The Experts below are selected from a list of 215259 Experts worldwide ranked by ideXlab platform
John L Gerin - One of the best experts on this subject based on the ideXlab platform.
-
immunosuppression reactivates viral replication long after resolution of woodchuck Hepatitis Virus infection
Hepatology, 2007Co-Authors: Stephan Menne, Scott D Butler, Illia A Toshkov, Paul J. Cote, John L GerinAbstract:Resolution of Hepatitis B Virus (HBV) infection is characterized by coordinated humoral and cellular immune responses. Immunity is durable over decades, protecting the host from reinfection and potential activation of residual HBV. Woodchucks infected at birth with woodchuck Hepatitis Virus (WHV) cleared viremia and developed antibodies to surface antigen (anti-WHs). Woodchucks became seronegative for anti-WHs 3-6 years later, but in some, WHV DNA was detected in serum, liver, and/or peripheral blood mononuclear cells (PBMCs). Those with WHV DNA had increased in vitro cellular immune responses to viral antigens, CD4 and CD8 markers, and Th1-type cytokines, suggesting active WHV-specific T lymphocytes. Immunosuppression for 12 weeks using cyclosporine A in such woodchucks resulted in transient reactivation of WHV replication. Serum of 1 woodchuck that became positive for WHV DNA during immunosuppression was inoculated into WHV-susceptible woodchucks, and a productive infection was demonstrated. The results indicate that after infection durable cellular immunity to WHV is essential for the long-term control of viral replication and is probably maintained by continuous priming from residual Virus. Conclusion: These experimental observations demonstrate the potential of immunosuppression to reactivate HBV after resolution of infection. (HEPATOLOGY 2007;45:614–622.)
-
antiviral activities of oral 1 o hexadecylpropanediol 3 phosphoacyclovir and acyclovir in woodchucks with chronic woodchuck Hepatitis Virus infection
Antimicrobial Agents and Chemotherapy, 2000Co-Authors: Karl Y. Hostetler, William E. Hornbuckle, John L Gerin, James R Beadle, Christine A Bellezza, Ilia A Tochkov, Paul J. Cote, Brent E KorbaAbstract:Acyclovir triphosphate is a potent inhibitor of Hepatitis B Virus DNA polymerase, but acyclovir treatment provides no benefit in patients with Hepatitis B Virus infection. This is due in part to the fact that Hepatitis B Virus, unlike herpes simplex Virus, does not code for a viral thymidine kinase which catalyzes the initial phosphorylation of acyclovir. We synthesized 1-O-octadecyl-sn-glycero-3-phospho (3-P)-acyclovir and found that it was highly active in reducing Hepatitis B Virus replication in 2.2.15 cells, while acyclovir was inactive. The greater antiviral activity of 1-O-octadecyl-sn-glycero-3-P-acyclovir appeared to be due to liver cell metabolism of the compound to acyclovir monophosphate (K. Y. Hostetler et al., Biochem. Pharmacol. 53:1815–1822, 1997). However, a closely related compound without a hydroxyl group at the sn-2 position of glycerol, 1-O-hexadecylpropanediol-3-P-acyclovir, was more active and selective in 2.2.15 cells in vitro. In this study, we treated woodchucks chronically infected with woodchuck Hepatitis Virus with increasing oral doses of 1-O-hexadecylpropanediol-3-P-acyclovir and assessed the response to therapy versus acyclovir or a placebo. At a dosage of 10 mg/kg of body weight twice a day, the test compound significantly inhibited viral replication in vivo, as indicated by a 95% reduction in serum woodchuck Hepatitis Virus DNA levels and by a 54% reduction in levels of woodchuck Hepatitis Virus replicative intermediates in the liver. Higher doses were somewhat less effective. In contrast, 20 mg of acyclovir/kg twice daily, a 5.3-fold-higher molar dosage, had no demonstrable activity against woodchuck Hepatitis Virus. Oral 1-O-hexadecylpropanediol-3-P-acyclovir appeared to be safe and effective in chronic woodchuck Hepatitis Virus infection.
