Therapeutic approach to hepatitis C using single-chain antibody and DNA gene transfer

本文报道了一株抗B型肝炎病毒核心蛋白（HBc）单链抗体（sFv）1C 9的cDNA。我们还克隆了对照sFv（γ9）的cDNA，其不能与HBc反应。用1C 9或γ9转染携带三拷贝HBV-DNA并产生HBV颗粒的HB 611细胞，我们分别建立了稳定表达1C 9或γ9的HB 611细胞。我们发现在表达1C 9的HB 611和表达γ9的HB 611之间，每种HBV转录物和蛋白的产生没有差异。然而，与表达γ9的HB 611相比，表达1C 9的HB 611中HBV复制中间体的表达受到抑制。这些结果表明，抗HBc的sFv可能抑制前基因组RNA包装入HBc颗粒。因此，抗病毒衣壳蛋白的sFv可有效抑制病毒基因组的扩增，抗丙型肝炎病毒核心蛋白的sFv有可能成为治疗丙型肝炎的候选药物。

A cDNA for single-chain antibody (sFv) against hepatitis B virus core protein (HBc), 1C9, was isolated. We also cloned a cDNA for control sFv (γ9) that could not react HBc. HB611 cells that carry three copies of HBV-DNA and produce HBV particles were transfected with 1C9 or γ9 and we established the HB611 cells that stably express 1C9 or γ9, respectively. We found no difference in production of each HBV transcript and protein between 1C9-expressing HB611 and γ9-expressing ones. However, expression of HBV replicative intermediate was inhibited in 1C9-expressing HB611 compared with γ9-expressing ones. These results suggested that sFv against HBc might inhibit the packaging of pregenome RNA into HBc particles. Thus sFv against viral capsid protein was shown to be useful for inhibition of encapsidation of viral genome and sFv against hepatitis C virus core protein may be a candidate for therapeutic application of hepatitis C.