Verification of the capacity the O26-BSA conjugate to induce antibodies capable of inhibiting the adhesion of O26 E. Coli to human epithelial cells

• Grant number: 11/06460-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2012
• End date: July 31, 2012
• Field of knowledge: Biological Sciences - Immunology - Applied Immunology
• Principal Investigator: Marta de Oliveira Domingos
• Grantee: Tiago Antonio Martinhago Broring
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

E. coli belonging to serogroup O26 are responsible for cases of infant death in underdeveloped countries and outbreaks of bloody diarrhea and hemolytic uremic syndrome in developed countries. In Brazil, E. coli O26 is often isolated from children with diarrhea and cattle, it can survive in soil contaminated with the feces of these animals for up to one year. Three different path types can be found in this serogroup, which is E. enteropathogenic atypical coli (EPEC) and E. coli enterohemorrhagic (EHEC), and E. coli enterotoxigenic (ETEC). In addition, this serogroup of E. coli has a variety of emerging clones considered high-risk pathogens. Due to the global impact of these pathogens on health and the lack of public sanitation in developing countries, the best way to fight diarrhea caused by E. coli belonging to the serogroup is vaccination. However, the vaccine against these pathogens should generate antibodies able to recognize all variants of E. coli O26 regardless of the mechanism of virulence of the same. It was demonstrated in our laboratory that antibodies against the O111 polysaccharide of LPS from E. coli were able to inhibit adherence to human epithelial cells of EPEC, EHEC, and EAEC (enteroaggregative E. coli) belonging to this serogroup. However, these antibodies were not able to inhibit the adhesion of bactéria belonging to a heterologous serogroup. These results suggest that the formulation of a vaccine against the O antigen of E. coli is able to recognize and inhibit the adhesion of all strains within the same serogroup, regardless of the mechanism of virulence of the same. in that project, we will determine the ability of antibodies against the antigen of O26 E. coli to inhibit adherence to human epithelial cells of EHEC, EPEC, and ETEC belonging to this serogroup.(AU)