Attenuated CagA oncoprotein in Helicobacter pylori from Amerindians in Peruvian Amazon.
J Biol Chem
; 286(34): 29964-72, 2011 Aug 26.
Article
em En
| MEDLINE
| ID: mdl-21757722
ABSTRACT
Population genetic analyses of bacterial genes whose products interact with host tissues can give new understanding of infection and disease processes. Here we show that strains of the genetically diverse gastric pathogen Helicobacter pylori from Amerindians from the remote Peruvian Amazon contain novel alleles of cagA, a major virulence gene, and reveal distinctive properties of their encoded CagA proteins. CagA is injected into the gastric epithelium where it hijacks pleiotropic signaling pathways, helps Hp exploit its special gastric mucosal niche, and affects the risk that infection will result in overt gastroduodenal diseases including gastric cancer. The Amerindian CagA proteins contain unusual but functional tyrosine phosphorylation motifs and attenuated CRPIA motifs, which affect gastric epithelial proliferation, inflammation, and bacterial pathogenesis. Amerindian CagA proteins induced less production of IL-8 and cancer-associated Mucin 2 than did those of prototype Western or East Asian strains and behaved as dominant negative inhibitors of action of prototype CagA during mixed infection of Mongolian gerbils. We suggest that Amerindian cagA is of relatively low virulence, that this may have been selected in ancestral strains during infection of the people who migrated from Asia into the Americas many thousands of years ago, and that such attenuated CagA proteins could be useful therapeutically.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Bactérias
/
Helicobacter pylori
/
Infecções por Helicobacter
/
Evolução Molecular
/
Fatores de Virulência
/
Antígenos de Bactérias
Limite:
Animals
/
Female
/
Humans
/
Male
País/Região como assunto:
America do sul
/
Peru
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article