| In the field of plastic surgery, We often faced extensive burn, wound, organ defects and dysfunction after tumor resection. Compared with the repairment by autologous tissue transplantation, composite tissue allotransplantation(CTA) is undoubtedly the most reliable method of repairment in clinical..After transplantation, immune rejection is the main cause of organ transplantation failure and even recipient death. At present, the main measure of clinical to prevent and reduce the immune rejection after transplantation is the use of immunosuppressive drugs, but effective immunosuppressive drugs are not only costly, but also increase the side effects associated with risk of infection and malignant tumor incidence. Even more, long-term use of immunosuppressive drugs may cause damage of digestive system, blood system and liver and kidney function, which seriously affect the patients’quality of life. Therefore, mesenchymal stem cells with effective immune rejection ability came into the line of sight. After years of research, mesenchymal stem cells for the ability to regulate the immune response after transplantation has been widely affirmed, and in clinical trials of treatment has also been recognized.At present, the immunosuppressive effect of MSC mechanism is not fully clear. It is generally believed that the mesenchymal stem cells may regulate immune function of immune cells through secretion of a variety of cytokines and by direct contact. Secondary lymphoid organs (secondary lymphatic, organs, SLOs) have played a critical role in MSC regulationin transplantation immunity. The effect of MSCs in GVHD treatment is not ideal enough, which is likely to be due to the inefficience of homing after systemic injection of MSCs. Chemokine (C-C motif) receptor 7 (CCR7) is a kind of chemokine receptor and its ligand chemokine ligand 21 (C-C motif) ligand (CCL21), secreted by secondary lymphoid organs and tissues, induce cells with expression of CCR7 chemotactic to spleen, lymph nodes and other secondary lymphoid organs.Objective To evaluate whether the CCR7 positive subgroup of C3H10 T1/2 cells are more efficient in immunosuppression effects than original ones, the study was performed by skin graft in the mice.Methods The C3H10 T1/2 cells were amplified and eGFP-CCR7 gene were transferred by lentivirus. The skin grafts were harvested from donators (C57BL/6 mice) and then transplanted to recipients (BALB/c mice). The recipients were divided into 4 groups randomly:CCR7+C3H10 T1/2 group:1×106 CCR7+C3H10 T1/2 cells suspended in 1 mL PBS were injected into the recipient mice by caudal vein. C3H10 T1/2 group:1×106 C3H10 T1/2 cells were injected into the recipient mice after skin graft. Allogenic control group:the mice were injected with lml normal saline; Congenic control group: the BALB/c mice received the skin from the congenic ones were injected with normal saline. The skin graft survival condition and histopathological changes were observed on the 12th postoperative day. The Thl7 cells and regulatory T cells (Tregs) subsets in the lymphocytes of spleen were detected by using mouse Thl7/Treg phenotyping kit.Results On the 12th postoperative day, based on the apprearance, pathologic change and FCM results, the grafts existence condition of both allograft treated with CCR7+ C3H10 T1/2 and C3H10 T1/2 were better than allogenic control group. Compared with C3H10 T1/2 group, CCR7+C3H10 T1/2 group had ever better grafts exitence condition and lighter immune response level.Conclusion CCR7+C3H10 T1/2 cells induce more intensive immunosuppressive effects than original C3H10 Tl/2 cells, CCR7+C3H10 T1/2 cells significantly inhibit inflammatory reaction and improve the living condition of skin allograft. |
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