Characterization of the reactivity pattern of murine monoclonal antibodies against wild-type hepatitis B surface antigen to G145R and other naturally occurring "a" loop escape mutations
Characterization of the reactivity pattern of murine monoclonal antibodies against wild-type hepatitis B surface antigen to G145R and other naturally occurring "a" loop escape mutations
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DOI：
10.1002/hep.510300508
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发表时间：
1999-11-01
期刊：
影响因子：
13.5
通讯作者：
Paulij, WP
中科院分区：
文献类型：
--
作者：
Cooreman, MP;van Roosmalen, VH;Paulij, WP
B型肝炎表面抗原（HBsAg）“a”结构域含有主要的B细胞表位。该区域突变的病毒在接种疫苗后或预防B型肝炎免疫球蛋白（HBIg）期间出现。G145 R置换的菌株几乎总是作为主要的逃逸突变体分离出来。我们研究了突变体抗原-抗体相互作用与直接结合试验。G145 R和其他16种天然存在的重组HBsAg突变体在哺乳动物Cos-1细胞中表达。用酶免疫测定法测定了一组28种鼠抗乙型肝炎B表面抗原（抗-HBs）单克隆抗体对突变抗原的反应性，并表示为每种抗体与野生型（wt）HBsAg信号相比的百分比。所有点突变的蛋白质显示对应于分泌途径的弥散细胞内免疫荧光标记。根据不同的结合模式对单克隆抗体（mAb）进行分类。突变对抗体结合的影响根据所涉及的氨基酸和“a”环内的位置而不同。正如预期的，大多数抗体与所有突变抗原（包括G145 R）的结合不存在或可忽略不计（40%）。G145 R的作用比G145 A更明显。抗体亚组对第一环中具有突变的抗原的识别显著增加（>120%）。我们证明了可以选择或组合与所有研究的突变体（包括G145 R）反应的抗体。这些数据为改善基于抗-HBs的预防B型肝炎提供了前景。
The hepatitis B surface antigen (HBsAg) "a" domain harbors major B-cell epitopes. Viruses with mutations in this region emerge after vaccination or during hepatitis B immune globulin (HBIg) prophylaxis. A strain with G145R replacement has been almost invariably isolated as a major escape mutant. We investigated mutant antigen-antibody interactions with direct binding assays. G145R and 16 other naturally occurring recombinant HBsAg mutants were expressed in mammalian Cos-1 cells. The reactivity of a panel of 28 murine anti-hepatitis B surface antigen (anti-HBs) monoclonal antibodies to mutant antigens was measured with enzyme immunoassay and expressed as percentage compared with the wild-type (wt) HBsAg signal for each antibody. All point-mutated proteins displayed diffuse intracellular immunofluorescent labeling corresponding to a secretory pathway. Monoclonal antibodies (mAbs) were classified according to different binding patterns. The effect of mutations on antibody binding differs depending on the amino acid involved and on the location within the "a" loop. As expected, most antibodies had absent or negligible binding (40%) with all mutant antigens, including G145R. The effect of G145R was more pronounced than that of G145A. A subgroup of antibodies had substantially increased recognition (>120%) of antigens with mutations in the first loop. We demonstrated that antibodies can be selected or combined that react with all mutants investigated, including G145R. These data offer perspectives for improving anti-HBs-based protection against hepatitis B.