ジャーナル: PLoS Pathog / 年: 2016 タイトル: Structural Basis for Recognition of Human Enterovirus 71 by a Bivalent Broadly Neutralizing Monoclonal Antibody. 著者: Xiaohua Ye / Chen Fan / Zhiqiang Ku / Teng Zuo / Liangliang Kong / Chao Zhang / Jinping Shi / Qingwei Liu / Tan Chen / Yingyi Zhang / Wen Jiang / Linqi Zhang / Zhong Huang / Yao Cong / 要旨: Enterovirus 71 (EV71) is the main pathogen responsible for hand, foot and mouth disease with severe neurological complications and even death in young children. We have recently identified a highly ...Enterovirus 71 (EV71) is the main pathogen responsible for hand, foot and mouth disease with severe neurological complications and even death in young children. We have recently identified a highly potent anti-EV71 neutralizing monoclonal antibody, termed D5. Here we investigated the structural basis for recognition of EV71 by the antibody D5. Four three-dimensional structures of EV71 particles in complex with IgG or Fab of D5 were reconstructed by cryo-electron microscopy (cryo-EM) single particle analysis all at subnanometer resolutions. The most critical EV71 mature virion-Fab structure was resolved to a resolution of 4.8 Å, which is rare in cryo-EM studies of virus-antibody complex so far. The structures reveal a bivalent binding pattern of D5 antibody across the icosahedral 2-fold axis on mature virion, suggesting that D5 binding may rigidify virions to prevent their conformational changes required for subsequent RNA release. Moreover, we also identified that the complementary determining region 3 (CDR3) of D5 heavy chain directly interacts with the extremely conserved VP1 GH-loop of EV71, which was validated by biochemical and virological assays. We further showed that D5 is indeed able to neutralize a variety of EV71 genotypes and strains. Moreover, D5 could potently confer protection in a mouse model of EV71 infection. Since the conserved VP1 GH-loop is involved in EV71 binding with its uncoating receptor, the scavenger receptor class B, member 2 (SCARB2), the broadly neutralizing ability of D5 might attribute to its inhibition of EV71 from binding SCARB2. Altogether, our results elucidate the structural basis for the binding and neutralization of EV71 by the broadly neutralizing antibody D5, thereby enhancing our understanding of antibody-based protection against EV71 infection.
超分子 #1000: EV71 VLP in complex with intact antibody D5
超分子
名称: EV71 VLP in complex with intact antibody D5 / タイプ: sample / ID: 1000 集合状態: One fab fragment of antibody D5 bind to one protomer of EV71 Number unique components: 2
分子量
理論値: 8 MDa
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超分子 #1: Human enterovirus 71
超分子
名称: Human enterovirus 71 / タイプ: virus / ID: 1 / NCBI-ID: 39054 / 生物種: Human enterovirus 71 / Sci species strain: G082 / ウイルスタイプ: VIRUS-LIKE PARTICLE / ウイルス・単離状態: STRAIN / ウイルス・エンベロープ: No / ウイルス・中空状態: Yes
The particles were boxed using e2boxer.py. CTF fitting was automatically performed using fitctf2.py in jspr, then visually validated and adjusted using EMAN1.9 ctfit program. The gold standard 3D reconstruction procedure was followed using jspr package, with the datasets split into two halves in the beginning.
CTF補正
詳細: Each particle
最終 再構成
アルゴリズム: OTHER / 解像度のタイプ: BY AUTHOR / 解像度: 5.5 Å / 解像度の算出法: OTHER / ソフトウェア - 名称: jspr, EMAN, EMAN2 / 使用した粒子像数: 2241