Showing papers by "Jens Bukh published in 2010"

Novel Infectious cDNA Clones of Hepatitis C Virus Genotype 3a (Strain S52) and 4a (Strain ED43): Genetic Analyses and In Vivo Pathogenesis Studies

Abstract: Previously, RNA transcripts of cDNA clones of hepatitis C virus (HCV) genotypes 1a (strains H77, HCV-1, and HC-TN), 1b (HC-J4, Con1, and HCV-N), and 2a (HC-J6 and JFH1) were found to be infectious in chimpanzees. However, only JFH1 was infectious in human hepatoma Huh7 cells. We performed genetic analysis of HCV genotype 3a (strain S52) and 4a (strain ED43) prototype strains and generated full-length consensus cDNA clones (pS52 and pED43). Transfection of Huh7.5 cells with RNA transcripts of these clones did not yield cells expressing HCV Core. However, intrahepatic transfection of chimpanzees resulted in robust infection with peak HCV RNA titers of approximately 5.5 log(10) international units (IU)/ml. Genomic consensus sequences recovered from serum at the times of peak viral titers were identical to the sequences of the parental plasmids. Both chimpanzees developed acute hepatitis with elevated liver enzymes and significant necroinflammatory liver changes coinciding with detection of gamma interferon-secreting, intrahepatic T cells. However, the onset and broadness of intrahepatic T-cell responses varied greatly in the two animals, with an early (week 4) multispecific response in the ED43-infected animal (3 weeks before the first evidence of viral control) and a late (week 11) response with limited breadth in the S52-infected animal (without evidence of viral control). Autologous serum neutralizing antibodies were not detected during the acute infection in either animal. Both animals became persistently infected. In conclusion, we generated fully functional infectious cDNA clones of HCV genotypes 3a and 4a. Proof of functionality of all genes might further the development of recombinant cell culture systems for these important genotypes.

Challenge Pools of Hepatitis C Virus Genotypes 1–6 Prototype Strains: Replication Fitness and Pathogenicity in Chimpanzees and Human Liver-Chimeric Mouse Models

Abstract: Chimpanzees represent the only animal model for studies of the natural history of hepatitis C virus (HCV). To generate virus stocks of important HCV variants, we infected chimpanzees with HCV strains of genotypes 1-6 and determined the infectivity titer of acute-phase plasma pools in additional animals. The courses of first- and second-passage infections were similar, with early appearance of viremia, HCV RNA titers of >10(4.7) IU/mL, and development of acute hepatitis; the chronicity rate was 56%. The challenge pools had titers of 10(3)-10(5) chimpanzee infectious doses/mL. Human liver-chimeric mice developed high-titer infections after inoculation with the challenge viruses of genotypes 1-6. Inoculation studies with different doses of the genotype 1b pool suggested that a relatively high virus dose is required to consistently infect chimeric mice. The challenge pools represent a unique resource for studies of HCV molecular virology and for studies of pathogenesis, protective immunity, and vaccine efficacy in vivo.

The influence of comorbid personality disorder and neuroticism on treatment outcome in first episode depression.

Abstract: Background: It has never been investigated whether comorbid personality disorder or neuroticism predicts a poor treatment outcome in first episode depression. Methods:

Does bereavement-related first episode depression differ from other kinds of first depressions?

Abstract: Background It has never been investigated whether first depression differs in patients who have experienced bereavement compared to patients who have not.

Molecular evolution of GB virus B hepatitis virus during acute resolving and persistent infections in experimentally infected tamarins

Abstract: GB virus B (GBV-B) causes acute hepatitis in experimentally infected tamarins. We compared evolutionary features in acute resolving and persistent GBV-B infection. We detected no evidence of evolution in four animals with clearance during weeks 9–12, whereas three animals with clearance during weeks 13–26 had several substitutions in their polyprotein sequence. A single tamarin had long-term GBV-B viraemia; analysis of virus recovered at weeks 2, 5, 12, 20, 26, 52 and 104 demonstrated that mutations accumulated over time. Overall, the amino acid substitution rate was 3.5×10−3 and 1.1×10−3 substitutions per site year−1 during weeks 1–52 and 53–104, respectively. Thus, there was a significant decrease in evolution over time, as found for hepatitis C virus. The rate of non-synonymous substitution per non-synonymous site compared with that of synonymous substitution per synonymous site decreased over time, suggesting reduction of positive selective pressure. These data demonstrate that prolonged GBV-B infection is associated with viral evolution.

Gender differences among patients with a single depressive episode.

Abstract: Background: Studies on gender differences in depression have usually included a mixture of patients with first-episode, chronic and recurrent depression Consequently, the results m

Molecular and epidemiological profiles of hepatitis C virus genotype 4 in Denmark

Abstract: The prevalence of hepatitis C virus (HCV) genotype 4 has increased throughout Europe. This is an epidemiological study of patients infected chronically with HCV genotype 4 in Denmark. The HCV strains analyzed originated from patient samples collected between 1999 and 2007 as part of the national Danish hepatitis B and C network, DANHEP. Sequence analyses were based on the envelope 1 region of HCV. Results from a total of 72 patients indicated a high degree of genetic heterogeneity. Fifty-six patients (78%) were infected with one of the three dominating subtypes: 4d, 4a, or 4r. The remaining 16 patients (22%) were infected with subtypes 4h, 4k, 4l, 4n, 4o, or 4Unclassified. Three epidemiological profiles were identified: (1) Patients infected with HCV by intravenous drug use were infected solely with subtype 4d. They were all of European origin, and 15 of the 16 patients were ethnic Danes. No single transmission event could be confirmed, but the pairwise nucleotide identity within the patients of Danish origin was relatively high (~95%), suggesting a recent introduction into Denmark. (2) The 21 patients infected with subtype 4a all came from Northern Africa, Egypt, Pakistan, or the Middle East. (3) Patients from Southern Africa dominated among patients infected with subtype 4r (10 of 12 patients). This study demonstrates that HCV genotype 4d has been introduced in and spread among Danish intravenous drug users. The remaining subtypes show restricted distribution, infecting almost exclusively patients from geographical areas with a relatively high prevalence of HCV genotype 4 infections.

Infectious hepatitis C viruses of genotype 3A and 4A and uses thereof

Abstract: The present invention relates to molecular approaches to the production of nucleic acid sequences, which comprises the genome of infectious hepatitis C virus. In particular, the invention provides nucleic acid sequences which comprise the genomes of infectious hepatitis C viruses of either genotype 3a (strain S52) or genotype 4a (strain ED43). The invention therefore relates to the use of the nucleic acid sequences and polypeptides encoded by all or part of the sequences in the development of vaccines and diagnostic assays for HCV and in the development of screening assays for the identification of antiviral agents for HCV. The invention therefore also relates to the use of viral particles derived from laboratory animals infected with S52 and ED43 viruses.

Jfh-1 based hcv cell culture systems for ns5a of genotypes 1-7

Abstract: The present inventors developed hepatitis C virus recombinants expressing NS5A from genotype Ia, 1b, 2a, 3a, 4a, 5a, 6a or 7a in the context of a genotype 2a backbone Additional recombinants express NS5A and the structural proteins (Core, E1 and E2), p7 and NS2 from genotype 1a, 1b, 3a, 4a, 5a, 6a or 7a in the genotype 2a backbone Sequence analysis of the recombinants recovered after viral passage in Huh75 cells revealed adaptive mutations in NS5A and/or NS3 The importance of these mutations for improved growth kinetics was shown in reverse genetic studies