Oral vaccination with live attenuated pathogenic bacteria protects immunocompromised hosts from lethal colitis

Abstract Enteropathogenic Escherichia coli(EPEC) and enterohemorrhagic E. coli(EHEC) are significant causative agents for diarrheal diseases globally. Vaccination has been deemed as the most effective strategy preventing EPEC EHEC caused foodborne illnesses; however, FDA not yet licensed any vaccine against or EHEC. Of note, live attenuated bacterial scarcely investigated infection, in particular immunocompromised populations where infections associated with severe symptoms outcomes. Infection Citrobacter rodentium(CR), murine equivalent of EHEC, mice widely used to develop novel strategies evaluate vaccination efficacy. CR infection such interleukin-22 knockout (Il22−/−) leads mortality, which mirrors outcomes populations. We explored whether oral inoculation mutants rationally virulence could protect lethal susceptible Il22−/−mice. showed that administration strains elicited efficient systemic humoral immunity variant proteins, hence protecting otherwise Our findings provide proof concept evidence prevent EPEC/EHEC hosts more lethality, reveal CR-specific antibody subtypes determinants critical offered immune protection.