Ma Guangpeng, Chen Xinyu, Gu Jianyou, Zhou Jiyong
Key Laboratory of Animal Epidemic Etiology & Immunological Prevention of Ministry of Agriculture, Zhejiang University, Hangzhou 310029, PR China.
Vet Immunol Immunopathol. 2010 Nov 15;138(1-2):45-50. doi: 10.1016/j.vetimm.2010.06.013. Epub 2010 Jun 23.
The cytokine interleukin (IL)-2 functions as a growth factor and central regulator in the immune system. Using a recombinant goose IL-2 (goIL-2) monomer expressed in prokaryotic cells as an immunogen, we synthesized 5 goIL-2 neutralizing mAbs to identify the functional domains of goIL-2, and used these mAbs to finely map the functional domains of the goIL-2 protein. The mimotopes of the 5 anti-goIL-2 mAbs, including HHDPWDXLP, ESLSRXXMXXLXP, SHHLPTSXL, HPDPWDAPLSS, and HEPWQLXL, were identified using a phage display library and peptide-competitive enzyme-linked immunosorbent assay (ELISA). These mimotopes constitute 1 conformational functional domain in the goIL-2 molecule--T¹¹I¹⁴K¹⁵D¹⁶E¹⁸K¹⁹L²⁰G²¹T²²S²³M²⁴K²⁵L²⁹E³⁰L³¹Y³²T³³P³⁴E³⁶S⁴¹W⁴²Q⁴³T⁴⁴L⁴⁵Q⁴⁶ (domain I). The neutralizing mAbs to goIL-2 inhibited the in vitro lymphocyte proliferation stimulated by domain I peptides of goIL-2. A tertiary structural model of goIL-2 showed that domain I is positioned in helix A, long A-B loop, and the N-terminal of helix B. These data provide a clue for defining the interaction between goIL-2 and its receptor.
细胞因子白细胞介素（IL）-2在免疫系统中作为生长因子和核心调节因子发挥作用。我们以原核细胞中表达的重组鹅IL-2（goIL-2）单体作为免疫原，合成了5种goIL-2中和单克隆抗体，以鉴定goIL-2的功能结构域，并利用这些单克隆抗体精细绘制goIL-2蛋白的功能结构域。使用噬菌体展示文库和肽竞争酶联免疫吸附测定（ELISA）鉴定了5种抗goIL-2单克隆抗体的模拟表位，包括HHDPWDXLP、ESLSRXXMXXLXP、SHHLPTSXL、HPDPWDAPLSS和HEPWQLXL。这些模拟表位在goIL-2分子中构成1个构象功能结构域——T¹¹I¹⁴K¹⁵D¹⁶E¹⁸K¹⁹L²⁰G²¹T²²S²³M²⁴K²⁵L²⁹E³⁰L³¹Y³²T³³P³⁴E³⁶S⁴¹W⁴²Q⁴³T⁴⁴L⁴⁵Q⁴⁶（结构域I）。goIL-2的中和单克隆抗体抑制了goIL-2结构域I肽刺激的体外淋巴细胞增殖。goIL-2的三级结构模型表明，结构域I位于螺旋A、长A-B环和螺旋B的N端。这些数据为确定goIL-2与其受体之间的相互作用提供了线索。
