Inflammatory Cytokine mRNA Expression during Early and PersistentHelicobacter pyloriInfection in Nonhuman Primates

Abstract

The role of mononuclear phagocytes in orchestrating the host responses to Helicobacter pylori is inadequately understood. Therefore, gene expression for the monocyte/macrophage-derived cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α was determined before and during H. pylori infection of rhesus monkeys by use of a highly sensitive quantitative reverse transcriptase polymerase chain reaction. The numbers of molecules of IL-1β, IL-6, and TNF-α mRNA in gastric tissue during early infection (7 weeks) significantly exceeded the preinfection numbers (P < .03). Moreover, the numbers of IL-1β, IL-6, and TNF-α mRNA molecules in persistently infected animals (6 years) also were elevated compared with preinfection numbers (P < .02, P = .03, P = .16, respectively). Cytokine gene expression coincided with progressive H. pylori gastritis, confirmed by increased gastritis scores over preinfection scores (P < .005). These findings provide quantitative evidence that H. pylori induces local gene expression of monocyte/macrophage-derived inflammatory cytokines and evokes an innate response in gastric tissue of nonhuman primates.