Taguchi F, Yoden S, Siddell S, Kikuchi T
National Institute of Neuroscience, NCNP, Tokyo, Japan.
Adv Exp Med Biol. 1990;276:211-6. doi: 10.1007/978-1-4684-5823-7_29.
The spike (S) protein of murine coronavirus JHM strain (JHMV) has been expressed in insect cells using a recombinant baculovirus vector. The expressed S protein was shown to be glycosylated and expressed on the cell surface, and to be similar in size and antigenic properties to the S protein produced in mouse cells infected by JHMV. However, no proteolytic cleavage was detected in insect cells. The sera from rats immunised with S protein derived from insect cells reacted in immunoprecipitation and immunofluorescence with the S protein produced in JHMV-infected mouse cells. However, the antisera failed to neutralize the infectivity of JHMV. The studies on two proteins expressed by recombinant baculoviruses, corresponding to the cleavage products S1 and S2, and a panel of monoclonal antibodies suggest that the majority of epitopes which elicit the neutralizing antibodies are present in the N terminal half of the S protein.
鼠冠状病毒JHM株（JHMV）的刺突（S）蛋白已通过重组杆状病毒载体在昆虫细胞中表达。表达的S蛋白显示为糖基化的，并表达于细胞表面，其大小和抗原特性与受JHMV感染的小鼠细胞中产生的S蛋白相似。然而，在昆虫细胞中未检测到蛋白水解切割。用源自昆虫细胞的S蛋白免疫的大鼠血清在免疫沉淀和免疫荧光反应中与JHMV感染的小鼠细胞中产生的S蛋白发生反应。然而，抗血清未能中和JHMV的感染性。对由重组杆状病毒表达的两种对应于切割产物S1和S2的蛋白以及一组单克隆抗体的研究表明，引发中和抗体的大多数表位存在于S蛋白的N端一半中。
