■脑微出血(CMBs)是许多神经系统疾病的早期征兆,并伴有局部神经炎症和脑损伤。作为免疫应答和神经炎症的重要调节因子,CMBs后γδT细胞的生物学行为和作用尚不清楚。
■我们通过双光子激光模拟CMBs模型,并在体内使用TCR-δGFP转基因小鼠跟踪CMBs诱导的γδT细胞的动力学行为。通过流式细胞术和拉曼光谱解码了外周CMBs实质中γδT细胞的生物学特征。在野生型和γδT细胞缺陷小鼠中,通过RNAseq研究了CMBs周围皮质的神经炎症和神经突变性,免疫染色和体内成像。
■在CMB之后,追踪硬脑膜血管中的γδT细胞穿过脑膜结构并在几天内侵入脑实质,其中捕获了γδT细胞的分裂过程。CXCR6和CCR6高表达实质γδT细胞,与脑膜γδT细胞相似,IL-17A和Ki67阳性(98%以上),它们含有丰富的能量代谢和核酸合成物质。在γδT细胞缺陷小鼠中,皮质样本显示了神经炎症信号通路的上调,增强的神经胶质反应和M1小胶质细胞极化,与野生型小鼠相比,CMBs周围脑实质的神经元变性较早。
■CMBs诱导γδT细胞在脑实质中的积累和局部增殖,γδT细胞在CMBs早期发挥抗神经炎和神经保护作用。
Cerebral microbleeds (CMBs) are an early sign of many neurological disorders and accompanied by local neuroinflammation and brain damage. As important regulators of immune response and neuroinflammation, the biological behavior and role of γδ T cells after CMBs remain largely unknown.
We made a spot injury of microvessel in the somatosensory cortex to mimic the model of CMBs by two-photon laser and in vivo tracked dynamical behaviors of γδ T cells induced by CMBs using TCR-δGFP transgenic mice. Biological features of γδ T cells in the peri-CMBs parenchyma were decoded by flow cytometry and Raman spectra. In wildtype and γδ T cell-deficient mice, neuroinflammation and neurite degeneration in the peri-CMBs cortex were studied by RNAseq, immunostaining and in vivo imaging respectively.
After CMBs, γδ T cells in the dural vessels were tracked to cross the meningeal structure and invade the brain parenchyma in a few days, where the division process of γδ T cells were captured. Parenchymal γδ T cells were highly expressed by CXCR6 and CCR6, similar to meningeal γδ T cells, positive for IL-17A and Ki67 (more than 98%), and they contained abundant substances for energy metabolism and nucleic acid synthesis. In γδ T cell-deficient mice, cortical samples showed the upregulation of neuroinflammatory signaling pathways, enhanced glial response and M1 microglial polarization, and earlier neuronal degeneration in the peri-CMBs brain parenchyma compared with wildtype mice.
CMBs induce the accumulation and local proliferation of γδ T cells in the brain parenchyma, and γδ T cells exert anti-neuroinflammatory and neuroprotective effects at the early stage of CMBs.