Division of Parasitology and Parasitic Diseases, Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, 02-786 Warsaw, Ciszewskiego 8, Poland.
Exp Parasitol. 2013 Apr;133(4):472-82. doi: 10.1016/j.exppara.2013.01.006. Epub 2013 Jan 29.
Ancylostoma ceylanicum belongs to the group of parasites commonly known as hookworms, blood-sucking nematodes which infect around 576 million people and hundreds of millions of animals. The interactions between these parasites and host immune systems are complicated and yet to be determined. Hookworm infections are usually long lasting and recurrent, due in part to their ability to synthesize macromolecules capable of modulating the host immune response. The interaction of parasite proteins with host immune systems has been proven, but so far there is no data describing the influence of astacin-like metalloproteases (expressed among different parasitic nematodes) on the human immune system. The cDNA encoding A. ceylanicum metalloprotease 2 (Ace-mtp-2) was cloned using RACE-PCR. Computational analysis was used to examine the immunogenicity and recombinant Ace-MTP-2 was used to investigate its influence on human THP-1 monocytes and macrophages. The Ace-mtp-2 gene encodes an astascin-like metalloprotease, with a theoretical molecular mass of 26.7 kDa. The protease has a putative signal peptide, 11 potential phosphorylation sites, and two disulfide bridges revealed by computational analysis. Maximal expression of Ace-mtp-2 by A. ceylanicum occurs in the adult stage of the parasite, and Western blot indicates the secretory nature of the protease. This suggests the protease is working at the host-parasite interface and would likely be exposed to the hosts immune response. Recombinant protein were expressed in Escherichia coli and Pichia pastoris. Recombinant Ace-MTP-2 amplified the in vitro release of TNFα and induced release of IFNγ by lipopolysaccharide activated THP-1 macrophages. The presence of Ace-MTP-2 in secretory products of the adult parasite and the induction of IFNγ release may suggest an important role for Ace-MTP-2 in host-parasite interactions since IFNγ is suggested to be responsible for the protective immune response against adult hookworms.
西里伯瑞列绦虫属于通常被称为钩虫的寄生虫群，是一种吸血线虫，感染了约 5.76 亿人和数亿动物。这些寄生虫与宿主免疫系统之间的相互作用很复杂，目前尚未确定。钩虫感染通常持续时间长且反复发作，部分原因是它们能够合成能够调节宿主免疫反应的大分子。寄生虫蛋白与宿主免疫系统的相互作用已得到证实，但迄今为止尚无数据描述（在不同寄生线虫中表达的）类星鼻鲀金属蛋白酶对人类免疫系统的影响。使用 RACE-PCR 克隆了西里伯瑞列绦虫金属蛋白酶 2（Ace-mtp-2）的 cDNA。通过计算分析研究了其免疫原性，并用重组 Ace-MTP-2 研究了其对人 THP-1 单核细胞和巨噬细胞的影响。Ace-mtp-2 基因编码一种类星鼻鲀金属蛋白酶，理论分子量为 26.7 kDa。通过计算分析揭示了蛋白酶具有一个假定的信号肽、11 个潜在的磷酸化位点和两个二硫键。A. ceylanicum 的 Ace-mtp-2 的最大表达发生在寄生虫的成虫阶段，Western blot 表明该蛋白酶具有分泌特性。这表明该蛋白酶在宿主-寄生虫界面起作用，并且可能会暴露于宿主的免疫反应中。在大肠杆菌和巴斯德毕赤酵母中表达了重组蛋白。重组 Ace-MTP-2 扩增了 TNFα 的体外释放，并诱导脂多糖激活的 THP-1 巨噬细胞释放 IFNγ。在成虫寄生虫的分泌产物中存在 Ace-MTP-2，并诱导 IFNγ 释放，这可能表明 Ace-MTP-2 在宿主-寄生虫相互作用中具有重要作用，因为 IFNγ 被认为负责针对成虫钩虫的保护性免疫反应。
