Analysis of the molecular mechanisms of host range determination of nucleopolyhedovirus

将4种核型多角体病毒(NPV)分别接种于SF21细胞、BMN-4细胞、SPIM细胞和Se301细胞，比较了接种细胞的细胞病变效应(CPE)表现、病毒DNA产量、病毒粒子产量、病毒结构蛋白产量、多角体蛋白产量和多角体形成情况。结果表明，AcNPV在4种细胞株中均能增殖并产生出芽病毒粒子，但仅在SF21、SPIM和Se301细胞中产生多角体和多角体，在BMN-4细胞中未见产生多角体；BmNPV在BMN-4细胞中高滴度增殖，在SPIM细胞中低滴度复制，仅有少数细胞出现CPE。在SF21细胞中，HcNPV只产生低滴度的出芽病毒粒子，既不产生多角体，也不产生多角体。在接种HcNPV的BMN-4细胞中，有大量的病毒DNA积累，但没有检测到病毒结构蛋白和多角体蛋白的积累以及出芽病毒粒子的产量。SeNPV仅在Se301细胞中明显增殖，并在SPIM培养的许多细胞中诱导细胞死亡。这些结果表明，NPV在细胞中表现出复杂的特性，这取决于NPV的种类和所接种的细胞，为NPV寄主范围确定的分子机制分析奠定了重要基础。

Autographa californica (Ac), Bombyx mori (Bm), Hyphantria cunea (Hc) and Spodoptera exigua (Se) nucleopolyhedroviruses (NPVs) were each inoculated to SF21cells, BmN-4 cells, SpIm cells and Se301 cells, and cytopathic effect (CPE) manifestation, viral DNA production, badded virion yield into the culture medium, viral structural protein production, polyhedrin (the matrix protein of polyhedra) production, and polyhedron formation in the inoculated cells were comparatively examined. The results showed that AcNPV were able to multiply and yield budded virions in all of four cell lines examined, but production of polyhedrin and polyhedra occurred only SF21cells, SpIm cells and Se301 cells, and not in BmN-4 cells.BmNPV multiplied to a high titre in BmN-4 cells and to a low titre in SpIm cells in which only a few number of cells manifested CPE.No clear CPE was observed in SF21 and Se301 cells inoculated with BmNPV.HcNPV multiplied unequivocally and produced polyhedra in SpIm and Se301 cells. In SF21 cells, HcNPV yielded budded virions only to a low titre and produced neither polyhedrin nor polyhedra. In HcNPV-inoculated BmN-4 cells, significant amount of viral DNA accumulated, but accumulation of viral structural protein and polyhedrin and budded virion yield were never detected. SeNPV multiplied clearly only in Se301 cells, and appeared to induce apoptotic form of cell death in many cells of SpIm culture.These results indicate that NPVs exhibit complex feature in the cells depending upon both the species of NPV and cultured cells being inoculated, and establish important basis for the analysis of molecular mechanisms of host range determination in NPVs.