The gastric H+/K+ ATPase is the causative autoantigen recognised by CD4(+)
T cells that mediate autoimmune gastritis. Pathogenic CD4(+) T cells are re
gulated by CD25(+)CD4(+) T cells. Here, it is proposed that waves of activa
tion and migration of antigen presenting cells and CD4(+) T cells to and fr
om the target organ and draining lymph node result in tissue damage.