B-cell receptor recognizing Colonization Factor Antigen 6 (BCR-CS6)

B-cell receptors (BCRs) and antibodies recognizing Colonization Factor Antigen 6 (CS6) are essential components of the adaptive immune response against Enterotoxigenic Escherichia coli (ETEC), a primary cause of traveler's diarrhea and childhood mortality in developing regions (Qadri et al., 2019). CS6 is a non-fimbrial adhesin and one of the most prevalent colonization factors expressed by ETEC strains worldwide (Tobias et al., 2010). These BCRs specifically target the CssA and CssB subunits of the CS6 protein complex, which the bacteria use to anchor themselves to the intestinal epithelium. When these receptors are engaged through vaccination or natural infection, they trigger the production of secretory IgA and systemic IgG antibodies that sterically block bacterial attachment, thereby preventing colonization and the subsequent release of enterotoxins (Svennerholm, 2011). In clinical development, these receptors are the primary targets for oral inactivated vaccines like ETVAX, which aim to elicit robust mucosal immunity (Lundgren et al., 2014). Monitoring the induction of CS6-specific memory B cells and antibody titers serves as a critical biomarker for assessing the protective efficacy of ETEC vaccine candidates.

Other names

Anti-CS6 antibodyCS6-specific B-cell receptorColonization Factor Antigen 6 antibodyCFA/VI antibodyCssA/CssB-specific antibody

Vaccines stimulate B-cells to express CS6-specific receptors and secrete antibodies that bind to the CS6 adhesin on ETEC, preventing bacterial attachment to intestinal epithelial cells.