Persistence of hepatitis C virus in a human megakaryoblastic leukaemia cell line

Thrombocytopenia is a frequent clinical finding in patients with hepatitis C virus (HCV) infection, Platelets from patients with HCV infection have be en identified as carriers of HCV RNA in our previous studies. The present s tudy was designed to further investigate the possibility of HCV replication in megakaryoblasts from which platelets are eventually released. A megakar yoblastic cell line (MEG-01), established from a chronic myelogenous leukae mia patient 13 years ago, was used for this study, The MEG-01 cells were in oculated with fresh serum from a patient with HCV infection and renamed MEG -01-I cells, Surprisingly, both MEG-01 and MEG-01-I were positive by HCV re verse transcription-polymerase chain reaction (RT-PCR) for the existence of HCV RNA and minus-strand HCV RNA, regardless of inoculation, This was furt her confirmed by in situ RT-PCR, The HCV antigens, such as core, envelope, and non-structural (NS)3 and NS4, were also present in both cell lines, as identified by Western blotting and indirect immunofluorescence staining, In addition, virus-like particles were observed by electron microscopy in the MEG-01 cell line as well as in the MEG-01-I cell line, These findings indi cate that the megakaryoblasts are vulnerable to HCV infection and that repl ication of HCV can occur in these cells, This may help us to better underst and the pathogenesis of thrombocytopenia in patients with HCV infection. Th e MEG-01 cell line, which may have been continuously shedding HCV for years , should be a useful model for experimental research into HCV.