| Patent application number | Description | Published |
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| 20100093841 | CELL CULTURE SYSTEM OF A HEPATITIS C GENOTYPE 3A AND 2A CHIMERA - The present inventors have developed a culture system for genotype 3a, which has a high prevalence worldwide. Since intergenotypic recombinant genomes exploiting the replication characteristics of JFH1 will be a valuable tool for the genotype specific study of the replaced genes and related therapeutics, the present inventors constructed a genotype 3a/2a (S52/JFH1) recombinant containing the structural genes (Core, E1, E2), p7 and NS2 of strain S52 and characterized it in Huh7.5 cells. S52/JFH1 and J6/JFH viruses passaged in cell culture had comparable growth kinetics and yielded similar peak HCV RNA titers and infectivity titers. Direct genome sequencing of cell culture derived S52/JFH1 viruses identified putative adaptive mutations in Core, E2, p7, NS3 and NS5A; clonal analysis revealed, that all genomes analyzed exhibited different combinations of these mutations. Finally, viruses resulting from transfection with RNA transcripts of five S52/JFH1 recombinant containing these combinations of putative adaptive mutations performed as efficiently as J6/JFH viruses in Huh7.5 15 cells and were all genetically stable after viral passage. In conclusion, the present inventors have developed a robust and genetically stable cell culture system for HCV genotype 3a. | 04-15-2010 |
| 20110021611 | EFFICIENT CELL CULTURE SYSTEM FOR HEPATITIS C VIRUS GENOTYPE 5A - The present inventors developed 5a/2a intergenotypic recombinants in which the JFH1 structural genes (Core, E1 and E2), p7 and all of or part of NS2 were replaced by the corresponding genes of the genotype 5a reference strain SA13. Compared to the J6/JFH control virus, after transfection of in vitro transcripts in Huh7.5 cells, production of infectious viruses was delayed. However, in subsequent viral passages efficient spread of infection and HCV RNA titers as high as for J6/JFH were obtained. Infectivity titers were at all time points analyzed comparable to J6/JFH control virus. Sequence analysis of recovered 5a/2a recombinants from 2 serial passages and subsequent reverse genetic studies revealed adaptive mutations in p7, NS2 and/or NS3. Infectivity of the 5a/2a viruses was CD81 and SR-BI dependant, and the recombinant viruses could be neutralized by chronic phase sera from patients infected with genotype 5a. Conclusion: The developed 5a/2a viruses provide a robust in vitro tool for research in HCV genotype 5, including vaccine studies and functional analyses of an increasingly important genotype in South Africa and Europe. | 01-27-2011 |
| 20110059513 | EFFICIENT CELL CULTURE SYSTEM FOR HEPATITIS C VIRUS GENOTYPE 1A AND 1B - The present inventors developed hepatitis C virus 1a/2a and 1b/2a intergenotypic recombinants in which the JFH1 structural genes (Core, E1 and E2), p7 and NS2 were replaced by the corresponding genes of the genotype Ia reference strain H77C or TN or the corresponding genes of the genotype Ib reference strain J4. Sequence analysis of recovered 1a/2a and 1b/2a recombinants from 2 serial passages and subsequent reverse genetic studies revealed adaptive mutations in e.g. p7, NS2 and/or NS3. In addition, the inventors demonstrate the possibility of using adaptive mutations identified for one HCV isolate in generating efficient cell culture systems for other isolates by transfer of mutations across isolates, subtypes or major genotypes. Furthermore neutralization studies showed that viruses of e.g. genotype 1 were efficiently neutralized by genotype Ia, 4a and 5a serum, an effect that could be utilized e.g. in vaccine development and immunological prophylaxis. The inventors in addition demonstrate the use of the developed systems for screening of antiviral substances in vitro and functional studies of the virus, e.g. identification of receptors required for HCV entry | 03-10-2011 |
