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Aim: To determine whether the nucleotide sequences homologous to GBV-C genome exist in the DNA from cell lines of human origin and from peripheral blood mononuclear cells (PBMC) of human and chimpanzee., Methods: DNA of MT2 cell, HeLa cell, and PBMC from six human and one chimpanzee were prepared by using PCR Temperate Preparation Kit. All of the DNA preparations were digested with DNase-free RN ase and then were extracted by phenol-chloroform method. By using these DNA as templates, direct nested-PCR (dPCR) respectively amplified with GBV-C 5'-NCR and NS3 primers were carried out. Nucleotide sequences of the dPCR products were analyzed and positions in chromosomes of the amplification fragments were detected by using primed in situ (PRINS) sequence-specific labeling with fluorescein., Results: DNA fragments amplified with GBV-C 5'-NCR primers were obtained from the DNA of MT2 and HeLa cells and the DNA in 4 of 6 human PBMC samples. DNA fragments amplified with GBV-C NS3 primers were obtained from MT2 and HeLa cells and the DNA in 5 of 6 human PBMC samples and one chimpanzee PBMC sample. The homology of the nucleotide sequences from these amplification products compared with the reported GBV-C genome sequence was from 73.80 % to 79.15 %. Fluorescence staining spots by using PRINS were shown in the PBMC and their chromosomes with positive dPCR results., Conclusion: The nucleotide sequences with high homology to GBV-C genome at the 5'-NCR and/or NS3 region exist in the DNA of MT2 and HeLa cells and the PBMC DNA of human and chimpanzee. These sequences locate in the chromosomes of PBMC with positive dPCR results.

No convincing support has been provided so far for the existence of extrahepatic hepatitis C virus particles that should correspond to the sometimes extremely high concentration of 'HCV-RNA' in serum or plasma. If a naturally occurring HCV-specific DNA were to be found, a concept for at least some phenomena in terms of the pathophysiology of HCV should become conceivable. DNA was extracted from peripheral blood mononuclear cells of eleven healthy, anti-HCV-negative individuals, including five long term blood donors, and cells from different cell lines. DNA was subjected to nested polymerase chain reaction omitting a reverse transcriptase step with primers of the 5'NC as well as part of the core region of HCV. Direct polymerase chain reaction, i.e. without a reverse transcriptase step, revealed HCV-specific sequences in the DNA fraction of peripheral blood mononuclear cells of different origin: healthy anti-HCV negative individuals, furthermore in HeLa and MT2 cells. The fragments found were of expected length as well as of shorter and of longer than expected length with respect to the sequence of the HCV genome framed by the primers applied. The results derived from additional hybridization, restriction endonuclase analysis, and sequencing demonstrated HCV-specific sequences in the expected fragments with both a high degree of homology and deletions, respectively, substitutions, as compared to a prototype strain. However, the longer than expected fragments also contained sequences not specific for HCV.

The DNA content in plasma of five healthy human individuals has been estimated. Structures ascertained by electron microscopy have been identified as double-stranded DNA. Depending on the isolation procedure applied the DNA molecules found may originate from free and/or complexed forms of DNA. The lengths range from less than 0.2 microns up to about 13 microns. DNA concentration is in the range of 3 to 11 ng/ml.