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作为阿尔茨海默症(AD)重要神经病理学特征之一的脑内老年斑主要由β-淀粉样蛋白Aβ40和Aβ42聚集而成,Aβ42是其中的毒性成分.Aβ的特异性主动免疫对不同的转基因AD模型小鼠均有治疗作用,但临床试验中以注射方式给药容易诱发炎症反应.为了能够更好、更安全地采用主动的AB免疫疗法达到预防和治疗AD的目的,尝试用家蚕杆状病毒表达系统表达Aβ42蛋白.将Aβ42基因克隆入转移载体质粒pBacPAK8中,并使该重组质粒和家蚕杆状病毒Bm-BacPAK6线性化的DNA共转染家蚕卵巢培养细胞BmN,经筛选、纯化获得的重组病毒命名为BmNPV-Aβ42.用BmNPV-Aβ42感染BmN细胞和家蚕5龄起蚕后,利用Western blotting在BmN细胞和5龄幼虫血淋巴中均可检测到5 kD左右的特异性条带,证明重组Aβ42蛋白表达成功.ELISA检测显示,重组Aβ42肽在感染后第4天的BmN细胞和感染后第6天的5龄幼虫血淋巴中的表达量分别达到1.1 pg/个、2μg/mL.进一步提高Aβ42在家蚕杆状病毒表达系统中的表达效率,有望为研发预防和治疗阿尔茨海默症的可食性疫苗提供新型原料.“,”One of the important neuropathological characteristics of Alzheimer’s disease (AD)is senile plaque formed mainly by aggregation of amyloid β-proteins Aβ40 and Aβ42,among which Aβ42 is a toxic component.Aβ-specific proactive immunotherapy has good effect in treating various transgenic AD model mice.However,injection of Aβ in clinical test is likely to cause inflammatory reaction.In order to take a better and safer proactive Aβ immunotherapy to achieve the purpose of AD prevention and treatment,we attempted to express Aβ42 protein using Bombyx mori baculovirus expression system.Aβ42 gene was cloned into the transfer vector pBacPAK8 and co-transfected into silkworm BmN cells with the linearized DNA of Bombyx mori baculovirus BmBacPAK6 to construct the recombinant Bombyx moii baculovirus.The screened and purified recombinant virus was named BmNPV-Aβ42.Western blotting analysis showed that a 5 kD specific band could be detected both in BmN cells and in hemolymph of the 5th instar silkworm larvae after being infected by BmNPV-Aβ42,indicating that the recombinant protein Aβ42 was expressed successfully.ELISA analysis showed that the content of Aβ42 protein in BmN cells reached the maximum value of 1.1 pg/cell at the 4th day and in the hemolymph of 5th instar silkworm larvae reached the maximum value of 2 ug/mL at the 6th day after infection.Further improvement on expression efficiency of Aβ42 protein in Bombyx mori baculovirus expression system would provide a new material for development of edible vaccine to prevent and treat Alzheimer’s disease.