MIGRATION OF HOST AND DONOR T-CELLS IN SMALL-BOWEL TRANSPLANTATION

In this study migration of host and donor CD4(+) and CD8(+) T cells in a fully allogeneic model was described and compared with the migratio n pattern in a graft-versus-host reaction (GVHR) model, where the T-ce ll traffic in the graft served as a physiological control. Heterotopic small bowel transplantations were performed in a rat model, with anim als being sacrificed on postoperative days (POD) 2, 3, 4, 5, and 7. Gr aft and host mesenteric lymph nodes were harvested, homogenized, and s tained with monoclonal antibodies against MHC class I, CD4(+), and CD8 (+) antigens. The host and donor T cell migration patterns were studie d using a double-staining flow cytometric technique. We found that dur ing the development of rejection, the normal physiological circulation of graft and host T cells was disrupted. In the graft of the allogene ic model, a shift from host cell to graft cell dominance occurred on P OD 3-4. This change in migration pattern coincided in the host with a 6 % peak in graft cell infiltration, which disappeared on POD 7. These patterns of T-cell migration may be further explored for diagnostic p urposes.