State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China; College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471023, China.
State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China.
Vet Microbiol. 2021 May;256:109043. doi: 10.1016/j.vetmic.2021.109043. Epub 2021 Mar 23.
Porcine reproductive and respiratory syndrome (PRRS) causes substantial economic losses to the global pig industry. Members of the tripartite motif (TRIM) family are the important effectors of the innate immune response against viral infections. We have previously characterized the entire porcine TRIM (pTRIM) family, and predicted pTRIM5, 14, 21, 25 and 38 as host restriction factors against PRRSV infection. However, little is known about whether and how pTRIMs restrict the infection of PRRSV. In this study, we firstly performed the amino acid alignments of the RING domain of pTRIM5, 21, 25 and 38, and found that pTRIM proteins contained the characteristic consensus C3HC4 type zinc-binding motif which is important for the ubiquitination function. Then we detected the mRNA changes of pTRIMs in porcine alveolar macrophages (PAMs) by transcriptome sequencing after PRRSV infection in piglets. Transcriptional profiles showed that the expression of pTRIM5, 21 and 26 was significantly (P < 0.05) up-regulated, consistent with their expression in vitro. Finally, as the most up-regulated gene after PRRSV infection both in vivo and in vitro, pTRIM21 was investigated for its anti-PRRSV activity in immortalized PAMs (iPAMs) in two aspects: knockdown and overexpression of pTRIM21. Knockdown of endogenic pTRIM21 could significantly promote PRRSV replication at 12 and 24 h post infection in iPAMs. Meanwhile, overexpression of pTRIM21 could significantly suppress PRRSV replication but not affect its attachment and endocytosis. Moreover, pTRIM21 RING-finger E3 ubiquitin ligase was essential for anti-PRRSV activity. Our data enhance our understanding of the pTRIMs against PRRSV infection, which may help us develop novel therapeutic tools to control PRRSV.
猪繁殖与呼吸综合征（PRRS）给全球养猪业造成了巨大的经济损失。三基序（TRIM）家族成员是抗病毒感染固有免疫反应的重要效应因子。我们之前已经对整个猪 TRIM（pTRIM）家族进行了特征描述，并预测 pTRIM5、14、21、25 和 38 是针对 PRRSV 感染的宿主限制因子。然而，对于 pTRIM 是否以及如何限制 PRRSV 的感染知之甚少。在这项研究中，我们首先对 pTRIM5、21、25 和 38 的 RING 结构域进行了氨基酸比对，发现 pTRIM 蛋白含有特征性的 C3HC4 型锌结合基序，这对于泛素化功能很重要。然后，我们通过仔猪 PRRSV 感染后的转录组测序检测了 pTRIM 在肺泡巨噬细胞（PAMs）中的 mRNA 变化。转录谱显示，pTRIM5、21 和 26 的表达显著上调（P<0.05），与体外表达一致。最后，作为 PRRSV 感染后体内和体外表达最上调的基因，pTRIM21 在永生化 PAMs（iPAMs）中从两个方面研究了其抗 PRRSV 活性：内源性 pTRIM21 的敲低和过表达。在 iPAMs 中，内源性 pTRIM21 的敲低可显著促进感染后 12 和 24 小时的 PRRSV 复制。同时，pTRIM21 的过表达可显著抑制 PRRSV 复制，但不影响其附着和内吞作用。此外，pTRIM21 的 RING 指 E3 泛素连接酶对其抗 PRRSV 活性至关重要。我们的数据增强了我们对 pTRIM 对抗 PRRSV 感染的理解，这可能有助于我们开发控制 PRRSV 的新型治疗工具。
