Antigenic mimicry between Helicobacter pylori and gastric mucosa: failure to implicate heat-shock protein Hsp60 using immunoelectron microscopy.
BACKGROUND
Helicobacter pylori infection induces autoantibodies that cross-react with human gastric mucosa from infected individuals. Candidates for the antigens responsible for molecular mimicry causing autoreactivity include the heat-shock protein HspB (Hsp60, sometimes called Hsp54) or Lewis x and Lewis y carbohydrate antigens.


OBJECTIVE
Our goal was to investigate the involvement of HspB (Hsp60) in autoreactivity between H. pylori and gastric biopsy tissue.


METHODS
Immunoelectron microscopy was used to study cross-reactivity among biopsy tissues from a patient with gastritis, gastric ulcer, and duodenal ulcer and his own serum as well as reactivity with serum raised against HspB from H. pylori and monoclonal antibodies against Lewis antigens.


RESULTS
The patient serum reacted with gastric mucosa, and the antibodies involved were predominantly IgG. Antibody raised to H. pylori HspB (Hsp60) reacted only with H. pylori cells but not with gastric mucosal tissue. In contrast, monoclonal antibodies specific for Lewis x and Lewis y antigens reacted with both H. pylori and human gastric epithelial tissue.


CONCLUSIONS
Hsp60 (Hsp54) is unlikely to be involved in autoreactivity seen in individuals infected with H. pylori. In contrast, we could not rule out the role of Lewis x and Lewis y carbohydrate antigens, expressed as a component of H. pylori lipopolysaccharides, in molecular mimicry and autoantibody production.
Taylor
D E
DE
Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada. Diane.Taylor@ualberta.ca
Fedorak
R N
RN
Sherburne
R
R
D000328:Adult; D000942:Antigens, Bacterial / Q000276:immunology*; D001323:Autoantibodies / Q000096:biosynthesis; D015551:Autoimmunity; D018834:Chaperonin 60 / Q000276:immunology*; D003429:Cross Reactions; D004381:Duodenal Ulcer / Q000276:immunology; D005753:Gastric Mucosa / Q000276:immunology*; D005756:Gastritis / Q000276:immunology; D016481:Helicobacter Infections / Q000276:immunology*; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D007983:Lewis Blood Group Antigens / Q000276:immunology; D016256:Lewis X Antigen / Q000276:immunology; D008297:Male; D016253:Microscopy, Immunoelectron; D018716:Molecular Mimicry; D013276:Stomach Ulcer / Q000276:immunology
D000942:Antigens, Bacterial; D001323:Autoantibodies; D018834:Chaperonin 60; D007983:Lewis Blood Group Antigens; D016256:Lewis X Antigen; C094162:Lewis Y antigen