New immunological investigations on Helicobacter pylori-induced gastric ulcer in patients

Authors

  • Hamid Reza Rahimi,

    1. Department of Immunology, Professor Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
    2. Department of Pharmacology and Toxicology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran
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  • Manoochehr Rasouli,

    Corresponding author
    • Department of Immunology, Professor Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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  • Akram Jamshidzadeh,

    1. Department of Pharmacology and Toxicology, Faculty of Pharmacy
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  • Shohreh Farshad,

    1. Department of Immunology, Professor Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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  • Mehdi Saberi Firoozi,

    1. Gastroenterohepatology Research Center, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
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  • Ali Reza Taghavi,

    1. Gastroenterohepatology Research Center, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran
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  • Simin Kiany

    1. Department of Immunology, Professor Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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Correspondence

Manoochehr Rasouli, Department of Immunology, Professor Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.

Tel: +98 711 6474304; fax: +98 711 6474303; email: rasoulim@sums.ac.ir

ABSTRACT

Although Helicobacter pylori (Hp) plays an important role in the pathogenesis of chronic gastritis and gastric ulcer, little is known about the probable mechanisms of these types of gastrointestinal damage. To determine the precise mechanisms involved in ulcer formation, immune responses in patients with gastric ulcer (GUP) caused by Hp infection (Hp+) were compared with those of other gastritis patients (GP). The sensitivity and proliferation of peripheral blood mononuclear cells (PBMNCs) obtained from patients were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against exposure with complex Hp crude antigen (HPCA) and mitogen (phytohemagglutinin, PHA). Production of inflammatory cytokines, including interleukin (IL)-1β and IL-8, in serum and supernatants of PBMNCs were then measured by ELISA. It was found that, after stimulation with PHA, both IL-8 and IL-1β concentrations in sera and supernatants as well as proliferation and sensitivity were statistically greater in GUP Hp+ than GP Hp. Furthermore, HPCA inhibited the proliferation of PBMNCs dose-dependently; however, it stimulated IL-8 and IL-1β production in supernatants of mononuclear cells. Therefore, the up-regulated concentrations of IL-8 and IL-1β may have been caused by increase in the size of mononuclear cell subpopulations or in their cytokine secretory activity, indicating the greatest cell responsiveness in GUP Hp+ patients. These results suggest that tissue damage and ulcers occur in patients who produce more IL-8 and IL-1β than patients who do not develop ulcers; the former consequently have more activated immune cells at the site of infection. Therefore, both host responses and Hp virulence factors may be involved in the development of gastric ulcers.

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