Proinflammatory activity of a cecropin-like antibacterial peptide from Helicobacter pylori

Helicobacter pylori, the bacterial pathogen associated with gastritis and p eptic ulcers, is highly successful in establishing infection in the human g astric mucosa, a process typically associated with massive infiltration of inflammatory cells, Colonization of the mucosa is suggested to be facilitat ed by H. pylori-produced cecropin-like peptides with antibacterial properti es, giving the microbe a competitive advantage over other bacteria. We show that a cecropin-like antibacterial peptide from H pylori, Hp (2-20), not o nly has a potent bactericidal effect but also induces proinflammatory activ ities in human neutrophils, e,g,, upregulation of integrins (Mac-l), induct ion of chemotaxis, and activation of the oxygen radical producing NADPH-oxi dase. Furthermore, we show that these effects are mediated through binding of Hp(2-20) to the promiscuous, G-protein-linked lipoxin A(4) receptor-form yl peptide-like receptor 1.