记忆性CD4^＋T淋巴细胞对小鼠腹腔移植心脏排斥反应的影响

The effect of memorial CD4^＋T cells on ectopic heart acute rejection in abdominal cavity of mice

目的探讨记忆性CD4^＋T淋巴细胞对来自同一抗原特异性移植心脏急性排斥反应的影响。方法将C57BL／6小鼠的皮肤移植给Balb／c小鼠，使其致敏，3个月后，取受者的脾脏，应用小鼠记忆性CD4^＋T淋巴细胞纯化试剂盒纯化记忆性CD4^＋T淋巴细胞。同时取未进行皮肤移植的Balb／c小鼠，同法获取非致敏CD4^＋T淋巴细胞。以C57BL／6小鼠为供者，正常Balb／c小鼠为受者，行腹腔心脏移植，移植前3周，实验组受者经阴茎背静脉注射记忆性CD4^＋T淋巴细胞；非致敏对照组受者经阴茎背静脉注射非致敏CD4^＋T淋巴细胞；空白对照组不注射任何T淋巴细胞。各组均于移植前1d、移植当天及移植后1d给予环孢素A。术后记录移植心脏存活时间；取移植心脏，进行病理学观察。结果实验组、非致敏对照组和空白对照组移植心脏存活时间分别为（8．5±1．5）d、（25．7±5．5）d和（21．2±9．2）d，实验组明显短于另两组（P〈0．05）。移植心脏急性排斥反应的病理学分级，实验组为3．43±0．68，非致敏对照组为1．29±0．46，空白对照组为1．31±0．49，实验组病理学分级明显高于非致敏对照组和空白对照组（P〈0．05）。结论当记忆性CD4^＋T淋巴细胞再次接触同一抗原特异性的移植心脏时，可促进急性排斥反应的发生，且对常规剂量的环孢素A不敏感。

Objective To explore the effect of memorial CD4^＋T cells on acute rejection of the same antigenic specificity graft heart in mice. Methods The skin of mice from the C57BL/6 mice was transplanted to the Balb/c mice for sensitization, and 3 months later the spleen of receptor was obtained. The memorial CD4^＋T cells were purified by the depuration kit of memorial CD4^＋T cells in mice. Meanwhile, the naive CD4^＋T cells of the Balb/c mice not subject to skin transplantation by the same method were obtained. The normal Balb/c mice and the C57BL/6 mice were taken as the recipients and the donors, receiving heart transplantation in abdominal cavity of mice. In experimental group, memorial CD4^＋T cells were injected into the mice,and in control group, naive CD4^＋T cells were injected. In blank group, no T cells were injected. At first day after transplantation, cyclosporine A （5 mg· kg^-1 · d^-1 ） was given. The survival time of heart allografts was recorded and pathological observation was carried out. Results The survival time of the heart allografts in experimental group, control group and blank group was （8. 5 ± 1.5）, （25.7 ± 5.5） and （21.2 ± 9. 2） days respectively. The survival time in experimental group was significantly shorter than in other two group （P〈0. 05）. The histological grade of heart allografts in experimental group, control group and blank group was 3. 43 ±0. 68, 1.29 ± 0. 46 and 1.31 ± 0. 49 respectively. The histological grade of heart allografts in experimental group was significantly higher than in control group and blank group （P〈0. 05）. Conclusion Memorial CD4 ^＋ T cells can cause acute rejection when it contacts again homogeneity variant implanted heart, and the rejection is insensitive to cyclosporine A of common dose.