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: 2700988
• 负责人: MURRAY W STINSON
• 金额: $ 23.41万
• 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/2700988
• 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.

急性链球菌感染后肾小球肾炎 (APSGN) 是一种非化脓性肾小球肾炎 A 组链球菌感染的并发症（咽炎或 脓皮病）常见于儿童。发病机制涉及免疫 肾脏中的复合物，但其机制仍不清楚。 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) 和脂磷壁酸 (LTA) 分别与基底中的硫酸乙酰肝素蛋白聚糖结合 体外肾组织膜和血管内皮细胞 和体内。我们的目标是定义肾炎的特性 这些链球菌成分并设计出一种疫苗 防止 APSGN。具体目标是：1）。定义，在大鼠中 模型，在肾脏中诱导的组织学和免疫病理学事件 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 肾小球沉积与血液浸润相关 携带促炎细胞（单核细胞、淋巴细胞和中性粒细胞）， 蛋白尿和组织学变化。 2）。鉴定 HlpA 的表位 这将引起血清抗体的形成来阻断乙酰肝素 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一级氨基酸序列合成， 与载体蛋白共价连接并用于刺激形成 单克隆抗体，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能力 产品（防御素）与调理链球菌相互作用并导致 HlpA 和 LTA 释放到环境中。这些实验将 通过脱粒吞噬细胞监测抗原和防御素的释放， 具有在体外吞噬链球菌并纯化的能力 防御素诱导活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-α、白细胞介素-L β、白介素-6）由人外周血单核细胞和脐带血 体外静脉内皮细胞。这些实验将决定 这些链球菌成分是否独立或 协同调节蛋白。