单纯疱疹病毒糖蛋白模拟位的研究

Screening of HSV glycoprotein C mimotope binding to McAb 1A12

目的为了充分认识单纯疱疹病毒(HSV)糖蛋白的抗原表位，寻找HSV多组分疫苗和新型基因工程疫苗更有效的小片段短肽作为该病毒疫苗的备选免疫原。方法利用有动物保护活性的抗HSV糖蛋白C（gC）单克隆抗体（McAb）1A12淘筛噬菌体随机12肽库，经4轮筛选后进行ELISA检测，随机挑取14个阳性克隆进行序列测定,序列比较后得到保守序列，做ELISA阻断实验进一步鉴定筛选结果并与相关天然蛋白HSV gC进行序列比较。结果获得保守序列-SG(L)RHII-和其侧翼辅助序列-AK-、-VW-，其与天然相关蛋白HSV gC 114～116位氨基酸十分相似。携有此短肽的噬菌体可以与McAb特异结合，并可部分阻断抗体与HSV囊膜抗原的反应。结论所筛选到的保守序列可模拟McAb针对的抗原表位，可能是HSV的替代抗原。这一研究方法有望使短肽替代庞大的糖蛋白全长氨基酸序列，为研制更有效及更广谱的基因工程疫苗提供依据，也使研制基于抗原表位水平的特异诊断试剂成为可能。

Objective To recognize characteristic of HSV glycoprotein epitopes thoroughly and provide subunit or genetic engineering vaccines with more oligo-peptide immunogens in support. Methods Screened a 12-mer phage peptide library for 4 rounds by using a HSV type-common McAb against HSV glycoprotein c(gC) as selective molecule, which has strong animal protective activity. The results was confirmed by ELISA. 14 positive clones was selected randomly to sequence. Sequences alignment and blocking test were achieved. Results Our study reveals that most of the sequences of the selected phage clones from the final eluate are highly homologous. High similarity is found in the region-SG(L)RHII-and its flanking sequence-AK-,-VW-, which contains 3 amino acids identical to those of the natural HSV gC. Phage containing this motif can react with the McAb specifically and can obviously block the reaction of mAb 1A12 and the natural HSV antigen. Conclusion The results imply that the motif selected could mimic the epitope on gC and may be a substitute antigen of gC. This strategy provides the potential for preparing more effective epitope vaccine instead of whole protein and a new approach for developing epitope-specific diagnostic reagents.