Inhibitory effect of IL-4 on the production of IL-1 beta and TNF-alpha by gastric mononuclear cells of Helicobacter pylori infected patients

Background The mechanisims by which Helicobacter pylori damages host tissue s are complex and unclear. Aims To determine the effect interleukin (IL)-4 and interferon-gamma (IFN-g amma) on the production of proinflammatory cytokines by the gastric mononuc lear cells of H. pylori infected patients was determined. Methods The effect of IL-4 and IFN-gamma on the production of proinflammato ry cytokines by the gastric mononuclear cells of H. pylori infected patient s was determined. Results IL-4 markedly reduced the production of IL-1 beta and tumour necros is factor-a (TNF-alpha) by the gastric mononuclear cells of H. pylori infec ted patients (P<0.01). Enzyme-linked immunospot (ELISPOT) assay indicated a decrease in IL-4 producing cells (P<0.05) and an increase in IFN-gamma sec reting cells (P<0.01). Conclusions The increased level of proinflammatory cytokines may be due to hyposecretion of IL-4 in H. pylori infected patients. T helper type 1 (Th1) immune response with increased IFN-<gamma> also contributes to the inflamm ation of the gastric mucosa.