大鼠脊髓损伤前后外周血CD3+ CD8+ CD28-和CD3+ CD8+ CD28+细胞亚群的变化

目的：：探讨SD大鼠脊髓损伤( spinal cord injury,SCI)前后外周血抑制性T细胞( suppress T lymphocytes,Ts)和细胞毒性T细胞( cytotoxic T lymphocytes,Tc)亚群的变化规律。方法：取10只健康雌性SD大鼠,采用纽约大学脊髓损伤撞击仪制作重物坠落SCI模型。于SCI前及后1、3、5、7、14、21、28和56 d收集外周血,流式细胞术检测外周血淋巴细胞CD3+CD8+CD28-Ts 和CD3+CD8+CD28+Tc亚群的变化规律。结果：SCI前,正常大鼠外周血中Ts和Tc亚群占CD3+总T细胞的百分比分别为(30.27±12.09)%和(14.75±4.29)%。损伤后1 d,Ts的比例为(22.58±12.12)%。术后5 d时其百分比下降至最低,为(20.86±10.41)%。术后7~21 d,其比例恢复至术前水平,28 d时显著升高,其比例为(37.90±12.98)%。56 d时其比例为(33.79±11.44)%,恢复至损伤前水平(P>0.05)。 Tc和Ts亚群的变化趋势相反,在损伤后1、5、21和28 d时其比例分别为(17.29±7.10)%、(20.02±6.24)%、(23.89±6.78)%和(13.81±11.21)%。但56 d时其比例没有恢复至术前水平,而是进一步下降至(8.71±6.44)%(P<0.01)。结论：在SCI后的早期阶段,SD大鼠外周血Tc占明显优势,提示Ts功能抑制、Tc功能增强是SCI免疫损伤机制之一。 SCI后5~21 d是进行免疫调节治疗的关键时间窗。

The changes of CD3 +CD8 +CD28 - and CD3 +CD8 +CD28 + T cell subsets in peripheral blood of rats with spinal cord injury

Objective:To observe the changes of CD3 +CD8 +CD28 - suppress T lymphocytes( Ts) and CD3 +CD8 +CD28 + cytotoxic T lymphocytes( Tc) subsets in peripheral blood of SD rats with spinal cord injury( SCI) . Methods:The SCI model of ten female SD rats were established using New York University Spinal Cord Contusion system. The changes of CD3 +CD8 +CD28 - and CD3 +CD8 +CD28 +T cell subsets in peripheral blood were evaluated using flow cytometry at the time points of pre-injury and days 1,3,5,7,14,21,28 and 56 post-injury. Results:The percentages of Ts and Tc in the CD3 + T cells of peripheral blood of healthy rats were(30. 27 ± 12. 09)%and(14. 75 ± 4. 29)%,respectively. The percentage of Ts was(22. 58 ± 12. 12)% at the first day of SCI. At the 5th day,it decreased to the lowest level(20. 86 ± 10. 41)%,it reached to the normal level from 7 to 21d after SCI. At 28th day,it increased to(37. 90 ± 12. 98)%. At 56th day(33. 79 ± 11. 44)%,it decreased to the normal level again(P>0. 05). The change trend of Tc was opposite to the Ts after SCI. The percentages of Tc at time points of days 1,5,21 and 28 post-injury were(17. 29 ± 7. 10)%,(20. 02 ± 6. 24)%, (23. 89 ± 6. 78)% and(13. 81 ± 11. 21)%,respectively. It didn't return to normal level,but decreased to(8. 71 ± 6. 44)% at the time points of 56 d(P<0. 01). Conclusions:In the early stage of SCI,Tc are predominant in the peripheral blood of SD rats,which suggest that the function inhibition of Ts and enhancement of Tc may be one of the important immune injury mechanism of the SCI. The period from 5 to 21 days post-injury may be a key time window for the immunomodulatory treatment of SCI.