Wu Hai-Wei, Hu Xue-Mei, Wang Yong, Kurtis J D, Zeng Fan-Jie, McGarvey S T, Wu Guan-Ling, Zhang Zhao-Song, Hua Zi-Chun
Department of Pathogen Biology, Nanjing Medical University, 140 Hanzhong Rd, Nanjing, Jiangsu 210029, PR China.
Acta Trop. 2006 Oct;99(2-3):200-7. doi: 10.1016/j.actatropica.2006.08.006. Epub 2006 Sep 26.
New antigens and strategies are necessary for vaccine development against schistosomiasis japonica. Using a pool of 43 high titred anti-SWA sera from individuals residing in an Schistosoma japonicum endemic area of China, we have cloned a S. japonicum gene by cDNA library screening. The recombinant Sj338 protein has 44-46% identity to a mitochondrial precursor receptor protein of humans and rats. Immunization of mice with the recombinant Sj338 conferred 27-32% (p<0.01) reduction in worm burdens following cercarial challenge. In an effort to identify protective epitopes in Sj338 and increase the level of protection, we screened a random 12-mer peptide library constructed in M13 using a polyspecific anti-Sj338 rabbit serum. After five rounds of biopanning, we identified 30 reactive clones consisting of 11 distinct peptide sequences. These clones shared limited primary sequence homology with the recombinant Sj338 protein. Anti-sera raised against these phage clones recognized recombinant Sj338 and SWAP by Western blot. In murine vaccination experiments using whole recombinant phage without adjuvant, four of these clones demonstrated worm reductions of 11.6-25.1% (p=ns - 0.05) compared to M13 vaccinated animals. Animals vaccinated with all four of these phage demonstrated 34.2% (p<0.01) worm reduction compared to controls vaccinated with M13 clone. These data suggest that mimotope peptides are potential vaccine candidates for S. japonicum.
开发针对日本血吸虫病的疫苗需要新的抗原和策略。我们使用来自中国日本血吸虫病流行区居民的43份高滴度抗日本血吸虫成虫可溶性抗原（SWA）血清，通过cDNA文库筛选克隆了一个日本血吸虫基因。重组Sj338蛋白与人及大鼠的线粒体前体受体蛋白有44%-46%的同源性。用重组Sj338免疫小鼠后，尾蚴攻击后虫负荷降低了27%-32%（p<0.01）。为了鉴定Sj338中的保护性表位并提高保护水平，我们用多特异性抗Sj338兔血清筛选了构建在M13中的随机12肽文库。经过五轮生物淘选，我们鉴定出30个反应性克隆，由11个不同的肽序列组成。这些克隆与重组Sj338蛋白的一级序列同源性有限。针对这些噬菌体克隆产生的抗血清通过蛋白质印迹法识别重组Sj338和SWA。在使用无佐剂的完整重组噬菌体的小鼠疫苗接种实验中，与接种M13的动物相比，其中四个克隆使虫负荷降低了11.6%-25.1%（p=无显著性差异-0.05）。与接种M13克隆的对照动物相比，接种所有这四种噬菌体的动物虫负荷降低了34.2%（p<0.01）。这些数据表明模拟表位肽是日本血吸虫潜在的疫苗候选物。
