Li Chunlin, Cui Jin, Zheng Hui, Sha Zhou, Wei Rong, Wu Rui, Ni Bo
China Animal Health and Epidemiology Center, Qingdao, China.
Heilongjiang Bayi Agricultural University, Daqing, China.
PLoS One. 2025 Mar 27;20(3):e0316239. doi: 10.1371/journal.pone.0316239. eCollection 2025.
Porcine reproductive and respiratory syndrome virus (PRRSV) is a highly contagious virus that poses a significant threat to the global pig farming industry, resulting in substantial economic losses. However, owing to the high variability of PRRSV and unclear mechanisms of infection, there are currently no effective vaccines or drugs available for its prevention and control. Our previous report revealed that highly pathogenic PRRSV (HP-PRRSV) requires the FAK-PI3K-AKT signaling pathway to facilitate its entry into cells. In this study, we further investigated whether the integrin subunit was involved in the entry process of NADC30-like PRRSV. First, the integrin subunits in Marc-145 cells were characterized by RT-PCR, and 11 of these subunits were identified, nearly all of which interacted with the integrin α V and β1 subunits to form heterodimers. Western blot analysis revealed that the integrin α V subunit was highly expressed in Marc-145 cells, and blocking this subunit with a functional antibody or siRNA significantly attenuated NADC30-like PRRSV entry without affecting virus binding. Moreover, in Marc-145 cells, NADC30-like PRRSV could activate the FAK-PI3K-AKT signaling pathway through the integrin α V subunit. Blocking the α V subunit significantly inhibited signal transduction and virus entry, and treatment of cells with the PI3K activator greatly reversed this inhibitory effect. Furthermore, the α V subunit activator manganese could also enhance NADC30-like PRRSV entry and signal transduction. In conclusion, our results revealed that NADC30-like PRRSV could activate the integrin α V subunit and subsequently transduce signals to the FAK-PI3K-AKT signaling pathway to facilitate entry into Marc-145 cells.
猪繁殖与呼吸综合征病毒（PRRSV）是一种具有高度传染性的病毒，对全球养猪业构成重大威胁，导致巨大的经济损失。然而，由于PRRSV的高度变异性和感染机制不明，目前尚无有效的疫苗或药物用于其防控。我们之前的报告显示，高致病性PRRSV（HP-PRRSV）需要FAK-PI3K-AKT信号通路来促进其进入细胞。在本研究中，我们进一步研究整合素亚基是否参与NADC30样PRRSV的进入过程。首先，通过RT-PCR对Marc-145细胞中的整合素亚基进行了表征，鉴定出其中11个亚基，几乎所有这些亚基都与整合素αV和β1亚基相互作用形成异二聚体。蛋白质印迹分析显示，整合素αV亚基在Marc-145细胞中高表达，用功能性抗体或小干扰RNA阻断该亚基可显著减弱NADC30样PRRSV的进入，而不影响病毒结合。此外，在Marc-145细胞中，NADC30样PRRSV可通过整合素αV亚基激活FAK-PI3K-AKT信号通路。阻断αV亚基可显著抑制信号转导和病毒进入，用PI3K激活剂处理细胞可大大逆转这种抑制作用。此外，αV亚基激活剂锰也可增强NADC30样PRRSV的进入和信号转导。总之，我们的结果表明，NADC30样PRRSV可激活整合素αV亚基，随后将信号转导至FAK-PI3K-AKT信号通路，以促进其进入Marc-145细胞。
