Enterotoxigenic Escherichia coli colonization factor antigen I fimbrial adhesin (CFA/I)

The Enterotoxigenic Escherichia coli (ETEC) colonization factor antigen I (CFA/I) fimbrial adhesin is a critical virulence factor responsible for the attachment of ETEC to the human intestinal epithelium (Qadri et al., 2005). It is the archetype of Class 5 fimbriae and is composed of a major structural subunit, CfaB, and a minor, tip-localized adhesive subunit, CfaE (Baker et al., 2009). CfaE mediates binding to host cell receptors, likely sialylated glycoproteins or glycosphingolipids, through a shear-enhanced "catch-bond" mechanism that allows the bacteria to remain attached despite the mechanical forces of intestinal peristalsis (Li et al., 2007; Tchesnokova et al., 2010). As a primary mediator of colonization, CFA/I is a major target for the development of vaccines and anti-adhesive therapeutics aimed at preventing ETEC-induced diarrhea, which is a leading cause of illness in travelers and children in developing countries (Svennerholm et al., 2015). Therapeutic strategies include the use of monoclonal antibodies to block adhesion and the development of oral vaccines, such as ETVAX, to induce protective mucosal immunity (Svennerholm et al., 2015).

Other names

Colonization factor antigen ICFA/ICfaE (adhesin subunit)CfaB (major subunit)ETEC CFA/I fimbriaeClass 5 fimbriae

Adhesion inhibition; Neutralization of colonization factors; Induction of protective mucosal IgA and serum IgG antibodies