Rapid migration of host lymphocytes into the lymphoid tissue of the intestinal graft at early stage after transplantation

AIM:To determine the migration mode of host lymphocytes into the intestinal graft by analyzing different lymphoid compartments of the graft. METHODS:2, 4, 6 days after transplantation, murine intestinal grafts were harvested for histologic assessment. Lymphocytes were collected from mesenteric lymph nodes (MLN), Peyer’s patch (PP), lamina propria lymphocytes (LPL) and intraepithelial lymphocytes (IEL) in the graft for analyzing by cytometry. RESULTS:At the day 2 and day 4, no evidence of rejection in intestinal allograft was found, while the rejection signs were apparent at the 6th day. At day 2 and day 4, host lymphocytes had rapidly replaced donor cell in graft MLN and PP. The migration of host lymphocytes into the LPL and IEL was not as fast as MLN and PP, however, the near-total replacement took place at the 6th post transplant day. The host lymphocytes were activated at the early stage of recruitment into the graft. CONCLUSION:The rapid recruitment of recipient lymphocytes and early activation could be responsible for the formidable rejection of intestinal transplantation.