CD8 + T Cells Are Associated with Severe Gastritis in Helicobacter pylori - Infected Mice in the Absence of CD4 + T Cells

Abstract

ABSTRACT Helicobacter pylori infection results in the development of chronic gastritis, and CD4 + T cells are a major component of the gastric cellular infiltrate. To examine whether CD4 + T cells are important in initiating and maintaining H. pylori -induced gastritis, mice deficient in CD4 + T cells (B6.BM1.GK 1.5 mice [GK 1.5 mice]) were infected with H. pylori . We found that as in normal mice, H. pylori -specific antibodies, mostly of the immunoglobulin M isotype, developed in GK 1.5 mice but were unable to cure H. pylori infection. Further, while the stomachs of H. pylori -infected GK 1.5 mice were more heavily infiltrated with CD8 + T cells and B cells, mice deficient in both CD4 + and CD8 + T cells developed mild inflammation comparable to the level observed for C57BL/6 mice. These observations suggest that CD4 + T cells may play an important role in regulating or suppressing gastric CD8 + T cells which, in the absence of CD4 + T cells, may mediate more-severe disease. These studies have revealed a potentially important role for CD8 + T cells in the gastric disease resulting from H. pylori infection.