Comparison of Helicobacter pylori and Escherichia coli in induction of TNF-α mRNA from human peripheral blood mononuclear cells

• Published in: Indian journal of medical microbiology Vol. 28; no. 3; pp. 233 - 237
• Main Authors: Ahmadzadeh, E, Zarkesh-Esfahani, H, Roghanian, R, Akbar, F Navab
• Format: Journal Article
• Language: English
• Published: India Elsevier B.V 01.07.2010
• Subjects: Adult; Biopsy; Cells, Cultured; Conformation; E. coli; Escherichia coli; Escherichia coli - immunology; Gene expression; Gene Expression Profiling; H. pylori; Helicobacter pylori; Helicobacter pylori - immunology; Humans; Leukocytes (mononuclear); Leukocytes, Mononuclear - immunology; Lipopolysaccharides; Outer membranes; PBMCs; Peripheral blood mononuclear cells; Polymerase chain reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Bacterial - biosynthesis; RNA, Messenger - biosynthesis; TNF-α; Tumor necrosis factor- alpha; Tumor Necrosis Factor-alpha - biosynthesis; H. pylori; TNF-α; PBMCs; E. coli
• ISSN: 0255-0857; 1998-3646
• DOI: 10.4103/0255-0857.66482

Purpose: To investigate the difference between the abilities of Helicobacter pylori and Escherichia coli to induce expression of TNF-α in human peripheral blood mononuclear cells (PBMC). Materials and Methods:H pylori was isolated from gastric biopsy specimens. The mononuclear cells were isolated from human blood, cultured, and treated with either intact or sonicated E coli or H pylori, and mRNA expression for TNF-α was detected using semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Results: TNF-α mRNA expression levels were significantly higher in PBMCs stimulated with E coli compared to those stimulated with H pylori at the same number and identical conditions (P < .001). The results also suggest that sonicated bacteria were significantly (P < .001) less stimulatory for PBMCs than intact bacteria for both E coli and H pylori. Conclusions: The ability of different H pylori strains isolated from biopsy samples to stimulate TNF-α from PBMCs was significantly lower than that of E coli. Sonicated bacteria, as compared to intact bacteria, was a very poor inducer of TNF-α mRNA expression, suggesting that the conformation of lipopolysaccharides (LPS) on the outer leaflet of the outer membrane is not totally conserved in sonicated bacteria.