介白素20接受器一(IL-20 receptor 1,IL-20R1)是第二型介白素接受器的成員之一，它會與介白素接受器二(IL-20 receptor 2,IL-20R2)形成一個二聚體複合物(heterodimer)。介白素19(IL-19)與介白素20(IL-20)會透過此受體複合物進行下游訊息傳遞。在過去的研究中顯示IL-19與IL-20會參與某些發炎疾病的致病機轉中，如:類風濕性關節、牛皮癬和腎衰竭…等。本實驗室最近的實驗結果亦證實IL-20會與骨質疏鬆症有關，也利用anti-IL-20 monoclonal antibody- 7E 處理OVX小鼠，可以有效保護小鼠減少骨質流失。另外，從實驗室建立的IL-20R1基因剔除的老鼠經卵巢摘除手術之後(OVX-mice)，亦可看到其骨頭有被保護的現象。因此我們想要生產一具有中和能力的anti-IL20R1 單株抗體。首先，將IL-20R1 膜外區域構築完成後，送入哺乳類細胞進行表現並純化，得到抗原antigen，再利用細胞融合瘤技術成功建立五株anti-IL-20R1單株抗體，經ELISA與western blot確認五個抗體確實會專一性辨識抗原，也用免疫組織染色得知有三株抗體可以辨識細胞上IL-20R1。其中三株抗體亦會辨識老鼠IL-20R1，除外，我們鑑定了抗體的序列，得知他們是屬於mIgG1 subtype，並界定了抗體與抗原間結合區。而在分析親和力則利用SPR技術測得抗體抗原間之平衡解離常數(KD)。最後，我們利用細胞實驗測詴anti-IL-20R1抗體是有中和作用(neutralization)的，也在動物實驗上看到anti-IL-20R1抗體有保護老鼠避免骨質疏鬆症病情，因此我們初步判定其可能有潛力作為臨床醫藥。

IL-20 receptor 1(IL-20R1) belongs to the class II cytokine receptor family, which forms a heterodimer complex with IL-20R2 and mediates IL-19 and IL-20 signal transduction. Previous studies showed that IL-19 and IL-20 are involved in several inflammatory diseases, such as psoriasis, renal failure, and rheumatoid arthritis. Therefore, we were aimed to generate the anti-IL-20R1 monoclonal antibody (mAb) to block the biological functions of IL-19 and IL-20. We generated and purified the recombinant human IL-20R1 protein from mammalian cell and used the protein as an antigen to immunize mice. The spleen-derived cells of immunized mice were fused with SP2/0-Ag14 myeloma cells. Five stable hybridoma cells were successfully established. Western blotting and ELISA showed that each mAb specifically recognized human IL-20R1. IHC staining confirmed that these antibodies could recognize the native membrane form of IL-20R1 protein. They also cross-reacted with mouse IL-20R1. In addition, we identified the sequence of the antibodies and found that they are immunoglobulin gamma 1 (IgG1) subtype. We calculated the equilibrium dissociation constants (KD) of antibodies by SPR. The preliminary result showed that the antibodies could neutralize the in vitro biological function and protect mice from bone loss in OVX mice in vivo. Therefore we speculated that anti-IL-20R1 mAb might be used as a therapeutic drug.

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