IGG SUBCLASS RESPONSE TO A ACTINOMYCETEMCOMITANS

局限性青少年牙周炎（LJP）的发展风险 在不同的e c组之间差异很大， 比白种人大约高出15倍 疾病LJP也倾向于在家庭内聚集，这表明 这种易感性可能是由基因决定的。然而，迄今为止， 尚未鉴定出LJP的遗传标记。黑色LJP 受试者对A产生强烈的IgG应答。 放线菌cornitans，这种疾病的病原体， IgG应答的显著比例包括 IgG 2亚类的抗体。这些IgG 2的有效性 抗体在宿主防御中的作用尚未确定。从基因上来说- 确定的IgG Fc受体（Fc-λ-R）多态性可 显著影响对人IgG亚类的受体亲和力， 特别是IgG 2。这项建议的一个主要目标是 评价Fc-λ-R多态性与肿瘤发生的关系， 抗A. 放线菌共生菌和种族差异的风险LJP。 此外，我们将检查初始IgG亚类反应， 这种生物体在疾病发作后。我们特别 提议： L.确定等位基因频率的变化 Fc-λ-R多态性存在于不同年龄的UP患者中， 种族背景。 2.定义Fc-λ-R多态性对 LJP血清中IgG亚类抗体促进 A.伴放线菌 3.评估IgG亚类对A. 放线菌共生体，发生在早期阶段， 从牙周健康状态转变为LJP。 4.比较不同种族LJP的IgG亚类反应 受试者的A.伴放线菌 从拟议研究中获得的信息将提供 深入了解Fc-λ-R多态性在定义 LJP在各种族群体中的风险，以及在监管 抗A. actinomycetemcomitans 在LJP受试者的血清中。此外，这些研究将提高我们的 了解IgG对A. 伴随放线菌的LJP发病后，以及 IgG应答的定性和/或定量变化 不同种族的人民正义党成员

Risk for development of localized juvenile periodontitis (LJP) varies markedly among different e c groups, with blacks being roughly 15 times more likely than Caucasians to develop this disease. LJP also tends to aggregate within families, suggesting that susceptibility may be genetically-defined. To date, however, a genetic marker for LJP has not been identified. Black LJP subjects mount a strong IgG response toward A. actinomycetemcornitans, the etiologic agent of this disease, a significant proportion of the IgG response being comprised of antibodies of the IgG2 subclass. The effectiveness of these IgG2 antibodies in host defense has not been defined. Genetically- defined polymorphism of IgG Fc receptors (Fc-lambda-R) can markedly affect receptor affinity for human IgG subclasses, particularly IgG2. A principal objective of this proposal is to evaluate the relationship between Fc-lambda-R polymorphism, opsonic activities of IgG subclass antibodies to A. actinomycetemcomitans, and ethnic variations in risk for LJP. Moreover, we will examine the initial IgG subclass responses to this organism following the onset of disease. Specifically, we propose to: l. Determine if variations in the frequency of allelic polymorphism of Fc-lambda-R exist among UP subjects of diverse ethnic background. 2. Define the influence of Fc-lambda-R polymorphism upon the effectiveness of IgG subclass antibodies in LJP sera in promoting opsonization of A. actinomycetemcomitans. 3. Assess temporal changes in the IgG subclass responses to A. actinomycetemcomitans which occur during the early stages of transition from a periodontally healthy state to one of LJP. 4. Compare the IgG subclass responses of ethnically diverse LJP subjects to key antigens of A. actinomycetemcomitans. The information derived from the proposed studies will provide insight into the role of Fc-lambda-R polymorphism in defining risk for LJP among various ethnic groups, and in regulating the properties of IgG subclass antibodies to A. actinomycetemcomitans in sera of LJP subjects. Moreover, these studies will enhance our understanding of the dynamics of the IgG response to A. actinomycetemcomitans following the onset of LJP, as well as of qualitative and/or quantitative variations in the IgG response of ethnically diverse LJP subjects to this organism.