嗜中性白血球在宿主的免疫防禦機制上扮演重要的角色。然而，過度的嗜中性白血球浸潤會使得組織受損進而導致發炎性疾病的產生。介白素8，IL-8是一種ELR-CXC趨化素，藉由與細胞表現上特定的穿膜受體CXCR1以及CXCR2結合，進而介導白血球的趨化以及活化。在先前的研究中，透過對IL-8結構特性分析設計出IL-8類似物，稱為RP4，能夠與IL-8共同競爭其受體CXCR1/2有效抑制IL-8與CXCR1/2結合後所導致下游一系列的訊號傳遞。
為了想要獲得足夠的CXCR1/2用於功能與結構研究上，我們初步的建立出一個以大腸桿菌生產重組膜蛋白，CXCR1以及CXCR2的純化方法。再將所生產的CXCR1/2與另外表現出來的IL-8以及RP4利用一個能夠快速檢測的分析方式，進一步的確認IL-8以及RP4的功效。ELISA親和力實驗指出RP4比起IL-8能夠以更高的親和力與CXCR1/2結合。
IL-8已被證實與數種癌症以及炎症有關，而總結本實驗結果與先前研究能夠清楚的呈現我們成功以大腸桿菌表現並純化CXCR1以及CXCR2，並且將純化到的CXCR1及CXCR2應用在ELISA結合力分析上。

Neutrophils play an important role in human host immune defense mechanisms. However, excessive neutrophil infiltration can cause tissue damage and lead to inflammatory diseases. Interleukin 8, IL-8, one of ELR CXC chemokine, mediates the chemotaxis and activation of neutrophils through binding to the two transmembrane G protein-coupled receptors, CXCR1 and CXCR2. In previous studies, we designed an IL-8 analogue, RP4, which competed with IL-8 for its receptors, CXCR1 and CXCR2, and blocked a series of downstream signal pathway induced by IL-8.
We establish the purification methods of recombinant membrane proteins, CXCR1 and CXCR2 by E. coli expression system in our lab. Then, the purified CXCR1, CXCR2, IL-8 and RP4 were further confirmed for the efficacy of IL-8 and RP4 by a rapidly detected assay. ELISA binding experiments indicated that RP4 bound to CXCR1 and CXCR2 with higher affinity than IL-8.
It has shown IL-8 is related to several cancers and inflammatory diseases. From our results and previous studies showed that we have successfully expressed and purified CXCR1 and CXCR2 in E. coli and the expressed CXCR1 and CXCR2 could be used for ELISA binding assay.

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