IGG AFFINITY FOR BACTERIAL ANTIGENS AND PHAGOCYTIC CELLS

这项研究计划将开发方法来量化 肺炎链球菌多糖类抗原免疫球蛋白G。 可透析的低聚糖将被制备和提纯以达到平衡 透析。这项技术测量标记的可透析物的结合 用透析膜分离免疫球蛋白G的抗原。Scatchard分析是 用来计算反应的亲和力K，(Ag)(Ab)产额 (阿加布)。根据朗缪尔方程绘制数据会产生一个 总抗体含量的测量。 将开发出测量免疫球蛋白激活吞噬细胞的方法， 包括化学发光、颗粒蛋白释放以及免疫球蛋白结合 到Fc受体。在这些实验中使用的免疫球蛋白将会很好 热凝聚法制备表征的免疫球蛋白低聚物 二硫代二(琥珀酸亚胺基丙酸酯)聚合 凝胶过滤提纯。 评估免疫球蛋白功能的方法将应用于一组 静脉用免疫球蛋白(IVIg)评价疗效 制备方法对免疫球蛋白功能的影响。在静脉注射时 免疫球蛋白已被提倡用于许多临床情况， 它们作为天然免疫球蛋白发挥全部功能的能力还没有 令人信服地展示了。此外，使用一种方法获得的临床结果 准备工作不能外推到另一个，因为这些IVIgG 采用多种酶促和化学改性方法制备。 该项目旨在建立不同的体外标准 静脉注射免疫球蛋白的制备可以与潜在的相关性进行比较。 具有临床疗效。 这些方法也将被用来检查对 多糖类抗原和检验抗肺炎球菌免疫球蛋白的假说 用多价肺炎球菌多糖免疫的受试者中 关于亲和力的同质种群。相关性将是 介于抗原亲和力和光学能力之间。

This research proposal will develop methods to quantitate the affinity of immunoglobulin G for polysaccharide antigens of Streptococcus pneumoniae. Dialyzable oligosaccharides will be prepared and purified for equilibrium dialysis. This technique measures the binding of a labelled dialyzable antigen to IgG separated by a dialysis membrane. Scatchard analysis is used to calculate the affinity, K, of the reaction, (Ag) + (Ab) yields (AgAb). Plotting data according to the Langmuir equation yields a measurement of total antibody content. Methods will be developed to measure phagocytic cell activation by IgG, including chemiluminescence, granule protein release, and also IgG binding to Fc receptors. The IgG used in these experiments will be well characterized IgG oligomers prepared by heat aggregation or by polymerization by dithiobis (succinimidylpropionate) with subsequent purification by gel filtration. The methods for assessing IgG function will be applied to a group of immunoglobulins prepared for intravenous use (IVIgG) to assess the effect of the method of preparation on IgG function. While intravenous immunoglobulins have been advocated for a number of clinical situations, their ability to function to the full extent as native IgG has not been convincingly shown. In addition, clinical results obtained with one preparation may not be extrapolated to another since these IVIgGs are prepared from a variety of enzymatic and chemically modifying methods. This project aims to establish in vitro standards by which different preparations of IVIgG may be compared, with the potential for correlation with clinical efficacy. These methods will also be used to examine the immune response to polysaccharide antigens and test the hypothesis that anti-pneumococcal IgG of subjects immunized with polyvalent pneumococcal polysaccharide is a homogeneous population with respect to affinity. Correlations will be drawn between antigen affinity and opsonic capacity.