INTERACTION OF ORAL STREPTOCOCCI WITH ANIMAL TISSUES

口腔链球菌与动物组织的相互作用

• 批准号: 2896920
• 负责人: MURRAY W STINSON
• 金额: $ 24.11万
• 依托单位: STATE UNIVERSITY OF NEW YORK AT BUFFALO
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-01 至 2002-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2896920
• 关键词: Streptococcus pyogenes; bacterial antigens; binding proteins; cytokine; defensins; disease /disorder model; epitope mapping; glomerulonephritis; heparan sulfate; heparin; histones; histopathology; human tissue; immune complex; immunoglobulins; inflammation; kidney metabolism; laboratory rabbit; laboratory rat; membrane permeability; molecular pathology; monocyte; neutrophil; phagocytes; protein sequence; proteoglycan; teichoate

Acute poststreptococcal glomerulonephritis (APSGN) is a non-suppurative complication of group A streptoccal infections (pharyngitis or pyoderma) often seen in children. Pathogenesis involves immune complexes in the kidneys but the mechanism remains poorly defined. Streptococcus pyogenes and several species of oral streptococci produce a cationic histone-like protein (HlpA) and lipoteichoic acid (LTA) that bind, respectively, to heparan sulfate proteoglycans in basement membranes and to vascular endothelial cells of kidney tissue in vitro and in vivo. Our goal is to define the nephritogenic properties of these streptococcal components and to devise a vaccine that will protect against APSGN. Specific aims are to: 1). Define, in a rat model, the histologic and immunopathologic events induced in kidneys by the deposition of immune complexes containing HlpA or HlpA-LTA complexes. The kinetics of immunoglobulin, antigen, and complement deposition in glomeruli will be correlated with infiltration by blood- borne proinflammatory cells (monocytes, lymphocytes and neutrophils), proteinuria, and histological changes. 2). Identify epitopes of HlpA that will elicit formation of serum antibodies to block the heparan sulfate-binding site and prevent its interaction with glycosaminoglycans in glomerular capillaries. Polypeptides will be synthesized according to the known primary amino acid sequence of HlpA, linked covalently to a carrier protein and used to stimulate formation of monoclonal antibodies, which will be evaluated in a in vitro tissue- binding assay. 3). Determine the ability of neutrophils and their products (defensins) to interact with opsonized streptococci and cause release of HlpA and LTA into the environment. These experiments will monitor antigen and defensin release by degranulating phagocytes, which have engulfed streptococci in vitro, and the ability of purified defensins to induce permeability changes in viable streptococci. 4). Quantify the ability of HlpA and LTA/HlpA complexes to stimulate synthesis of cytokines (tumor necrosis factor-alpha, interleukin-l beta, interleukin-6) by human peripheral blood monocytes and umbilical vein endothelial cells in vitro. These experiments will determine whether these streptococcal components act as independent or synergistic modulins.

急性链球菌肾小球肾炎（APSGN）是一种非支持性的 A组链球菌感染的并发症（咽炎或 脓皮菌）经常在儿童中看到。发病机理涉及免疫 肾脏中的复合物，但机制的定义仍然很差。 化脓性链球菌和几种口腔链球菌产生 阳离子组蛋白样蛋白（HLPA）和脂甲酸（LTA） 分别与地下室的硫酸乙酰肝素蛋白聚糖结合 体外肾脏组织的膜和血管内皮细胞 和体内。我们的目标是定义 这些链球菌成分，并设计一种疫苗 防止APSGN。具体目标是：1）。定义，在老鼠中 模型，肾脏引起的组织学和免疫病理事件 通过含有HLPA或HLPA-LTA的免疫复合物的沉积 复合物。免疫球蛋白，抗原和补体的动力学 肾小球中的沉积将与血液浸润有关 传播促炎细胞（单核细胞，淋巴细胞和中性粒细胞）， 蛋白尿和组织学变化。 2）。识别HLPA的表位 这将引起血清抗体的形成以阻断乙酰肝素 硫酸盐结合位点，并防止其与 肾小球毛细血管中的糖胺聚糖。多肽将是 根据已知的HLPA的原代氨基酸序列合成 共价连接到载体蛋白，用于刺激形成 单克隆抗体的，该抗体将在体外组织中进行评估 结合测定。 3）。确定中性粒细胞及其的能力 产品（防御素）与链球菌相互作用并引起 将HLPA和LTA释放到环境中。这些实验会 通过脱粒化吞噬细胞来监测抗原和防御素的释放，其中 在体外吞噬了链球菌，并且纯化的能力 防御素会诱导可行链球菌的渗透性变化。 4）。 量化HLPA和LTA/HLPA复合物刺激的能力 细胞因子的合成（肿瘤坏死因子-Alpha，白介素-L Beta，白介素6）由人类外周血单核细胞和脐带 体外静脉内皮细胞。这些实验将决定 这些链球菌成分是独立的还是 协同模量。