Faria-Pinto P, Meirelles M N L, Lenzi H L, Mota E M, Penido M L O, Coelho P M Z, Vasconcelos E G
Departamento de Bioquímica, ICB, Universidade Federal de Juiz de Fora, 36015-400 Juiz de Fora, MG, Brazil.
Mem Inst Oswaldo Cruz. 2006 Sep;101 Suppl 1:359-63. doi: 10.1590/s0074-02762006000900059.
We have previously showed that Schistosoma mansoni ATP-diphosphohydrolase and Solanum tuberosum potato apyrase share epitopes and the vegetable protein has immunostimulatory properties. Here, it was verified the in situ cross-immunoreactivity between mice NTPDases and anti-potato apyrase antibodies produced in rabbits, using confocal microscopy. Liver samples were taken from Swiss Webster mouse 8 weeks after infection with S. mansoni cercariae, and anti-potato apyrase and TRITC-conjugated anti-rabbit IgG antibody were tested on cryostat sections. The results showed that S. mansoni egg ATP diphosphohydrolase isoforms, developed by anti-potato apyrase, are expressed in miracidial and egg structures, and not in granulomatous cells and hepatic structures (hepatocytes, bile ducts, and blood vessels). Therefore, purified potato apyrase when inoculated in rabbit generates polyclonal sera containing anti-apyrase antibodies that are capable of recognizing specifically S. mansoni ATP diphosphohydrolase epitopes, but not proteins from mammalian tissues, suggesting that autoantibodies are not induced during potato apyrase immunization. A phylogenetic tree obtained for the NTPDase family showed that potato apyrase had lower homology with mammalian NTPDases 1-4, 7, and 8. Further analysis of potato apyrase epitopes could implement their potential use in schistosomiasis experimental models.
我们之前已经表明，曼氏血吸虫ATP二磷酸水解酶和马铃薯块茎中的马铃薯apyrase具有共同表位，且该植物蛋白具有免疫刺激特性。在此，利用共聚焦显微镜验证了小鼠NTPDases与兔产生的抗马铃薯apyrase抗体之间的原位交叉免疫反应性。在感染曼氏血吸虫尾蚴8周后，从瑞士韦伯斯特小鼠身上采集肝脏样本，并在低温恒温切片上检测抗马铃薯apyrase和TRITC偶联的抗兔IgG抗体。结果显示，由抗马铃薯apyrase产生的曼氏血吸虫卵ATP二磷酸水解酶同工型在毛蚴和卵结构中表达，而不在肉芽肿细胞和肝结构（肝细胞、胆管和血管）中表达。因此，纯化的马铃薯apyrase接种到兔体内会产生含有抗apyrase抗体的多克隆血清，这些抗体能够特异性识别曼氏血吸虫ATP二磷酸水解酶表位，但不能识别哺乳动物组织中的蛋白质，这表明在马铃薯apyrase免疫过程中不会诱导自身抗体产生。NTPDase家族的系统发育树显示，马铃薯apyrase与哺乳动物NTPDases 1-4、7和8的同源性较低。对马铃薯apyrase表位的进一步分析可能会实现其在血吸虫病实验模型中的潜在应用。
