# Enterotoxigenic E. coli pathogenesis and human enteroids

> **NIH NIH P01** · UNIVERSITY OF MARYLAND BALTIMORE · 2020 · $266,259

## Abstract

Project Summary
 Project 4 will examine the pathogenesis of ETEC diarrhea using the human enteroid
monolayer model. Acute ETEC diarrhea is one of the four leading causes of diarrhea and
diarrheal death world wide. ETEC and its major virulence factors, STa and LT, have been
extensively studied in animal intestine, human colon cancer cells lines, but there is minimal
mechanistic information from human intestine. Moreover, additional virulence factors have been
identified, including the bacterial protease and mucinase EatA, the role of which in ETEC
diarrhea has only been partially defined. Since ST-containing ETEC were highly associated with
clinical disease, we will particularly focus on the role of STa and EatA in ETEC pathogenesis. A
human proximal small intestinal enteroid model is being developed using ETEC producing its
virulence factors STa, LT and EatA., with the model demonstrating microcolonies of ETEC
attached to human enteroid BB, production of STa in the luminal fluid and activation by STa of
GCC/cGMP. Aim 1 will characterize the roles of STa in pathogenesis using isogenic mutants
and purified Sta, including mutants being proposed as toxoids for vaccine development. Effects
will be defined on Na absorptive and Cl secretory transport proteins that contribute to other
diarrheas, changes in tight junctions and other BB and BLM structural proteins, as well as
epithelial cytokine release. Biochemical and proteomics approaches will be used to further
characterize the signaling complexes affected by STa binding to BB GCC, which are involved in
NHE3 inhibition, thus identifying multiple additional potential drug targets to treat acute ETEC
diarrhea. Aim 2 will examine the role of EatA in ETEC pathogenesis determining its effects on
release of other ETEC virulence factors, whether it alters intestinal transport processes to
contribute directly to diarrhea, and if it cleaves intestinal mucins including the consequences of
cleaving these mucins. Aim 3 will determine if ETEC produces longer lasting effects on the
enteroids that could contribute to environmental enteropathy By developing an acute ETEC
diarrhea model in normal human enteroids, insights in pathobiology of human ETEC diarrhea
and identification of new targets to develop drug treatment will be identified, which will
complement approaches by others to develop ETEC vaccines.

## Key facts

- **NIH application ID:** 9982184
- **Project number:** 5P01AI125181-05
- **Recipient organization:** UNIVERSITY OF MARYLAND BALTIMORE
- **Principal Investigator:** MARK DONOWITZ
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $266,259
- **Award type:** 5
- **Project period:** — → 2021-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9982184

## Citation

> US National Institutes of Health, RePORTER application 9982184, Enterotoxigenic E. coli pathogenesis and human enteroids (5P01AI125181-05). Retrieved via AI Analytics 2026-05-29 from https://api.ai-analytics.org/grant/nih/9982184. Licensed CC0.

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