细菌脂多糖对猪圆环病毒2型在PK-15细胞中复制的影响

Effects of Bacterial Lipopolysaccharide on Replication of Porcine Circovirus Type 2 in PK-15 Cells

研究脂多糖(LPS)对PCV2在PK-15细胞复制的影响,并探究其内在机制。用不同来源的LPS刺激感染PCV2的PK-15细胞,实时荧光定量PCR检测不同时间点对病毒复制的影响,以及NF-κB信号通路相关分子表达水平,吸附试验验证LPS对PCV2感染过程的影响,用Pymol软件对PCV2衣壳蛋白与LPS进行分子对接。结果表明,LPS刺激PK-15细胞12 h抑制PCV2的复制,而刺激24 h和48 h促进PCV2的复制,LPS还可以抑制PCV2病毒的吸附过程。对LPS与PCV2的Cap蛋白进行结构功能预测,发现二者有多处结合位点,表明LPS可能通过与PCV2核衣壳蛋白直接作用抑制PCV2与受体结合影响病毒前期吸附过程。后期LPS通过激活TLR4/NF-κB信号通路,促进IFN-β的表达,使病毒复制滴度增加。说明LPS对PCV2的复制存在双重影响,总体上促进PCV2的复制。

In order to study the effect of lipopolysaccharide(LPS)on the replication of PCV2 in PK-15 cells,and to explore its internal mechanism,LPS from different bacterial sources was used to stimulate PK-15 cells infected with PCV2,real-time quantitative PCR was used to detect the effects of viral replication on different time points and the expression levels of NF-κB signaling pathway,adsorption experiment was used to verify the effect of LPS on the process of PCV2 infection,and the PCV2 capsid protein was molecularly docked with LPS by Pymol software.The results showed that:LPS stimulated PK-15 cells for 12h inhibited the replication of PCV2,and after 24h and 48h of stimulation,it transformed to promote virus replication.LPS can also inhibit the adsorption process of PCV2 virus.The structure and function prediction of LPS and PCV2 Cap protein found that they have multiple binding sites,indicating that LPS may directly interact with PCV2 nucleocapsid protein to inhibit the binding of PCV2 to the receptor and affect the early adsorption process of the virus.Subsequently,LPS promotes viral replication by activating the TLR4/NF-κB signaling pathway and promoting the expression of IFN-β.In conclusion,LPS has a dual effect on PCV2 replication and generally promotes PCV2 replication.