ANALYSIS OF VIRAL REPLICATION AND INFECTION MECHANISM OF THE DUCK HEPATITIS B VIRUS

鸭乙型肝炎病毒的病毒复制及感染机制分析

• 批准号: 10670452
• 负责人: TAKASHI Ishikawa
• 金额: $ 2.11万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10670452/
• 关键词: hepatitis B virus; receptor; infection; duck hepatitis B virus; viral entry; 増殖; カルボキシペプチダーゼD

In an attempt to identify receptor candidates for DHBV, we have previously identified a glycoprotein of 180 kDa, which binds DHBV particles and Escherichia coli-derived GST-preS polypeptides. Sequence comparisons of gp18O cDNA with known sequences suggested that it represents the prototype of a new family of membrane bound carboxypeptidases. The primary sequence analysis indicates that CPDs consist of three luminal/extracellular carboxypeptidase B or H like domains (called A, B, and C), a hydrophobic transmembrane anchor and a highly conserved cytoplasmic tail. Domain C has been elucidated to have the DHBV preS-binding site. Now gp180, a Golgi-resident protein, is thought to be the cellular receptor for avian hepadnaviruses that mediates virus attachment and internalization into the host cell.All hepatitis B viruses (HBVs) display marked species specificity in their infection. We have examined the molecular basis for this narrow host range, using duck HBV (DHBV) and heron HBV (HHBV) as a model system. We have previously revealed that the preS domain of the large viral envelope protein determines host range in avian hepatitis B viruses, by pseudotyping of HHBV env with DHBV/HHBV chimeric envelope proteins. To further map the determinant in the DHBV preS region, we have made DHBV/HHBV chimeric envelope proteins (HDC 6-12). The replacement of as few as 15 amino acids of the preS domain of the HHBV L protein by their counterparts is sufficient to permit infection of duck hepatocytes. This domain is located between amino acid 22 and 37 in the DHBV preS sequence, which is outside of and more amino terminal domain of duck carboxypeptidase D (dCPD) binding sites (amino acid 43-108).These results suggest that dCPD could not be the sole determinant of viral entry, and this domain might be responsible for the binding of the putative second receptor in hepadnaviral infection.

为了鉴定DHBV的候选受体，我们之前已经鉴定了180kda的糖蛋白，该糖蛋白结合DHBV颗粒和大肠杆菌衍生的GST-preS多肽。gp18O cDNA与已知序列的序列比较表明，它代表了一个新的膜结合羧基肽酶家族的原型。初级序列分析表明，CPDs由三个腔内/细胞外羧基肽酶B或H样结构域（称为A， B和C），疏水跨膜锚点和高度保守的细胞质尾部组成。结构域C已被证实具有DHBV前结合位点。现在，高尔基驻留蛋白gp180被认为是禽肝病毒的细胞受体，介导病毒附着和内化进入宿主细胞。所有乙型肝炎病毒（HBVs）在其感染中表现出明显的物种特异性。我们以鸭乙肝病毒（DHBV）和苍鹭乙肝病毒（HHBV）为模型系统，研究了这一狭窄宿主范围的分子基础。我们之前已经发现，通过用DHBV/HHBV嵌合包膜蛋白对HHBV进行假分型，大病毒包膜蛋白的preS结构域决定了禽乙型肝炎病毒的宿主范围。为了进一步定位DHBV preS区的决定因子，我们制作了DHBV/HHBV嵌合包膜蛋白（HDC 6-12）。只要HHBV L蛋白的preS结构域的15个氨基酸被相应的氨基酸取代，就足以使鸭肝细胞受到感染。该结构域位于DHBV preS序列第22 ~ 37个氨基酸之间，位于鸭羧基肽酶D （dCPD）结合位点（43 ~ 108个氨基酸）的氨基末端结构域之外。这些结果表明，dCPD不可能是病毒进入的唯一决定因素，该结构域可能负责在肝炎病毒感染中与假定的第二受体结合。

项目成果

Ishikawa,T.et al.: "Cloning,functional expression,and Chromosomal localization of the human and mouse qp180-carlohypeptide like anycyne" GENE. 215. 361-370 (1998)

Ishikawa,T.et al.：“人类和小鼠 qp180-carlohypeptide 样 Anycyne 的克隆、功能表达和染色体定位”基因。

Ishikawa,T. et.al: "Cloning, functional expression and chromosomal localization of the human and mouse gp180-carboxypeptidase D-like enzym"GENE. 215. 361-370 (1998)

石川，T.