# Bacteria-Virus interactions in genital herpes infections

> **NIH NIH R21** · HARVARD UNIVERSITY D/B/A HARVARD SCHOOL OF PUBLIC HEALTH · 2024 · $199,375

## Abstract

Virus-Bacterial interactions in genital herpes infections
Mucosal viruses encounter resident bacteria before they encounter and activate the immune
response and these interactions can affect viral infection and replication. These virus-bacterial
interactions heavily influence viral infections in the intestinal tract but are understudied in the
vaginal mucosa. Studies have shown that vaginal lactobacilli can interact with herpes simplex
virus however the bacterial components involved in this interaction remain unknown. Our
preliminary data show that vaginal lactobacilli interact with herpes simplex virus and inhibit
infectivity to a much greater extent than gut lactobacilli. Additionally, this interaction is
independent of lactic acid as dead bacteria are equivalently inhibitory. Further, we were able to
mimic this interaction using peptidoglycan from non-vaginal gram-positive bacteria.
In this proposal, we aim to explore the role of purified peptidoglycan from vaginal lactobacilli
strains and compare their efficacy against gut lactobacilli (Aim 1). We will explore the role of
peptidoglycan-sensing innate immune receptors in this viral suppression (Aim 2). We will define
the relevance of these observations to human health by quantifying vaginal peptidoglycan in
vaginal samples from people with lactobacilli-dominant microbiomes and bacterial vaginosis
patients who have lost their vaginal lactobacilli and have been clinically shown to have
increased shedding of herpes simplex virus. These experiments aim to propose a mechanistic
basis for clinical observations linking abundance of vaginal lactobacilli to reduced viral infection
and replication.

## Key facts

- **NIH application ID:** 10786357
- **Project number:** 1R21AI180508-01
- **Recipient organization:** HARVARD UNIVERSITY D/B/A HARVARD SCHOOL OF PUBLIC HEALTH
- **Principal Investigator:** Smita Gopinath
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $199,375
- **Award type:** 1
- **Project period:** 2023-12-01 → 2025-10-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10786357

## Citation

> US National Institutes of Health, RePORTER application 10786357, Bacteria-Virus interactions in genital herpes infections (1R21AI180508-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10786357. Licensed CC0.

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