Evaluation of PLGA-Encapsulated Recombinant GroEL of S. typhi immune Responses Against Enterohaemorrhagic and Enteropathogenic Escherichia coli

Background: heat shock proteins (hsps) elicit humoral and cellular immune responses. due to their high sequence homology, they can be developed as a new immunogen for cross prophylactic and vaccination effects against infectious agents such as enteropathogenic and enterohemorrhagic escherichia coli (epec and ehec). this study aimed to evaluate the immunogenicity and cross-protective efficacy of rgroel of salmonella typhi (s. typhi) encapsulated in poly lactic-co-glycolic acid (plga) nanoparticles against epec and ehec. methods: recombinant groel was expressed in escherichia coli (e. coli) and purified using ni-nta affinity chromatography. the protein was encapsulated in plga by the double emulsion method, and the nanoparticles were characterized physicochemically. balb/c mice were immunized, and the efficacy of the protein to elicit immune responses was assessed. results: over-expression in e. coli led to corresponding 64.5 kda protein bands in sodium dodecyl sulphate-polyacrylamide gel electrophoresis (sds-page). non-aggregated nanoparticles had a spherical shape with a mean diameter of 194.3±3 nm and encapsulation efficiency of 89.5±2.5%. antibody isotyping revealed that groel immunization induced both igg1 and igg2a antibodies. moreover, immunization of the mice with recombinant groel protein conferred 80 and 60% protection against lethal infections by epec and ehec, respectively. furthermore, organ burden studies revealed a significant reduction in infection in the immunized mice compared to the non-immunized ones. passive immunization with anti-groel sera also protected 50% of the mice against the lethal doses of ehec and epec strains. conclusion: the findings indicated that immunization of the mice with recombinant groel of s. typhi elicited cross-protection against other bacterial infections. this represented the immense potential of groel to be developed as a single vaccine against multiple pathogens.