Activation of lymphocytes isolated from the gastric mucosa of the mouse.

A method for the isolation of lymphocytes and epithelial cells from the murine gastric mucosa has been developed. Gastric lymphocytes were stimulated by T-cell mitogens in vitro. When mice were sensitized systemically with human gammaglobulin (HGG) and given the antigen orally 4 days before cell isolation, both the number of mucosal lymphocytes and their capacity to incorporate [3H]thymidine ([3H]TdR) was enhanced. Gastric epithelial cells added to cultures of syngeneic spleen cells enhanced both phytohaemagglutinin (PHA) responsiveness and mixed lymphocyte reactions (MLR) in low numbers, but significantly suppressed these responses at high concentrations. These findings suggest that gastric lymphocytes, like those of the gut, are involved in the immune response against antigens taken in by mouth, and that there may be in vivo interactions between gastric mucosa lymphocytes and epithelial cells.