-
titration of recombinant woodchuck Hepatitis Virus dna in adult woodchucks
Journal of Medical Virology, 1998Co-Authors: Hongshu Chen, William E. Hornbuckle, Paul J. Cote, John L GerinAbstract:In vivo transfection of Eastern woodchucks (Marmota monax) with recombinant woodchuck Hepatitis Virus (WHV) DNA is effective in inducing Virus infection for the study of replication, pathogenicity, and oncogenicity of wild-type and mutated WHV. The one drawback to this procedure is the need for preparation of large amounts of WHV DNA. Reduction of the amount of WHV DNA in the transfection protocol necessary to induce infection would save considerable time and resources. Therefore, we conducted a titration of WHV DNA, ranging from 50 μg to 50 pg of DNA, in adult woodchucks to determine the minimum infectious dose of recombinant WHV DNA. As little as 50 ng of transfected WHV DNA induced productive infection in adult woodchucks. Thus, transfection with large amounts of recombinant WHV DNA appears to be unnecessary. J. Med. Virol. 54:92–94, 1998. © 1998 Wiley-Liss,Inc.
-
Titration of recombinant woodchuck Hepatitis Virus DNA in adult woodchucks
Journal of medical virology, 1998Co-Authors: Hongshu Chen, William E. Hornbuckle, Paul J. Cote, John L GerinAbstract:In vivo transfection of Eastern woodchucks (Marmota monax) with recombinant woodchuck Hepatitis Virus (WHV) DNA is effective in inducing Virus infection for the study of replication, pathogenicity, and oncogenicity of wild-type and mutated WHV. The one drawback to this procedure is the need for preparation of large amounts of WHV DNA. Reduction of the amount of WHV DNA in the transfection protocol necessary to induce infection would save considerable time and resources. Therefore, we conducted a titration of WHV DNA, ranging from 50 micrograms to 50 pg of DNA, in adult woodchucks to determine the minimum infectious dose of recombinant WHV DNA. As little as 50 ng of transfected WHV DNA induced productive infection in adult woodchucks. Thus, transfection with large amounts of recombinant WHV DNA appears to be unnecessary.
-
hepatic expression of the woodchuck Hepatitis Virus x antigen during acute and chronic infection and detection of a woodchuck Hepatitis Virus x antigen antibody response
Hepatology, 1997Co-Authors: James R Jacob, Carol A Roneker, Mary Ascenzi, Illia A Toshkov, P. J. Cote, John L GerinAbstract:Abstract The expression and localization of the woodchuck Hepatitis Virus X-antigen (WHxAg) was examined and compared with other markers of a woodchuck Hepatitis Virus (WHV) infection using rabbit antisera generated against recombinant WHxAg produced in bacteria. Cellular fractionation studies showed that WHxAg was localized to the soluble and cytoskeletal fractions of the cell when assayed by immunoprecipitation of [ 35 S]-met-cys labeled extracts derived from primary cultures of acute WHV-infected hepatocytes. Immunohistochemical examination of liver from chronic WHV-infected animals showed WHV core antigen (WHcAg) and WHxAg expression in non-neoplastic tissue. The WHxAg was found localized to the cytoplasm of infected cells, similar to WHcAg. WHxAg expression was diminished in the foci of altered hepatocytes and in hepatocellular adenomas but was found in only 1 of 11 hepatocellular carcinomas (HCC). Hepatic biopsies from woodchucks experimentally inoculated with WHV were examined during the acute phase of infection and during convalescence for WHcAg and WHxAg expression by immunohistochemistry. Concurrent expression of WHcAg and WHxAg was observed during the viremic phase of infection. The two antigens exhibited similar localization to the cell cytoplasm, similar distribution within the liver lobule, and similar patterns of clearance during convalescence. An immune response to WHxAg was documented in some woodchucks following acute WHV infection. These studies further define the woodchuck model of HBV infection and should allow for the investigation of the role of hepadnaviral X-antigen expression in the pathogenesis of chronic Hepatitis and HCC. (Hepatology 1997 Dec;26(6):1607-15)
Paul J. Cote - One of the best experts on this subject based on the ideXlab platform.
-
Serologic Survey of Woodchuck Hepatitis Virus in North Carolina Woodchucks (Marmota monax)
Journal of Zoo and Wildlife Medicine, 2008Co-Authors: John M. Cullen, D. Lindsey-pegram, Paul J. CoteAbstract:Abstract The prevalence of woodchuck Hepatitis Virus (WHV) in wild populations of woodchucks is understudied and therefore unclear. Although infection is common in the southeastern region of Pennsylvania and surrounding states, it is virtually absent in New York and New England. Sera were collected from wild woodchucks from Orange County, North Carolina and tested for the presence of markers of current or previous infection with WHV. Of the 24 woodchucks tested, there were three animals (12.5%) with WHV surface antigen as well as antibodies to woodchuck Hepatitis core antigen in their serum, indicative of active infection. There were four (17%) animals with antibodies to WHV core antigen but no woodchuck Hepatitis surface antigen, indicative of prior infections. The remaining 17 animals had no detectable markers of WHV infection. These data indicate that WHV is present in central North Carolina at rates approaching those seen in endemic areas, such as the mid-Atlantic region of the United States.
