脑出血小鼠外周血中调节性T细胞比例与炎性因子表达水平的改变

Influence of intracerebral hemorrhage on proportion of regulatory T cells and inflanunatory factors in peripheral blood

目的观察脑出血小鼠外周血中调节性T细胞（Treg）比例与炎性因子表达水平的改变，探讨脑出血后免疫状态的改变及脑出血小鼠神经功能的缺损程度与免疫抑制状态之间的关系。方法按完全随机数字表法将24只成年雄性C57BL／6小鼠分为假手术组、脑出血组。采用胶原酶立体定位注射法制作脑出血小鼠模型。流式细胞术检测外周血中Treg细胞占单核细胞的比例，酶联免疫吸附技术检测外周血中肿瘤坏死因子-α（TNF-α）与干扰素-γ（IFN-γ）的水平，并通过改良神经功能缺损程度评分（mNSS）评价小鼠神经功能变化。结果脑出血后1、3d后外周血中Treg细胞的比例[（6．58±1．47）％与（7．07±1．60）％]均高于假手术组[（4．82±0．59）％]，差异有统计学意义（P〈0．05）；脑出血后1、3d外周血中TNF-α的水平[（110．23±11．59）og／ml、（102．56±10．35）pg／ml]亦较假手术组[（30．01±5．59）pg／ml）明显升高，但IFN-γ的水平（（2．62±0．45）pg／ml与2．09±0．60）pg／ml]较假手术组[（3．48±0．61）pg／ml]明显下降，差异均有统计学意义（P〈0．05）。mNSS显示，脑出血小鼠均有不同程度的神经功能缺损，且神经功能的缺损程度与Treg细胞的比例呈正相关（P〈0．05）。结论脑出血后存在外周血中免疫细胞比例与炎性因子表达水平的改变；Treg细胞的增多与免疫抑制有关，该变化提示脑出血后可能存在免疫状态的抑制。

Objective To study the influence of intracerebral hemorrhage （ICH） on the proportion of Treg cells and inflammatory factors in peripheral blood in order to explore the changes in the immune status after ICH and the relationship between immunosuppression and ICH. Methods Twenty - four adult male C57BL/6 mice were randomly divided into sham - operated group and ICH group. ICH was induced with collagenase injection in mice. We used flow cytometry to determine the percentage of Treg cells in peripheral blood. Enzyme linked immunosorbent assay （ELISA） was used to detect the serum levels of tumor necrosis factor-α （TNF-α） and interferon （IFN） -γ. In addition, neurological deficits were assessed by modified neurologic severity score （mNSS）. Results The percentage of Treg cells [ （6. 58 ± 1.47）% and （7. 07 ±1.60）%] and the serum levels of TNF-α [（110.23±11.59） pg/ml and （102.56± 10. 35 ） pg/ml] in peripheral blood were increased significantly as compared with sham -operated group on day 1 and 3 after ICH （ P 〈 0. 05 ）. However, the serum levels of IFN - γ [ （ 2. 62± 0. 45 ） pg/mland （2. 09 ± 0. 60） pg/ml ] were reduced significantly when compared with sham - operated group [ （ 3.48 ± 0. 61） pg/ml] on day 1 and 3 after ICH （P〈0. 05）. There was also an increased mNSS observed in the ICH mice compared to vehicle - treated ICH group. In addition, the percentage of Treg cells in peripheral blood was positively correlated with mNSS after ICH. Conclusion The expression of inflammatory cytokines and immune cells in peripheral blood changed significantly after ICH, and the increase of Treg cells is related to the immunosuprression, suggesting that immunesuppression may exist after ICH.