Mello Francisco C A, Martel Nora, Gomes Selma A, Araujo Natalia M
Laboratory of Molecular Virology, Oswaldo Cruz Institute, FIOCRUZ, Avenida Brasil 4365, 21045-900 Rio de Janeiro, RJ, Brazil.
Hepat Res Treat. 2011;2011:695859. doi: 10.1155/2011/695859. Epub 2011 Feb 6.
Small hepatitis B virus surface protein (S-HBsAg) variant Y100C has been associated with HBsAg-negative phenotype. To determine whether Y100C substitution yields impaired HBsAg or small amounts of HBsAg that may reduce HBsAg detection by commercial anti-HBsAg antibodies, two eukaryotic expression plasmids, one containing a wild-type S and the other an S gene from a Y100C variant, were constructed and their levels of HBsAg compared by ELISA after transfection of HuH7 cells. Unexpectedly, the extracellular HBsAg levels detected with Y100C plasmid were higher than those observed with the wild-type plasmid, but without statistical significance. We concluded that the Y100C substitution alone did not play a role in reducing HBsAg amounts or HBsAg affinity by commercial ELISA assay. Further studies on in vitro replication fitness with the complete genome of HBV isolates displaying or not Y100C substitution may elucidate whether this mutation affects HBV replication and consequently HBsAg production.
乙肝病毒小表面蛋白（S-HBsAg）变体Y100C与HBsAg阴性表型有关。为了确定Y100C替换是否会导致HBsAg受损或产生少量可能降低商业抗HBsAg抗体对HBsAg检测能力的HBsAg，构建了两个真核表达质粒，一个含有野生型S基因，另一个含有Y100C变体的S基因，并在转染HuH7细胞后通过ELISA比较它们的HBsAg水平。出乎意料的是，用Y100C质粒检测到的细胞外HBsAg水平高于野生型质粒，但无统计学意义。我们得出结论，单独的Y100C替换在通过商业ELISA检测降低HBsAg量或HBsAg亲和力方面不起作用。对显示或不显示Y100C替换的HBV分离株的完整基因组进行体外复制适应性的进一步研究，可能会阐明这种突变是否影响HBV复制，进而影响HBsAg的产生。
