College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China.
Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
Toxins (Basel). 2019 Mar 4;11(3):145. doi: 10.3390/toxins11030145.
The (CpGV) GP37 has synergistic effects on the infectivity of (NPVs), however, the mechanism employed is unclear. In this study, in vitro and in vivo binding assays indicated that GP37 efficiently bound to the midgut peritrophic membrane (PM) of larvae. Treatment with GP37 led to the damage of the PM's compacted structure and the generation of the PM perforations, and the enhancement of the PM's permeability. qPCR results further demonstrated that GP37 increased the ability of occlusion-derived virions (ODV) to cross the PM. R18-labeling experiments exhibited that GP37 also promoted the fusion of ODVs and insect midgut epithelia. Altogether, our present results revealed that the synergistic mechanism of GP37 to the infectivity of NPV might involve two parts. GP37 damaged the integrity of the PM after binding, which enhanced the PM's permeability and increased the ability of ODVs to cross the PM, finally facilitating the ODVs reaching the midgut. In addition, GP37 promoted the fusion of ODVs and insect midgut epithelia. Our data expand the understanding of the mechanism used by baculovirus synergistic factors and provide a foundation for the development of high-efficiency baculoviral insecticides.
（CpGV）GP37 对（NPV）的感染力具有协同作用，但作用机制尚不清楚。在本研究中，体外和体内结合实验表明 GP37 可有效地与 幼虫的中肠围食膜（PM）结合。用 GP37 处理会导致 PM 紧密结构的破坏和 PM 穿孔的产生，并增强 PM 的通透性。qPCR 结果进一步表明，GP37 增加了包埋病毒（ODV）穿过 PM 的能力。R18 标记实验表明，GP37 还促进了 ODV 与昆虫中肠上皮的融合。总之，我们的研究结果表明，GP37 对 NPV 感染力的协同机制可能涉及两个部分。GP37 在结合后破坏 PM 的完整性，增强 PM 的通透性并增加 ODV 穿过 PM 的能力，最终促进 ODV 到达中肠。此外，GP37 促进了 ODV 与昆虫中肠上皮的融合。我们的数据扩展了杆状病毒协同因子作用机制的理解，并为高效杆状病毒杀虫剂的开发提供了基础。
