ANTIGENIC STRUCTURE OF HEPATITIS A VIRUS

甲型肝炎病毒的抗原结构。甲型肝炎病毒(HAV)是一种 小核糖核酸病毒家族的成员，但与其他病毒有远亲关系 属于该科，并将被归入自己的属。当病毒出现时 已在几个实验室克隆和测序，有用的多肽或 多肽抗原还没有产生。我们已经使用了两个技巧来 研究甲型肝炎病毒的抗原结构。一种由以下组成的cDNA表达文库 在lambda中产生甲型肝炎病毒衣壳编码区的随机片段 Gt11.该文库已经用20多种中和抗体进行了筛选。 对于甲型肝炎病毒，但没有克隆被这些抗体识别。另一方面 手，当这个文库被定向抗体筛选时 针对代表4个区域中每一个区域的合成寡肽 衣壳蛋白、克隆较易检出。这表明， 由单克隆识别的抗原是非线性的或构象的 受抚养人。 中和逃逸的序列分析(在其他实验室完成) 甲型肝炎病毒的突变株已经发现了两个潜在的抗原点。第一个是 VP3的第70位氨基酸(370)和VP1105的第二位氨基酸。 利用定点突变技术，我们共获得了30个突变体。 以及预测的抗原点附近。到目前为止，这些突变体中有10个是 可行的，正在分析中。到目前为止，我们已经确认了370地点和 在那个位置产生了一个突变体，与所选择的抗体不同 变种人，是稳定的逆转。我们还将VPL站点扩展到 氨基酸114(1114)。 我们已经启动了一个项目来研究人类对甲型肝炎病毒的T细胞免疫 黑猩猩模型。T细胞克隆正在开发中，最终将 协助分析T细胞表位。

Antigenic Structure of Hepatitis A Virus. Hepatitis A virus (HAV) is a member of the picornavirus family but is distantly related to other viruses in that family and will be classified into its own genus. While the virus has been cloned and sequenced in several laboratories, useful peptide or polypeptide antigens have not been produced. We have used 2 techniques to study the antigenic structure of HAV. A cDNA expression library consisting of random fragments of HAV capsid coding region was produced in lambda gt11. This library has been screened with over 20 neutralizing antibodies for HAV but no clones were recognized by these antibodies. On the other hand, when this library was screened with antibodies that were directed against synthetic oligopeptides representing regions of each of the 4 capsid proteins, clones were easily detected. This indicates that the antigens recognized by the monoclones were non-linear or conformation dependant. Sequence analysis (done in other laboratories) of neutralization escape mutants of HAV have revealed 2 potential antigenic sites. The first is around the 70th amino acid of VP3 (370) and the second around VP1 105. Using site directed mutagenesis we have produced a total of 30 mutants in and around predicted antigenic sites. Ten of these mutants to date are viable and are being analyzed. Thus far we have confirmed the 370 site and produced a mutant at that position that, unlike the antibody selected mutants, is stable to reversion. We have also extended the VPl site to amino acid 114 (1114). We have initiated a project to study T-cell immunity to HAV in the chimpanzee model. T-cell colones are being developed which will eventually aid in the analysis of the T cell epitopes.