Junior Research Group Experimental Allergy Models, Paul-Ehrlich-Institut, Langen, Germany.
J Allergy Clin Immunol. 2011 Nov;128(5):1022-30.e1-7. doi: 10.1016/j.jaci.2011.04.020. Epub 2011 May 14.
Allergen-specific immunotherapy for food allergies, including peach allergy, has not been established. Use of allergens with reduced allergenic potential and preserved immunogenicity could improve the safety and efficacy of allergen-specific immunotherapy.
We sought to create a hypoallergenic derivative of the major peach allergen Pru p 3 and to characterize its biochemical and immunologic properties.
A Pru p 3 folding variant generated by means of reduction and alkylation was investigated for structural integrity and stability to gastrointestinal enzymes. IgE reactivity and allergenic potency were determined by means of immunoblotting, ELISA, and in vitro mediator release assay with sera from patients with peach allergy. T-cell immunogenicity was investigated by using human allergen-specific T cells and CBA/J mice immunized with either native Pru p 3 (nPru p 3) or reduced and alkylated (R/A) Pru p 3. Pru p 3 processing by endolysosomal fractions of dendritic cells and antigenicity was examined in mice.
Unfolding of Pru p 3 reduced its high resistance to gastrointestinal proteolysis and almost completely abrogated its IgE reactivity and allergenic potency. However, R/A Pru p 3 was capable of stimulating human and murine T cells. Endolysosomal degradation of R/A Pru p 3 was accelerated in comparison with nPru p 3, but similar peptides were generated. IgG and IgE antibodies raised against nPru p 3 showed almost no cross-reactivity with R/A Pru p 3. Moreover, the antigenicity of R/A Pru p 3 was strongly reduced.
Unfolded Pru p 3 showed reduced allergenicity and antigenicity and preserved T-cell immunogenicity. The hypoallergenic variant of Pru p 3 could be a promising vaccine candidate for specific immunotherapy of peach allergy.
针对食物过敏（包括桃过敏）的过敏原特异性免疫疗法尚未确立。使用具有降低的变应原性和保留的免疫原性的过敏原可以提高过敏原特异性免疫疗法的安全性和疗效。
我们试图创建主要桃过敏原 Pru p 3 的低致敏性衍生物，并对其生化和免疫学特性进行表征。
通过还原和烷基化生成的 Pru p 3 折叠变体，研究其结构完整性和对胃肠道酶的稳定性。通过免疫印迹、ELISA 和体外介质释放试验，用桃过敏患者的血清测定 IgE 反应性和变应原效力。通过使用人过敏原特异性 T 细胞和用天然 Pru p 3（nPru p 3）或还原和烷基化（R/A）Pru p 3 免疫的 CBA/J 小鼠，研究 T 细胞免疫原性。通过内体溶酶体小泡研究桃过敏原的加工和抗原性。
Pru p 3 的展开降低了其对胃肠道蛋白水解的高抗性，几乎完全消除了其 IgE 反应性和变应原效力。然而，R/A Pru p 3 能够刺激人类和鼠类 T 细胞。与 nPru p 3 相比，R/A Pru p 3 的内体溶酶体降解加速，但产生了相似的肽。针对 nPru p 3 产生的 IgG 和 IgE 抗体几乎与 R/A Pru p 3 没有交叉反应性。此外，R/A Pru p 3 的抗原性大大降低。
展开的 Pru p 3 显示出降低的变应原性和抗原性，并保留了 T 细胞免疫原性。Pru p 3 的低致敏性变体可能是桃过敏特异性免疫治疗的有前途的候选疫苗。
