The Third Party Immature Dendritic Cells Loaded With Donor Antigen Induce Ag-specific Tolerance

It is an ideal way to relieve the rejection after transplantation of allogeneic skin by inducing host alloantigen-specific tolerance to donor.Dendritic cells(DCs) are the most important professional antigen-presenting cells(APC).In the process of antigen-presenting, DCs with deficience or blocking of their co-costimulatory molecules (CD80,CD86etc),can not stimulate naive T lymphocyte proliferation.They induce T lymphocyte anergy and promote antigen-specific tolerance. Immature dendritic cells (imDCs) have congenital characteristic of tolerance,because they are deficient in costimulatory molecules. Therefore, imDCs can inducing tolerance to allografts in vivo obviously.It is sure that applicating with imDCs, allogenic skin likely has longer survival time than usual after transplantation.According to the current situation of burn surgery,we often have an operation on patients by allogenic skin transplantation or a large piece of allogenic skin+auto-microskin transplantation on escharectomy after large area of deep burns. The survival time of allogenic skin is very important to stabilization of patient's condition and the survival of auto-microskin.Better result will be gained if imDCs are applicated in the skin transplantation.Nowadays,the DCs which can be applied clinically are mainly from healthy adult donors ,cultured and conserved in vitro;The skin for transplantation comes from dead bodies wich had been donated.Therefore,the donor DCs and skin are not from the same body, so called"the third party mode".The third party DCs do not contain the same antigen of skin allografts. So they are hard to induce specific tolerance to skin allograft directly.To induce the Ag-specific tolerance,firstly we must have imDCs uptake and be treated with the donor antigen,then the imDCs present it to naive T lymphocyte to induce tolerance. So we must reconstruct the third party imDCs and make them load and expess donor antigens.Then the imDCs can induce Ag-specific immue tolerance to donor.ImDCs have powerful ability of phagocytosing antigen.It is well known that imDCs can phagocytose and load foreign antigens. ImDCs after phagocytosing apoptotic cells can...