# Virulence inducing signals of Vibrio cholerae

> **NIH NIH R21** · UNIVERSITY OF TOLEDO HEALTH SCI CAMPUS · 2020 · $192,501

## Abstract

Vibrio cholerae is a bacterial pathogen endemic to many regions of the world where it is
commonly found in the aquatic environment. When water contaminated with V. cholerae is
ingested by a human host, the bacteria colonize the small intestine where they produce cholera
toxin, resulting in disease. Virulence genes, including cholera toxin, are expressed at a very
high level near the epithelium of the small intestine, but not in the lumen. In the lumen, the
bacteria encounter high concentrations of bile, a negative regulator of virulence genes. When
the bacteria penetrate the mucus layer and approach the epithelium, bile levels decrease and
they encounter bicarbonate, a positive regulator of virulence genes. They also meet with rising
levels of antimicrobial peptides (APs), which are produced by the intestinal epithelial cells as
part of innate immunity. Our laboratory recently found that several cationic APs further elevate
virulence gene expression in combination with bicarbonate treatment. Therefore, we
hypothesize that V. cholerae uses antimicrobial peptides from intestinal epithelial cells in the
human host as a key spatial signal to increase virulence gene expression. The objective of the
proposed studies is to better understand the role of this signal in cholera pathogenesis. The
objective of this proposal will be accomplished by pursuing two specific aims: 1) Characterize
the molecular mechanism(s) by which antimicrobial peptides enhance virulence gene
expression; and 2) Determine the consequences of responding to these antimicrobial peptide
signals in the pathogenesis of cholera. Completion of this two-year study will produce a
foundation of knowledge on a previously uninvestigated signal that enhances virulence gene
expression in this important bacterial pathogen. This will add to our greater understanding of
the spatial cues that govern the production of virulence factors by V. cholerae.

## Key facts

- **NIH application ID:** 9852573
- **Project number:** 5R21AI144567-02
- **Recipient organization:** UNIVERSITY OF TOLEDO HEALTH SCI CAMPUS
- **Principal Investigator:** JYL S MATSON
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $192,501
- **Award type:** 5
- **Project period:** 2019-01-22 → 2021-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9852573

## Citation

> US National Institutes of Health, RePORTER application 9852573, Virulence inducing signals of Vibrio cholerae (5R21AI144567-02). Retrieved via AI Analytics 2026-06-11 from https://api.ai-analytics.org/grant/nih/9852573. Licensed CC0.

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