Centro de Pesquisas René Rachou (CPqRR), Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, MG 30190-002, Brazil; Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG 31270-901, Brazil.
Centro de Pesquisas René Rachou (CPqRR), Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, MG 30190-002, Brazil; Faculdade Promove de Tecnologia, Belo Horizonte, MG 30130-180, Brazil.
Int J Parasitol. 2017 Aug;47(9):529-544. doi: 10.1016/j.ijpara.2017.01.007. Epub 2017 Mar 21.
Helminths cause a number of medical and agricultural problems and are a major cause of parasitic infections in humans, animals and plants. Comparative analysis of helminth genes and genomes are important to understand the genomic biodiversity and evolution of parasites and their hosts in terms of different selective pressures in their habitats. The interactions between the infective organisms and their hosts are mediated in large part by secreted proteins, known collectively as the "secretome". Proteins secreted by parasites are able to modify a host's environment and modulate their immune system. The composition and function of this set of proteins varies depending on the ecology, lifestyle and environment of an organism. The present study aimed to predict, in silico, the secretome in 44 helminth species including Nematoda (31 species) and Platyhelminthes (13 species) and, understand the diversity and evolution of secretomes. Secretomes from plant helminths range from 7.6% (943 proteins) to 13.9% (2,077 proteins) of the filtered proteome with an average of 10.2% (1,412 proteins) and from free-living helminths range from 4.4% (870 proteins) to 13% (3,121 proteins) with an average of 9.8% (2,126 proteins), respectively, and thus are considerably larger secretomes in relation to animal helminth secretomes which range from 4.2% (431 proteins) to 11.8% (2,419 proteins) of the proteomes, with an average of 7.1% (804 proteins). Across 44 secretomes in different helminth species, we found five conserved domains: (i) PF00014 (Kunitz/Bovine pancreatic trypsin inhibitor domain), (ii) PF00046 (Homeobox domain), (iii) PF00188 (cysteine-rich secretory proteins, antigen 5, and pathogenesis-related 1 proteins), (iv) PF00085 (Thioredoxin) and (v) PF07679 (Immunoglobulin I-set domain). Our results detected secreted proteins associated with invasion, infection, adhesion and immunoregulation processes as protease inhibitors and cytokines, among other functions. In summary, this study will contribute towards the understanding of host-parasite interactions and possibly identify new molecular targets for the treatment or diagnosis of helminthiases.
寄生虫引起了许多医学和农业问题，是人类、动物和植物寄生虫感染的主要原因。比较分析寄生虫的基因和基因组对于了解寄生虫及其宿主在不同栖息地的选择压力下的基因组多样性和进化非常重要。感染生物与宿主之间的相互作用在很大程度上是由分泌蛋白介导的，这些蛋白统称为“分泌组”。寄生虫分泌的蛋白质能够改变宿主的环境并调节其免疫系统。这组蛋白质的组成和功能因生物体的生态、生活方式和环境而异。本研究旨在预测包括线虫（31 种）和扁形动物（13 种）在内的 44 种寄生虫物种的分泌组，以期从计算的角度理解分泌组的多样性和进化。植物寄生虫的分泌组占过滤后蛋白质组的 7.6%（943 个蛋白）到 13.9%（2077 个蛋白），平均为 10.2%（1412 个蛋白）；自由生活的寄生虫的分泌组占过滤后蛋白质组的 4.4%（870 个蛋白）到 13%（3121 个蛋白），平均为 9.8%（2126 个蛋白），因此与动物寄生虫的分泌组相比，它们的分泌组要大得多，动物寄生虫的分泌组占蛋白质组的 4.2%（431 个蛋白）到 11.8%（2419 个蛋白），平均为 7.1%（804 个蛋白）。在不同寄生虫物种的 44 种分泌组中，我们发现了五个保守结构域：（i）PF00014（Kunitz/牛胰蛋白酶抑制剂结构域），（ii）PF00046（Homeobox 结构域），（iii）PF00188（富含半胱氨酸的分泌蛋白、抗原 5 和与发病机制相关的 1 蛋白），（iv）PF00085（硫氧还蛋白）和（v）PF07679（免疫球蛋白 I 集结构域）。我们的结果检测到与入侵、感染、粘附和免疫调节过程相关的分泌蛋白，如蛋白酶抑制剂和细胞因子等功能。总之，本研究将有助于了解宿主-寄生虫相互作用，并可能为寄生虫病的治疗或诊断确定新的分子靶点。
