【摘要】 丝氨酸蛋白酶抑制剂(serpin)对昆虫的免疫反应起重要调节作用。根据家蚕基因组数据库序列设计引物,从家蚕幼虫血细胞中克隆了Bmserpin6的编码基因,并构建重组表达载体,在大肠杆菌中成功表达了重组Bmserpin6蛋白。将纯化的重组Bmserpin6注射家蚕5龄幼虫后6 h提取家蚕血液制备血清,检测血清样品中的酚氧化酶原活性显著下降(P<0.05)。体腔注射重组Bmserpin6后的家蚕5龄幼虫再通过微球菌诱导蚕体内抗菌肽gloverin2基因的表达,结果显示幼虫脂肪体和血细胞中的gloverin2基因表达显著下调(P<0.05)。依据上述结果推测:体外表达的重组Bmserpin6可以调节蚕体内2个重要的免疫途径,即抑制蚕体酚氧化酶原的激活和外源细菌诱导的蚕体抗菌肽的产生。更多还原

【Abstract】 Serine protease inhibitor( serpin) plays an important regulatory role in insect immunity. With primers designed according to the sequence information in the silkworm( Bombyx mori) database,we cloned Bmserpin6 coding gene from hemocytes of silkworm larvae and constructed the recombinant expression vector. Furthermore,we expressed the recombinant Bmserpin6 protein in E. coli. At 6 h after the purified recombinant Bmserpin6 protein was used to inject the 5th instar silkworm larvae,silkworm haemolymph was collected to prepare serum sample. It was found that the activity of prophenoloxidase in serum sample was significantly decreased( P < 0. 05). After intravitreous injection of the recombinant Bmserpin6 into the 5th instar silkworm larvae,the expression of antimicrobial peptide gloverin2 coding gene in silkworm was induced with Micrococcus lysodeikticus. The results showed that the expressional level of gloverin2 coding gene in fat body and hemocytes was significantly decreased( P < 0. 05). It is suggested that the recombinant Bmserpin6 expressed in vitro can inhibit prophenoloxidase activation pathway and antimicrobial peptide production induced by exogenous bacteria.更多还原