Meisel H, Sominskaya I, Pumpens P, Pushko P, Borisova G, Deepen R, Lu X, Spiller G H, Krüger D H, Grens E
Institute of Medical Virology, Humboldt University, Berlin, Germany.
Intervirology. 1994;37(6):330-9. doi: 10.1159/000150397.
A set of monoclonal antibodies (mAbs) directed against the preS2 region of hepatitis B virus (HBV) surface antigen (HBsAg) was generated by immunization of mice with native HBsAg isolated from the blood of HBV carriers. According to (1) mutual competition binding of mAb to natural HBsAg, (2) recognition of full-length preS2 displayed on hepatitis B core particles, (3) recognition of synthetic partial preS2 peptides, and (4) Western blotting using a fusion protein library of truncated preS2 fragments of different legths, mAbs were assigned to two groups which coincided with groups I and III described by Mimms et al. [Virology 1990; 176:604-619]. All mAbs recognized linear epitopes and were glycosylation independent. Six out of eight fine-mapped mAbs recognized common epitopes located in the amino-terminal part of the preS sequence between amino acids 131 and 144 (group I), and inhibited binding of HBsAg to polymerized human serum albumin. Only two mAbs recognized a carboxy-terminal HBV-genotype-specific epitope covering amino acid residues 162 to 168 (group III). These mAbs bound to the highly variable proteolysis-sensitive hinge of preS2. Although four out of six mAbs targeted to immunodominant region I require the full-length sequence 131-L[Q/L]DPRVRGLY[F/L]PAG-144, two mAbs recognize the shorter and slightly carboxy-terminal-shifted sequences 133-DPRVRGLY[F/L]-141 or 135-PVRGLY[F/L]PAG-144. Together with previously identified preS2 epitopes 133-DPRVRGL-139, 137-RGLYFPA-143, and 132-QDPR-135, these data indicate diversity of the immune response against epitopes within the same immunodominant region. This diversity may be generated by a labile secondary structure. Sequence analysis suggests the transition from an alpha-helix to a loop structure at this site.
通过用从乙肝病毒携带者血液中分离出的天然乙肝表面抗原（HBsAg）免疫小鼠，产生了一组针对乙肝病毒（HBV）表面抗原前S2区的单克隆抗体（mAb）。根据（1）单克隆抗体与天然HBsAg的相互竞争结合，（2）对乙肝核心颗粒上展示的全长前S2的识别，（3）对合成的部分前S2肽段的识别，以及（4）使用不同长度的截短前S2片段的融合蛋白文库进行蛋白质印迹分析，单克隆抗体被分为两组，这与Mimms等人[《病毒学》1990年；176：604 - 619]描述的I组和III组一致。所有单克隆抗体识别线性表位且不依赖糖基化。在八个精细定位的单克隆抗体中，有六个识别位于前S序列氨基酸131和144之间氨基末端部分的共同表位（I组），并抑制HBsAg与聚合人血清白蛋白的结合。只有两个单克隆抗体识别覆盖氨基酸残基162至168的羧基末端HBV基因型特异性表位（III组）。这些单克隆抗体与前S2高度可变的蛋白水解敏感铰链区结合。尽管靶向免疫显性区域I的六个单克隆抗体中有四个需要全长序列131 - L[Q/L]DPRVRGLY[F/L]PAG - 144，但有两个单克隆抗体识别较短且羧基末端略有偏移的序列133 - DPRVRGLY[F/L] - 141或135 - PVRGLY[F/L]PAG - 144。连同先前鉴定的前S2表位133 - DPRVRGL - 139、137 - RGLYFPA - 143和132 - QDPR - 135，这些数据表明针对同一免疫显性区域内表位的免疫反应具有多样性。这种多样性可能由不稳定的二级结构产生。序列分析表明该位点从α螺旋向环结构转变。
