摘要
为提高HBVpreS1aa21 47的免疫原性,将1～6拷贝的preS1(21 47)片段以串联方式插入HBcAg的aa78和aa82之间,在大肠杆菌中进行表达和纯化.携带1～3拷贝的重组抗原CI、CII和CIII的表达产量约占菌体总蛋白的20%,而携带4～6拷贝的重组抗原则未见明显表达.电镜检测显示重组抗原CI、CII和CIII可以形成形态与HBcAg类似的类病毒颗粒,颗粒直径在30～34nm之间.ELISA分析显示这3种VLP抗原具有很强的preS1抗原的免疫反应性,而对HBc单克隆抗体则基本失去反应性.提示外源多肽pre(21 47)可被有效地递呈至类HBc颗粒的表面,且外源多肽的插入使HBc主要的免疫优势表位遭到了破坏.这些证据表明利用HBcAg的专一性呈递能力来构建多价抗原可作为免疫原设计时的一种策略.
To improve the immunogenicity of HBV preS1 aa21-47, 1～6 tandem copies of HBV preS1(21-47) fragment were inserted into HBcAg at the sites of amino acid 78 and 82, and expressed inE.coli and purified by gel filtration and anion exchange chromatography. The yields of three recombinant proteins, CI、CII、CIII, carrying 1～3 copies of HBV preS1(21-47) individually were about 20% in total bacterial proteins. While recombinant antigens carrying 4～6 copies of HBV preS1(21-47) were poorly expressed inE.coli. Negative stain electron microscopy showed recombinant antigens CI、CII、CIII could form virus-like particles (VLPs), similar to HBcAg morphologically. These particles have an average diameter of 30～34 nm. ELISA results indicated that all three VLP antigens could strongly recognize anti-preS1(21-47) monoclonal antibodies, but were lack of immunoreactivity with anti-HBc monoclonal antibodies. It indicates that foreign epitope preS1(21-47) could be displayed on the surface of HBV core-like particles, and that dominant B cell epitope of HBc was destroyed because of the deletion of MIR and further destroyed by insertion of foreign epitopes. It might be a feasible strategy in immunogen designs for improving the immunogenicity of specific peptides in virtue of the display capability of HBcAg.
出处
《厦门大学学报（自然科学版）》
CAS
CSCD
北大核心
2004年第4期436-440,共5页
Journal of Xiamen University：Natural Science
基金
国家重点科技(攻关)计划(96 920 37 09)
