Protection against Helicobacter pylori infection in mice by intragastric vaccination with H. pylori antigens is achieved using a non-toxic mutant of E. coli heat-labile enterotoxin (LT) as adjuvant

Marta Marchetti, Michela Rossi, Valentina Giannelli, Marzia M. Giuliani, Mariagrazia Pizza, Stefano Censini, Antonello Covacci, Paola Massari, Cristina Pagliaccia, Roberto Manetti, John L. Telford, Gill Douce, Gordon Dougan, Rino Rappuoli, Paolo Ghiara

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We have previously shown that infection of mice with H. pylori can be prevented by oral immunization with H. pylori antigens given together with E. coli heat-labile enterotoxin (LT) as adjuvant. Since LT cannot be used in humans because of its unacceptable toxicity, we investigated whether protection of mice could be achieved by co-administration of antigens with non-toxic LT mutants. Here we show that CD1/SPF mice are protected against infection after oral vaccination with either purified H. pylori antigens (native and recombinant VacA, urease and CagA), or whole-cell vaccine formulations, given together with the non-toxic mutant LTK63 as a mucosal adjuvant. Furthermore we show that such protection is antigen-specific since immunization with recombinant or native VacA plus LTK63 conferred protection against infection by an H. pylori Type I strain, which expresses VacA, but not against challenge with a type II strain which is not able to express this antigen. These results show that: (1) protection against H. pylori can be achieved in the mouse model of infection using subunit recombinant constructs plus non-toxic mucosal adjuvants; and (2) this mouse model is an useful tool in testing H. pylori vaccine formulations for eventual use in humans.

Original languageEnglish
Pages (from-to)33-37
Number of pages5
Issue number1
Publication statusPublished - 1 Jan 1998
Externally publishedYes


  • H. pylori mouse model
  • H. pylori vaccine
  • Non-toxic LT mutants

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