ABSTRACT

Abnormalities in CD4⁺ T cell (Th cell) differentiation play an important role in the pathogenesis of viral myocarditis (VMC). Our previous studies demonstrated that activation of the cholinergic anti-inflammatory pathway (CAP) alleviated the inflammatory response. In addition, we observed that right cervical vagotomy aggravates VMC by inhibiting CAP. However, the vagus nerve’s effect on differentiation of CD4⁺ T cells has not been studied in VMC mice to date. In this study, we investigated the effects of cervical vagotomy and the α7nAChR agonist pnu282987 on CD4⁺ T cell differentiation in a murine myocarditis model (BALB/c) infected with coxsackievirus B3 (CVB3). Splenic CD4⁺ T cells from CVB3-induced mice obtained and cultured to investigate the potential mechanism of CD4⁺ T cell differentiation. Each Th cell subset was analyzed by flow cytometry. Our results showed that right cervical vagotomy increased proportions of Th1 and Th17 cells and decreased proportions of Th2 and Treg cells in the spleen. Vagotomy-induced upregulation of T-bet, Ror-γ, IFN-γ, and IL-17 expression while downregulating the expression of Gata3, Foxp3, and IL-4 in the heart. In addition, we observed upregulated levels of proinflammatory cytokines, aggravated myocardial lesions and cellular infiltration, and worsened cardiac function in VMC mice. Pnu282987 administration reversed these outcomes. Furthermore, vagotomy inhibited JAK2-STAT3 activation and enhanced NF-κB activation in splenic CD4⁺ T cells. The CD4⁺ T cell differentiation was related to JAK2-STAT3 and NF-κB signal pathways. In conclusion, vagus nerve modulates the inflammatory response by regulating CD4⁺ T cell differentiation in response to VMC.

摘要

CD4 ⁺ T 细胞（Th 细胞）分化异常在病毒性心肌炎（VMC）的发病机制中起重要作用。我们之前的研究表明，胆碱能抗炎通路 (CAP) 的激活减轻了炎症反应。此外，我们观察到右颈迷走神经切断术通过抑制 CAP 加重 VMC。然而，迄今为止，尚未在 VMC 小鼠中研究迷走神经对 CD4 ⁺ T 细胞分化的影响。在这项研究中，我们研究了宫颈迷走神经切断术和 α7nAChR 激动剂 pnu282987 对柯萨奇病毒 B3 (CVB3) 感染的小鼠心肌炎模型 (BALB/c) 中CD4 ⁺ T 细胞分化的影响。脾CD4 ⁺获得并培养来自 CVB3 诱导小鼠的 T 细胞，以研究 CD4 ⁺ T 细胞分化的潜在机制。通过流式细胞术分析每个 Th 细胞亚群。我们的结果表明，右侧颈迷走神经切断术增加了脾脏中 Th1 和 Th17 细胞的比例，降低了 Th2 和 Treg 细胞的比例。迷走神经切断术诱导的 T-bet、Ror-γ、IFN-γ 和 IL-17 表达上调，同时下调心脏中 Gata3、Foxp3 和 IL-4 的表达。此外，我们观察到 VMC 小鼠促炎细胞因子水平上调、心肌病变和细胞浸润加重、心脏功能恶化。Pnu282987 管理逆转了这些结果。此外，迷走神经切断术抑制了 JAK2-STAT3 激活并增强了脾 CD4 ^{+ 中的}NF-κB 激活T细胞。CD4 ⁺ T细胞分化与JAK2-STAT3和NF-κB信号通路有关。总之，迷走神经通过调节 CD4 ⁺ T 细胞分化以响应 VMC来调节炎症反应。