Stanford University School of Medicine, Stanford, California, USA.
School of Pharmacy, Division of Molecular Therapeutics and Formulation, University of Nottingham, Nottingham, United Kingdom.
Infect Immun. 2017 Nov 17;85(12). doi: 10.1128/IAI.00301-17. Print 2017 Dec.
Urogenital schistosomiasis, caused by the parasitic trematode , affects over 112 million people worldwide. As with infections, the pathology of urogenital schistosomiasis is related mainly to the egg stage, which induces granulomatous inflammation of affected tissues. Schistosoma eggs and their secretions have been studied extensively for the related organism , which is more amenable to laboratory studies. Indeed, we have shown that IPSE/alpha-1 (here M-IPSE), a major protein secreted from eggs, can infiltrate host cells. Although the function of M-IPSE is unknown, its ability to translocate to the nuclei of host cells and bind DNA suggests a possible role in immune modulation of host cell tissues. Whether IPSE homologs are expressed in other schistosome species has not been investigated. Here, we describe the cloning of two paralog genes, H03-IPSE and H06-IPSE, which are orthologs of M-IPSE, from egg cDNA of Using PCR and immunodetection, we confirmed that the expression of these genes is restricted to the egg stage and female adult worms, while the H-IPSE protein is detectable only in mature eggs and not adults. We show that both H03-IPSE and H06-IPSE proteins can infiltrate HTB-9 bladder cells when added exogenously to culture medium. Monopartite C-terminal nuclear localization sequence (NLS) motifs conserved in H03-IPSE, SKRRRKY, and H06-IPSE SKRGRKY, are responsible for targeting the proteins to the nucleus of HTB-9 cells, as demonstrated by site-directed mutagenesis and green fluorescent protein (GFP) tagging. Thus, eggs express IPSE homologs that appear to perform similar functions in infiltrating host cells.
泌尿生殖系统血吸虫病由寄生性吸虫引起，影响全球超过 1.12 亿人。与 感染一样，泌尿生殖系统血吸虫病的病理学主要与卵期有关，卵期会引起受影响组织的肉芽肿性炎症。血吸虫卵及其分泌物已被广泛研究，因为相关生物更适合实验室研究。事实上，我们已经表明，从 卵中分泌的主要蛋白质 IPSE/alpha-1（这里称为 M-IPSE）可以渗透宿主细胞。虽然 M-IPSE 的功能未知，但它能够转移到宿主细胞的细胞核并结合 DNA，这表明它可能在宿主细胞组织的免疫调节中发挥作用。是否在其他血吸虫物种中表达 IPSE 同源物尚未得到研究。在这里，我们描述了从 卵 cDNA 中克隆两个平行基因 H03-IPSE 和 H06-IPSE 的情况，这两个基因是 M-IPSE 的同源物。通过 PCR 和免疫检测，我们证实这些基因的表达仅限于卵期和雌性成虫，而 H-IPSE 蛋白仅在成熟卵中检测到，而不在成虫中检测到。我们表明，当外源添加到培养基中时，H03-IPSE 和 H06-IPSE 蛋白都可以渗透 HTB-9 膀胱细胞。在 H03-IPSE 中保守的单部分 C 端核定位序列 (NLS) 基序 SKRRRKY 和 H06-IPSE SKRGRKY 负责将蛋白质靶向 HTB-9 细胞的细胞核，这通过定点突变和绿色荧光蛋白 (GFP) 标记得到证实。因此， 卵表达的 IPSE 同源物似乎在渗透宿主细胞方面具有相似的功能。
