Duke Human Vaccine Institute and Departments of Medicine, Duke University Medical Center, Durham, NC 27710, United States.
Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, United States.
J Immunol Methods. 2014 Feb;404:1-12. doi: 10.1016/j.jim.2013.11.026. Epub 2013 Dec 4.
Establishment of humoral immunity against pathogens is dependent on events that occur in the germinal center and the subsequent induction of high-affinity neutralizing antibodies. Quantitative assays that allow monitoring of affinity maturation and duration of antibody responses can provide useful information regarding the efficacy of vaccines and adjuvants. Using an anthrax protective antigen (rPA) and alum model antigen/adjuvant system, we describe a methodology for monitoring antigen-specific serum antibody concentration and avidity by surface plasmon resonance during primary and secondary immune responses. Our analyses showed that following a priming dose in mice, rPA-specific antibody concentration and avidity increases over time and reaches a maximal response in about six weeks, but gradually declines in the absence of antigenic boost. Germinal center reactions were observed early with maximal development achieved during the primary response, which coincided with peak antibody avidity responses to primary immunization. Boosting with antigen resulted in a rapid increase in rPA-specific antibody concentration and five-fold increase in avidity, which was not dependent on sustained GC development. The described methodology couples surface plasmon resonance-based plasma avidity measurements with germinal center analysis and provides a novel way to monitor humoral responses that can play a role in facilitating vaccine and adjuvant development.
体液免疫对病原体的建立依赖于生发中心发生的事件，以及随后诱导高亲和力中和抗体。定量检测方法可以监测亲和力成熟和抗体反应的持续时间，为疫苗和佐剂的疗效提供有用的信息。我们使用炭疽保护性抗原（rPA）和明矾模型抗原/佐剂系统，描述了一种在原发性和继发性免疫反应期间通过表面等离子体共振监测抗原特异性血清抗体浓度和亲和力的方法。我们的分析表明，在小鼠进行初始剂量接种后，rPA 特异性抗体浓度和亲和力随时间增加，约在六周时达到最大反应，但在没有抗原增强的情况下逐渐下降。生发中心反应在早期就观察到，在原发性反应期间达到最大程度的发展，这与原发性免疫时抗体亲和力反应的峰值相吻合。用抗原增强会导致 rPA 特异性抗体浓度迅速增加，亲和力增加五倍，这与生发中心的持续发展无关。所描述的方法将基于表面等离子体共振的血浆亲和力测量与生发中心分析相结合，为监测体液反应提供了一种新方法，这可能有助于疫苗和佐剂的开发。
