家蚕核型多角体病毒广东分离株Bm126基因编码基序RGD的功能研究

Functional Analysis on RGD Motif Encoded by Bm126 Gene of Bom-byx mori Nucleopolyhedrovirus Guangdong Isolate

杆状病毒因专一感染昆虫而作为治理农林害虫的生物农药以及作为表达载体在生物医药产业得到广泛应用。前期研究发现家蚕核型多角体病毒(Bm NPV)中国广东分离株(Bm NPV-GD)的orf126基因(Bm126)包含一个编码精氨酸-甘氨酸-天冬氨酸(RGD)的基序。采用点突变技术构建RGD编码基序突变的转移载体,利用Bm NPV Bac-to-Bac系统转座获得重组bacmid,通过转染Bm N细胞获得重组病毒,分析突变病毒在感染细胞后期的多角体产量变化,并在病毒感染过程中进一步应用RGD竞争性多肽Cyclo[RGDf-N(Me)V-]分析突变病毒多角体产量的变化,以此探究Bm NPV Bm126编码的RGD基序是否在病毒感染增殖中发挥作用。经t检验统计表明突变病毒感染Bm N细胞后产生的多角体数量与对照病毒没有显著性差异,Cyclo[RGDf-N(Me)V-]处理结果也显示其与对照没有显著差异,表明Bm NPV-GD Bm126基因编码的RGD基序可能不是直接参与病毒感染宿主细胞后的增殖过程,而是辅助病毒的其他因子与宿主细胞互作。

Baculoviruses have been widely used as biological pesticide against agricultural and forestry pests and expression vector in biological medicine industry for specially infect insect. Previous study revealed that orf126 gene of Bombyx mori nucleopolyhedrovirus（ Bm NPV） Guangdong isolate Bm NPV-GD（ Bm126） contained a RGD motif which encoded Arginine-Glycine-Aspartic acid. In present study,the transfer vectors carrying RGD mutated sequence were constructed by point mutant technology and were transposed into Bm NPV Bac-to-Bac system to construct recombinant bacmids. The recombinant viruses were obtained after the recombinant bacmids were used to transfect Bm E cells. In order to investigate whether RGD motif encoded by Bm126 play roles in infection and propagation of Bm NPV,the polyhedron productivity variation of mutational viruses at the late infectious stages was analysed,and it was analysed by using competitive polypeptide Cyclo[RGDf-N（ Me） V-] during viral infection. t test statistics indicated that the polyhedron productivity of mutational viruses showed no significant difference with that of control virus,and there was no signifi-cant difference between Cyclo[RGDf-N（ Me） V-]treatment group and the control group. These results suggest that RGD motif encoded by Bm NPV-GD Bm126 gene is not involved in viral replication process directly,but facilitates the interaction between other viral factors and host cells.