-
immunosuppression reactivates viral replication long after resolution of woodchuck Hepatitis Virus infection
Hepatology, 2007Co-Authors: Stephan Menne, Scott D Butler, Illia A Toshkov, Paul J. Cote, John L GerinAbstract:Resolution of Hepatitis B Virus (HBV) infection is characterized by coordinated humoral and cellular immune responses. Immunity is durable over decades, protecting the host from reinfection and potential activation of residual HBV. Woodchucks infected at birth with woodchuck Hepatitis Virus (WHV) cleared viremia and developed antibodies to surface antigen (anti-WHs). Woodchucks became seronegative for anti-WHs 3-6 years later, but in some, WHV DNA was detected in serum, liver, and/or peripheral blood mononuclear cells (PBMCs). Those with WHV DNA had increased in vitro cellular immune responses to viral antigens, CD4 and CD8 markers, and Th1-type cytokines, suggesting active WHV-specific T lymphocytes. Immunosuppression for 12 weeks using cyclosporine A in such woodchucks resulted in transient reactivation of WHV replication. Serum of 1 woodchuck that became positive for WHV DNA during immunosuppression was inoculated into WHV-susceptible woodchucks, and a productive infection was demonstrated. The results indicate that after infection durable cellular immunity to WHV is essential for the long-term control of viral replication and is probably maintained by continuous priming from residual Virus. Conclusion: These experimental observations demonstrate the potential of immunosuppression to reactivate HBV after resolution of infection. (HEPATOLOGY 2007;45:614–622.)
-
antiviral activities of oral 1 o hexadecylpropanediol 3 phosphoacyclovir and acyclovir in woodchucks with chronic woodchuck Hepatitis Virus infection
Antimicrobial Agents and Chemotherapy, 2000Co-Authors: Karl Y. Hostetler, William E. Hornbuckle, John L Gerin, James R Beadle, Christine A Bellezza, Ilia A Tochkov, Paul J. Cote, Brent E KorbaAbstract:Acyclovir triphosphate is a potent inhibitor of Hepatitis B Virus DNA polymerase, but acyclovir treatment provides no benefit in patients with Hepatitis B Virus infection. This is due in part to the fact that Hepatitis B Virus, unlike herpes simplex Virus, does not code for a viral thymidine kinase which catalyzes the initial phosphorylation of acyclovir. We synthesized 1-O-octadecyl-sn-glycero-3-phospho (3-P)-acyclovir and found that it was highly active in reducing Hepatitis B Virus replication in 2.2.15 cells, while acyclovir was inactive. The greater antiviral activity of 1-O-octadecyl-sn-glycero-3-P-acyclovir appeared to be due to liver cell metabolism of the compound to acyclovir monophosphate (K. Y. Hostetler et al., Biochem. Pharmacol. 53:1815–1822, 1997). However, a closely related compound without a hydroxyl group at the sn-2 position of glycerol, 1-O-hexadecylpropanediol-3-P-acyclovir, was more active and selective in 2.2.15 cells in vitro. In this study, we treated woodchucks chronically infected with woodchuck Hepatitis Virus with increasing oral doses of 1-O-hexadecylpropanediol-3-P-acyclovir and assessed the response to therapy versus acyclovir or a placebo. At a dosage of 10 mg/kg of body weight twice a day, the test compound significantly inhibited viral replication in vivo, as indicated by a 95% reduction in serum woodchuck Hepatitis Virus DNA levels and by a 54% reduction in levels of woodchuck Hepatitis Virus replicative intermediates in the liver. Higher doses were somewhat less effective. In contrast, 20 mg of acyclovir/kg twice daily, a 5.3-fold-higher molar dosage, had no demonstrable activity against woodchuck Hepatitis Virus. Oral 1-O-hexadecylpropanediol-3-P-acyclovir appeared to be safe and effective in chronic woodchuck Hepatitis Virus infection.
