日本血吸虫保护性单克隆抗体SSj14识别模拟表位的筛选及其免疫原性分析

为分析日本血吸虫保护性单抗SSj14的模拟表位,观察其免疫保护作用,利用SSj14单抗筛选富集噬菌体的随机六肽库,应用免疫印迹法确定阳性克隆并分析其核苷酸序列,采用竞争ELISA法分析阳性克隆的抗原性,用筛选的阳性噬菌体克隆免疫小鼠进行日本血吸虫病免疫保护试验,计算减虫效果,并用ELISA法检测小鼠免疫前后的特异性抗体水平。结果显示,经3轮富集筛选后,免疫印迹法鉴定到4个阳性克隆,它们对SSj14单抗的抑制率分别为20.0%、40.8%、58.6%、61.5%,并分别在小鼠中诱导了7.42%、9.43%、11.74%、22.30%的减虫率。用噬菌体克隆免疫的小鼠均产生了较高水平的特异性抗体。结果表明,筛选到的阳性噬菌体克隆和SSj14单抗有较高的亲和力,并诱导了抗小鼠日本血吸虫的部分保护效果。

Screening and immunogenicity analysis of mimotopes of protective monoclonal antibody SSj14 against Schistosoma japonicum

To analyze peptides mimicking epitope of a protective monoclonal antibodies(McAb) SSjl4 against Schistosoma japonicum and investigate their immune-protective effects,a phage random 6-peptide library was screened using the purified McAb SSj14,and some clones were picked up.Western-blotting analysis confirmed that 4 positive clones were obtained.The epitope of each positive clone was detected by sequence analysis.The suppression rates of the 4 positive clones to McAb SSjl4 were 20.0%,40.8%,58.6% and 61.5% in the competitive ELISA,respectively.They induced adult worm reduction by 7.42%,9.43%,11.74% and 22.30% in mice,respectively.Meanwhile,levels of the specific antibody in sera of the vaccinated mice was higher than that in the blank control.These results showed that the 4 positive phage clones had high affinity with McAB SSj14,and provided partial protection against schistosomiasis.