产肠毒素大肠杆菌K88黏附素蛋白亚基Fae G在L.lactis中的表达及其抗原性

Expression of the fae G gene of enterotoxigenic Escherichia coli K88 fimbrial subunit in Lactococcus lactis and its antigenicity

在构建L.lactis表达载体pNZ8148-faeG的基础上,将该载体转化到L.lactisNZ9000中,重组菌经5μg/Lnisin诱导3 h,SDS-PAGE结果显示,Fae G在L.lactis中表达的目的蛋白相对分子质量大小约为27 000,表达产物的量达菌体可溶性总蛋白的10.89%。Western blot分析结果表明,该目的蛋白具有良好反应原性。将重组L.lactis口服免疫BALB/c小鼠,小鼠产生特异性IgG及黏膜sIgA。本试验为进一步研究仔猪口服重组L.lactis疫苗,诱导其产生抗ETEC K88黏膜免疫的同时,发挥L.lactis的益生功能,预防仔猪腹泻奠定了基础。

According to enterotoxigenic Escherichia coil （ETEC） fae G possessing strong immunity and adherence to F4 receptor （F4R） on brush borders of piglets villous enterocytes,the expression vector of pNZ8148-fae G was constructed and transformed into L.lactis NZ9000,the Fae G was expressed after induced with 5μg/L nisin. The protein production was up to 10.89% of the total cellular soluble protein. The Western blot results indicated that the protein possessed reactionogenicity. Oral with recombinant L. lactis of BALB/c mice immunization showed F4-specifc sIg A and IgG antibody responses. These results provide a foundation for further study on oral L.lactis Nz9000/ 8148-Fae G inducing mucosal immune response and preventing diarrhea of piglets.