Role of local cytokines in increased gastric expression of the secretory component in Helicobacter pylori infection

Abstract

Using immunohistochemical staining, we examined the presence of secretory component (SC) on epithelial cells in gastric and duodenal biopsy specimens collected from Helicobacter pylori-infected individuals and healthy controls. Gastric epithelial cells from healthy volunteers expressed low, but detectable, levels of SC. In contrast, significantly higher level of expression of SC (P < 0.001) was observed on epithelial cells in the antra of H. pylori-infected individuals. The antral SC expression correlated with staining for gamma interferon of intraepithelial and lamina propria lymphocytes (r(s) = 0.76 and 0.69, respectively, P < 0.001) and correlated weakly with production of tumor necrosis factor alpha (r(s) = 0.43, P < 0.05), but it did not correlate at all with interleukin-4 production.

FIG. 1

Expression of SC on epithelial cells in duodenal and gastric mucosae. The expression of SC on duodenal (A), antral (B), and corpus (C) epithelial cells was determined by using immunohistochemistry, and the staining intensity was graded from 0 to 5 (negative to very intense). Tissues from DU patients (DU), asymptomatic H. pylori carriers (AS), and H. pylori-negative healthy volunteers (Hp−) were examined. Each dot represents the individual value for one volunteer, and the horizontal bars denote the medians for individual groups. The staining intensity for H. pylori-infected individuals (DU and AS) was significantly different from that for uninfected individuals (P < 0.001) for the antrum but not (P > 0.05) for the duodenum and corpus.

FIG. 2

Immunohistochemical staining of SC and IgA in gastrointestinal tissues. (A and B), staining of SC in sections of the antrum (A) and duodenum (B) from an H. pylori-infected individual. (C and D), staining of IgA in sections of the antra from an H. pylori-infected individual (C) and an uninfected healthy individual (D). Original magnification, ×200.