Human rhinoviruses (RVs) are positive-strand RNA viruses that cause respiratory tract disease in children and adults. Here we show that the innate immune signaling protein STING is required for efficient replication of members of two distinct RV species, RV-A and RV-C. The host factor activity of STING was identified in a genome-wide RNA interference (RNAi) screen and confirmed in primary human small airway epithelial cells. Replication of RV-A serotypes was strictly dependent on STING, whereas RV-B serotypes were notably less dependent. Subgenomic RV-A and RV-C RNA replicons failed to amplify in the absence of STING, revealing it to be required for a step in RNA replication. STING was expressed on phosphatidylinositol 4-phosphate (PI4P)-enriched membranes and was enriched in RV-A16 compared with RV-B14 replication organelles isolated in isopycnic gradients. The host factor activity of STING was species-specific, as murine STING (mSTING) did not rescue RV-A16 replication in STING-deficient cells. This species specificity mapped primarily to the cytoplasmic, ligand-binding domain of STING. Mouse-adaptive mutations in the RV-A16 2C protein allowed for robust replication in cells expressing mSTING, suggesting a role for 2C in recruiting STING to RV-A replication organelles. Palmitoylation of STING was not required for RV-A16 replication, nor was the C-terminal tail of STING that mediates IRF3 signaling. Despite co-opting STING to promote its replication, interferon signaling in response to STING agonists remained intact in RV-A16 infected cells. These data demonstrate a surprising requirement for a key host mediator of innate immunity to DNA viruses in the life cycle of a small pathogenic RNA virus.

人鼻病毒 (RVs) 是正链 RNA 病毒，可导致儿童和成人呼吸道疾病。在这里，我们表明先天免疫信号蛋白 STING 是有效复制两种不同 RV 物种 RV-A 和 RV-C 的成员所必需的。STING 的宿主因子活性在全基因组 RNA 干扰 (RNAi) 筛选中得到鉴定，并在原代人小气道上皮细胞中得到证实。RV-A 血清型的复制严格依赖于 STING，而 RV-B 血清型的依赖性明显较低。在没有 STING 的情况下，亚基因组 RV-A 和 RV-C RNA 复制子无法扩增，这表明它是 RNA 复制步骤所必需的。与在等密度梯度中分离的 RV-B14 复制细胞器相比，STING 在富含磷脂酰肌醇 4-磷酸 (PI4P) 的膜上表达，并且富含 RV-A16。STING 的宿主因子活性是物种特异性的，因为鼠 STING (mSTING) 不能挽救 STING 缺陷细胞中的 RV-A16 复制。这种物种特异性主要映射到 STING 的细胞质配体结合域。RV-A16 2C 蛋白中的小鼠适应性突变允许在表达 mSTING 的细胞中进行稳健复制，这表明 2C 在将 STING 募集到 RV-A 复制细胞器中的作用。RV-A16 复制不需要 STING 的棕榈酰化，介导 IRF3 信号传导的 STING 的 C 末端尾部也不需要。尽管选择 STING 来促进其复制，响应 STING 激动剂的干扰素信号在 RV-A16 感染的细胞中保持完整。这些数据表明，在小病原性 RNA 病毒的生命周期中，对 DNA 病毒先天免疫的关键宿主介质提出了惊人的要求。