Knackmuss Stefan, Krause Sebastian, Engel Kathrin, Reusch Uwe, Virchow J Christian, Mueller Thomas, Kraich Michael, Little Melvin, Luttmann Werner, Friedrich Karlheinz
Affimed Therapeutics AG, Im Neuenheimer Feld 582, D-69120 Heidelberg, Germany.
Biol Chem. 2007 Mar;388(3):325-30. doi: 10.1515/BC.2007.036.
Interleukin-13 (IL-13) is a T-cell-derived pleiotropic cytokine of particular medical importance because of its critical role in the development of allergic asthma. The effects of IL-13 on its target cells are mediated through a dimeric transmembrane receptor (IL-13R), which shares the IL-4Ralpha subunit with the IL-4R system, but contains as a specific component the IL-13Ralpha1 chain. We have generated a set of single-chain Fv fragments with specific binding capacity to the extracellular domain of the human IL-13Ralpha1 receptor. Bacteriophage clones displaying receptor-binding antibody domains were selected from both naive and synthetic libraries by repetitive panning on recombinant and cell surface-expressed recombinant IL-13Ralpha1. Their specific reactivity with native human IL-13Ralpha1 expressed on the surface of transfected cells was demonstrated by flow cytometry. One binder that specifically interfered with cell activation by IL-13 was extensively characterized. This scFv inhibited IL-13-driven gene transcription and cell proliferation in test cell lines, as well as IL-13-induced activation of primary human monocytes in a dose-dependent manner, with an IC(50) below 300 nM. This novel reagent thus constitutes a valuable tool for the further elucidation of IL-13 function in disease and offers potential therapeutic perspectives.
白细胞介素-13（IL-13）是一种由T细胞产生的多效性细胞因子，因其在过敏性哮喘发展过程中起关键作用而具有特殊的医学重要性。IL-13对其靶细胞的作用是通过一种二聚体跨膜受体（IL-13R）介导的，该受体与IL-4R系统共用IL-4Rα亚基，但含有作为特定成分的IL-13Rα1链。我们已生成了一组对人IL-13Rα1受体胞外域具有特异性结合能力的单链Fv片段。通过在重组的和细胞表面表达的重组IL-13Rα1上进行重复淘选，从天然文库和合成文库中筛选出展示受体结合抗体结构域的噬菌体克隆。通过流式细胞术证明了它们与转染细胞表面表达的天然人IL-13Rα1的特异性反应性。对一种特异性干扰IL-13介导的细胞活化的结合物进行了广泛表征。这种单链抗体片段（scFv）在测试细胞系中以剂量依赖性方式抑制IL-13驱动的基因转录和细胞增殖，以及IL-13诱导的原代人单核细胞活化，其半数抑制浓度（IC50）低于300 nM。因此，这种新型试剂构成了进一步阐明IL-13在疾病中的功能的宝贵工具，并提供了潜在的治疗前景。
