Kraiem Amin, Pelamatti Erica, Grosse-Kathoefer Sophie, Demir Hilal, Vollmann Ute, Ehgartner Caroline, Stigler Maria, Punz Benjamin, Johnson Litty, Hüsing Nicola, Bohle Barbara, Aglas Lorenz
Department of Biosciences and Medical Biology, University of Salzburg, Salzburg, Austria.
Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
Allergol Int. 2025 Jan;74(1):126-135. doi: 10.1016/j.alit.2024.07.007. Epub 2024 Aug 17.
Solubility is a common feature of allergens. However, the causative relationship between this protein-intrinsic feature and sensitization capacity of allergens is not fully understood. This study aimed to proof the concept of solubility as a protein intrinsic feature of allergens.
The soluble birch pollen allergen Bet v 1 was covalently coupled to 1 μm silica particles. IgE-binding and -cross-linking capacity was assessed by inhibition ELISA and mediator release assay, respectively. Alterations in adjuvanticity by particle-loading were investigated by activation of dendritic cells, mast cells and the Toll-like receptor 4 pathway as well as by Th2 polarization in an IL-4 reporter mouse model. In BALB/c mice, particle-loaded and soluble Bet v 1 were compared in a model of allergic sensitization. Antigen uptake and presentation was analysed by restimulating human Bet v 1-specific T cell lines.
Covalent coupling of Bet v 1 to silica particles resulted in an insoluble antigen with retained IgE-binding and -cross-linking capacity and no increase in adjuvanticity. In vivo, particle-loaded Bet v 1 induced significantly lower Bet v 1-specific (s)IgE, whereas sIgG1 and sIgG2a levels remained unaffected. The ratio of Th2 to Th1 cells was significantly lower in mice sensitized with particle-loaded Bet v 1. Particle-loading of Bet v 1 resulted in a 24-fold higher T cell activation capacity in Bet v 1-specific T cell lines, indicating more efficient uptake and presentation than of soluble Bet v 1.
Our results show that solubility is a decisive factor contributing to the sensitization capacity of allergens. The reduction in sensitization capacity of insoluble, particle-loaded antigens results from enhanced antigen uptake and presentation compared to soluble allergens.
溶解性是变应原的一个常见特征。然而，这种蛋白质固有特性与变应原致敏能力之间的因果关系尚未完全阐明。本研究旨在验证溶解性作为变应原蛋白质固有特性的概念。
将可溶性桦树花粉变应原Bet v 1共价偶联至1μm二氧化硅颗粒上。分别通过抑制ELISA和介质释放试验评估IgE结合及交联能力。通过激活树突状细胞、肥大细胞和Toll样受体4通路以及在IL-4报告基因小鼠模型中进行Th2极化，研究颗粒负载对佐剂性的影响。在BALB/c小鼠中，在变应性致敏模型中比较颗粒负载的和可溶性的Bet v 1。通过再次刺激人Bet v 1特异性T细胞系分析抗原摄取和呈递情况。
Bet v 1与二氧化硅颗粒的共价偶联产生了一种不溶性抗原，其保留了IgE结合及交联能力，且佐剂性未增加。在体内，颗粒负载的Bet v 1诱导产生的Bet v 1特异性(s)IgE显著降低，而sIgG1和sIgG2a水平未受影响。用颗粒负载的Bet v 1致敏的小鼠中Th2与Th1细胞的比例显著降低。Bet v 1的颗粒负载导致Bet v 1特异性T细胞系中的T细胞激活能力提高24倍，表明其摄取和呈递比可溶性Bet v 1更有效。
我们的结果表明，溶解性是影响变应原致敏能力的决定性因素。与可溶性变应原相比，不溶性、颗粒负载抗原致敏能力的降低是由于抗原摄取和呈递增强所致。
