Roles of mucosal mast cells in intestinal cell-mediated immunity.

Mucosal mast cells in rats with GvHR have been studied by cell counts, tissue levels of the specific protease RMCPII, and, as an index of MMC activation, serum RMCPII. In semi-allogeneic GvHR without host irradiation, GvHR produced modest increases in these three indices. In contrast, irradiation profoundly depleted MMC even though enteropathy was more severe than in non-irradiated hosts. We suggest that enteropathy is not dependent on the presence of MMC. In rats given cyclosporin A, lesions of GvHR were mild and numbers of MMC were low.