Department of Biomedical Science, Jungwon University, Goesan-gun 28024, Republic of Korea.
Division of Cardiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon Dong, Gangnam-gu, Seoul 06351, Republic of Korea.
Int J Mol Sci. 2023 Mar 10;24(6):5309. doi: 10.3390/ijms24065309.
The coxsackievirus and adenovirus receptor (CAR) is very well known as an epithelial tight junction and cardiac intercalated disc protein; it mediates attachment and infection via the coxsackievirus B3 (CVB3) and type 5 adenovirus. Macrophages play important roles in early immunity during viral infections. However, the role of CAR in macrophages is not well studied in relation to CVB3 infection. In this study, the function of CAR was observed in the Raw264.7 mouse macrophage cell line. CAR expression was stimulated by treatment with lipopolysaccharide (LPS) and tumor necrosis factor-α (TNF-α). In thioglycollate-induced peritonitis, the peritoneal macrophage was activated and CAR expression was increased. The macrophage-specific CAR conditional knockout mice (KO) were generated from lysozyme Cre mice. The expression of inflammatory cytokine (IL-1β and TNF-α) was attenuated in the KO mice's peritoneal macrophage after LPS treatment. In addition, the virus was not replicated in CAR-deleted macrophages. The organ virus replication was not significantly different in both wild-type (WT) and KO mice at days three and seven post-infection (p.i). However, the inflammatory M1 polarity genes (IL-1β, IL-6, TNF-α and MCP-1) were significantly increased, with increased rates of myocarditis in the heart of KO mice compared to those of WT mice. In contrast, type1 interferon (IFN-α and β) was significantly decreased in the heart of KO mice. Serum chemokine CXCL-11 was increased in the KO mice at day three p.i. compared to the WT mice. The attenuation of IFN-α and β in macrophage CAR deletion induced higher levels of CXCL-11 and more increased CD4 and CD8 T cells in KO mice hearts compared to those of WT mice at day seven p.i. These results demonstrate that macrophage-specific CAR deletion increased the macrophage M1 polarity and myocarditis in CVB3 infection. In addition, chemokine CXCL-11 expression was increased, and stimulated CD4 and CD8 T cell activity. Macrophage CAR may be important for the regulation of innate-immunity-induced local inflammation in CVB3 infection.
柯萨奇病毒和腺病毒受体 (CAR) 作为上皮紧密连接和心脏闰盘蛋白而广为人知；它通过柯萨奇病毒 B3 (CVB3) 和 5 型腺病毒介导附着和感染。巨噬细胞在病毒感染的早期免疫中发挥重要作用。然而，CAR 在 CVB3 感染相关的巨噬细胞中的作用尚未得到很好的研究。在这项研究中，观察了 CAR 在 Raw264.7 小鼠巨噬细胞系中的功能。用脂多糖 (LPS) 和肿瘤坏死因子-α (TNF-α) 处理刺激 CAR 表达。在巯基乙醇诱导的腹膜炎中，激活腹腔巨噬细胞并增加 CAR 表达。从溶菌酶 Cre 小鼠中生成巨噬细胞特异性 CAR 条件性敲除 (KO) 小鼠。用 LPS 处理后，KO 小鼠的腹腔巨噬细胞中炎症细胞因子 (IL-1β 和 TNF-α) 的表达减弱。此外，在 CAR 缺失的巨噬细胞中病毒未复制。在感染后第 3 天和第 7 天，野生型 (WT) 和 KO 小鼠的器官病毒复制没有明显差异。然而，炎性 M1 极性基因 (IL-1β、IL-6、TNF-α 和 MCP-1) 显著增加，KO 小鼠的心肌炎发生率高于 WT 小鼠。相比之下，在 KO 小鼠的心脏中，I 型干扰素 (IFN-α 和 β) 显著减少。与 WT 小鼠相比，KO 小鼠在感染后第 3 天血清趋化因子 CXCL-11 增加。在巨噬细胞 CAR 缺失诱导 IFN-α 和 β 衰减的情况下，与 WT 小鼠相比，KO 小鼠心脏中的 CXCL-11 水平更高，CD4 和 CD8 T 细胞更多增加。这些结果表明，巨噬细胞特异性 CAR 缺失增加了 CVB3 感染中的巨噬细胞 M1 极性和心肌炎。此外，趋化因子 CXCL-11 的表达增加，并刺激 CD4 和 CD8 T 细胞的活性。巨噬细胞 CAR 可能对调节 CVB3 感染中固有免疫诱导的局部炎症很重要。
