Clostridium difficile infection (CDI) is the most common cause of antibiotic-associated diarrhea and gastroenteritis-associated death among developed countries, and it is classified as one of thetopthree?urgentthreats?bytheUSCentersforDiseaseControlandPrevention(CDC).The diseaseassociatedwithCDIismainlymediatedbytwohomologousexotoxins,TcdAandTcdB. Theytargetanddisruptthecolonicepithelium,leadingtodiarrheaandcolitis.Receptor-binding is a critical step in the toxin?s action and largely determine toxin tropisms, and these receptors are also molecular targets for therapeutic interventions. The goal of our proposal is to identify and characterize toxin receptors, establish a structural basis for toxin-receptor recognition, and harness this knowledge to gain a mechanistic understanding of the biology, pathogenesis, and therapy of TcdA and TcdB. We will take a multi-disciplinary approach, bringing together the expertise in toxin structure/function of Dr. Rongsheng Jin?s group with the expertise in toxin receptor identification/pathogenesis of Dr. Min Dong?s group. This proposed work is built on bothourpublishedworkonidentifyingFrizzled(FZD)proteinsasTcdBreceptors,andextensive preliminary data on toxin-receptor interactions. We will focus on three aims: (1) elucidate the structuralbasisandpathogenicrelevanceofTcdB-FZDrecognition;?(2)understandthestructure of TcdB and the influence of FZD binding;? and (3) identify and characterize novel TcdA receptors through a CRISPR/Cas9 mediated genome-wide screens. These proposed studies will provide a comprehensive understanding of toxin-receptor interactions and how they contributetothetoxinbiologyandpathogenesisofTcdAandTcdB.

Public Health Relevance

Clostridium difficile toxin A (TcdA) and toxin B (TcdB) are responsible for diseases associated withC.difficileinfection(CDI).Hereweseektoidentifythetoxinreceptors,establishastructural basis for toxin-receptor recognition, and harness this knowledge to gain a mechanistic understandingofthebiologyandpathogenesisofTcdAandTcdB.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI139087-03
Application #
9913462
Study Section
Bacterial Pathogenesis Study Section (BACP)
Program Officer
Ranallo, Ryan
Project Start
2018-05-15
Project End
2023-04-30
Budget Start
2020-05-01
Budget End
2021-04-30
Support Year
3
Fiscal Year
2020
Total Cost
Indirect Cost
Name
Boston Children's Hospital
Department
Type
DUNS #
076593722
City
Boston
State
MA
Country
United States
Zip Code
02115
Chen, Peng; Tao, Liang; Liu, Zheng et al. (2018) Structural insight into Wnt signaling inhibition by Clostridium difficile toxin B. FEBS J :