Helicobacter pylori cag pathogenicity island is associated with reduced expression of interleukin-4 (IL-4) mRNA and modulation of the IL-4delta2 mRNA isoform in human gastric mucosa

Abstract

Interleukin-4 (IL-4) and IL-4delta2 mRNA gastric expression was evaluated in healthy subjects and patients who did not have ulcers but were infected with Helicobacter pylori with or without the cag pathogenicity island (cag PAI). IL-4 mRNA was physiologically expressed by gastric epithelium and negatively influenced by H. pylori. Also, nonepithelial cells in the lamina propria of H. pylori-infected patients expressed IL-4 mRNA, whereas IL-4delta2 mRNA was found only in cag PAI-negative patients. Thus, gastric IL-4 takes part in the local immune response to H. pylori.

FIG. 1.

ISH for IL-4 mRNA in gastric antrum biopsy sections. Bright-field photomicrographs with ³⁵S-labeled antisense IL-4 RNA probe of the surface epithelium and pits from a control subject (A and B), a cag PAI-negative patient (C and D), a cag PAI-positive patient (E and F) and from a cytospin sample of clonal T cells producing IL-4 (G). Original magnifications, ×20 (left) and ×40 (right).

FIG. 2.

Nested RT-PCR for IL-4 and IL-4δ2 in a cag PAI-positive patient (A), cag PAI-negative patient (B), and an uninfected control subject (C). Pictures were obtained from the original Polaroid films for 1.5% agarose gel electrophoresis and ethidium bromide staining. Lane MW, 100-bp DNA ladder; lane 1, first-round PCR (R1) for IL-4; lane 2, second-round PCR (R2) for IL-4; lane 3, R1 for IL-4δ2; lane 4, R2 for IL-4δ2.