FIG. 1.

NK cells in peripheral blood mononuclear cells (PBMC) and in the gastrointestinal mucosa. Cells were obtained from biopsies of the antrum and duodenum of noninfected healthy (A) or H. pylori-infected (B) volunteers. Lamina propria cells were obtained by treatment with EDTA and collagenase, and the cells were stained with anti-CD56 and anti-CD3 antibodies and analyzed for the presence of NK cells. Each plot shows at least 5,000 lymphocytes gated based on forward and side scatter characteristics.