EFFECTS OF REBAMIPIDE ON PRODUCTION OF SEVERAL CYTOKINES BY HUMAN PERIPHERAL-BLOOD MONONUCLEAR-CELLS

Recently, the relative contributions of local T helper cell responses of the Th1-type and Th2-type to the pathogenesis of gastritis and pept ic ulcers associated with Helicobacter pylori infection have been exam ined. However, the results were controversial with respect to whether cellular immunity (Th1-type) or humoral immunity (Th2-type) responses predominate in H. pylori infection and with respect to how these respo nses may contribute to disease pathogenesis. In this study, we investi gated the characteristics of the production of various cytokines induc ed by H. pylori or lipopolysaccharide (LPS), which was derived from H. pylori or Escherichia coli, in human peripheral blood mononuclear cel ls (PBMC). Live Pi. pylori induced production of many cytokines, such as IL-1 beta, IL-10, IL-8, IFN-gamma, and TNF-alpha, whereas we could not detect IL-2 or IL-4. Moreover, we evaluated the effect of rebamipi de on the production of several cytokines from PBMC induced by various stimuli. Rebamipide suppressed the production of IL-8, IL-10, TNF-alp ha, and IL-1 beta induced by PI. pylori in a dose-dependent manner. On the other hand, the production of IL-12 induced by H. pylori showed a tendency to increase as a result of treatment of the cells with rebam ipide. These results suggested that rebamipide might be effective in r egulating cytokine responses in the H. pylori-infected host and mainta ining host immunity. Moreover, it might contribute positively to disea se progression and bacterial eradication.