CD8+IFN-gamma+T淋巴细胞活化巨噬细胞触发细胞因子风暴介导大动脉炎血管损伤及重塑的机制研究

Takayasu arteritis (TA) is an autoimmune large vessel vasculitis with poor prognosis and poor response to medical treatment. Interferon (IFN)-gamma can enlarges the inflammatory response in vessel wall through activates macrophages. Our previous research has found that the peripheral CD8+IFN-gamma+T cells significantly increased in TA patients and correlated with TA disease activity; cultured peripheral CD8+T cells of TA patients presented more severe cytotoxicity. However, the mechanism of CD8+IFN-gamma+T cells triggers inflammatory responses and mediate vascular wall injury and remodeling remains unclear. Here, we hypothesize that CD8+IFN-gamma+T cells can triggers cytokine storm and enlarge inflammatory response in vessel wall and aggravates vascular injury and remodeling by activates macrophages. To test our hypothesis, we will detect the proportion of peripheral CD8+ IFN-gamma+T cells in TA patients and healthy donor by using flow cytometry, cytometric bead array will use to detect the levels of IFN-gamma and other cytokines, immunohistochemistry will use to confirm the activation of CD8+ IFN-gamma+T cells in aortic lesions in TA patients. To explore the mechanism of CD8+IFN-gamam+T cell trigger the macrophage cytokine storm, CD8+ T cells，macrophages with ECs or VSMCs will culture in 3D environment in vitro. Moreover, we will analyze the relationship between CD8+ IFN-gamma+T cells with disease activity and imaging progress in TA patients. We anticipate finding a novel therapeutic target of refractory TA.

大动脉炎(Takayasu arteritis, TA)是预后极差的自身免疫性大血管炎，药物治疗效果不佳。干扰素(interferon, IFN)-r可活化巨噬细胞，放大血管壁炎症。我们发现，TA患者外周血中CD8+IFN-r+T细胞显著增多，与疾病活动相关；体外培养TA患者外周血CD8+T细胞杀伤功能显著增强。然而CD8+IFN-r+T细胞触发炎症反应放大，介导血管壁损伤和重塑的机制尚不清楚。我们假设TA患者CD8+IFN-r+T细胞通过活化巨噬细胞，触发细胞因子风暴，导致血管壁损伤和重塑。本课题拟采用流式细胞术检测患者外周血CD8+IFN-r+T细胞比例，高通量CBA技术检测多种细胞因子水平，免疫组化证实病变部位CD8+IFN-r+T细胞的活化，体外细胞三维共培养探讨CD8+IFN-r+T细胞活化巨噬细胞放大炎症反应的机制，分析其与TA疾病活动、影像学进展的关系，为TA的治疗提供靶点。

大动脉炎（TAK）是一种慢性系统性大血管炎。免疫炎症反应在TA的发病机理中起着至关重要的作用。干扰素-γ（IFN-γ）是参与TA发生发展的重要的细胞因子。活化的CD4 + T细胞，CD8 + T细胞、自然杀伤（NK）细胞以及巨噬细胞等都可以释放IFN-γ。本课题旨在探讨CD8+T细胞分泌IFN-γ在TAK中的关键作用。本课题研究结果发现TAK患者血清IFN-γ水平明显高于对照组（P <0.05）。TAK患者外周血CD3 +细胞中CD3 +IFN-γ+细胞的百分比明显高于健康对照组（P=0.002），CD3+CD8+IFN-γ+细胞/CD3 +IFN-γ+细胞的比例高于对照组（p=0.049），而且TAK组的CD3 +CD4+IFN-γ+ / CD3 + CD8 +IFN-γ+比率也高于对照组（p=0.027）。 CD3+CD8+IFN-γ+/CD3+IFN-γ+比值CD3 +IFN-γ+细胞/ CD3 +细胞比值（r = 0.430，P = 0.001），血清IFN-γ水平（r＝0.318，P＝0.040）和IL-17水平（r＝0.326，P＝0.031）呈正相关。它与CD3 + CD4 +IFN-γ+ / CD3 +IFN-γ+比率（r = -0.845，P = 0.000）呈负相关。TAK患者中CD3 + CD8 + T细胞中CD3 + CD8 + Granzyme B + T细胞（P = 0.030）和CD3 + CD8 + Perforin +T细胞（P = 0.000）的百分比高于对照组。治疗6个月后TAK患者CD3 + CD8 + Granzyme B + T细胞/ CD3 + CD8 + T细胞的比例降低（P = 0.011）。CD3 + CD8 + Granzyme B + T细胞/ CD3 + CD8 + T细胞比例的变化与ITAS的变化呈正相关（r = 0.721，P = 0.002），ITAS-A（r = 0.637，P = 0.008）。免疫荧光染色显示TAK患者主动脉组织中CD8 + Granzyme B +细胞浸润。我们的结果揭示了CD8 + T细胞分泌的IFN-γ是TA患者血清IFN-γ的重要来源。靶向CD8 + T淋巴细胞，IFN-γ或颗粒酶B可能是治疗TA的潜在方法。