Previous Article | Next Article ![]()
Infect. Immun., 04 1995, 1183-1187, Vol 63, No. 4
GI Perez-Perez, VL Shepherd, JD Morrow and MJ Blaser
The mechanism by which Helicobacter pylori, which has little or no invasive
activity, induces gastric-tissue inflammation and injury has not been well
characterized. We have previously demonstrated that water- extracted
proteins of H. pylori are capable of activating human monocytes by a
lipopolysaccharide (LPS)-independent mechanism. We have now compared
activation of macrophages by purified LPS from H. pylori and from
Escherichia coli. LPS was prepared by phenol-water extraction from H.
pylori 88-23 and from E. coli O55. THP-1, a human promyelomonocytic cell
line, and macrophages derived from rat bone marrow each were incubated with
the LPS preparations, and cell culture supernatants were assayed for
production of tumor necrosis factor alpha (TNF-alpha), prostaglandin E2
(PGE2), and nitric oxide. THP-1 cells showed maximal activation by the LPS
molecules after cell differentiation was induced by phorbol 12-myristate
13-acetate. Maximal TNF-alpha and PGE2 production occurred by 6 and 18 h,
respectively, in both types of cells. In contrast, NO was produced by rat
bone marrow- derived macrophages only and was maximal at 18 h. The minimum
concentration of purified LPS required to induce TNF-alpha, PGE2, and NO
responses in both types of cells was 2,000- to 30,000-fold higher for H.
pylori than for E. coli. Purified LPS from three other H. pylori strains
with different polysaccharide side chain lengths showed a similarly low
level of activity, and polymyxin B treatment markedly reduced activity as
well, suggesting that activation was a lipid A phenomenon. These results
indicate the low biological activity of H. pylori LPS in mediating
macrophage activation.
Copyright © 1995, American Society for Microbiology
Activation of human THP-1 cells and rat bone marrow-derived macrophages by Helicobacter pylori lipopolysaccharide
Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2605.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|