Christoph Heynen

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Two flavivirus-like genomes have recently been cloned from infectious tamarin (Saguinus labiatus) serum, derived from the human viral hepatitis GB strain, which is known to induce hepatitis in tamarins. In order to study the natural history of GB infections, further transmission studies were carried out in tamarins. Reverse-transcription-polymerase chain(More)
Exposure to GB virus C (GBV-C) was determined in several U.S. populations by both reverse-transcription-polymerase chain reaction (RT-PCR) and by an enzyme linked immunosorbent assay (ELISA) for antibodies to mammalian cell-expressed GBV-C envelope protein, E2 (GBV-C E2). Most individuals exposed to GBV-C were either RNA positive/ELISA negative or ELISA(More)
The effects of various cytokines were examined in an in vitro model of human immunodeficiency virus type 1 (HIV-1) infection of human peripheral blood monocyte-derived macrophages (MDM). Monocytes were obtained from blood of normal donors by Ficoll/hypaque gradient centrifugation and adherence. These cells were allowed to mature in the presence of varying(More)
Viral characterization studies were carried out on GB virus C (GBV-C) RNA positive plasma from normal human donors and from donors co-infected with GBV-C and hepatitis C virus (HCV). GBV-C RNA was detected by reverse-transcriptase polymerase chain reaction (RT-PCR) and probe hybridization in a single tube assay. Sequential filtration of GBV-C positive(More)
A 315 amino acid recombinant segment of the GB virus C (GBV-C) E2 envelope glycoprotein (E2-315) was expressed and secreted from CHO cells. E2-315 was purified by affinity chromatography using a monoclonal antibody directed to a FLAG sequence genetically engineered onto the C terminus of the recombinant protein. The secreted protein had a molecular mass of(More)
The hepatitis C virus (HCV) may be an important cause of chronic liver disease in renal transplant recipients. We investigated retrospectively the incidence and outcome of HCV infection in long-term renal transplant recipients and patients on hemodialysis. Stored, pretransplant sera of transplant recipients with normal liver biochemistry at surgery were(More)
Serum and plasma samples were collected from blood donors who were confirmed positive for antibodies to HIV-1 in the United States, and from blood donors and individuals in West Africa and Portugal who were positive for antibodies to HIV-1, HIV-2, or both. Western blots and sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE)(More)
OBJECTIVE Markers of HIV disease progression such as soluble p24 antigen detection and CD4 lymphocyte depletion are most useful in the later stages of HIV disease and are relatively insensitive as therapeutic monitors. Flow cytometric detection of HIV-1 replication in CD4 lymphocytes was evaluated for use as a marker in predicting disease progression(More)
Peripheral blood mononuclear cells (MNC) from three chimpanzees infected with hepatitis C virus (HCV) and from two uninfected animals were analyzed by monoclonal antibody phenotyping using flow cytometry. Significant differences in numbers of MNC's expressing cluster designation (CD) phenotypes CD4, CD14, CD19, and CD45RA were found. Additionally,(More)
Mouse monoclonal antibodies directed against the transmembrane proteins of HIV-1 or HIV-2 provided site-directed, unambiguous discrimination between HIV-1 and HIV-2 antibody-positive sera, when employed in immunoassays as competitive probes against serum antibodies. These monoclonal antibodies mapped to epitopes outside of the well-characterized(More)