高致病性禽流感病毒血凝素蛋白广谱中和表位模拟肽的筛选与鉴定

Identification of Peptide Mimotopes of an Abroad-spectrum Neutralizing Epitope of Highly Pathogenic Avian Influenza Hemagglutinin

以H5N1型禽流感病毒HA蛋白广谱中和单抗8H5为基础,利用噬菌体展示肽库技术及类病毒颗粒融合表达技术研究HA模拟表位。ELISA检测结果显示:筛选获得模拟HA表位的模拟肽123,进行类病毒颗粒融合蛋白表达后,仍具有与8H5单抗特异结合的能力。免疫荧光检测结果说明,类病毒颗粒免疫小鼠后产生了能与HA交叉反应的抗体。禽流感病毒HA模拟表位的研究与性质的分析及类病毒颗粒融合蛋白的表达与活性分析、免疫原性分析,都为研制禽流感通用表位疫苗奠定了基础。

A monoclonal antibody （8H5）, which showed strong neutralization activity against 33 strains of H5N1 viruses isolated from hosts at various regions from 2002 to 2006, was characterized in our lab recently. This result indicated the presence of highly conserved neutralizing site on hemagglutinin （HA） of various H5N1 subtypes. In the present study, the peptide phage display technique was applied to generate mimotope of the conserved neutralizing epitope recognized by 8H5 mAb. Five peptides displayed on phage were identified to specifically bind to 8H5 mAb. One of the five peptides, 123, was further displayed on the virus-like particle assembled from aa 1-149 fragment of HBcAg. The chimeric particle HBc-T123 conserved the specific binding to 8H5 mAb, and competed with HSN1 viruses for 8H5 mAb. The antiserum induced by HBc-T123 intensively stained on SF21 cells infected by recombinant baculovirus containing HA gene of YU22 virus, indicating the production of cross-reactive antibody to HSN1 HA.