Dendritic Cells In Allogeneic After Auricle Transplantation In Rats Migration And Chemotactic Factor Expression

Objective To study composite tissue allotransplantation, rat auricle allograft model was established. The migration of dendritic cells and the expression of correlative chemokines were detected post-operation to explore the role of DC's migration in transplantation immunity and the possible mechanism of regulation by chemokines. Methods The rat auricle transplantation with vessel pedicles was performed under microsurgery. The gross appearance and histologic changes of grafts were observed to evaluate rejection response. The expression of MIP-la~ MIP-3ct in grafts were immunohistochemically detected. The quantity of Langerhans cells within epidermis and dendritic cells in draining lymph nodes was measured by anti-Ia immunofluorescence and anti-S 100 immunohistochemistry, respectively. The concentration of MIP-3f3 in DLNs homogenate was determined by ELISA, and the chemotaxis to DC was detected in modified Boyden-type microchainber chemotaxis assay. Results (i ) The immune rejection began at the third day post-operation in allotransplantation. The gross appearance of rejection included skin ulceration, swelling, necrosis, deformation, and so on. The main histological changes were dermal edema companied with infiltrated lymphocytes and monocytes. There appeared vasculitis and folliculitis together with either muscle degeneration or cartilage damage in later phase. The mean survival time of auricle allograft was 7.8?.7 days; (ii) The quantity of LC in allograft epidermis increased with cell body largened and dendrite extended, which culminated at 3 days post- operation. The infiltrating DC in DLNs accumulated continuously; (iii) The expression of MIP-.3a within epidermis peaked at 24h and 5d after allotransplantation, however, MIP-lct extensively expressed mainly in dermis and subcutaneous parts by time. The DLNs homogenate displayed the increasing content of MIP-313 that showed enhanced chemotaxis to cultured DC in vitro, and this chemotaxis capacity could be blocked by M1P313 antibody; (iv) In isograft group, the number of DC and the expression of chemokines lightly increased during first 1224h, then declined to baseline throughout follow-up period. Conclusions Rat ear allograft is an ideal animal model for study of composite tissue allotransplantation. The exaggerated expression of chemo- kines caused by injuries during operation in earlier phase and rejection in later phase accelerate the migration of dendritic cells, which promotes allo-antigen presenting and rejection response.