Jiyarom Boonyanudh, Giannakopoulos Stefanos, Strange Daniel P, Panova Nataliya, Gale Michael, Verma Saguna
Department of Tropical Medicine, Medical Microbiology, and Pharmacology, John A. Burns School of Medicine, University of Hawai'i at Mānoa, Honolulu, HI, United States.
Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Mānoa, Honolulu, HI, United States.
Front Microbiol. 2023 Jan 12;13:1062499. doi: 10.3389/fmicb.2022.1062499. eCollection 2022.
Sexual transmission of Zika virus (ZIKV) is associated with virus persistence in the testes and shedding in the seminal fluid for months after recovery. We previously demonstrated that ZIKV can establish long-term replication without causing cytotoxicity in human Sertoli cells (SC), responsible for maintaining the immune privileged compartment of seminiferous tubules. Functional gene expression analyses also predicted activation of multiple virus sensing pathways including TLR3, RIG-I, and MDA5. Here, we elucidated which of the RNA virus sensing receptors play a decisive role in restricting ZIKV replication. We show that both poly I:C and IFN-β treatment induced a robust antiviral state and reduced ZIKV replication significantly, suggesting that virus sensing and antiviral signaling are functional in SC. Silencing of TLR3, 7, and 9 did not affect virus replication kinetics; however, both RIG-I and MDA5 played a synergistic role in inducing an anti-ZIKV response. Further, the impact of SC-specific immunosuppressive pathways that collectively regulate SC function, specifically the TGF-β superfamily members, TGF-β, Activin A, and BMP6, on ZIKV replication was investigated. While ZIKV did not modulate the expression of TGF-β and Activin A, BMP6 signaling was suppressed at later stages of infection. Notably, treatment with BMP6 increased IFN-β, p-IRF3, and p-STAT1 levels, and expression of key interferon-stimulated genes including MDA5, suggesting that BMP6 enhances antiviral response in SC. Collectively, this study further delineates the key role of the RIG-I-like receptors in sensing ZIKV in SC, and reveals a novel role of BMP6 in modulating innate immune and antiviral response in the testes.
寨卡病毒（ZIKV）的性传播与病毒在睾丸中的持续存在以及康复后数月精液中的排出有关。我们之前证明，ZIKV可以在不引起人支持细胞（SC）细胞毒性的情况下建立长期复制，而支持细胞负责维持生精小管的免疫豁免区室。功能基因表达分析还预测了包括TLR3、RIG-I和MDA5在内的多种病毒传感途径的激活。在这里，我们阐明了哪些RNA病毒传感受体在限制ZIKV复制中起决定性作用。我们发现，聚肌胞苷酸（poly I:C）和IFN-β处理均诱导了强大的抗病毒状态并显著降低了ZIKV复制，这表明病毒传感和抗病毒信号传导在支持细胞中起作用。TLR3、7和9的沉默不影响病毒复制动力学；然而，RIG-I和MDA5在诱导抗ZIKV反应中发挥了协同作用。此外，我们研究了共同调节支持细胞功能的支持细胞特异性免疫抑制途径，特别是TGF-β超家族成员TGF-β、激活素A和骨形态发生蛋白6（BMP6）对ZIKV复制的影响。虽然ZIKV没有调节TGF-β和激活素A的表达，但BMP6信号在感染后期受到抑制。值得注意的是，用BMP6处理可增加IFN-β、p-IRF3和p-STAT1水平，以及包括MDA5在内的关键干扰素刺激基因的表达，这表明BMP6增强了支持细胞中的抗病毒反应。总的来说，这项研究进一步阐明了RIG-I样受体在支持细胞中感知ZIKV的关键作用，并揭示了BMP6在调节睾丸先天性免疫和抗病毒反应中的新作用。
