Discussion
These results suggest that immunization avoids HUS outcome and allows to elicit a specific immune response against other virulence factors.
Methods
The cellular and humoral immune response after H7 nasal immunization in mice were studied by the analysis of systemic and intestinal specific antibody production, as well as cytokine production and lymphocyte proliferation against H7 flagellin ex vivo.
Results
Immunized mice developed a strong and specific anti-H7 IgG and IgA response, at systemic and mucosal level, as well as a cellular Th1/Th2/Th17 response. H7 induced activation of bone marrow derived dendritic cells in vitro and a significant delayed-type hypersensitivity (DTH) response in immunized mice. Most relevant, immunized mice were completely protected against the challenge with an E. coli O157:H7 virulent strain in vivo, and surviving mice presented high titres of anti-H7 and Stx antibodies.