Lebecque S, Dolecek C, Laffer S, Visco V, Denépoux S, Pin J J, Guret C, Boltz-Nitulescu G, Weyer A, Valenta R
Schering-Plough, Laboratory for Immunological Research, Dardilly, France.
J Allergy Clin Immunol. 1997 Mar;99(3):374-84. doi: 10.1016/s0091-6749(97)70056-3.
Bet v 1 and homologous proteins represent major allergens for almost 95% of patients allergic to tree pollen and approximately 70% of those allergic to fruits and vegetables. As yet, no continuous (sequential) IgE epitopes have been determined for Bet v 1, and evidence has accumulated that Bet v 1 IgE epitopes belong to the conformational (discontinuous) type.
A panel of 85 mouse monoclonal anti-Bet v 1 antibodies was raised as a tool with which to study the interaction of human IgE antibodies with Bet v 1.
The epitopes of selected monoclonal antibodies (mAbs) were characterized by mapping with synthetic overlapping peptides and by cross-competition experiments. Cross-reactivity of Bet v 1-specific mAbs with tree and plant food allergens was investigated by Western blotting. The influence of Bet v 1-specific mAbs on the IgE-Bet v 1 interaction was studied by competition assays with immobilized purified recombinant Bet v 1 and by basophil histamine release experiments.
Antibodies that increased the IgE binding to Bet v 1 up to fivefold could be defined, whereas others inhibited IgE binding to Bet v 1 up to 99% and competed with the Bet v 1-induced histamine release from patients' basophils.
The activity of the enhancing antibodies is interpreted as a stabilization of Bet v 1 states/IgE epitopes, which are either more accessible for certain IgE antibodies or are recognized with higher affinity. Those mAbs that competed with the Bet v 1-IgE interaction, if humanized or produced as recombinant antibody fragments, might be considered as potential tools for local allergy therapy.
Bet v 1及其同源蛋白是几乎95%对树花粉过敏患者以及约70%对水果和蔬菜过敏患者的主要过敏原。迄今为止，尚未确定Bet v 1的连续（序列）IgE表位，并且已有证据表明Bet v 1 IgE表位属于构象（不连续）型。
制备一组85种小鼠抗Bet v 1单克隆抗体，作为研究人IgE抗体与Bet v 1相互作用的工具。
通过与合成重叠肽进行图谱分析和交叉竞争实验来表征所选单克隆抗体（mAb）的表位。通过蛋白质印迹法研究Bet v 1特异性mAb与树和植物性食物过敏原的交叉反应性。通过与固定化纯化重组Bet v 1的竞争试验以及嗜碱性粒细胞组胺释放实验，研究Bet v 1特异性mAb对IgE - Bet v 1相互作用的影响。
可以鉴定出能将IgE与Bet v 1的结合增加至五倍的抗体，而其他抗体则可将IgE与Bet v 1的结合抑制达99%，并与Bet v 1诱导的患者嗜碱性粒细胞组胺释放竞争。
增强性抗体的活性被解释为对Bet v 1状态/IgE表位的稳定作用，这些状态/表位对于某些IgE抗体而言更容易接近，或者能以更高的亲和力被识别。那些与Bet v 1 - IgE相互作用竞争的mAb，如果进行人源化或作为重组抗体片段生产，可能被视为局部过敏治疗的潜在工具。
