Prechl József, Kovács Ágnes, Papp Krisztián, Hérincs Zoltán, Pfeil Tamás
R&D Laboratory, Diagnosticum Zrt, 1047 Budapest, Hungary.
Department of Biostatistics, University of Veterinary Medicine Budapest, 1078 Budapest, Hungary.
Antibodies (Basel). 2025 Aug 13;14(3):68. doi: 10.3390/antib14030068.
When an antigen molecule is exposed to serum, many different kinds of antibodies bind to it. The complexity of these binding events is only poorly characterized by assays that generate a single variable, generally reflecting the fractional saturation of the antigen, as the readout.
We have previously devised an assay that delivers the essential biochemical variables to determine fractional saturation as the output: an equilibrium dissociation constant for affinity, the ratio of antibody concentration to the equilibrium constant and the concentration of bound antibodies under reference conditions. Here we propose a visualization method for the practical and informative display of these variables.
Using total antigen concentration and free and bound antibody concentration as coordinates in a three-dimensional space, a surface plot can depict the behavior of serum antibodies in the measurement range and identify the values of the key variables of binding activity. This surface display (antibody binding in 3-concentration display, Ab3cD) was used for the characterization of antibody binding to the SARS-CoV-2 spike protein in seronegative and seropositive sera. We demonstrate that this visualization scheme is suitable for presenting both individual and group differences and that epitope density changes, not commonly measured by immunoassays, are also revealed by the method.
We recommend the use of 3D visualization whenever detailed, informative and characteristic differences in serum antibody reactivity are studied.
当抗原分子暴露于血清中时，许多不同种类的抗体都会与之结合。这些结合事件的复杂性仅通过产生单个变量的检测方法来表征，该变量通常反映抗原的分数饱和度，并作为读数。
我们之前设计了一种检测方法，该方法可输出用于确定分数饱和度的基本生化变量：亲和力的平衡解离常数、抗体浓度与平衡常数的比值以及参考条件下结合抗体的浓度。在此，我们提出一种可视化方法，以便实际且信息丰富地展示这些变量。
使用总抗原浓度以及游离和结合抗体浓度作为三维空间中的坐标，表面图可以描绘血清抗体在测量范围内的行为，并识别结合活性关键变量的值。这种表面展示（三浓度展示中的抗体结合，Ab3cD）用于表征血清阴性和血清阳性血清中抗体与严重急性呼吸综合征冠状病毒2（SARS-CoV-2）刺突蛋白的结合情况。我们证明这种可视化方案适用于呈现个体差异和群体差异，并且该方法还揭示了免疫测定通常未测量的表位密度变化。
当研究血清抗体反应性的详细、信息丰富且具有特征性的差异时，我们建议使用三维可视化。
