Figure 1.

Antigen specificity of H. pylori-reactive T cell clones derived from the gastric mucosa of H. pylori-infected patients with low-grade MALT B cell lymphoma (MALT) or uncomplicated chronic gastritis (CG). In vivo activated T cells were recovered from biopsy specimens of gastric mucosa and cloned by limiting dilution. T cell blasts from each clone were seeded in triplicate cultures with irradiated autologous peripheral blood mononuclear cells in the presence of medium alone or optimal doses of H. pylori lysate (10 μg/mL), or CagY (1 μg/mL). After 60 h, [³H] thymidine uptake was measured and expressed as mitogenic index. A significant difference (*) was found between the mitogenic index of CagY-specific MALT lymphoma-derived T clones and CG-derived ones. A highly significant (***) proliferation to CagY than to H.pylori lysate was found in MALT lymphoma-derived T clones.