Frizzled proteins are colonic epithelial receptors for C. difficile toxin B

  • Nature. 2016 Oct 20;538(7625):350-355. doi: 10.1038/nature19799.
Liang Tao  1  2 ,  Jie Zhang  1  2 ,  Paul Meraner  3 ,  Alessio Tovaglieri  4 ,  Xiaoqian Wu  5 ,  Ralf Gerhard  6 ,  Xinjun Zhang  7  8 ,  William B Stallcup  9 ,  Ji Miao  4  10 ,  Xi He  7  8 ,  Julian G Hurdle  5 ,  David T Breault  4  10  11 ,  Abraham L Brass  3  12 ,  Min Dong  1  2
Affiliations
  • 1. Department of Urology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
  • 2. Department of Microbiology and Immunobiology and Department of Surgery, Harvard Medical School, Boston, Massachusetts 02115, USA.
  • 3. Department of Microbiology and Physiological Systems (MaPS), University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.
  • 4. Division of Endocrinology, Boston Children's Hospital, Boston, Massachusetts 02115, USA.
  • 5. Center for Infectious and Inflammatory Diseases, Texas A &M Health Science Center, Houston, Texas 77030, USA.
  • 6. Institute of Toxicology, Hannover Medical School, 30625 Hannover, Germany.
  • 7. The F. M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
  • 8. Department of Neurology, Harvard Medical School, Boston, Massachusetts 02115, USA.
  • 9. Tumor Microenvironment and Cancer Immunology Program, Sanford-Burnham Prebys Medical Discovery Institute, Cancer Center, La Jolla, California 92037, USA.
  • 10. Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA.
  • 11. Harvard Stem Cell Institute, Cambridge, Massachusetts 02138, USA.
  • 12. Gastroenterology Division, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.
PMID: 27680706 DOI: 10.1038/nature19799
Abstract

Clostridium difficile toxin B (TcdB) is a critical virulence factor that causes diseases associated with C. difficile Infection. Here we carried out CRISPR-Cas9-mediated genome-wide screens and identified the members of the Wnt receptor Frizzled family (FZDs) as TcdB receptors. TcdB binds to the conserved Wnt-binding site known as the cysteine-rich domain (CRD), with the highest affinity towards FZD1, 2 and 7. TcdB competes with Wnt for binding to FZDs, and its binding blocks Wnt signalling. FZD1/2/7 triple-knockout cells are highly resistant to TcdB, and recombinant FZD2-CRD prevented TcdB binding to the colonic epithelium. Colonic organoids cultured from FZD7-knockout mice, combined with knockdown of FZD1 and 2, showed increased resistance to TcdB. The colonic epithelium in FZD7-knockout mice was less susceptible to TcdB-induced tissue damage in vivo. These findings establish FZDs as physiologically relevant receptors for TcdB in the colonic epithelium.