Discovery of Anti-Claudin-1 Antibodies as Candidate Therapeutics against Hepatitis C Virus
Discovery of Anti-Claudin-1 Antibodies as Candidate Therapeutics against Hepatitis C Virus
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DOI：
10.1124/jpet.114.217653
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发表时间：
2015-04-01
影响因子：
3.5
通讯作者：
Kondoh, Masuo
中科院分区：
文献类型：
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作者：
Yamashita, Mayo;Iida, Manami;Kondoh, Masuo
Claudin-1（CLDN 1）是丙型肝炎病毒（HCV）进入和细胞间传播的已知宿主因子，是抑制HCV感染的靶分子。我们先前开发了四种小鼠抗CLDN 1单克隆抗体（mAb）的克隆，可在体外预防HCV感染。其中两种单克隆抗体显示出最高的抗病毒活性。在这里，我们通过蛋白质工程优化了作为治疗候选物的抗CLDN 1 mAb。虽然Fab片段的单克隆抗体防止在体外HCV感染，其抑制作用远远弱于那些完整的单克隆抗体。相比之下，通过移植小鼠mAb轻链和重链的可变结构域产生的人嵌合IgG 1 mAb与亲本小鼠mAb一样有效地抑制体外HCV感染。然而，嵌合IgG 1 mAb激活Fc γ受体，表明通过诱导抗体依赖性细胞毒性（ADCC），发生了针对mAb结合的CLDN 1表达细胞的细胞毒性。为了避免ADCC诱导的副作用，我们制备了人嵌合IgG 4 mAb。嵌合IgG 4 mAb不激活Fc γ受体或诱导ADCC，但它们与亲本小鼠mAb一样有效地预防体外HCV感染。这些发现表明IgG 4形式的人嵌合抗CLDN 1 mAb可能是临床适用的HCV治疗的候选分子。
Claudin-1 (CLDN1), a known host factor for hepatitis C virus (HCV) entry and cell-to-cell transmission, is a target molecule for inhibiting HCV infection. We previously developed four clones of mouse anti-CLDN1 monoclonal antibody (mAb) that prevented HCV infection in vitro. Two of these mAbs showed the highest antiviral activity. Here, we optimized the anti-CLDN1 mAbs as candidates for therapeutics by protein engineering. Although Fab fragments of the mAbs prevented in vitro HCV infection, their inhibitory effects were much weaker than those of the whole mAbs. In contrast, human chimeric IgG1 mAbs generated by grafting the variable domains of the mouse mAb light and heavy chains inhibited in vitro HCV infection as efficiently as the parental mouse mAbs. However, the chimeric IgG1 mAbs activated Fc gamma receptor, suggesting that cytotoxicity against mAb-bound CLDN1-expressing cells occurred through the induction of antibody-dependent cellular cytotoxicity (ADCC). To avoid ADCC-induced side effects, we prepared human chimeric IgG4 mAbs. The chimeric IgG4 mAbs did not activate Fc gamma receptor or induce ADCC, but they prevented in vitro HCV infection as efficiently as did the parental mouse mAbs. These findings indicate that the IgG4 form of human chimeric anti-CLDN1 mAb may be a candidate molecule for clinically applicable HCV therapy.