Study of biologic characteristics on Epstein-Barr virus transformed B lymphocytes carrying hepatitis C virus type II
Objective To study persistence and replication of hepatitis C virus (HCV) in the patients′ peripheral blood mononuclear cells (PBMC) transformed by Epstein-Barr virus (EBV) in vitro and in order to explore the possibility of establishing a cell line for HCV reproduction. Methods EBV infected peripheral B lymphocytes from one patient with HCV positive of PBMC were transformed into permanent lymphoblastoid cell lines (LCL). The general and special biology characteristics of LCL were studied by cell culture, chromosome banding technique, flow fluorescent-activated cell sorter, reverse transcription-polymerase chain reaction (RT-PCR), in situ PCR, immunohistochemistry and electronic microscopy. Results 1. G-banded karyotype of the LCL was 47, XX, +mar, CD19 and CD20, CD antigens of LCL cell surface were positive and CD21 was not expressed. 2. Positive and negative HCV RNA strands from cultured cells and supernatants were detected by RT-PCR every month. HCV RNA plus strands persisted in the cultured cells for more than one year. It is interesting that the minus-strand RNA in LCL and the plus-strand RNA in supernatants were observed intermittently and HCV genome type of the LCL was type Ⅱ. 3. Immunohistochemical study found that HCV NS3 and C proteins were mostly expressed in LCL cytoplasm. In situ PCR showed that HCV RNA positive signal was mainly located in LCL cytoplasm. Electronic microscopy found HCV spherical virus-like particles with diameter of approximately 45 to 70nm, some particles were 110nm in LCL cytoplasmic vesicles. Conclusion HCV may exist in LCL cultured cells for a longer period and reproduce in and secrete into the media. It offers a strong evidence for persistence of HCV RNA in PBMC of HCV-infected patients.