Molecular mechanisms of Plasmodium fertilization

疟原虫受精的分子机制

基本信息

批准号：
10064068
负责人：
MARCELO JACOBS-LORENA
金额：
$ 40.94万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-12-07 至 2022-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10064068
关键词：
Affinity Antibodies Antibody Formation Binding Biological Assay Biology Biotin Blood Cell Separation Communicable Diseases Culicidae Development Disease Economics Enzyme-Linked Immunosorbent Assay Event Female Fertilization Genes Germ Cells Goals Human Immunofluorescence Immunologic In Vitro Intervention Knock-out Knowledge Laboratories Lead Libraries Life Cycle Stages Ligands Light Liver Malaria Mass Spectrum Analysis Membrane Proteins Midgut Molecular Molecular and Cellular Biology Nature Organism Parasites Parasitic Diseases Peptide Phage Display Library Peptide antibodies Peptides Persons Phage Display Plasmodium Play Population Process Proteins Proteome Receptor Gene Recombinants Refractory Research Role Salivary Glands Sexual Development Sexual Reproduction Structure Surface Surface Plasmon Resonance Tertiary Protein Structure Testing Transgenic Organisms Western Blotting base experimental study in vivo insight malaria transmission male novel parasite invasion peptide structure peptidomimetics prevent receptor receptor function sex tool transmission process transmission-blocking vaccine vector mosquito

项目摘要

ABSTRACT Malaria remains one of the most devastating infectious diseases. It kills over a million people every year while causing immense suffering and economic losses worldwide. Whereas much progress has been made in understanding the life cycle of the parasite in the human host and in the mosquito vector, significant gaps of knowledge remain. Fertilization of malaria parasites is a poorly understood process that takes place in the lumen of the mosquito gut. This process is important because survival in nature is completely dependent on the ability of the parasite to undergo sexual reproduction. The proposed research aims to identify molecular interactions that take place during fertilization of malaria parasites. This project is based on an unorthodox approach (identification of peptides that bind to the gamete surface) made possible by the recent development of an important tool, a transgenic parasite that produces red-fluorescent female gametes and green-fluorescent male gametes. Pure populations of malaria female and male gametes from this transgenic parasite were isolated by cell sorting and then used to screen a phage display library for peptides that recognize molecules on the gamete surfaces. A peptide (FG1) that binds to female gametes and another peptide (MG1) that binds to male gametes were identified. Importantly, when added to a malaria infectious blood meal, each of these peptides blocked parasite fertilization, suggesting that the peptides bound to a receptor and prevented its interaction with a ligand on the gamete of the opposite sex. Our working hypothesis is that the peptide structurally mimics the gamete ligand and that peptide and ligand compete for binding to the corresponding receptor. This proposal lays out a research plan to identify the receptor to which the FG1 and MG1 peptides bind and the ligands on the gametes of the opposite sex that the two peptides structurally mimic. An additional aim is to characterize the proteome on the surface of female gametes before and after fertilization, to gain insights on additional proteins involved in fertilization and possible block to polyspermy. Elucidation of mechanisms of fertilization is important not only for understanding the basic biology of malaria and other parasitic diseases but could also lead to the identification of new targets for blocking transmission and the spread of disease. Moreover, should the mechanisms be conserved, our findings could be extended to the biology of fertilization of higher organisms.

抽象的疟疾仍然是最具破坏性的传染病之一。它杀死了超过一百万人每年都会给全世界造成巨大的痛苦和经济损失。鉴于很多在了解寄生虫在人类宿主和体内的生命周期方面已经取得了进展。关于蚊子媒介，仍然存在重大的知识空白。疟疾寄生虫的受精是人们对蚊子肠道内发生的过程知之甚少。这个过程是重要的是，因为在自然界中的生存完全取决于寄生虫的能力进行有性生殖。拟议的研究旨在确定受精过程中发生的分子相互作用疟疾寄生虫。该项目基于非正统方法（肽的鉴定）与配子表面结合）最近开发的一种重要工具使之成为可能，一种转基因寄生虫，产生红色荧光雌性配子和绿色荧光雄性配子配子。来自这种转基因寄生虫的疟疾雌性和雄性配子的纯群体通过细胞分选分离，然后用于筛选噬菌体展示库中的肽，识别配子表面的分子。与雌配子结合的肽 (FG1) 还鉴定出了另一种与雄配子结合的肽（MG1）。重要的是，添加后到疟疾传染性血粉中，这些肽中的每一种都会阻止寄生虫受精，表明肽与受体结合并阻止其与配体相互作用异性的配子。我们的工作假设是肽在结构上模仿配子配体以及肽和配体竞争结合相应的配体受体。该提案制定了一项研究计划，以确定 FG1 和 MG1肽与这两种肽结合的异性配子上的配体结构上模仿。另一个目的是表征女性表面的蛋白质组受精前后的配子，以了解参与受精的其他蛋白质受精并可能阻止多精受精。阐明受精机制不仅对于理解受精的基本原理很重要疟疾和其他寄生虫病的生物学，但也可能导致新的疾病的鉴定阻止疾病传播和蔓延的目标。此外，机制是否应该保守地说，我们的发现可以扩展到高等生物受精的生物学。