Jully Vanessa, Mathot Frédéric, Moniotte Nicolas, Préat Véronique, Lemoine Dominique
Université Catholique de Louvain, Louvain Drug Research Institute, Advanced Drug Delivery and Biomaterials, Brussels 1200, Belgium; GSK Vaccines, Vaccine Discovery and Development, Rixensart 1330, Belgium.
GSK Vaccines, Vaccine Discovery and Development, Rixensart 1330, Belgium.
J Pharm Sci. 2016 Jun;105(6):1829-1836. doi: 10.1016/j.xphs.2016.03.032.
The adsorption mechanism of antigen on aluminum adjuvant can affect antigen elution at the injection site and hence the immune response. Our aim was to evaluate adsorption onto aluminum hydroxide (AH) by ligand exchange and electrostatic interactions of model proteins and antigens, bovine serum albumin (BSA), β-casein, ovalbumin (OVA), hepatitis B surface antigen, and tetanus toxin (TT). A high-throughput screening platform was developed to measure adsorption isotherms in the presence of electrolytes and ligand exchange by a fluorescence-spectroscopy method that detects the catalysis of 6,8-difluoro-4-methylumbelliferyl phosphate by free hydroxyl groups on AH. BSA adsorption depended on predominant electrostatic interactions. Ligand exchange contributes to the adsorption of β-casein, OVA, hepatitis B surface antigen, and TT onto AH. Based on relative surface phosphophilicity and adsorption isotherms in the presence of phosphate and fluoride, the capacities of the proteins to interact with AH by ligand exchange followed the trend: OVA < β-casein < BSA < TT. This could be explained by both the content of ligands available in the protein structure for ligand exchange and the antigen's molecular weight. The high-throughput screening platform can be used to better understand the contributions of ligand exchange and electrostatic attractions governing the interactions between an antigen adsorbed onto aluminum-containing adjuvant.
抗原在铝佐剂上的吸附机制会影响抗原在注射部位的洗脱，进而影响免疫反应。我们的目的是通过模型蛋白和抗原（牛血清白蛋白（BSA）、β-酪蛋白、卵清蛋白（OVA）、乙型肝炎表面抗原和破伤风毒素（TT））的配体交换和静电相互作用来评估其在氢氧化铝（AH）上的吸附情况。开发了一个高通量筛选平台，通过荧光光谱法测量电解质存在下的吸附等温线和配体交换，该方法通过检测AH上的游离羟基对6,8-二氟-4-甲基伞形酮磷酸酯的催化作用来实现。BSA的吸附主要依赖于静电相互作用。配体交换有助于β-酪蛋白、OVA、乙型肝炎表面抗原和TT吸附到AH上。基于相对表面亲磷性以及磷酸盐和氟化物存在下的吸附等温线，蛋白质通过配体交换与AH相互作用的能力遵循以下趋势：OVA < β-酪蛋白 < BSA < TT。这可以通过蛋白质结构中可用于配体交换的配体含量以及抗原的分子量来解释。该高通量筛选平台可用于更好地理解配体交换和静电引力对吸附在含铝佐剂上的抗原之间相互作用的贡献。
