Feigelstock D, Thompson P, Mattoo P, Kaplan G G
Laboratory of Hepatitis Viruses, Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland 20892, USA.
J Virol. 1998 Jul;72(7):6218-22. doi: 10.1128/JVI.72.7.6218-6222.1998.
Monoclonal antibody (MAb) 190/4 blocks binding of hepatitis A virus (HAV) to the HAV cellular receptor 1 (havcr-1) and protects African green monkey kidney (AGMK) clone GL37 cells (GL37 cells) against HAV infection. BS-C-1 and CV-1 cells, two widely used AGMK cell lines, did not react with MAb 190/4 but expressed havcr-1, as judged by Western blot analysis. The cDNA coding for havcr-1 was amplified from BS-C-1 and CV-1 total cellular RNA by reverse transcription-PCR. Alignment of the amino acid sequences inferred from the cDNA nucleotide sequences showed that BS-C-1 and CV-1 havcr-1 differed from GL37 havcr-1 by having two substitutions in the Cys-rich region, N48H and K108Q, and 10 to 11 additional substitutions plus the insertion of 18 to 22 amino acids in the mucin-like region. Studies with chimeras of GL37 havcr-1 and BS-C-1 havcr-1 showed that the K108Q substitution was responsible for the lack of reaction of MAb 190/4 with BS-C-1 and CV-1 cells. Binding studies indicated that HAV bound to dog cell transfectants expressing the BS-C-1 havcr-1 as well as the GL37/BS-C-1 havcr-1 chimeras. These results indicate that antigenic variants of havcr-1 are expressed in AGMK cells and that binding of HAV to these havcr-1 variants tolerates changes in protective epitope 190/4.
单克隆抗体（MAb）190/4可阻断甲型肝炎病毒（HAV）与甲型肝炎病毒细胞受体1（havcr-1）的结合，并保护非洲绿猴肾（AGMK）克隆GL37细胞（GL37细胞）免受HAV感染。两种广泛使用的AGMK细胞系BS-C-1和CV-1细胞不与MAb 190/4反应，但通过蛋白质免疫印迹分析判断，它们表达havcr-1。通过逆转录聚合酶链反应从BS-C-1和CV-1细胞总RNA中扩增出编码havcr-1的cDNA。从cDNA核苷酸序列推断的氨基酸序列比对显示，BS-C-1和CV-1的havcr-1与GL37的havcr-1不同，在富含半胱氨酸区域有两个替换位点，即N48H和K108Q，在粘蛋白样区域还有10至11个额外替换位点以及18至22个氨基酸的插入。对GL37 havcr-1和BS-C-1 havcr-1嵌合体的研究表明，K108Q替换是MAb 190/4不与BS-C-1和CV-1细胞反应的原因。结合研究表明，HAV可与表达BS-C-1 havcr-1以及GL37/BS-C-1 havcr-1嵌合体的犬细胞转染子结合。这些结果表明，havcr-1的抗原变体在AGMK细胞中表达，并且HAV与这些havcr-1变体的结合可耐受保护性表位190/4的变化。
