紫杉醇抑制大鼠原位肝移植急性排斥反应的机制

目的 探讨紫杉醇抑制大鼠原位肝移植急性排斥反应的机制。方法 建立大鼠原位肝移植模型（Lewis-BN），将大鼠分为生理盐水对照组（A组），紫杉醇低剂量干预组（B组），高剂量干预组（C组）检测病理组织学改变，细胞免疫学指标。结果 紫杉醇明显延长术后生存（A组与B组，Log Rank=9．06，B组与C组，Log Rank=7．81，P均〈0．05），减轻肝脏病理组织学改变，降低外周血单核细胞特异的Th前体细胞的比率（t=8．9和11．8，P均〈0．05），促进脾CI）4^＋的淋巴细胞凋亡（T0=27．49和93．4，P均〈0．05），同时使Th1／Th2细胞平衡向Th2移动（t=4．93和5．92，P值均〈0．05）。结论 紫杉醇能够有效减轻肝移植大鼠的急性排斥反应，其机制可能与诱导活化的CD4^＋Th细胞凋亡，从而降低受体对供体细胞的反应，并促使Th1／Th2细胞平衡向Th2移动有关。

Immunosuppressive effect of paclitaxel on liver transplant rats

Objective To study the effect of paclitaxel on liver transplant rats.Methods Ortho- topic liver transplantation was performed on Lewis-to-BN rats(n=45).The rats were randomly divided into three groups:Normal saline control group(A),low-dose paclitaxel group(B)and high-dose pacli- taxel group(C).Survival,IFN-7/IL-4(Th1/Th2)and histopathological findings were compared among groups,and T helper precursor frequencies by limiting dilution analysis and CD4 + cells apoptosis by two- color staining of annexin V were determined.Results Paclitaxel could protect allografts against immunolog- ic rejection,and prolong the recipients'survival,meanwhile treatment of paclitaxel could contribute to a significant decrease in Th-p frequencies,and a shift of the Thl/Th2 balance toward Th2 direction.Con- clusion Paclitaxel could protect rat liver graft from acute rejection by decreasing Th-p frequencies,and inducing a shift of the Thl/Th2 balance toward Th2 direction through promoting apoptosis of CD4+ cells.