Unit of Parasitology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, Trasmontaña s/n. 35413-Arucas, Las Palmas, Spain.
Vet Parasitol. 2012 Aug 13;188(1-2):53-9. doi: 10.1016/j.vetpar.2012.03.010. Epub 2012 Mar 16.
A preliminary analysis of the significance of genetic diversity in cysteine proteinase genes has been performed simultaneously in sheep and goats, with regard to the immunological control using these enzymes against haemonchosis. For this purpose, we have studied the cross-immunoprotective effect of cysteine protease-enriched protein fractions (CPFs) in adult worms of two Haemonchus contortus strains from North America and Spain that are adapted to sheep and goats, respectively. Previous genetic analysis of cysteine proteinase genes in both strains has shown that some of loci are polymorphic and these differences are translated into changes in the amino acid sequences. However, our results show that CPFs from H. contortus adult worms have a protective effect against the parasite in both sheep and goats. These results are similar regardless of whether they were obtained from sheep or goat-adapted H. contortus strains, which could be very important in case H. contortus CPFs were commercially used in different countries, as vaccines to prevent the negative effects of this parasite. Interestingly, this experimental inoculation of both species with a heterologous strain of H. contortus contributes to the idea shown in previous studies about how difficult is the interpretation and the comparison of vaccination where strains not adapted to a specific host are used. Therefore, the challenger of using heterologous strains could provide similar results to those observed in immunised animals. This study suggests the possibility of exploring the mechanisms involved in natural protection against non-adapted strains, in order to develop strategies to control haemonchosis.
同时对绵羊和山羊的半胱氨酸蛋白酶基因遗传多样性的意义进行了初步分析，以便利用这些酶对血矛线虫病进行免疫控制。为此，我们研究了两种分别适应绵羊和山羊的来自北美的和西班牙的捻转血矛线虫成虫的富含半胱氨酸蛋白酶的蛋白部分（CPFs）的交叉免疫保护作用。以前对这两种捻转血矛线虫菌株的半胱氨酸蛋白酶基因的遗传分析表明，一些基因座是多态的，这些差异转化为氨基酸序列的变化。然而，我们的结果表明，来自捻转血矛线虫成虫的 CPFs 对绵羊和山羊寄生虫都具有保护作用。无论它们是来自绵羊还是山羊适应的捻转血矛线虫菌株，结果都是相似的，这在捻转血矛线虫 CPFs 在不同国家被商业化用作疫苗以预防这种寄生虫的负面影响的情况下可能非常重要。有趣的是，这两种物种用异源捻转血矛线虫菌株进行的实验接种有助于解释以前的研究中关于使用不适应特定宿主的菌株进行疫苗接种时解释和比较的困难。因此，使用异源菌株的挑战可能会提供与免疫动物观察到的相似的结果。这项研究表明了探索针对非适应菌株的天然保护机制的可能性，以便制定控制血矛线虫病的策略。
