Evaluation of a new tumor necrosis factor-alpha-inducing membrane protein of Helicobacter pylori as a prophylactic vaccine antigen.
BACKGROUND
Tumor necrosis factor (TNF)-alpha-inducing protein (Tip alpha) is a newly identified carcinogenic factor present in Helicobacter pylori. Tip alpha has the unique function of inducing TNF-alpha production by gastric cells in vitro and is assumed to be related with the development of gastritis and gastric cancer. We investigated the effects of vaccination with Tip alpha against H. pylori infection and analyzed the immune responses.


METHODS
C57BL/6 mice were immunized via the intranasal route with CpG, recombinant Tip alpha + CpG, and recombinant del-Tip alpha (a mutant of Tip alpha) + CpG. Eight weeks after the mice were infected with H. pylori (5 x 10(7) CFU), the number of colonizing bacteria in the stomach was calculated, and the histological severity of gastritis was evaluated. Levels of Tip alpha-specific IgG and IgA antibodies in mouse serum were measured by an enzyme-linked immunosorbent assay (ELISA). Local production of cytokines including Interleukin (IL)-10, TNF-alpha and Interferon (IFN)-gamma in gastric mucosa was also measured by real time-PCR.


RESULTS
Levels of Tip alpha-specific antibodies were significantly higher in Tip alpha-immunized and del-Tip alpha-immunized mice than in the infection control group. The numbers of colonizing bacteria were significantly reduced in Tip alpha-immunized mice (4.29 x 10(5) CFU/g) and del-Tip alpha immunized mice (2.5 x 10(5 )CFU/g) compared with infection control mice (5.7 x 10(6) CFU/g). The levels of IFN-gamma and IL-10 were significantly higher in del-Tip alpha-immunized mice than the infection control group.


CONCLUSIONS
Vaccinations with Tip alpha and del-Tip alpha were effective against H. pylori infection. The inhibition of H. pylori colonization is associated mainly with Th1 cell-mediated immunity.
Inoue
Kunimitsu
K
Department of Microbiology, Faculty of Medicine, Oita University, Oita, Japan.
Shiota
Seiji
S
Yamada
Kentaro
K
Gotoh
Kazuyo
K
Suganuma
Masami
M
Fujioka
Toshio
T
Ahmed
Kamruddin
K
Iha
Hidekatsu
H
Nishizono
Akira
A
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001426:Bacterial Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D005260:Female; D016481:Helicobacter Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D016480:Helicobacter pylori / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007114:Immunization; D051379:Mice; D008810:Mice, Inbred C57BL; D013047:Specific Pathogen-Free Organisms; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000276:immunology
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; C505332:Tipalpha protein, Helicobacter pylori; D014409:Tumor Necrosis Factor-alpha