamydia intracellular life style is its bi-phasic
developmental cycle, during which the bacteria alternate between infectious (EB) and replicative (RB) forms
within the lumen of a membrane-bound compartment called the inclusion. The mechanisms that govern
progression through the developmental cycle are poorly understood. Here we describe a Chlamydia conditional
mutant in an inclusion membrane protein. The mutant displays a severe, yet complementable, developmental
defect in the early stages of the developmental cycle, most likely during EB to RB conversion. Moreover, this Inc
protein interacts with a host factor involved in the late stages of the developmental cycle, when the bacteria exit
the cell via extrusion. We propose to test the hypothesis that this Inc protein plays a dual role early (Aim 1) and
late (Aim2) during the developmental cycle and to determine its contribution to pathogenesis (Aim 3). Through
the use of cell biology, bacterial genetics, transcriptomics, proteomics and in vivo approaches, our studies will
further our understanding of the molecular mechanisms governing the host-Chlamydia interactions that control
the developmental cycle. Altogether our work has the potential to identify therapeutic targets to block
transmission of and pathogenesis associated with this important sexually transmitted pathogen.

## Key facts

- **NIH application ID:** 10275536
- **Project number:** 1R01AI162758-01
- **Recipient organization:** UNIVERSITY OF VIRGINIA
- **Principal Investigator:** ISABELLE DERRE
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $479,721
- **Award type:** 1
- **Project period:** 2021-08-01 → 2025-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10275536

## Citation

> US National Institutes of Health, RePORTER application 10275536, Host-pathogen interactions controlling Chlamydia developmental cycle (1R01AI162758-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10275536. Licensed CC0.

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