传染性法氏囊病毒的抗原及分子特征(英文)  

Antigenic and Molecular Characterization of Infectious Bursal Disease Virus in China From Layer Chicken Flocks

作　　者：周继勇[1,2,3] 叶菊秀[1] 叶伟成[1] 陈庆新[1] 郑肖娟[1] 郭军庆[1] 

机构地区：[1]浙江大学动物预防医学研究所 [2]国家濒危野生动植物种质基因保护中心 [3]教育部濒危野生动物保护遗传与繁殖生物学重点实验室,杭州310029

出　　处：《生物化学与生物物理进展》2005年第1期37-45,共9页Progress In Biochemistry and Biophysics

基　　金：国家自然科学基金重点资助项目(30230270).~~

摘　　要：用鸡胚成纤维细胞对来自野外的5个传染性法氏囊病毒株(IBDV-JD1、JD2、NB、HZ1、HZ2)进行分离,测定理化特性、致病性,同时进行血清亚型测定及A片段基因组的克隆分析.试验所用5个法氏囊组织悬液在鸡胚成纤维细胞盲传2～14代后适应细胞并产生细胞病变.细胞适应的IBDV毒株的理化和形态特征与经典传染性法氏囊病毒株一致.除IBDV-HZ1、HZ2属经典IBDV血清型外,IBDV-JD1、JD2和NB毒株分属不同的血清亚型.人工感染实验结果显示,分离的IBDV毒株产生与野外病例相似的临床症状和病变,出现法氏囊滤泡髓质的淋巴细胞变性、坏死和消失.基因组序列分析显示,IBDV-NB毒株A片段由3 264个核苷酸组成,编码由145个氨基酸残基组成的VP5和由1 012个氨基酸残基组成的多聚蛋白.与来自GenBank的IBDV Ⅰ型毒株比较,NB毒株A片段编码的多聚蛋白与JD1毒株的同源性最高,达99.5%,VP2与JD1、CEF94、D78的同源性为99.8%,VP3与JD1的同源性为99.2%,VP4与JD1的同源性为100%,VP5与JD1,HZ2,P2,CEF94,CT,Cu-1和D78毒株的同源性为99.3%.NB毒株VP2蛋白的第253、280、284位氨基酸残基与IBDV变异毒株和经典毒株一致,但不同于IBDV超强毒株.这些结果暗示IBDV的抗原表位是构象依赖性表位,IBDV血清亚型的形成与IBDV弱毒疫苗病毒株密切相关.Five field isolates of infectious bursal disease virus (IBDV) were isolated from bursae of sick young chickens by inoculating chicken embryo fibroblasts (CEF) while the morphological and physiochemical properities of these isolates were detected. Subtype of the virus isolates were analysed by cross virus neutralization. Virulence of IBDV isolates was determined with specific pathogen-free (SPF) chicken inoculation. Nucleotide sequence of genomic segment A of the isolate NB was further sequenced and analysed. All bursal suspensions produced cytopathic effects (CPE) in CEF after 2similar to14 passages. The physiochemical and morphological proper-ties of IBDV isolates were in accordance with that of typical IBDV. The three CEF-adapted virus isolates JD1, JD2 and NB were divided into 3 subtypes of serotype I IBDV except IBDV isolates HZ1 and HZ2 belonged to classical IBDV. In a pathogenicity experiment, the clinical signs and bursal atrophy resembling those of field outbreaks were produced and microscopic bursa lesions revealed that there was degeneration, necrosis and disappearance of lymphocytes in the medullary area of bursal follicles. Sequence data demonstrated that genomic A-segment of the isolate NB was composed of 3 259 nucleotides, encoding VP5 of 145 amino acid residues and the polyprotein (VP243) of 1 012 amino acid residues. Compared with serotype I IBDV strains from GenBank, within serotype I IBDV strains, the isolate NB has the highest identity to the polyprotein of the isolate JD1 (99.5%), VP2 of the isolates JD1, CEF94 and D78 (99.8%), VP3 of the isolate JD1 (99.2%), VP4 of the isolate JD1 (100%) and VP5 of the isolates JD1, HZ2, P2, CEF94, CT, Cu-1 and D78 (99.3%). In the VP2-predicted amino acid sequence of the isolate NB, amino acid residues at positions 253, 280 and 284 were consistent with and other published variant and classical IBDV strains, and different from very virulent IBDV. These results indicated that antigenic epitopes of IBDV are conformational and subtype forming of IBDV isolates ori

关 键 词：传染性法氏囊病毒 理化特性 血清亚型 基因组A片段 

分 类 号：S858[农业科学—临床兽医学]