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Human cell types important for hepatitis C virus replication in vivo and in vitro: old assertions and current evidence.

Revie D, Salahuddin SZ - Virol. J. (2011)

Bottom Line: We analyzed 75 RT-PCR studies that tested for negative strand HCV RNA in liver and other human tissues. 85% of the studies that investigated extrahepatic replication of HCV found one or more samples positive for replicative RNA.These systems vary in their purposes and methods, but long term culturing of HCV in B cells, T cells, and other cell types has been used to analyze replication.It is therefore now possible to study HIV-HCV co-infections and HCV replication in vitro.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biology, California Lutheran University, Thousand Oaks, USA. revie@clunet.edu

ABSTRACT
Hepatitis C Virus (HCV) is a single stranded RNA virus which produces negative strand RNA as a replicative intermediate. We analyzed 75 RT-PCR studies that tested for negative strand HCV RNA in liver and other human tissues. 85% of the studies that investigated extrahepatic replication of HCV found one or more samples positive for replicative RNA. Studies using in situ hybridization, immunofluorescence, immunohistochemistry, and quasispecies analysis also demonstrated the presence of replicating HCV in various extrahepatic human tissues, and provide evidence that HCV replicates in macrophages, B cells, T cells, and other extrahepatic tissues. We also analyzed both short term and long term in vitro systems used to culture HCV. These systems vary in their purposes and methods, but long term culturing of HCV in B cells, T cells, and other cell types has been used to analyze replication. It is therefore now possible to study HIV-HCV co-infections and HCV replication in vitro.

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Flow chart for long term in vitro culturing of HCV isolated from patient serum or plasma. Figure adapted from reference [23].
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Figure 2: Flow chart for long term in vitro culturing of HCV isolated from patient serum or plasma. Figure adapted from reference [23].

Mentions: Culturing of HCV in PBMC has been performed by multiple groups, but after about 25 days the HCV titers drops. This is probably due to changes as the macrophages start to mature after about two weeks of culture. They change from releasing cytokines that promote other cell types to releasing cytokines that inhibit them [142]. A novel culture system was therefore developed to take into account the properties of PBMC and its components (Figure 2). The system uses HCV from serum or plasma to infect macrophages. The macrophages and other cell types are purified from umbilical cord blood. After a week of culture, a cell-free extract of HCV is used to infect other cell types [23]. The virus is called CIMM-HCV (Figure 3). EBV infected B cells have been used to culture HCV by this system for over two years. T cells, neuronal cells, and non-committed lymphoid cells can also be infected using this system. Cell lines selected for permissiveness to HCV were not used in this system, so the replication of HCV in this system is likely to be closer to natural replication than the other systems described above. In addition, it can be used to study replication in a greater variety of cell types than the other long term culture systems. Analysis of the 5'UTR of HCV cultured using this system showed only minor changes when HCV genotype 1 was cultured in these cell types [143]. Comparison of sequences of the 5'UTR for HCV samples containing deletions or that were genotype 3 provided evidence that cord blood macrophages select for 5'UTR sequences similar to HCV genotype 1 [144,145]. As both macrophages and T cells can be infected by HCV using this system, the system has been used to co-infect T cells with HCV, HIV, and HHV-6 [146]. Cells containing all three viruses were observed (Figures 4 and 5), demonstrating that this isolation system can be used to study co-infection by these three viruses. As noted above, it is unclear how or whether HIV and HCV interact in vivo, so this system could provide a method to investigate interactions between these viruses.


Human cell types important for hepatitis C virus replication in vivo and in vitro: old assertions and current evidence.

Revie D, Salahuddin SZ - Virol. J. (2011)

Flow chart for long term in vitro culturing of HCV isolated from patient serum or plasma. Figure adapted from reference [23].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3142522&req=5

Figure 2: Flow chart for long term in vitro culturing of HCV isolated from patient serum or plasma. Figure adapted from reference [23].
Mentions: Culturing of HCV in PBMC has been performed by multiple groups, but after about 25 days the HCV titers drops. This is probably due to changes as the macrophages start to mature after about two weeks of culture. They change from releasing cytokines that promote other cell types to releasing cytokines that inhibit them [142]. A novel culture system was therefore developed to take into account the properties of PBMC and its components (Figure 2). The system uses HCV from serum or plasma to infect macrophages. The macrophages and other cell types are purified from umbilical cord blood. After a week of culture, a cell-free extract of HCV is used to infect other cell types [23]. The virus is called CIMM-HCV (Figure 3). EBV infected B cells have been used to culture HCV by this system for over two years. T cells, neuronal cells, and non-committed lymphoid cells can also be infected using this system. Cell lines selected for permissiveness to HCV were not used in this system, so the replication of HCV in this system is likely to be closer to natural replication than the other systems described above. In addition, it can be used to study replication in a greater variety of cell types than the other long term culture systems. Analysis of the 5'UTR of HCV cultured using this system showed only minor changes when HCV genotype 1 was cultured in these cell types [143]. Comparison of sequences of the 5'UTR for HCV samples containing deletions or that were genotype 3 provided evidence that cord blood macrophages select for 5'UTR sequences similar to HCV genotype 1 [144,145]. As both macrophages and T cells can be infected by HCV using this system, the system has been used to co-infect T cells with HCV, HIV, and HHV-6 [146]. Cells containing all three viruses were observed (Figures 4 and 5), demonstrating that this isolation system can be used to study co-infection by these three viruses. As noted above, it is unclear how or whether HIV and HCV interact in vivo, so this system could provide a method to investigate interactions between these viruses.

Bottom Line: We analyzed 75 RT-PCR studies that tested for negative strand HCV RNA in liver and other human tissues. 85% of the studies that investigated extrahepatic replication of HCV found one or more samples positive for replicative RNA.These systems vary in their purposes and methods, but long term culturing of HCV in B cells, T cells, and other cell types has been used to analyze replication.It is therefore now possible to study HIV-HCV co-infections and HCV replication in vitro.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biology, California Lutheran University, Thousand Oaks, USA. revie@clunet.edu

ABSTRACT
Hepatitis C Virus (HCV) is a single stranded RNA virus which produces negative strand RNA as a replicative intermediate. We analyzed 75 RT-PCR studies that tested for negative strand HCV RNA in liver and other human tissues. 85% of the studies that investigated extrahepatic replication of HCV found one or more samples positive for replicative RNA. Studies using in situ hybridization, immunofluorescence, immunohistochemistry, and quasispecies analysis also demonstrated the presence of replicating HCV in various extrahepatic human tissues, and provide evidence that HCV replicates in macrophages, B cells, T cells, and other extrahepatic tissues. We also analyzed both short term and long term in vitro systems used to culture HCV. These systems vary in their purposes and methods, but long term culturing of HCV in B cells, T cells, and other cell types has been used to analyze replication. It is therefore now possible to study HIV-HCV co-infections and HCV replication in vitro.

Show MeSH
Related in: MedlinePlus