负链RNA病毒通过相分离或病毒和细胞蛋白的生物分子凝聚形成代表病毒复制灶的细胞质包涵体(IBs)。作为他们感染的标志。或者,哺乳动物细胞形成停滞的mRNA含有抗病毒应激颗粒(SGs),由于真核起始因子2α(eIF2α)通过包括TIA-1在内的几种RNA结合蛋白的缩合而磷酸化。是否以及如何发展昌迪普拉病毒(CHPV),一种引起流感样疾病的新兴人类病原体,昏迷和死亡,形成IBs和逃避抗病毒SGs仍然未知。通过对CHPV感染的Vero-E6细胞进行共聚焦成像,我们发现CHPV感染不会诱导不同的典型SGs的形成。相反,CHPV蛋白与SG蛋白缩合并共同定位,形成异质IBs,独立于eIF2α和eIF2α激酶的激活,蛋白激酶R(PKR)。有趣的是,siRNA介导的PKR或TIA-1消耗显着降低病毒转录和病毒体产生。此外,CHPV感染还导致PKR凝结和募集到IBs。与SGs相比,IBs在拆卸动力学中表现出显著的快速性。总之,我们的研究表明,CHPV复制与SG蛋白共同优化,并揭示了TIA-1/PKR的前所未有的前病毒作用,这可能对理解调节CHPV-IB形成的机制和设计抗病毒疗法有影响.重要性:CHPV是一种新兴的热带病原体,据报道可导致儿童急性流感样疾病和脑炎,死亡率很高,约为70%。缺乏针对CHPV的疫苗和有效疗法使其成为在全球热带地区引起流行的有效病原体。鉴于这些警告,必须全面了解CHPV生物学至关重要。由于病毒基因组中通常较高的突变率,宿主因子的靶向提供了优于靶向病毒组分的几个优点。在这项研究中,我们旨在了解SGs形成细胞RNA结合蛋白在CHPV复制中的作用.我们的研究有助于了解细胞因子在CHPV复制中的参与,并有助于开发有效的抗病毒疗法。
Negative-strand RNA viruses form cytoplasmic inclusion bodies (IBs) representing virus replication foci through phase separation or biomolecular condensation of viral and cellular proteins, as a hallmark of their infection. Alternatively, mammalian cells form stalled mRNA containing antiviral stress granules (SGs), as a consequence of phosphorylation of eukaryotic initiation factor 2α (eIF2α) through condensation of several RNA-binding proteins including TIA-1. Whether and how Chandipura virus (CHPV), an emerging human pathogen causing influenza-like illness, coma and death, forms IBs and evades antiviral SGs remain unknown. By confocal imaging on CHPV-infected Vero-E6 cells, we found that CHPV infection does not induce formation of distinct canonical SGs. Instead, CHPV proteins condense and co-localize together with SG proteins to form heterogeneous IBs, which ensued independent of the activation of eIF2α and eIF2α kinase, protein kinase R (PKR). Interestingly, siRNA-mediated depletion of PKR or TIA-1 significantly decreased viral transcription and virion production. Moreover, CHPV infection also caused condensation and recruitment of PKR to IBs. Compared to SGs, IBs exhibited significant rapidity in disassembly dynamics. Altogether, our study demonstrating that CHPV replication co-optimizes with SG proteins and revealing an unprecedented proviral role of TIA-1/PKR may have implications in understanding the mechanisms regulating CHPV-IB formation and designing antiviral therapeutics. Importance: CHPV is an emerging tropical pathogen reported to cause acute influenza-like illness and encephalitis in children with a very high mortality rate of ~70%. Lack of vaccines and an effective therapy against CHPV makes it a potent pathogen for causing an epidemic in tropical parts of globe. Given these forewarnings, it is of paramount importance that CHPV biology must be understood comprehensively. Targeting of host factors offers several advantages over targeting the viral components due to the generally higher mutation rate in the viral genome. In this study, we aimed at understanding the role of SGs forming cellular RNA-binding proteins in CHPV replication. Our study helps understand participation of cellular factors in CHPV replication and could help develop effective therapeutics against the virus.