ANTIBODY AND CYTOKINE RESPONSES IN HELICOBACTER-PYLORI-INFECTED VARIOUS MOUSE STRAINS

Helicobacter pylori (H. pylori) infection in the stomach is etiologica lly closely associated with chronic active gastritis, peptic ulcer, ga stric cancer and gastric mucosa-associated lymphoid tissue lymphoma. I n this study, we examined the antibody responses and cytokine profiles of three strains of mice (BALB/c, C3H/He, and C57BL/6) infected with H. pylori. Following this, correlations between host-immune reactions and intensity of inflammation were analyzed. H. pylori (ATCC43504) was intragastrically administered once a week to the mice from 4 weeks of age, and they were sacrificed at the ages of 4 and 7 months. In these mice, we examined the histology of the stomach, antibody titers again st H. pylori, and serum levels of cytokines (IL-4, IL-10, TNF-alpha, I L-2 and Interferon-gamma). In BALB/c mice, inflammation of the stomach was minimal. Inflammation was observed in 63.6% of C57BL/6 mice and 3 3.3% of C3H/He mice. In C57BL/6 and C3H/He mice, all the cytokines ten ded to increase, In contrast, BALB/c mice were inactive in cytokine pr oduction except for IL-2, Two C3H/He mice developed severe inflammatio n with lymph follicles; one showed a response largely typical of Th-1, and the other showed a response largely typical of Th-2. Although a d efinite correlation was not shown between Th-1/Th-2 response evaluated by cytokine production and intensity of inflammation, it appears that in H. pylori-induced inflammation both cell-mediated (Th-1) and humor al (Th-2) immunity play a role in pathogenesis.