Antigenic diversity among Helicobacter pylori vacuolating toxins

• Published in: Infection and immunity Vol. 69; no. 7; pp. 4329 - 4336
• Main Authors: VINION-DUBIEL, Arlene D, MCCLAIN, Mark S, PING CAO, MERNAUGH, Raymond L, COVER, Timothy L
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.07.2001
• Subjects: Animals; Antibodies, Monoclonal - biosynthesis; Antigenic Variation - immunology; Antigens, Bacterial - immunology; Bacterial diseases; Bacterial diseases of the digestive system and abdomen; Bacterial Proteins - immunology; Bacterial Toxins - immunology; Bacteriology; Biological and medical sciences; Epitope Mapping; Epitopes, B-Lymphocyte - immunology; Female; Fundamental and applied biological sciences. Psychology; Helicobacter pylori; Helicobacter pylori - immunology; Human bacterial diseases; Infectious diseases; Medical sciences; Mice; Mice, Inbred BALB C; Microbiology; Molecular Pathogenesis; Neutralization Tests; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Recombinant Fusion Proteins - immunology; VacA protein; vacuolating toxin; vacuolating toxins; Immunization; Immunoglobulins; Spirillales; Secretion; Rodentia; Diversity; Spirillaceae; Monoclonal antibody; Protein A; Strain; Toxin; Vertebrata; Generation; Type; Mammalia; Antigenicity; Helicobacter pylori; Mouse; Bacteria; Epithelial cell
• ISSN: 0019-9567; 1098-5522
• DOI: 10.1128/IAI.69.7.4329-4336.2001

Helicobacter pylori vacuolating cytotoxin (VacA) is a secreted protein that induces vacuolation of epithelial cells. To study VacA structure and function, we immunized mice with purified type s1-m1 VacA from H. pylori strain 60190 and generated a panel of 10 immunoglobulin G1kappa anti-VacA monoclonal antibodies. All of the antibodies reacted with purified native VacA but not with denatured VacA, suggesting that these antibodies react with conformational epitopes. Seven of the antibodies reacted with both native and acid-treated VacA, which suggests that epitopes present on both oligomeric and monomeric forms of the toxin were recognized. Two monoclonal antibodies, both reactive with epitopes formed by amino acids in the carboxy-terminal portion of VacA (amino acids 685 to 821), neutralized the cytotoxic activity of type s1-m1 VacA when toxin and antibody were mixed prior to cell contact but failed to neutralize the cytotoxic activity of type s1-m2 VacA. Only 3 of the 10 antibodies consistently recognized type s1-m1 VacA toxins from multiple H. pylori strains, and none of the antibodies recognized type s2-m2 VacA toxins. These results indicate that there is considerable antigenic diversity among VacA toxins produced by different H. pylori strains.