Istituto di Biomedicina ed Immunologia Molecolare, Palermo, Italy.
Clin Exp Allergy. 2012 Mar;42(3):471-80. doi: 10.1111/j.1365-2222.2011.03938.x.
Parietaria pollen is one of the major cause of pollinosis in the southern Europe. Specific immunotherapy is the only treatment able to modify the natural outcome of the disease restoring a normal immunity against allergens.
We designed a recombinant molecule (PjEDloop1) comprised of genetic-engineered variants of the major allergens of the Parietaria pollen (Par j 2/Par j 1). Purity and chemical-physical properties of the derivative were analysed by RP-HPLC chromatography and Photon Correlation Spectroscopy. Immunological activity was evaluated by means of Western blotting, ELISA inhibition and PBMC proliferation assay in 10 Parietaria allergic patients. Basophil activation was studied in six subjects. The immunogenicity of the hybrid was studied looking at the immune responses induced in a mouse model of sensitization.
The PjEDloop1 hybrid was produced as a purified recombinant protein with high stability in solution. Western blot, ELISA inhibition and basophil activation test showed that the PjEDloop1 displays a remarkable reduced IgE binding and anaphylactic activity. CD3 reactivity was conserved in all patients. Mice immunization with the rPjEDloop1 induced antibodies and T cell responses comparable to that obtained by the wild type allergens. Such antibodies shared the specificities to rPar j 1 and rPar j 2 with human IgE antibodies.
Our results demonstrated that a mutant hybrid expressing genetically engineered forms of the major P. judaica allergens displayed reduced allergenicity and retained T cell reactivity for the induction of protective antibodies in vaccination approaches for the treatment of Parietaria pollinosis.
豚草花粉是欧洲南部花粉过敏的主要原因之一。特异性免疫疗法是唯一能够改变疾病自然进程的治疗方法，它可以恢复对过敏原的正常免疫。
我们设计了一种重组分子（PjEDloop1），它由豚草花粉的主要过敏原（Par j 2/Par j 1）的基因工程变体组成。通过反相高效液相色谱（RP-HPLC）层析和光相关光谱法分析了衍生化合物的纯度和理化性质。通过 Western blot、ELISA 抑制和 PBMC 增殖试验在 10 名豚草过敏患者中评估了免疫原性。在 6 名受试者中研究了嗜碱性粒细胞的激活。通过研究在致敏的小鼠模型中诱导的免疫反应来研究杂交体的免疫原性。
PjEDloop1 杂交体作为一种高稳定性的纯化重组蛋白产生。Western blot、ELISA 抑制和嗜碱性粒细胞激活试验表明，PjEDloop1 显示出显著降低的 IgE 结合和过敏活性。所有患者的 CD3 反应性均保持不变。用 rPjEDloop1 免疫小鼠可诱导抗体和 T 细胞反应，与野生型过敏原相当。这些抗体与人 IgE 抗体具有针对 rPar j 1 和 rPar j 2 的特异性。
我们的结果表明，表达基因工程形式的主要豚草过敏原的突变杂交体显示出降低的变应原性，并保留了 T 细胞反应性，可用于诱导保护性抗体的疫苗接种方法治疗豚草花粉症。
