重组乳酸乳球菌表达禽流感病毒HA1基因载体的构建及在禽流感病毒防治领域的应用

Construction of recombinant Lactococcus lactisrector expressing HA1 gene of avian influenza virus and application in preventing avian influenza virus

目的构建以重组乳酸乳球菌为基础的黏膜输送载体。方法以高致病性禽流感病毒H5N1的HA1基因作为研究对象,利用nisin诱导表达控制系统,构建分泌型与非分泌型重组乳酸乳球菌表达载体,经口服灌胃途径免疫BALB/c小鼠,通过ELISA检测小鼠血清IgG和粪便IgA,最后,对免疫后的小鼠进行H5N1病毒攻击实验,进而比较分泌型与非分泌型重组乳酸乳球菌表达载体的免疫效率。结果分泌型重组乳酸乳球菌免疫小鼠后产生的抗体水平(IgG和IgA)高于非分泌型重组乳酸乳球菌,经过同型H5N1病毒攻击后,分泌型重组乳酸乳球菌免疫的小鼠的存活率为80%,而非分泌型重组乳酸乳球菌免疫的小鼠的存活率为60%。结论本研究为防治高致病性禽流感病毒提供可行的思路与方法。

Objective To construct mucosal vaccine based on the delivery vector of recombinant L.lactis.Method We focused on the HA1 gene of highly pathogenic avian influenza virus H5N1 subtype,used nisin-controlled expression（NICE） system to construct secreted and non-secreted form of recombinant L.lactis,and evaluated the immune effects after oral administration.Sera IgG and fecal IgA were detected by ELISA.Finally,after H5N1virus challenge experiment,immune efficacy was determined by comparing the secreted and non-secreted forms of recombinant L.lactis.Result Antibody levels（IgG and IgA） produced by secreted form of recombinant L.lactis was more than that non-secreted form of recombinant L.lactis.After H5N1 virus challenge,the percent surrival of mice with immunization of secreted form of recombinant L.lactis was 80%,that of non-secreted form of recombinant L.lactis was 60%.Conclusion This study provides feasible idea and method for the prevention of highly pathogenic avian influenza virus.