IGG SUBCLASS RESPONSE TO A ACTINOMYCETEMCOMITANS

儿童定植的局限性青少年牙周炎(LJP) 革兰氏阴性球菌伴生放线杆菌 经常表现出明显升高的血清免疫球蛋白抗体效价 有机体。最近的研究表明，体液反应 LJP受试者包括产生特定的免疫球蛋白抗体 对于外膜蛋白和脂多糖存在于 这种有机体的外膜。然而，这一事件的意义在于 对伴放线放线菌表面抗原的抗体反应 不完全理解。多年来，人们一直意识到 人血清免疫球蛋白由四个不同的亚类组成。这四个人 亚类不仅在生物学特性上不同(特别是 关于补体的激活和与吞噬细胞Fc的结合 受体)，但在诱导其受体的抗原的性质上 制作。仅激活的免疫球蛋白亚类(IgG1和IgG3) 与吞噬细胞表面Fc受体的互补和相互作用 促进细菌调理和吞噬杀灭。总体而言, 蛋白质抗原优先诱导IgG1，而多糖优先诱导 抗原主要诱导IgG2。主要的免疫球蛋白亚类对 细菌感染可显著影响免疫球蛋白的贡献 来主持防守。我们不知道有任何发表的报告描述了 LJP受试者对蛋白质和多糖的免疫球蛋白亚类反应 伴生放线菌表面的抗原。初级阶段 这项建议的目标是： 1.测定LJP受试者对分离株的免疫球蛋白亚类反应 伴生放线菌表面抗原，包括外膜 蛋白质和脂多糖。 2.定义已知存在于 一些LJP受试者的血清。 3.识别光学免疫球蛋白识别的外膜成分 伴放线放线菌抗体。 从拟议的研究中获得的信息将提供重要的 深入了解免疫球蛋白抗体的性质和生物学后果 局限性青少年牙周炎受试者对A. 伴生放线菌。

Localized juvenile periodontitis (LJP) subjects colonized by the gram-negative coccobacillus Actinobacillus actinomycetemcomitans frequently exhibit markedly elevated serum IgG antibody titers to this organism. Recent studies have demonstrated that the humoral response of LJP subjects includes production of specific IgG antibodies directed toward outer membrane proteins and lipopolysaccharide present in the outer membrane of this organism. However, the significance of the antibody response to A. actinomycetemcomitans surface antigens is incompletely understood. It has been appreciated for some years that human serum IgG consists of four distinct subclasses. These four subclasses differ not only in their biologic properties (particularly with respect to complement activation and binding to phagocyte Fc receptors), but in the nature of the antigens which induce their production. Only IgG subclasses (IgG1 and IgG3) which activate complement and interact well with Fc receptors on phagocytic cells tend to promote bacterial opsonization and phagocytic killing. In general, protein antigens preferentially induce IgG1, whereas polysaccharide antigens induce mainly IgG2. The predominant IgG subclass response to bacterial infection can significantly influence the contribution of IgG to host defense. We are unaware of any published reports describing the IgG subclass response of LJP subjects to protein and polysaccharide antigens on the surface of A. actinomycetemcomitans. The primary objectives of this proposal are to: 1. Determine the IgG subclass response of LJP subjects to isolated surface antigens of A. actinomycetemcomitans, including outer membrane proteins and lipopolysaccharide. 2. Define the subclass of opsonic IgG antibody known to be present in sera of some LJP subjects. 3. Identify the outer membrane constituent recognized by opsonic IgG antibody against A. actinomycetemcomitans. The information derived from the proposed studies will provide important insight into the nature and biological consequences of the IgG antibody response of localized juvenile periodontitis subjects to A. actinomycetemcomitans.