JH-Department of Molecular Medicine, School of Interdisciplinary Sciences and Technology, Jamia Hamdard, New Delhi 110062, India.
Centre for Research in Nanotechnology & Science, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Parasitol Int. 2023 Feb;92:102661. doi: 10.1016/j.parint.2022.102661. Epub 2022 Aug 29.
Currently, no licensed vaccine is available for human visceral leishmaniasis (VL), a fatal disease caused by the protozoan parasite Leishmania donovani. Two of our live attenuated L. donovani vaccine candidates, either deleted for Centrin1 (LdCen1) or p27 gene (Ldp27), that display reduced growth in macrophages were studied to be safe, immunogenic and protective against VL in various animal models. This report involves the identification of differentially expressed proteins, their related pathways and its underlying mechanism in the intracellular stage of these parasites, using Isobaric Tags for Relative and Absolute Quantitation (iTRAQ) methods. Out of 50-60 proteins, found to be differentially expressed in these mutant parasites, 36 were found to be common in both the parasites. Such proteins mainly belong to the functional categories viz. metabolic enzymes, chaperones and stress proteins, proteins involved in translation, processing and transport and proteins involved in nucleic acid processing. Proteins known to be host protective, like Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), cytochrome c, calreticulin and those responsible for inducing immune response, namely tubulins, DEAD box RNA helicases, HSP70 and tryparedoxin, have been detected to be modulated in these parasites. Such proteins could be predicted as biomarkers, with further scope of study for their role in growth attenuation. SIGNIFICANCE: This study aims at predicting proteomic biomarkers of Leishmania parasite growth attenuation, that have immunomodulatory role in the disease leishmaniasis. Advanced studies could be helpful in establishing the role of these identified proteins in parasitic virulence and to predict the host interaction at molecular level. Also, these proteins could be exploited as attenuation markers during the development of genetically modified live attenuated parasites as vaccine candidates. These could be cross validated in varied species of Leishmania and other tyrpanosomatids for similar response towards identifying them as universal biomarkers of attenuation.
目前，尚无针对内脏利什曼病（VL）的许可疫苗，VL 是一种由原生动物寄生虫利什曼原虫引起的致命疾病。我们研究了两种减毒活的利什曼原虫疫苗候选物，一种缺失 Centrin1（LdCen1）的基因，另一种缺失 p27 基因（Ldp27）的基因，它们在巨噬细胞中的生长能力降低，在各种动物模型中显示出安全性、免疫原性和对 VL 的保护作用。本报告涉及使用等重同位素标记相对和绝对定量（iTRAQ）方法鉴定这些寄生虫细胞内阶段差异表达蛋白、相关途径及其潜在机制。在这些突变寄生虫中，发现有 50-60 种蛋白差异表达，其中 36 种在两种寄生虫中都有表达。这些蛋白主要属于代谢酶、伴侣和应激蛋白、参与翻译、加工和运输的蛋白以及参与核酸加工的蛋白等功能类别。已发现一些已知对宿主具有保护作用的蛋白，如甘油醛-3-磷酸脱氢酶（GAPDH）、细胞色素 c、钙网蛋白和诱导免疫反应的蛋白，如微管蛋白、DEAD 盒 RNA 解旋酶、HSP70 和 tryparedoxin，在这些寄生虫中被检测到被调节。这些蛋白可以作为生物标志物进行预测，进一步研究其在生长衰减中的作用。意义：本研究旨在预测利什曼原虫生长衰减的蛋白质组生物标志物，这些标志物在利什曼病中具有免疫调节作用。深入研究有助于确定这些鉴定蛋白在寄生虫毒力中的作用，并预测分子水平上的宿主相互作用。此外，这些蛋白可作为遗传修饰的减毒活疫苗候选物在开发过程中的衰减标志物。这些蛋白可以在不同种属的利什曼原虫和其他锥虫中进行交叉验证，以确定它们作为普遍衰减生物标志物的相似反应。