-
titration of recombinant woodchuck Hepatitis Virus dna in adult woodchucks
Journal of Medical Virology, 1998Co-Authors: Hongshu Chen, William E. Hornbuckle, Paul J. Cote, John L GerinAbstract:In vivo transfection of Eastern woodchucks (Marmota monax) with recombinant woodchuck Hepatitis Virus (WHV) DNA is effective in inducing Virus infection for the study of replication, pathogenicity, and oncogenicity of wild-type and mutated WHV. The one drawback to this procedure is the need for preparation of large amounts of WHV DNA. Reduction of the amount of WHV DNA in the transfection protocol necessary to induce infection would save considerable time and resources. Therefore, we conducted a titration of WHV DNA, ranging from 50 μg to 50 pg of DNA, in adult woodchucks to determine the minimum infectious dose of recombinant WHV DNA. As little as 50 ng of transfected WHV DNA induced productive infection in adult woodchucks. Thus, transfection with large amounts of recombinant WHV DNA appears to be unnecessary. J. Med. Virol. 54:92–94, 1998. © 1998 Wiley-Liss,Inc.
-
Titration of recombinant woodchuck Hepatitis Virus DNA in adult woodchucks
Journal of medical virology, 1998Co-Authors: Hongshu Chen, William E. Hornbuckle, Paul J. Cote, John L GerinAbstract:In vivo transfection of Eastern woodchucks (Marmota monax) with recombinant woodchuck Hepatitis Virus (WHV) DNA is effective in inducing Virus infection for the study of replication, pathogenicity, and oncogenicity of wild-type and mutated WHV. The one drawback to this procedure is the need for preparation of large amounts of WHV DNA. Reduction of the amount of WHV DNA in the transfection protocol necessary to induce infection would save considerable time and resources. Therefore, we conducted a titration of WHV DNA, ranging from 50 micrograms to 50 pg of DNA, in adult woodchucks to determine the minimum infectious dose of recombinant WHV DNA. As little as 50 ng of transfected WHV DNA induced productive infection in adult woodchucks. Thus, transfection with large amounts of recombinant WHV DNA appears to be unnecessary.
Susan R. Weiss - One of the best experts on this subject based on the ideXlab platform.
-
murine Hepatitis Virus nsp14 exoribonuclease activity is required for resistance to innate immunity
Journal of Virology, 2018Co-Authors: James Brett Case, Susan R. Weiss, Nicole R. Sexton, Ruth Elliott, Kevin W Graepel, Everett Clinton Smith, Mark R. DenisonAbstract:CoronaViruses (CoVs) are positive-sense RNA Viruses that infect numerous mammalian and avian species and are capable of causing severe and lethal disease in humans. CoVs encode several innate immune antagonists that counteract the host innate immune response to facilitate efficient viral replication. CoV nonstructural protein 14 (nsp14) encodes 3'-to-5' exoribonuclease activity (ExoN), which performs a proofreading function and is required for high-fidelity replication. Outside of the order Nidovirales, arenaViruses are the only RNA Viruses that encode an ExoN, which functions to degrade double-stranded RNA (dsRNA) replication intermediates. In this study, we tested the hypothesis that CoV ExoN also functions to antagonize the innate immune response. We demonstrate that Viruses lacking ExoN activity [ExoN(-)] are sensitive to cellular pretreatment with interferon beta (IFN-β) in a dose-dependent manner. In addition, ExoN(-) Virus replication was attenuated in wild-type bone marrow-derived macrophages (BMMs) and partially restored in interferon alpha/beta receptor-deficient (IFNAR-/-) BMMs. ExoN(-) Virus replication did not result in IFN-β gene expression, and in the presence of an IFN-β-mediated antiviral state, ExoN(-) viral RNA levels were not substantially reduced relative to those of untreated samples. However, ExoN(-) Virus generated from IFN-β-pretreated cells had reduced specific infectivity and decreased relative fitness, suggesting that ExoN(-) Virus generated during an antiviral state is less viable to establish a subsequent infection. Overall, our data suggest murine Hepatitis Virus (MHV) ExoN activity is required for resistance to the innate immune response, and antiviral mechanisms affecting the viral RNA sequence and/or an RNA modification act on Viruses lacking ExoN activity.IMPORTANCE CoVs encode multiple antagonists that prevent or disrupt an efficient innate immune response. Additionally, no specific antiviral therapies or vaccines currently exist for human CoV infections. Therefore, the study of CoV innate immune antagonists is essential for understanding how CoVs overcome host defenses and to maximize potential therapeutic interventions. Here, we sought to determine the contributions of nsp14 ExoN activity in the induction of and resistance to the innate immune response. We show that Viruses lacking nsp14 ExoN activity are more sensitive than wild-type MHV to restriction by exogenous IFN-β and that Viruses produced in the presence of an antiviral state are less capable of establishing a subsequent viral infection. Our results support the hypothesis that murine Hepatitis Virus ExoN activity is required for resistance to the innate immune response.
