Effects Of Paclitaxel On Murine T Cell Behaviors And Skin Allograft Rejection

Objective:To investigate the effects of paclitaxel(PTX)on murine T cell behaviors and skin allograft rejection, especially its underlying mechanisms, in order to develop a new immunointervention reagent. Methods:T lymphocytes were stimulated with concanavalin(Con A) or (PDB no+/+Ion), and its behaviors were evaluated with flow cytometry: expression level of CD69 and CD25 activation of T cells was evaluated by Fluorescence conjugated monoclonal antibodies labeling , proliferation of T lymphocytes was detected by CFDA-SE labeling, distribution of cell cycle was analyzed by propidium iodide(PI) staining and cell apoptosis was measured by double staining of annexin V and PI; We established murine skin allograft model, the effect of PTX on skin allograft was evaluated, mixed lymphocyte reaction was measured, CD4~+CD25~+ regulatory T cells were measured by three fluorescent staining together with flow cytometry, the production of cytokines were investigated by luminex, and chimerism was analyzed by fluorescence conjugated monoclonal antibodies labeling. Results:1, PTX significantly downregulated expression level of CD25 of murine T cells, inhibited proliferation , blocked cell cycle progression in G2/M phase and induced cell apoptosis in a dose-dependent in response to ConA or (PDB no+/+Ion), but had no effect on expression lever of CD69. Besides, PTX and CsA inhibited proliferation of T cells in a synergistic manner. Moreover, PTX inducedapoptosis of actived T cells in a dose-dependent and time-dependent manner, nor naive T cells2^ PTX has immunosuppressive properties that can effectively promote allograft survival in a murine skin transplant model. Besides, PTX could upregulated relative quantity of CD4+CD25+ regulatory T cells, decreased interferon-y and leukin-2, increased IL-10. Murine skin allograft was prolonged ,without immunointervention reagent, treated with PTX in combination with donor cells before transplantation. Conclusion:PTX significantly inhibited murine T cell in vitro in response to polyclonal stimulus Con A or (PDB no+/+Ion) which was related to multi-mechanisms of expression of CD25 downregulated, proliferateion inhibited, G2/M arrested and apoptosis induced. These immunosuppression effect can promote allograft survival in a murine skin transplant model. Besides, the immunosuppression effect of PTX maybe also associated with upregulation relative quantity of the CD4+CD25+ regulatory T cells and regulation the cytokine secretion from Thl to Th2 type. While the immunosuppression effect of PTX in combination with CsA is related to downregulation of the cytokine of Thl type, no related to the CD4+CD25+ regulatory T cells. BALB/c were treated with PTX in combination with donor cells before skin transplantation , so light tolerance was produced and skin allograft was prolonged. These data provide useful information in order that PTX can develop a new immunointervention reagent.