Li Liyang, Yu Liyun, Hou Xilin
College of Animal Science and Veterinary Medicine, HeiLongJiang BaYi Agricultural University, Daqing 163319, China; College of Life Science and Technology, HeiLongJiang BaYi Agricultural University, Daqing 163319, China.
College of Life Science and Technology, HeiLongJiang BaYi Agricultural University, Daqing 163319, China.
Res Vet Sci. 2017 Oct;114:341-347. doi: 10.1016/j.rvsc.2017.04.009. Epub 2017 May 11.
Lipid rafts are specialized lipid domains enriched in cholesterol and sphingolipid, which can be utilized in the lifecycle of numerous enveloped viruses. Bovine parainfluenza virustype3 (BPIV3) entry to cell is mediated by receptor binding and membrane fusion, but how lipid rafts in host cell membrane and BPIV3 envelope affect virus infection remains unclear. In this study, we investigated the role of lipid rafts in the different stages of BPIV3 infection. The MDBK cells were treated by methyl-β-cyclodextrin (MβCD) to disrupt cellular lipid raft, and the virus infection was determined. The results showed that MβCD significantly inhibited BPIV3 infection in a dose-dependent manner, but didn't block the binding of virus to the cell membrane. Whereas, the MDBK cells treated by MβCD after virus-entry had no effects on the virus infection, to suggest that BPIV3 infection was associated with lipid rafts in cell membrane during viral entry stage. To further confirm lipid rafts in viral envelope also affected BPIV3 infection, we treated BPIV3 with MβCD to determine the virus titer. We found that disruption of the viral lipid raft caused a significant reduction of viral yield. Cholesterol reconstitution experiment showed that BPIV3 infection was successfully restored by cholesterol supplementation both in cellular membrane and viral envelope, which demonstrated that cholesterol-rich lipid rafts played a critical role in BPIV3 infection. These findings provide insights on our understanding of the mechanism of BPIV3 infection and imply that lipid raft might be a good potential therapeutic target to prevent virus infection.
脂筏是富含胆固醇和鞘脂的特殊脂质结构域，可被多种包膜病毒用于其生命周期。牛副流感病毒3型（BPIV3）进入细胞是由受体结合和膜融合介导的，但宿主细胞膜中的脂筏和BPIV3包膜如何影响病毒感染仍不清楚。在本研究中，我们调查了脂筏在BPIV3感染不同阶段的作用。用甲基-β-环糊精（MβCD）处理MDBK细胞以破坏细胞脂筏，并测定病毒感染情况。结果表明，MβCD以剂量依赖性方式显著抑制BPIV3感染，但不阻断病毒与细胞膜的结合。然而，病毒进入后用MβCD处理的MDBK细胞对病毒感染没有影响，这表明BPIV3感染在病毒进入阶段与细胞膜中的脂筏有关。为了进一步证实病毒包膜中的脂筏也影响BPIV3感染，我们用MβCD处理BPIV3以测定病毒滴度。我们发现破坏病毒脂筏会导致病毒产量显著降低。胆固醇重建实验表明，通过在细胞膜和病毒包膜中补充胆固醇，BPIV3感染得以成功恢复，这表明富含胆固醇的脂筏在BPIV3感染中起关键作用。这些发现为我们理解BPIV3感染机制提供了见解，并暗示脂筏可能是预防病毒感染的一个良好潜在治疗靶点。
