Immune responses in mice to intranasal and intracutaneous administration of a DNA vaccine encoding Helicobacter pylori-catalase

We previously reported that the intracutaneous injection of DNA vaccines encoding Helicobacter pylori heat shock proteins elicited 0 specific immune responses, and led to reduced infection in mice. In this study, we constructed DNA vaccine encoding H. pylori-catalase (pcDNA3.1-kat) and investigated the immune responses to intranasal and intracutaneous administration of pcDNA3.1-kat. C57/BL6 mice were immunized intracutaneously with 10 mug of pcDNA3.1-kat or intranasally with 50 mug of pcDNA3.1-kat. Catalase-specific IgG antibody was detected in the sera of intranasal and intracutaneous immunized mice. Both intranasal and intracutaneous immunized mice were significantly protected from colonization by H. pylori and had significantly reduced degrees of gastritis. These results demonstrate that DNA vaccine encoding H. pylori-catalase can induce an immune response against H. pylori, and that intranasal immunization works as well as intracutaneous immunization. (C) 2002 Elsevier Science Ltd. All rights reserved.