神经干细胞脑出血大鼠脑内移植对T淋巴细胞亚群的影响

Effects of Neural Stem Cells Intracerebral Transplantion on T Lymphocyte Subpopulations in Intracerebral Hemorrhage Rats

目的探讨神经干细胞(neural stem cells,NSCs)移植入脑出血大鼠模型脑内后,观察脑组织内和血液中T淋巴细胞亚群的变化。方法选择成年雄性SD大鼠作为模型动物,采用Ⅳ型胶原酶诱导法建立脑出血模型,脑出血后3h移植神经干细胞,3天进行各项指标检测。应用流式细胞仪分析脑组织与血液中的T淋巴细胞亚群变化。应用酶联免疫吸附试验检测脑组织与血液中细胞因子的变化。通过组织免疫荧光了解T淋巴细胞与NSCs在脑出血大鼠脑内的分布情况。结果在血液中,与对照组相比较,NSCs移植组能够增加调节性T细胞(regulatory T cells,Treg)与CD4+T细胞表达,减少γδT与CD8+T细胞表达。在脑组织中,NSCs移植组能够增加Treg细胞表达,减少γδT、CD4+T和CD8+T细胞表达。与对照组比较,NSCs移植组增加血液与脑组织中IL-4(interleukin-4)、IL-10(interleukin-10)和TGF-β(transforming growth factor-β)的表达,并且减少IL-6(interleukin-6)与IFN-γ(interferon-γ)的表达。结论脑出血早期NSCs脑内移植促进保护性的T细胞亚群和抑制破坏性的T细胞亚群表达,提示移植的NSCs可能通过发挥免疫调节作用起到神经保护作用。

Objective To discuss the role of neural stem cells（ NSCs） intracerebral transplantation in the modulation of T lymphocyte subpopulations in the brain and blood after intracerebral hemorrhage in rats. Methods NSCs were injected intracerebrally at 3 hours after collagenase induced ICH in sprague dawley rat models. All experimental results were tested at 3 days after ICH. Flow cytometry was used to quantify T lymphocyte subpopulations in the brain and blood 3 days post-ICH. Cytokine enzyme-linked immunosorbent assay（ ELASA） investigated changes in the levels of inflammatory mediators. Immunohistochemistry detect distribution of injected NSCs and invaded T lymphocyte in the brain. Results In the blood,Treg cells and CD4＋T cells increased but γδT and CD8＋T cells decreased in the NSCs-ic-3 h group compared to the vehicle-injected control animals. NSCs-ic-3 h group detected Treg cells infiltration increasion and γδT,CD4＋T and CD8＋T cells infiltration decreasion in the brain after ICH. We also observed that expression of anti-inflammatory cytokines,IL-4,IL-10 and TGF-β increased while expression of pro-inflammatory cytokines,IL-6,and IFN-γ decreased in the brain and blood after NSCs transplantation. Conclusion Our data suggest that early intracerebral NSCs injection after ICH protect brain injury mainly by promoting protective T lymphocyte expression and inhibiting detrimental T lymphocyte expression.