Serum neutralizing antibody response to the vacuolating cytotoxin of Helicobacter pylori.
Approximately 50% of Helicobacter pylori isolates produce a cytotoxin in vitro that induces vacuolation of eukaryotic cells. To determine the in vivo relevance of this phenomenon, we sought to detect cytotoxin-neutralizing antibodies in sera from H. pylori-infected persons. As a group, sera from 29 H. pylori-infected patients neutralized the activity of the purified cytotoxin to a significantly greater extent than sera from 24 uninfected persons (P = 0.007). The cytotoxin neutralizing activity in sera from H. pylori-infected persons was mediated predominantly by the purified IgG fraction. Sera from H. pylori-infected persons neutralized the cytotoxins produced by multiple H. pylori strains, but failed to neutralize trimethylamine-induced cell vacuolation. Neutralization of cytotoxin activity by human or immune rabbit sera was associated with immunoblot IgG recognition of an 87-kD H. pylori protein. Similarly, neutralization of the toxin by sera was associated with IgG recognition of the purified cytotoxin in an enzyme-linked immunosorbent assay (P less than 0.0001). The presence of cytotoxin-neutralizing antibodies in sera from H. pylori-infected persons indicates that the cytotoxin is synthesized in vivo.
Cover
T L
TL
Department of Veterans Affairs Medical Center, Nashville, Tennessee 37232.
Cao
P
P
Murthy
U K
UK
Sipple
M S
MS
Blaser
M J
MJ
D000328:Adult; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D003603:Cytotoxins / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000276:immunology; D009500:Neutralization Tests; D011817:Rabbits; D014617:Vacuoles / Q000187:drug effects
D000907:Antibodies, Bacterial; D003603:Cytotoxins; D007074:Immunoglobulin G