ジャーナル: J Virol / 年: 2015 タイトル: The enterovirus 71 procapsid binds neutralizing antibodies and rescues virus infection in vitro. 著者: Kristin L Shingler / Javier O Cifuente / Robert E Ashley / Alexander M Makhov / James F Conway / Susan Hafenstein / 要旨: Enterovirus 71 (EV71) is responsible for seasonal outbreaks of hand, foot, and mouth disease in the Asia-Pacific region. The virus has the capability to cause severe disease and death, especially in ...Enterovirus 71 (EV71) is responsible for seasonal outbreaks of hand, foot, and mouth disease in the Asia-Pacific region. The virus has the capability to cause severe disease and death, especially in young children. Although several vaccines are currently in clinical trials, no vaccines or therapeutics have been approved for use. Previous structural studies have revealed that two antigenically distinct capsid forms are produced in EV71-infected cells: an expanded empty capsid, sometimes called a procapsid, and the infectious virus. Specifically, an immunodominant epitope of EV71 that maps to the virus canyon is structurally different in the procapsid and virus. This structure-function study shows that the procapsid can sequester antibodies, thus enhancing EV71 infection in vitro. The results presented here suggest that, due to conformational differences between the EV71 procapsid and virus, the presence of the procapsid in natural virus infections should be considered in the future design of vaccines or therapeutics. IMPORTANCE: In a picornavirus infection, both an infectious and a noninfectious empty capsid, sometimes referred to as a procapsid, are produced. It was novel to discover that the procapsid form of ...IMPORTANCE: In a picornavirus infection, both an infectious and a noninfectious empty capsid, sometimes referred to as a procapsid, are produced. It was novel to discover that the procapsid form of EV71 was expanded and antigenically distinct from the infectious virus. Previously, it had been supposed that this empty capsid was an off-pathway dead end or at best served for storage of pentameric subunits, which was later shown to be unlikely. It remains unexplained why picornaviruses evolutionarily conserve the wasteful production of so much noninfectious capsid. Here, we demonstrate that the EV71 procapsid has different antigenic properties than the infectious virus. Thus, the procapsid has the capacity to sequester neutralizing antibody and protect the virus, promoting or restoring a successful infection in vitro. This important observation should be considered in the future design and development of vaccines and therapeutics.
全体 : Fab fragment of 22A12 monoclonal antibody bound to Enterovirus 71...
全体
名称: Fab fragment of 22A12 monoclonal antibody bound to Enterovirus 71 procapsid at the VP1 GH Loop
要素
試料: Fab fragment of 22A12 monoclonal antibody bound to Enterovirus 71 procapsid at the VP1 GH Loop
ウイルス: Human enterovirus 71 (エンテロウイルス)
タンパク質・ペプチド: neutralizing antibody 22A12 Fab
-
超分子 #1000: Fab fragment of 22A12 monoclonal antibody bound to Enterovirus 71...
超分子
名称: Fab fragment of 22A12 monoclonal antibody bound to Enterovirus 71 procapsid at the VP1 GH Loop タイプ: sample / ID: 1000 / Number unique components: 2
-
超分子 #1: Human enterovirus 71
超分子
名称: Human enterovirus 71 / タイプ: virus / ID: 1 / Name.synonym: EV71 詳細: Virus procapsid was complexed with Fab fragments of neutralizing antibody 22A12. NCBI-ID: 39054 / 生物種: Human enterovirus 71 / Sci species strain: 1095/Shiga / データベース: NCBI / ウイルスタイプ: VIRION / 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 / Syn species name: EV71
宿主
生物種: Homo sapiens (ヒト) / 別称: VERTEBRATES
ウイルス殻
Shell ID: 1 / 直径: 300 Å / T番号(三角分割数): 3
-
分子 #1: neutralizing antibody 22A12 Fab
分子
名称: neutralizing antibody 22A12 Fab / タイプ: protein_or_peptide / ID: 1 / 組換発現: No / データベース: NCBI
由来(天然)
生物種: unidentified (未定義)
-
実験情報
-
構造解析
手法
クライオ電子顕微鏡法
解析
単粒子再構成法
試料の集合状態
particle
-
試料調製
濃度
1.0 mg/mL
緩衝液
pH: 7.5 / 詳細: 10 mM Tris, 200 mM NaCl, 50 mM MgCl2
グリッド
詳細: holey carbon Quantifoil EM grids
凍結
凍結剤: ETHANE-PROPANE MIXTURE / 装置: FEI VITROBOT MARK III
-
電子顕微鏡法
顕微鏡
FEI TECNAI F20
日付
2011年7月15日
撮影
カテゴリ: FILM / フィルム・検出器のモデル: KODAK SO-163 FILM デジタル化 - スキャナー: NIKON SUPER COOLSCAN 9000 デジタル化 - サンプリング間隔: 6.35 µm
電子線
加速電圧: 200 kV / 電子線源: FIELD EMISSION GUN
電子光学系
照射モード: FLOOD BEAM / 撮影モード: BRIGHT FIELD / Cs: 2.0 mm / 倍率(公称値): 50000
試料ステージ
試料ホルダーモデル: GATAN LIQUID NITROGEN
実験機器
モデル: Tecnai F20 / 画像提供: FEI Company
-
画像解析
詳細
Processing was completed with EMAN2 and AUTO3DEM.
CTF補正
詳細: CTFFind3
最終 再構成
解像度のタイプ: BY AUTHOR / 解像度: 8.8 Å / 解像度の算出法: OTHER / ソフトウェア - 名称: EMAN, EMAN2, AUTO3DEM, Chimera / 使用した粒子像数: 15226