Center for Anatomy, Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, Berlin, Germany.
J Cereb Blood Flow Metab. 2013 Jan;33(1):37-47. doi: 10.1038/jcbfm.2012.128. Epub 2012 Sep 12.
Local and peripheral immune responses are activated after ischemic stroke. In our present study, we investigated the temporal distribution, location, induction, and function of regulatory T cells (Tregs) and the possible involvement of microglia, macrophages, and dendritic cells after middle cerebral artery occlusion (MCAO). C57BL/6J and Foxp3(EGFP) transgenic mice were subjected to 30 minutes MCAO. On days 7, 14, and 30 after MCAO, Tregs and antigen presenting cells were analyzed using fluorescence activated cell sorting multicolor staining and immunohistochemistry. A strong accumulation of Tregs was observed on days 14 and 30 in the ischemic hemisphere accompanied by the elevated presence and activation of microglia. Dendritic cells and macrophages were found on each analyzed day. About 60% of Foxp3(+) Tregs in ischemic hemispheres were positive for the proliferation marker Ki-67 on days 7 and 14 after MCAO. The transfer of naive CD4(+) cells depleted of Foxp3(+) Tregs into RAG1(-/-) mice 1 day before MCAO did not lead to a de novo generation of Tregs 14 days after surgery. After depletion of CD25(+) Tregs, no changes regarding neurologic outcome were detected. The sustained presence of Tregs in the brain after MCAO indicates a long-lasting immunological alteration and involvement of brain cells in immunoregulatory mechanisms.
局部和外周免疫反应在缺血性中风后被激活。在我们目前的研究中，我们调查了调节性 T 细胞（Tregs）的时间分布、位置、诱导和功能，以及缺血性中风后小胶质细胞、巨噬细胞和树突状细胞的可能参与。C57BL/6J 和 Foxp3(EGFP)转基因小鼠接受 30 分钟大脑中动脉闭塞（MCAO）。在 MCAO 后第 7、14 和 30 天，使用荧光激活细胞分选多色染色和免疫组织化学分析 Tregs 和抗原呈递细胞。在缺血半球观察到 Tregs 在第 14 和 30 天大量积聚，伴随着小胶质细胞的存在和激活增加。在每个分析的日子都发现了树突状细胞和巨噬细胞。在 MCAO 后第 7 和 14 天，缺血半球中约 60%的 Foxp3(+)Tregs 对增殖标记物 Ki-67 呈阳性。在 MCAO 前 1 天将幼稚 CD4(+)细胞耗尽 Foxp3(+)Tregs 转移到 RAG1(-/-)小鼠中，术后 14 天不会导致 Tregs 的新生生成。在耗尽 CD25(+)Tregs 后，未检测到神经功能结局的变化。MCAO 后 Tregs 在大脑中的持续存在表明存在持久的免疫改变和脑细胞参与免疫调节机制。
