Shigella and Enterotoxigenic Escherichia coli (ETEC) virulence proteins and multi-epitope fusion antigens (Shigella-ETEC MEFA)

Shigella and Enterotoxigenic Escherichia coli (ETEC) virulence proteins and multi-epitope fusion antigens (MEFAs) represent a complex set of targets used in the development of broad-spectrum vaccines against diarrheal diseases (Zhang & Sack, 2015, Expert Review of Vaccines). Shigella species utilize a Type III Secretion System (T3SS) and proteins like IpaB and IpaD to invade the colonic epithelium, while ETEC relies on various colonization factors (CFAs) and enterotoxins, specifically Heat-labile toxin (LT) and Heat-stable toxin (ST), to cause secretory diarrhea (Niyogi, 2005, Journal of Microbiology). The MEFA approach involves the genetic fusion of immunodominant epitopes from multiple bacterial strains or species into a single recombinant protein scaffold, often using the non-toxic B subunit of LT (LTB) as a carrier and adjuvant (Ruan et al., 2014, Vaccine). This strategy aims to overcome the high antigenic diversity of these pathogens by eliciting a cross-protective immune response that targets both bacterial attachment and toxin-mediated pathology. These antigens are primarily targeted by prophylactic vaccines currently in various stages of preclinical and clinical development to prevent shigellosis and traveler's diarrhea (World Health Organization, 2023). By combining epitopes from Shigella invasion proteins and ETEC colonization factors, these fusion antigens provide a synergistic approach to enteric disease prevention in high-risk populations.

Other names

Shigella-ETEC fusion antigensMEFAETEC-Shigella bivalent vaccine targetsMulti-epitope fusion antigenShigella-ETEC chimeric antigens

Induction of protective immunity through the production of neutralizing antibodies (IgA and IgG) against bacterial colonization factors and enterotoxins, thereby preventing bacterial attachment to intestinal epithelial cells and neutralizing toxic effects (Ruan et al., 2014, Vaccine).