CD4+ T cells, but not CD8+ T cells, are required for the development of experimental autoimmune gastritis

Murine autoimmune gastritis, induced by neonatal thymectomy, is characterized by a mononuclear infiltrate within the gastric mucose, loss of parietal and zymogenic cells and circulating autoantibodies to the gastric H/K ATPase. The infiltrate contains both CD4(+) and CD8(-) T cells. Here we have investigated the roles of CD4(+) and CD8(+) T cells in the development of gastritis by in vivo treatment with depleting rat anti-CD4 and anti-CD8 monoclonal antibodies. Depletion of CD4(+) T cells decreased the incidence of gastric mononuclear infiltrates from 63% (5/8), observed in normal rat immunoglobulin G (IgG)-injected mice, to 8%(1/12) and also abolished the production of antigastric autoantibodies. In contrast, depletion of CD8(+) T cells did not reduce the incidence of gastritis. The absence of CD8(+) T cells in the infiltrate of the stomach of anti-CD8(+)-treated mice was confirmed by immunocytochemistry. These results argue that neonatal thymectomy-induced autoimmune gastritis is mediated by CD4(+) cells and that CD8(+) T cells do not play a significant role in the development of the gastric lesion.