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。在这些感染者中，约有500万人将发展为严重的心脏和/或消化系统疾病。每年可能有多达5万人死亡，还有许多人将成为身体残疾。最近，由于长期感染该病的移民人数不断增加，恰加斯病在美国成为一个令人关切的公共卫生问题。目前，市场上只有一种部分有效的药物；目前还没有人类疫苗。我们的长期目标是了解克氏锥虫与宿主细胞相互作用的分子事件，旨在为开发更有效的治疗方法建立合理的基础。我们的假设是克氏锥虫（TcalphaGalVes）感染锥虫期脱落的含有α gal的囊泡含有主要的寄生虫毒力因子，负责复发性细胞入侵和逃离宿主免疫。我们还提出TcalphaGalVes可能是在疾病的慢性期观察到的明显炎症过程的原因。我们的假设是基于TcalphaGalVes通过参与toll样受体2 （TLR2）极大地增强宿主细胞入侵的观察结果。我们的具体目标是：具体目标# 1：确定TcalphaGalVes的分子组成。我们将详细分析蛋白质和翻译后修饰（PTMs），如糖基化、糖基磷脂酰肌醇（GPI）锚定和磷酸化。特定目标# 2：确定TcalphaGalVes如何与宿主细胞受体相互作用并增强细胞侵袭。我们打算鉴定和表征宿主α gal结合蛋白，研究其与TLR2的相互作用，并了解这如何导致寄生虫进入细胞的增加。电子显微镜和共聚焦显微镜将对TcalphaGalVes和宿主细胞之间的早期相互作用进行分析。我们相信，这些特定目标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认识。我们的最终目标是为开发更有效的疗法来对抗这种致命的病原体建立一个合理的基础。

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.