IGG AFFINITY FOR BACTERIAL ANTIGENS AND PHAGOCYTIC CELLS

这项研究提案将开发方法来量化的亲和力， 肺炎链球菌多糖抗原免疫球蛋白G。 将制备可透析低聚糖并纯化用于平衡 透析 该技术测量标记的可透析的 通过透析膜将抗原与IgG分离。 斯卡查德分析是 用于计算反应的亲和力K，（Ag）+（Ab）产率 （AgAb）。 根据朗缪尔方程绘制数据， 总抗体含量的测量。 将开发通过IgG测量吞噬细胞活化的方法， 包括化学发光、颗粒蛋白释放以及IgG结合 Fc受体。 在这些实验中使用的IgG将是良好的。 通过热聚集或通过 通过二硫代双（琥珀酰亚胺基丙酸酯）聚合， 通过凝胶过滤纯化。 评估IgG功能的方法将应用于一组 静脉注射用免疫球蛋白（IVIgG），以评估效果 对IgG功能的影响。 静脉注射时 免疫球蛋白已经被提倡用于许多临床情况， 它们作为天然IgG发挥全部功能的能力还没有被充分利用。 令人信服地显示。 此外，用一种药物获得的临床结果 制备可能无法外推到另一个，因为这些IVIgG是 由多种酶和化学修饰方法制备。 该项目旨在建立体外标准， IVIgG的制备可以进行比较，具有相关性的潜力 临床疗效。 这些方法也将用于检查免疫反应， 多糖抗原和测试的假设，抗肺炎球菌IgG 多价肺炎球菌多糖免疫的受试者中， 在亲和力方面的同质群体。 相关性将是 在抗原亲和力和调理能力之间绘制。

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.