Design of a live-attenuated bacterial vaccine using effector network engineering
File(s)
Published version (article in press)
Author(s)
Frankel, Gad
Type
Journal Article
Abstract
Enteropathogenic Escherichia coli (EPEC) and Citrobacter rodentium (CR) are extracellular enteric attaching and effacing (A/E) pathogens of humans and mice, respectively. Their virulence relies on intimate bacterial attachment and a network of type III secretion system effectors. Here, through systematic reduction and redesign of the effector network in CR, we develop an attenuated strain, CRV (CR Vaccine), encoding a subset of ten effectors. CRV colonises C57BL/6 mice ~100-fold lower than wild type CR (CRWT) without causing overt pathogenesis. Moreover, C3H/HeN mice, which succumb to CRWT infection, survive CRV challenge. Vaccination with CRV confers protection against subsequent CRWT infection in both mouse strains. Serological analysis reveals a repertoire of dominant CR antigens, including the O-antigen, the virulence factors intimin, EspA and Tir and the outer membrane proteins Lpp, OmpA, MetQ and CARC (an AIDA-like autotransporter). We show that CRWT and CRV immunisation elicits comparable B cell and antibody responses, which is contingent on intimate bacterial attachment. A corresponding EPEC strain (E. coli Vaccine, ECV) effectively colonises epithelial cells in a gut-on-chip model. These findings establish effector network minimisation as a generalisable strategy for rational bacterial attenuation and live-attenuated vaccine design.
Date Issued
2026-08-07
Date Acceptance
2026-07-21
Citation
Nature Communications, 2026
ISSN
2041-1723
Publisher
Nature Portfolio
Journal / Book Title
Nature Communications
Copyright Statement
© The Author(s) 2026. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
License URL
Publication Status
Published online
Date Publish Online
2026-08-07