Cross-reactivity of anti-CagA antibodies with vascular wall antigens: possible pathogenic link between Helicobacter pylori infection and atherosclerosis.
BACKGROUND
Helicobacter pylori-CagA positive strains have been shown to be associated with atherosclerosis. However, the pathogenesis is still undetermined. The aim of this study was to determine whether anti-CagA antibodies cross-react with antigens of normal and atherosclerotic arteries.


RESULTS
Eight umbilical cord sections, 14 atherosclerotic artery sections, and 10 gastrointestinal tract sections were examined by immunohistochemistry using polyclonal anti-CagA antibodies. Five atherosclerotic and 3 normal artery samples were also lysed in ice-cold lysis buffer containing protease inhibitors and were immunoprecipitated using the same antibodies. Anti-CagA antibodies reacted with cytoplasm and nuclei of smooth muscle cells in umbilical cord and atherosclerotic vessel sections, cytoplasm of fibroblasts-like cells in intimal atherosclerotic plaques, and the cell membranes of endothelial cells. Anti-CagA antibodies also specifically immunoprecipitated 2 high molecular weight antigens of 160 and 180 kDa from both normal and atherosclerotic artery lysates.


CONCLUSIONS
Anti-CagA antibodies cross-react with antigens of both normal and atherosclerotic blood vessels. We speculate that the binding of anti-CagA antibodies to those antigens in injured arteries could influence the progression of atherosclerosis in CagA-positive H pylori-infected patients.
Franceschi
Francesco
F
Department of Pathology, VA Medical Center and Baylor College of Medicine, Houston, Tex 77030, USA.
Sepulveda
Antonia R
AR
Gasbarrini
Antonio
A
Pola
Paolo
P
Silveri
Nicolò Gentiloni
NG
Gasbarrini
Giovanni
G
Graham
David Y
DY
Genta
Robert M
RM
D000907:Antibodies, Bacterial / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology*; D001158:Arteries / Q000276:immunology; D001161:Arteriosclerosis / Q000276:immunology* / Q000382:microbiology; D001324:Autoantigens / Q000276:immunology*; D001426:Bacterial Proteins / Q000276:immunology*; D003429:Cross Reactions; D016481:Helicobacter Infections / Q000150:complications; D016480:Helicobacter pylori / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D011233:Precipitin Tests
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001324:Autoantigens; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori