【摘要】 重组志贺样毒素Ⅱ型变异体A亚单位pGEX＿Ansp及其酶活性部位的基因缺失株pGEX＿Ade及突变株pGEX＿Amu转化的大肠杆菌经诱导后,表达产物经超声波裂解并滤过除菌。ICR小鼠腹腔注射三种重组质粒转化菌诱导后菌体裂解物的除菌滤液,以检验重组表达产物的毒性和免疫原性;在Vero细胞上检测重组菌表达产物对Vero细胞的半数致死量(CD50)及免疫鼠血清对SLT＿Ⅱe毒素的中和实验三方面来比较pGEX＿Ansp、pGEX＿Ade和pGEX＿Amu的生物学特性,结果表明这三种基因工程菌表达产物经腹腔注射后可以诱导机体产生一定程度的保护性抗体。在Vero细胞上,pGEX＿Ansp的表达产物可在一定程度上使Vero细胞产生细胞病变,pGEX＿Amu的表达产物可在一定程度上抑制Vero细胞单层形成时间,而pGEX＿Ade对Vero细胞的生长无影响。更多还原

【Abstract】 ICR mice were immunized twice with the sonicated E.coli(pGEX_Ansp,pGEX_Amuand pGEX_Ade) expressing the three mutated A subunits of Shiga_like toxin II variant,and the immunized sera were tested with ELISA titers of 214,217 and 215 respectively and then challenged with purified wild type of the SLT_Ⅱe.80?% of the mice immunized with pGEX_Ade and 100?% of the mice immunized with pGEX_Amu or pGEX_Ansp survived from the challenge.And the neutralization of immunized sera against SLT_Ⅱe were 25,27,24 SLT_Ⅱrespectively.The expression of the three recombinants filtered at 0.45?um were diluted to inoculate Vero cells, resulted in cell death,significant growth suppression and no appearance each by pGEX_Ansp, pGEX_Amu and pGEX_Ade.更多还原