Molecular Composition and Function of Trypanosoma cruzi Shed Vesicles

描述：克氏锥虫引起恰加斯病，影响拉丁美洲1100多万人。在感染者中，约有500万人将发展为严重的心脏和/或消化系统疾病。每年，多达50,000人可能死亡，许多人将成为肢体残疾。最近，由于慢性感染移民人数的增加，恰加斯病成为美国的一个公共卫生问题。目前，商业上只有一种部分有效的药物；没有人类疫苗。我们的长期目标是了解克氏毛滴虫与宿主细胞相互作用所涉及的分子事件，旨在为开发更有效的治疗方法建立合理的基础。我们的假设是，克氏毛滴虫(TcalphaGalVes)感染类乳虫期释放的含有α-氨基半乳糖的囊泡含有主要的寄生虫毒力因子，负责反复的细胞入侵和逃避宿主免疫。我们还提出，TcalphaGalVes可能是在疾病慢性期观察到的显著炎症过程的责任。我们的假设是基于观察到TcalphaGalVes通过与Toll样受体2(TLR2)结合而极大地增强宿主细胞的侵袭。我们的具体目标是：具体目标1：确定TcalphaGalVes的分子组成。我们将对蛋白质和翻译后修饰(PTM)进行详细的分析，如糖基化、糖基磷脂酰肌醇(GPI)锚定和磷酸化。具体目标2：确定TcalphaGalVes如何与宿主细胞受体相互作用并增强细胞侵袭。我们打算鉴定和鉴定宿主的AlphaGal结合蛋白，研究它与TLR2的相互作用，并了解这如何导致寄生虫进入细胞的增加。将对TcalphaGalVes和宿主细胞之间的早期相互作用进行电子和共聚焦显微镜分析。我们相信，这些特定目的的成功实现将极大地促进我们对克氏锥虫入侵宿主细胞和逃避宿主抗寄生虫免疫的精细分子机制的了解。我们的最终目标是为开发针对这种致命病原体的更有效的治疗方法建立合理的基础。

DESCRIPTION: Trypanosoma cruzi causes Chagas' disease, which affects over 11 million people in Latin America. Of those infected, about 5 million will develop severe cardiac and/or digestive disorders. Annually, up to 50,000 people may die and many others will become physically disabled. Recently, Chagas' disease became a public health concern in the United States, owing to the rising number of chronically infected migrants. Currently, there is only one partially effective drug commercially available; there is no human vaccine. Our long-term goal is to understand the molecular events involved in the interaction of T. cruzi with host cells, aiming at the establishment of rational bases for the development of more effective therapies Our hypothesis is that alphaGal-containing vesicles shed by the infective trypomastigote stage of T. cruzi (TcalphaGalVes) contain the major parasite virulence factors, responsible for both the recurrent cell invasion and escaping from host immunity. We also propose that TcalphaGalVes might be accountable for the marked inflammatory process observed in the chronic phase of the disease. Our hypothesis is based on the observations that TcalphaGalVes greatly enhance the host cell invasion by engaging Toll-like receptor 2 (TLR2). Our specific aims are: Specific Aim # 1: To determine the molecular composition of TcalphaGalVes. We will perform a detailed analysis of proteins and post-translational modifications (PTMs), such as glycosylation, glycosylphosphatidylinositol (GPI) anchoring, and phosphorylation. Specific Aim # 2: To define how TcalphaGalVes interact with host cell receptors and enhance cell invasion. We intend to identify and characterize the host alphaGal-binding protein, study its interaction with TLR2, and learn how this leads to the increase of parasite entry into the cell. Electron and confocal microscopy analyses of the early interactions between TcalphaGalVes and host cells will be carried out. We believe that the successful achievement of these specific aims will greatly advance our knowledge of the fine molecular mechanisms used by T. cruzi to invade host cells and escape from the host anti-parasitic immunity. Our ultimate goal is to establish a rational basis for the development of more effective therapies against this deadly pathogen.