Protective anti-Helicobacter immunity is induced with aluminum hydroxide or complete Freund's adjuvant by systemic immunization

To determine whether systemic immunization against Helicobacter pylori coul d be achieved with an adjuvant approved for human use, the efficacy of vacc ination with Helicobacter antigen in combination with aluminum hydroxide (A lOH) was evaluated in a murine model of Helicobacter infection. Immunizatio n with antigen and AlOH induced interleukin-5-secreting, antigen-specific T cells, and immunization with antigen and complete Freund's adjuvant induce d interferon-gamma -secreting, antigen-specific T cells, as determined by E LISPOT assay. Both immune responses conferred protection after challenge wi th either H. pylori or H. felis, as confirmed by the complete absence of an y bacteria, as assessed by both histology and culture of gastric biopsy sam ples. Protection was antibody independent, as demonstrated with antibody-de ficient mu MT mice (immunoglobulin-gene knockout mice), and CD4(+) spleen T cells from immunized mice were sufficient to transfer protective immunity to otherwise immunodeficient rag1(-/-) recipients. These results suggest an alternative and potentially more expeditious strategy for development of a human-use H. pylori vaccine.