基于慢病毒载体系统构建重组JSRV-NM假病毒

Construction of JSRV-NM Pseudovirions by High Efficiency Packaging System of the Lentivirus

目的采用慢病毒质粒结构重组JSRV-NM假病毒,克服JSRV-NM病毒只能通过绵羊支气管穿刺接种扩增,不能通过体外细胞培养扩增的问题。方法采用慢病毒高效包装系统pMD.G、pCMV-HIV△8.2和pHIV-eGFP,以JSRV-NM病毒的env包膜质粒pCMVJSRV-NM替代VSV-G病毒的包膜质粒pMD.G,转染293T细胞,复制、包装并产出重组的JSRV-NM假病毒。用real-time PCR检测WPRE表达来测定假病毒的滴度,用接种24孔板的293T细胞检测假病毒感染力。结果成功重组了基于慢病毒质粒结构的JSRV-NM假病毒,可超速离心浓缩成高滴度(1×108TU/mL)的病毒,Lv-JSRV-NM包膜与Lv-VSV-G包膜按感染复数(MOI)=3的比例感染Hela细胞具有相同的感染能力。结论基于慢病毒质粒构建的JSRV-NM假病毒,能够在293T细胞中复制和扩增,产出的假病毒具有稳定性、感染力和安全性,符合二级生物实验室安全的要求。

Objective To overcome the fact that SRV-NM virus can only multiple and amplify through partially pu-rified jaagsiekte retrovirus inoculated intratracheally in sheep but it cannot be augmented using in vitro cell culture, we con-structed JSRV-NM pseudovirions based on high efficiency packing system of lentivirus. Methods Lentivirus of three high efficiency packing plasmids system pMD.G, pCMV-HIV 8.2 and pHIV-eGFP was developed, and JSRV-NM-env coated plasmid pCMVJSRV-NM was used to substitute VSV-G virus coated plasmid pMD.G then co-transfected into 293T cells to replicate, package and produce restructured JSRV-NM pseudovirions. Gene expression of pseudovirion was determined through WPRE using real time PCR; Virus infectivity was detected through inoculating JSRV-NM pseudovirions into 24 pore plates. Results We construct JSRV-NM pseudovirions successfully based on the lentivirus system. JSRV-NM pseudo-virions can also be concentrated to higher titer （108 TU/mL detected by real time PCR by ultracentrifugation without signifi-cant loss of activity. JSRV-NM and VSV-G pseudovirions infected on Hela cells （both MOI= 3） respectively and no obvi-ous difference were shown on their infection efficiency detected by real time PCR. Conclusion Based on lentivirus system, JSRV-NM pseudovirions can be multipled and amplified in 293T cell culture in vitro. JSRV-NM pseudovirions is stable without loss its infection activity and the requirements of biological laboratory safety II was also met. JSRV-NM pseudoviri-ons will provide a useful tool for further study of JSRV-NM-env infection across species or its induction of lung adenocarci-noma.