PATHOGENESIS OF ACANTHAMOEBA KERATITIS

棘阿米巴角膜炎的发病机制

• 批准号: 2162962
• 负责人: Noorjahan Panjwani
• 金额: $ 25.24万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-01-01 至 1996-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2162962
• 关键词: Acanthamoeba; animal tissue; blocking antibody; cell adhesion; cell membrane; corneal epithelium; enzyme inhibitors; enzyme mechanism; enzyme structure; enzyme substrate; exo alpha sialidase; glycoproteins; glycosidases; glycosphingolipids; guinea pigs; host organism interaction; human tissue; immunocytochemistry; keratitis; laboratory mouse; laboratory rabbit; lectin; macromolecule; molecular pathology; oligosaccharides; protozoal antigen; protozoal infection; receptor binding; spectrometry; surface antigens; tissue /cell culture

We shall attempt to elucidate the mechanism of the development of Acanthamoeba keratitis by examining the plasma membrane molecules of corneal epithelium and Acanthamoeba. In project 1 we shall (1) identify and characterize those rabbit corneal epithelial cell surface glycoconjugates which play a role in the host-parasite interactions, (2) pinpoint the sites of parasite attachment on Acanthamoeba-reactive cell surface glycoconjugates of rabbit corneal epithelium, (3) prepare monoclonal and polyclonal antibodies against those Acanthamoeba and corneal epithelial cell surface glycoconjugates which play a role in the host-parasite interactions, (4) determine using immunohistochemical techniques, whether Acanthamoeba-reactive glycoconjugate, found on rabbit corneal epithelial cells in culture are present on normal human and rabbit corneas in vivo, and (5) determine whether it is possible to block the adherence of Acanthamoeba to human and rabbit corneas using the above antibodies and by various saccharides, exoglycosidases and lectins. Since the neuraminidase of many pathogens, including influenza virus and parasite Trypanosoma cruzi, plays a role in the pathogenesis of infection, we shall, in project 2, try to determine whether Acanthamoeba neuraminidase plays a role in the pathogenesis of Acanthamoeba keratitis. In this study, we shall (1) isolate and characterize the neuraminidase produced by human corneal isolates of Acanthamoeba and establish whether the enzyme is structurally related to the neuraminidases of other parasites, especially T cruzi, (2) identify those rabbit corneal epithelial cell surface glycoconjugates which serve as substrates for Acanthamoeba neuraminidase and determine whether asialation of corneal epithelial cell surface glycoconjugates by the parasite enzyme exposes the parasite attachment sites and (3) determine whether anti-neuraminidase antibodies and non-immune inhibitors of neuraminidases inhibit or enhance the adherence of Acanthamoeba to human and rabbit corneal epithelium and thereby establish whether Acanthamoeba neuraminidase, like the T cruzi enzyme, regulates the infection by a negative control mechanism. It is hoped that the proposed studies will lead to a better understanding of the molecular basis of Acanthamoeba keratitis and to the development of more effective therapy for this sight threatening and difficult to treat disease.

我们将试图阐明……的发展机制。 棘阿米巴角膜炎的质膜分子检测 角膜上皮和棘阿米巴。在项目1中，我们将(1)确定 并对兔角膜上皮细胞表面进行表征 在宿主-寄生虫相互作用中发挥作用的糖结合物，(2) 精确定位寄生虫附着在棘阿米巴反应细胞上的位置 兔角膜上皮细胞表面糖结合物，(3)制备 抗棘阿米巴和棘阿米巴的单抗和多克隆抗体 角膜上皮细胞表面糖偶联物在角膜内皮生长中的作用 宿主-寄生虫相互作用，(4)用免疫组织化学方法确定 在兔身上发现的棘阿米巴反应性糖偶联物的技术 培养中的角膜上皮细胞存在于正常人和 活体兔角膜，以及(5)判断是否有可能阻断 棘阿米巴在人和兔角膜上的黏附 抗体和各种糖类、外切糖苷酶和凝集素。 由于许多病原体的神经氨酸酶，包括流感病毒和 克氏锥虫寄生虫在鸡传染性支气管炎发病机制中的作用 感染，我们将在项目2中尝试确定棘阿米巴是否 神经氨酸酶在棘阿米巴角膜炎的发病机制中起作用。 在本研究中，我们将(1)分离和鉴定神经氨酸酶 由人类角膜棘阿米巴分离株产生，并确定 这种酶在结构上与其他动物的神经氨酸酶有关 寄生虫，特别是T ruzi，(2)识别那些兔的角膜 作为底物的上皮细胞表面糖偶联物 棘阿米巴神经氨酸酶与角膜唾液酸化 寄生虫酶暴露上皮细胞表面糖偶联物 寄生虫附着位置以及(3)确定 抗神经氨酸酶抗体和神经氨酸酶非免疫性抑制剂 抑制或增强棘阿米巴对人和兔的黏附 从而确定棘阿米巴是否 神经氨酸酶，就像T ruzi酶一样，通过一种 负向控制机制。 希望拟议的研究将有助于更好地了解 棘阿米巴角膜炎的分子基础及其对发病的影响 对这种具有威胁性和难治性的视力进行更有效的治疗 治病。