# Epigenetic Determinants and Mechanisms Influencing Genital Chlamydia trachomatis Reinfection in African American Women

> **NIH NIH R21** · UNIVERSITY OF ALABAMA AT BIRMINGHAM · 2021 · $259,875

## Abstract

Summary/Abstract: Chlamydia trachomatis (Ct) infection is the most prevalent sexually transmitted bacterial
infection in the world. In the US alone, an estimated 3 million chlamydia cases are expected to occur annually.
Ascending Ct infection in women can lead to pelvic inflammatory disease (PID), resulting in reproductive
sequelae such as ectopic pregnancy, infertility, and chronic pelvic pain. Ct infections also disproportionally affect
African Americans, who have almost a 6-fold higher Ct infection rate than Caucasians. Ct infection rates remain
high despite active prevention and control efforts, and 20% of diagnosed patients are re-infected within one year,
suggesting some infected persons do not develop sufficient immune protection. Reinfection contributes to
continued Ct transmission and risk for Ct infection sequelae. Better prevention measures, such as a vaccine,
are needed. The development of a Ct vaccine as well as other measures to prevent and control Ct infection in
humans have been hindered in part by an incomplete understanding of the immune mechanisms that contribute
to protection against Ct infections in humans. The goal of the research proposed in this application is to identify
epigenetic alterations that influence immune responses and Ct reinfection risk. Several studies have shown that
DNA methylation variation at individual CpG site has strong genetic component. The genetic effects on DNA
methylation variations can be explained, in part, by SNPs located in close vicinity of the target CpG sites. Genetic
variants that are associated with methylation variation are commonly referred to as methylation quantitative trait
loci (meQTL), are crucial for understanding the epigenetic mechanisms underlying genotype-trait associations.
DNA variants available from an existing ImmunoArray, together with DNAm profiling available from this proposal,
will allow understanding of immunogenetic mechanisms that contribute to the pathogenesis of Ct reinfection.
Central hypothesis: We hypothesize that altered epigenetic variation affects the immune response to Ct and
therefore the risk for Ct reinfection. Furthermore, we hypothesize that identifying linked genetic and epigenetic
variants that influence immune responses and Ct reinfection risk will allow us to pinpoint functional
immunogenetic mechanisms. In Aim 1, we will conduct Epigenetic-Wide Association Analysis (EWAS) to identify
epigenetic variations associated with immune responses that mediate protection against Ct reinfection in African
American women. In Aim 2, we will use epigenetic, genetic, and immune response data to model how they
influence Ct reinfection risk. In summary, our studies will investigate epigenetic mechanisms that modulate
immune responses to Ct and influence Ct reinfection risk. To our knowledge, these will be the first studies of
epigenetics in human Ct infection. We expect our studies will advance knowledge on how epigenetic and genetic
factors influence immune respo...

## Key facts

- **NIH application ID:** 10109176
- **Project number:** 1R21AI156142-01
- **Recipient organization:** UNIVERSITY OF ALABAMA AT BIRMINGHAM
- **Principal Investigator:** WILLIAM M GEISLER
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $259,875
- **Award type:** 1
- **Project period:** 2021-01-22 → 2022-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10109176

## Citation

> US National Institutes of Health, RePORTER application 10109176, Epigenetic Determinants and Mechanisms Influencing Genital Chlamydia trachomatis Reinfection in African American Women (1R21AI156142-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10109176. Licensed CC0.

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