IHEM, Universidad Nacional de Cuyo, CONICET, Mendoza, Argentina.
Facultad de Ciencias Veterinarias y Ambientales, Universidad Juan Agustín Maza, Mendoza, Argentina.
J Virol. 2022 Feb 23;96(4):e0200521. doi: 10.1128/JVI.02005-21. Epub 2021 Dec 8.
Birnaviruses are members of the Birnaviridae family, responsible for major economic losses to poultry and aquaculture. The family is composed of nonenveloped viruses with a segmented double-stranded RNA (dsRNA) genome. Infectious bursal disease virus (IBDV), the prototypic family member, is the etiological agent of Gumboro disease, a highly contagious immunosuppressive disease in the poultry industry worldwide. We previously demonstrated that IBDV hijacks the endocytic pathway for establishing the viral replication complexes on endosomes associated with the olgi omplex (GC). Here, we report that IBDV reorganizes the GC to localize the endosome-associated replication complexes without affecting its secretory functionality. By analyzing crucial proteins involved in the secretory pathway, we showed the essential requirement of Rab1b for viral replication. Rab1b comprises a key regulator of GC transport and we demonstrate that transfecting the negative mutant Rab1b N121I or knocking down Rab1b expression by RNA interference significantly reduces the yield of infectious viral progeny. Furthermore, we showed that the Rab1b downstream effector olgi-specific FA resistance actor (GBF1), which activates the small GTPase DP ibosylation actor 1 (ARF1), is required for IBDV replication, since inhibiting its activity by treatment with reeldin (BFA) or olgiide (GCA) significantly reduces the yield of infectious viral progeny. Finally, we show that ARF1 dominant negative mutant T31N overexpression hampered IBDV infection. Taken together, these results demonstrate that IBDV requires the function of the Rab1b-GBF1-ARF1 axis to promote its replication, making a substantial contribution to the field of birnavirus-host cell interactions. Birnaviruses are unconventional members of the dsRNA viruses, with the lack of a transcriptionally active core being the main differential feature. This structural trait, among others that resemble those of the plus single-stranded (+ssRNA) viruses features, suggests that birnaviruses might follow a different replication program from that conducted by prototypical dsRNA members and the hypothesis that birnaviruses could be evolutionary links between +ssRNA and dsRNA viruses has been argued. Here, we present original data showing that IBDV-induced GC reorganization and the cross talk between IBDV and the Rab1b-GBF1-ARF1 mediate the intracellular trafficking pathway. The replication of several +ssRNA viruses depends on the cellular protein GBF1, but its role in the replication process is not clear. Thus, our findings make a substantial contribution to the field of birnavirus-host cell interactions and provide further evidence supporting the proposed evolutionary connection role of birnaviruses, an aspect which we consider especially relevant for researchers working in the virology field.
双 RNA 病毒是双 RNA 病毒科的成员,对家禽和水产养殖业造成重大经济损失。该科由无包膜病毒组成,具有分段双链 RNA(dsRNA)基因组。传染性法氏囊病病毒 (IBDV) 是该科的模式成员,是全球家禽业传染性免疫抑制病 Gumboro 病的病原体。我们之前证明 IBDV 劫持内吞途径,在与高尔基复合体 (GC) 相关的内体上建立病毒复制复合物。在这里,我们报告 IBDV 重组 GC 以定位不影响其分泌功能的内体相关复制复合物。通过分析参与分泌途径的关键蛋白,我们表明 Rab1b 对病毒复制是必需的。Rab1b 是 GC 运输的关键调节剂,我们证明转染负突变 Rab1b N121I 或通过 RNA 干扰敲低 Rab1b 表达显着降低感染性病毒后代的产量。此外,我们表明 Rab1b 下游效应物 olgi 特异性 FA 抗性因子 (GBF1),它激活小 GTPase DP 酰基化因子 1 (ARF1),是 IBDV 复制所必需的,因为用 reeldin (BFA) 或 olgiide (GCA) 处理抑制其活性显着降低感染性病毒后代的产量。最后,我们表明 ARF1 显性负突变 T31N 过表达阻碍了 IBDV 感染。总之,这些结果表明 IBDV 需要 Rab1b-GBF1-ARF1 轴的功能来促进其复制,这为双 RNA 病毒-宿主细胞相互作用领域做出了重大贡献。双 RNA 病毒是非传统的 dsRNA 病毒成员,缺乏转录活性核心是主要的差异特征。这种结构特征,以及其他类似于单链 (+ssRNA) 病毒特征的特征,表明双 RNA 病毒可能遵循与典型 dsRNA 成员不同的复制程序,并且双 RNA 病毒可能是+ ssRNA 和 dsRNA 病毒之间进化联系的假说已经提出。在这里,我们提供了原始数据,表明 IBDV 诱导的 GC 重排和 IBDV 与 Rab1b-GBF1-ARF1 之间的串扰介导了细胞内运输途径。几种+ ssRNA 病毒的复制依赖于细胞蛋白 GBF1,但它在复制过程中的作用尚不清楚。因此,我们的发现为双 RNA 病毒-宿主细胞相互作用领域做出了重大贡献,并提供了进一步的证据支持双 RNA 病毒的拟议进化联系作用,我们认为这对于在病毒学领域工作的研究人员尤为重要。