Wu X P, Fu B Q, Wang X L, Yu L, Yu S Y, Deng H K, Liu X Y, Boireau P, Wang F, Liu M Y
Key Laboratory for Zoonosis Research, Ministry of Education, Institute of Zoonosis, Jilin University, 5333 Xian Road, Changchun, PR China.
Vet Parasitol. 2009 Feb 23;159(3-4):272-5. doi: 10.1016/j.vetpar.2008.10.035. Epub 2008 Oct 22.
Genes encoding antigens of adult worm, newborn larvae and muscle larvae of Trichinella spiralis were identified by immunoscreening their corresponding cDNA libraries. The cDNA libraries of T. spiralis adult (3 day old, Ad3) and newborn larvae (NBL) were screened using the serum of a pig infected with 20,000 muscle larvae (ML) at 26 days post-infection (dpi). Fifty-two positive clones representing 18 unique genes were obtained from the Ad3 cDNA library. The deduced amino acid sequences of 8 cDNAs were sequence homologues of the serine protease-like protein family. In the screening of NBL cDNA library, 81 positive clones representing 8 unique genes were isolated and of these, 70 clones corresponded to an NBL stage-specific serine protease gene. The ML cDNA library was screened using pig anti-Trichinella serum obtained at 60 dpi and 18 positive clones representing 8 unique genes were identified. Ten clones encoded a protein that is identical to a T. spiralis serine protease inhibitor. In general, our results revealed that antigenic serine protease-like proteins were found during the two invasive stages, Ad and NBL when these libraries were screened using 26 dpi antiserum, whereas a serine protease inhibitor was found in abundance in the ML library when it is screened using 60 dpi antiserum. These data are consistent with serine proteases playing an important role during the invasive stages of Trichinella infections, but become inhibited or internally controlled when the parasite enters a more stable, non-developing environment.
通过免疫筛选旋毛虫成虫、新生幼虫和肌幼虫的相应cDNA文库，鉴定出编码这些阶段抗原的基因。用感染20,000条肌幼虫的猪在感染后26天（dpi）的血清，筛选旋毛虫成虫（3日龄，Ad3）和新生幼虫（NBL）的cDNA文库。从Ad3 cDNA文库中获得了52个阳性克隆，代表18个独特基因。8个cDNA的推导氨基酸序列是丝氨酸蛋白酶样蛋白家族的序列同源物。在筛选NBL cDNA文库时，分离出81个阳性克隆，代表8个独特基因，其中70个克隆对应于一个NBL阶段特异性丝氨酸蛋白酶基因。用60 dpi时获得的猪抗旋毛虫血清筛选肌幼虫cDNA文库，鉴定出18个阳性克隆，代表8个独特基因。10个克隆编码一种与旋毛虫丝氨酸蛋白酶抑制剂相同的蛋白质。总体而言，我们的结果表明，当使用26 dpi抗血清筛选这些文库时，在成虫和新生幼虫这两个侵入阶段发现了抗原性丝氨酸蛋白酶样蛋白，而当使用60 dpi抗血清筛选肌幼虫文库时，发现大量丝氨酸蛋白酶抑制剂。这些数据与丝氨酸蛋白酶在旋毛虫感染的侵入阶段发挥重要作用一致，但当寄生虫进入更稳定、非发育环境时，丝氨酸蛋白酶会受到抑制或内部调控。
