RT Journal Article SR Electronic T1 Cell-specific targeting by Clostridium perfringens β-toxin unraveled: the role of CD31 as the toxin receptor JF bioRxiv FD Cold Spring Harbor Laboratory SP 787242 DO 10.1101/787242 A1 Julia Bruggisser A1 Basma Tarek A1 Marianne Wyder A1 Guillaume Witz A1 Gaby Enzmann A1 Urban Deutsch A1 Britta Engelhardt A1 Horst Posthaus YR 2019 UL http://biorxiv.org/content/early/2019/10/01/787242.abstract AB Clostridium perfringens β-toxin (CPB) is a highly active hemolysin β-pore forming toxin and the essential virulence factor for a severe, necro-hemorrhagic enteritis in animals and humans. In vivo and in vitro it exerts a remarkable cell type specificity towards endothelial cells, platelets and some leucocytic cell lines. The target cell specificity of CPB is, however, poorly understood and a receptor explaining this selective toxicity has not been identified. This has hampered further research into the pathogenesis of C. perfringens type C induced enteritis. Here we identify Platelet Endothelial Cell Adhesion Molecule-1 (CD31 or PECAM-1) as the specific membrane receptor for CPB on endothelial cells. CD31 expression is essential for CPB toxicity in endothelial cells and lethality in mice and sufficient to render previously resistant cells highly susceptible to the toxin. We further demonstrate, that the extracellular membrane proximal Ig6 domain of CD31 is required for the interaction with CPB and that expression of CD31 corresponds with the specificity of the toxin towards cultured cell lines. Our results thus provide an explanation for the cell type specificity of CPB and can be linked to the characteristic lesions observed a devastating enteric disease in animals and humans.