36 results about "Hepatitis C virus genotype" patented technology

The present invention provides compositions and methods for the detection and characterization of HCV sequences. More particularly, the present invention provides compositions, methods and kits for using invasive cleavage structure assays (e.g. the INVADER assay) to screen nucleic acid samples, e.g., from patients, to determine HCV genotype.

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.

Genotype 7a has been identified recently, thus not much is known about the biology of this new, major HCV genotype. The present inventors developed hepatitis C virus 7a / 2a intergenotypic recombinants in which the JFH1 structural genes (Core, E1 and E2), p7 and the complete NS2 were replaced by the corresponding genes of the genotype 7a strain QC69 and characterized them in Huh7.5 cells. Sequence analysis of 7a / JFH1 recombinants recovered after viral passage in Huh7.5 cells following 4 independent transfection experiments revealed adaptive mutations in Core, E2, NS2, NS5A and NS5B. In reverse genetic studies the importance of these mutations for improved growth kinetics was shown. Adapted 7a / JFH1 viruses showed growth kinetics, infectivity and RNA titers comparable to a previously developed 3a / JFH1 reference virus. Conclusion: The developed 7a / JFH1 viruses provide a robust in vitro tool for research in HCV genotype 7, including vaccine studies and functional analyses.

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.