R&D Department, Laboratorios LETI S.L., Calle del Sol 5, Tres Cantos, 28760 Madrid, Spain.
Biomed Res Int. 2013;2013:284615. doi: 10.1155/2013/284615. Epub 2013 Oct 8.
The synthesis of allergen-specific blocking IgGs that interact with IgE after allergen immunotherapy (SIT) has been related to clinical efficacy. The objectives were to investigate the epitope specificity of IgG-antibodies induced by depigmented-polymerized (Dpg-Pol) allergoids and unmodified allergen extracts, and examine IgE-blocking activity of induced IgG-antibodies.
Rabbits were immunized with native and Dpg-Pol extracts of birch pollen, and serum samples were obtained. Recognition of linear IgG-epitopes of Bet v 1 and Bet v 2 and the capacity of these IgG-antibodies to block binding of human-IgE was determined.
Serum from rabbits immunized with native extracts recognised 11 linear epitopes from Bet v 1, while that from Dpg-Pol-immunized animals recognised 8. For Bet v 2, 8 epitopes were recognized by IgG from native immunized animals, and 9 from Dpg-Pol immunized one. Dpg-Pol and native immunized serum did not always recognise the same epitopes, but specific-IgG from both could block human-IgE binding sites for native extract.
Depigmented-polymerized birch extract stimulates the synthesis of specific IgG-antibodies which recognize common but also novel epitopes compared with native extracts. IgG-antibodies induced by Dpg-Pol effectively inhibit human-IgE binding to allergens which may be part of the mechanism of action of SIT.
变应原免疫治疗（SIT）后与 IgE 相互作用的过敏原特异性阻断 IgG 的合成与临床疗效有关。目的是研究脱色素聚合（Dpg-Pol）变应原和未修饰变应原提取物诱导的 IgG 抗体的表位特异性，并检测诱导的 IgG 抗体的 IgE 阻断活性。
用桦树花粉的天然和 Dpg-Pol 提取物免疫兔子，并获得血清样本。确定了 Bet v 1 和 Bet v 2 的线性 IgG 表位的识别以及这些 IgG 抗体阻断人 IgE 结合的能力。
用天然提取物免疫的兔子的血清识别了 Bet v 1 的 11 个线性表位，而用 Dpg-Pol 免疫的动物的血清识别了 8 个。对于 Bet v 2，天然免疫的 IgG 识别了 8 个表位，Dpg-Pol 免疫的 IgG 识别了 9 个表位。Dpg-Pol 和天然免疫的血清并不总是识别相同的表位，但两者的特异性 IgG 都可以阻断人 IgE 结合天然提取物的结合位点。
脱色素聚合的桦树提取物刺激特异性 IgG 抗体的合成，与天然提取物相比，这些抗体识别共同的但也有新的表位。Dpg-Pol 诱导的 IgG 抗体可有效抑制人 IgE 与过敏原的结合，这可能是 SIT 作用机制的一部分。
