尼帕病毒融合蛋白、受体结合蛋白的表达及特异性高免血清制备

Expression of Nipah virus structural proteins F1 and G and preparation of hyperimmune antisera against two proteins

摘要:

尼帕病毒膜融合蛋白F和受体结合蛋白G在病毒感染和诱导机体产生保护性免疫中起重要的作用。通过PCR扩增获得尼帕病毒F1和G基因片段(均去掉信号肽和跨膜区),克隆至原核表达载体,IPTG诱导大肠杆菌表达目的蛋白,Western blot表明重组F1、G蛋白与兔抗尼帕病毒血清具有良好的反应原性;同时将F1和G基因克隆至经改造过的杆状病毒表达载体,获得了含有目的基因的重组杆状病毒,接种sf9单层细胞,间接免疫荧光检测表明F1、G蛋白在杆状病毒中正确表达,并与抗尼帕病毒血清具有良好的反应原性。以纯化原核表达的F1、G蛋白免疫兔获得了抗F1和抗G重组蛋白的特异血清,Western blot和间接免疫荧光检测表明所制备的血清具有特异性。试验所表达的抗原和制备的特异血清可用于尼帕病的诊断。

Abstract:

The fusion protein (F) and attachment glycoprotein (G) of Nipah virus (NiV) are important for the virus to infect cells and induce protective immunity. In this study, the NiV F1 and G gene fragments without the sequences of signal peptide and transmembrane domain were amplified by PCR, then cloned into E.coli expression vector pGEX-6P-1 and modified baculovirus vector, respectively. After induction by IPTG, NiV F1 and G proteins were efficiently expressed in E.coli when analyzed by SDS-PAGE, both showing good reactivity with the rabbit antiserum anti-NiV serum in Western blot. The expression of NiV F1 and G in baculovirus system were also detected by indirect immunofluorescent assay (IFA) of fixed Sf9 cells monolayer infected with the recombinant baculoviruses expressing F1 and G. Furthermore the anti-F1 and anti-G hyperimmune sera were prepared by immunization of rabbits respectively with purified E.coli-expressed F1 and G proteins. Western blot and IFA as well as ELISA showed that antisera against both protein had high titers with good reactivity and specificity. The present study has provided a base for development of diagnostic reagents for detection of NiV infection.