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Systematic studies of the circulation of hepatitis C virus (HCV) recombinants in different parts of the world have been initiated only recently, and no detailed information on this subject is available. The aim of the current investigation was to determine the frequency of HCV recombinants in intravenous drug users (IVDU) from two European countries. HCV RNA from serum samples was tested by RT-PCR with primers derived from the core and NS5B regions with subsequent sequencing and genotype assignment. The 118 samples from Germany (100%) and 45 out of 47 (96%) sera from Russia demonstrated concordant genotyping results. In the two genotype discrepant sera from Russia 2k/1b recombinants were identified. In order to test the hypothesis that the individuals from the IVDU group might be multiply exposed to various genotypes, 145 out of 165 genotyped serum samples, which were found to be positive for anti-NS4 antibodies, were serotyped with the Murex HCV serotyping kit that is based on detection of antibodies to type-specific peptides derived from the NS4 proteins of different HCV genotypes. Discrepancy in genotype and serotype attributions was observed in 11% cases. Retesting of 99 type 1a or 3a samples with a set of type- and subtype-specific primers revealed the presence of a mixed infection only in one case (1a/3a). Thus, the cases of the mixed infection with different HCV genotypes as well as the recombinant forms of HCV are very rare even in such a highly exposed group as IVDU., ((c) 2009 Wiley-Liss, Inc.)

Its stable particle structure combined with its high immunogenicity makes the hepatitis A virus (HAV) a perfect carrier to expose foreign epitopes to the host immune system. In an earlier report [Beneduce, F., Kusov, Y., Klinger, M., Gauss-Müller, V., Morace, G., 2002. Chimeric hepatitis A virus particles presenting a foreign epitope (HIV gp41) at their surface. Antiviral Res. 55, 369-377] chimeric virus-like particles (HAV-gp41) were described that carried at their surface the dominant gp41 epitope 2F5 (2F5e) of the human immunodeficiency virus HIV-1. Extending this work, we now report that chimeric virus HAV-gp41 replicates in HAV-susceptible cells as well as in non-human primates. Infected marmosets developed both an anti-HAV and anti-2F5 epitope immune response. Furthermore, an HIV-neutralizing antibody response was elicited in guinea pigs immunized with HAV-gp41 chimeric particles. The results demonstrate that the replication-competent chimeric HAV-gp41 can serve as either a live or a subunit vaccine for eliciting of antibodies directed against a foreign antigenic epitope.

GBV-B, a member of the Flaviviridae family of viruses, is the virus most closely related to HCV, and GBV-B infection in tamarin monkeys might represent a valuable surrogate animal model of HCV infection. In the current study, GBV-B was successfully transmitted to two marmosets (Callithrix jaccus). The infection resulted in viremia of 14- and 17-week duration, respectively, and was accompanied by elevation of isocitrate dehydrogenase activity. These data confirm that marmosets might represent an attractive model for GBV-B infection. The sequence of GBV-B NS5A, which was previously reported to have one of the highest mutation rates during infection in tamarins, was determined for viruses recovered from the inoculum and from marmoset blood samples obtained at weeks 1, 8, and 14 post inoculation in one marmoset and at weeks 2, 8, and 17 post inoculation in the other marmoset. In both animals, we detected four substitutions (R1945K, K2052G, F2196L, and G2268E), in the virus recovered immediately before viral clearance. Interestingly, two of these mutations (F2196L and G2268E) were described recently for viruses recovered from persistently infected tamarins. Appearance of these mutations presumably reflects a mechanism of immune escape rather than adaptation of the virus to a new host.

This study aimed to examine anti hepatitis C virus (HCV) antibody titres, their changes and differences in acute, chronic and past HCV infection and to examine them after IFN-alpha-therapy. Ninety five patients were studied in a cross-sectional investigation and 18 of them were followed long-term. Titres of IgM and IgG antibodies against core, NS3, NS4 (A + B), NS5A proteins were determined by the third generation enzyme immunoassays. Patients with acute hepatitis C developed IgG antibodies against core protein in titres 1/5-1/800 and against individual NS proteins at the same titres. During the first to second month of acute hepatitis C IgG antibody titres to HCV proteins were very low, but they had risen considerably by the fourth to sixth month. Anti-HCV IgM antibodies were found in half the acute hepatitis serum samples, titres were 1/5-1/40. Sixty individuals with chronic hepatitis C showed IgG antibodies against core in titres 1/800-1/40,000 and against individual NS proteins in titres 1/5-1/20,000. Eight patients with chronic hepatitis C had invariable anti-HCV IgG antibodies over 2-3 years. About 81.7% of chronically infected patients had anti-HCV IgM antibodies in titres 1/5-1/160. Patients with resolution of HCV infection showed only anti-core IgG antibodies (titres 1/5-1/200) or no virus-specific antibodies. Individuals with different response to IFN-alpha-therapy showed two distinct patterns of anti-HCV antibody titres. Acute and chronic HCV infection may be distinguished by anti-core titres.

A new method has been developed for the production of radioactive wires and "hairpins" showing from their middle up to their ends a linear increase of specific activity. The advantages offered by these wires and "hairpins" have been introduced with good results in a series of new implantation methods for the interstitial curietherapy of malignant tumors.