ACCUMULATION OF DONOR-SPECIFIC CYTOTOXIC T-CELLS IN INTESTINAL LYMPHOID-TISSUES FOLLOWING INTESTINAL TRANSPLANTATION

Utilizing a rat model of semiallogeneic intestinal transplantation, re cipients were evaluated for accumulation of donor-specific cytotoxic T cells in spleen, mesenteric lymph nodes, Peyer's patches, lamina prop ria, and intraepithelial lymphocytes using Limiting dilution analysis. Naive animals exhibited a low frequency of cytotoxic T cells in splee n and mesenteric lymph nodes with minimal activity detected in Peyer's patches and intraepithelial lymphocytes, but no detectable activity i n lamina propria. Orthotopic intestinal transplantation resulted in si gnificant increases in cytotoxic T-cell activity in recipient Peyer's patches as early as Day 6 and by Day 8 in spleen, mesenteric lymph nod es, lamina propria and intraepithelial lymphocyte populations. Graft l amina propria and intraepithelial lymphocytes exhibited significant cy totoxic T-cell activity as early as 4 days following transplant. The h ighest donor-specific cytotoxic T-cell activity was observed in graft intraepithelial lymphocytes on Day 8 posttransplant. These studies dem onstrate rapid expansion of donor-specific cytotoxic T cells which mig rate to the graft site within 4 days after semiallogeneic intestinal t ransplantation.