Porcine reproductive and respiratory syndrome virus (PRRSV) modulates host innate immunity which plays a key role against PRRSV infection. As a RNA virus, PRRSV is mainly sensed by innate immune RNA receptors, whereas the role of innate immune DNA sensors in the PRRSV infection has not been elucidated. Here, we investigated the roles of DNA sensing cGAS-STING pathway in both PRRSV infected Marc-145 cells and porcine macrophages. The results show that in Marc-145 cells, the stable expression of STING with or without stimulations exhibited anti-PRRSV activity, and STING knockout heightened PRRSV infection. In CD163-3D4/21 porcine macrophages, either expression of STING or stimulation of cGAS-STING signaling obviously suppressed PRRSV infection, whereas in STING knockdown macrophages, the PRRSV infection was upregulated. Our results clearly demonstrate that the host cGAS-STING signal exerts an important antiviral role in PRRSV infection.

中文翻译：

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先天免疫 DNA 感应 cGAS-STING 信号通路介导抗 PRRSV 功能

猪繁殖与呼吸综合征病毒 (PRRSV) 调节宿主先天免疫，这在对抗 PRRSV 感染方面起关键作用。作为一种 RNA 病毒，PRRSV 主要由先天免疫 RNA 受体感知，而先天免疫 DNA 传感器在 PRRSV 感染中的作用尚未阐明。在这里，我们研究了 DNA 感应 cGAS-STING 通路在 PRRSV 感染的 Marc-145 细胞和猪巨噬细胞中的作用。结果表明，在 Marc-145 细胞中，无论有没有刺激，STING 的稳定表达都表现出抗 PRRSV 活性，而 STING 敲除增强了 PRRSV 感染。在 CD163-3D4/21 猪巨噬细胞中，STING 的表达或 cGAS-STING 信号的刺激明显抑制了 PRRSV 感染，而在 STING 敲低的巨噬细胞中，PRRSV 感染上调。