-
crystal structure of the mouse Hepatitis Virus ns2 phosphodiesterase domain that antagonizes rnase l activation
Journal of General Virology, 2016Co-Authors: Baokun Sui, Susan R. Weiss, Junhua Huang, Babal K Jha, Ping Yin, Ming Zhou, Robert H Silverman, Guiqing Peng, Ling ZhaoAbstract:Prior studies have demonstrated that the mouse Hepatitis Virus (MHV) A59 strain ns2 protein is a member of the 2H phosphoesterase family and exhibits 2′,5′-phosphodiesterase (PDE) activity. During the IFN antiviral response, ns2 cleaves 2′,5′-oligoadenylate (2-5A), a key mediator of RNase L activation, thereby subverting the activation of RNase L and evading host innate immunity. However, the mechanism of 2-5A cleavage by ns2 remains unclear. Here, we present the crystal structure of the MHV ns2 PDE domain and demonstrate a PDE fold similar to that of the cellular protein, a kinase anchoring protein 7 central domain (AKAP7CD) and rotaVirus VP3 carboxy-terminal domain. The structure displays a pair of strictly conserved HxT/Sx motifs and forms a deep, positively charged catalytic groove with β-sheets and an arginine-containing loop. These findings provide insight into the structural basis for 2-5A binding of MHV ns2.
-
murine Hepatitis Virus a model for Virus induced cns demyelination
Journal of NeuroVirology, 2002Co-Authors: Amy E Matthews, Susan R. Weiss, Yvonne PatersonAbstract:Most murine Hepatitis Virus (MHV) strains, as their name suggests, infect the liver. However, several murine strains are tropic for the central nervous system (CNS) and cause encephalitis with subsequent CNS demyelination. The CNS demyelination shares pathological similarities with human CNS demyelinating diseases such as multiple sclerosis (MS). These Viruses are, therefore, used to study the role of the immune system in viral clearance from the CNS, in CNS demyelination, and in remyelination. Nevertheless, it is still unclear exactly how MHV induces demyelination and to what extent the immune system plays a role in this pathology. Here we review this field in the context of the immune response to MHV in the liver and the CNS focusing on studies that have been published in the past 5 years.
-
antibody is required for clearance of infectious murine Hepatitis Virus a59 from the central nervous system but not the liver
Journal of Immunology, 2001Co-Authors: Amy E Matthews, Susan R. Weiss, James L Gombold, Mark J Shlomchik, Lynn G Hannum, Yvonne PatersonAbstract:Intracerebral inoculation with mouse Hepatitis Virus strain A59 results in viral replication in the CNS and liver. To investigate whether B cells are important for controlling mouse Hepatitis Virus strain A59 infection, we infected muMT mice who lack membrane-bound IgM and therefore mature B lymphocytes. Infectious Virus peaked and was cleared from the livers of muMT and wild-type mice. However, while Virus was cleared from the CNS of wild-type mice, Virus persisted in the CNS of muMT mice. To determine how B cells mediate viral clearance, we first assessed CD4 + T cell activation in the absence of B cells as APC. CD4 + T cells express wild-type levels of CD69 after infection in muMT mice. IFN-γ production in response to viral Ag in muMT mice was also normal during acute infection, but was decreased 31 days postinfection compared with that in wild-type mice. The role of Ab in viral clearance was also assessed. In wild-type mice plasma cells appeared in the CNS around the time that Virus is cleared. The muMT mice that received A59-specific Ab had decreased Virus, while mice with B cells deficient in Ab secretion did not clear Virus from the CNS. Viral persistence was not detected in FcR or complement knockout mice. These data suggest that clearance of infectious mouse Hepatitis Virus strain A59 from the CNS requires Ab production and perhaps B cell support of T cells; however, Virus is cleared from the liver without the involvement of Abs or B cells.
-
demyelination determinants map to the spike glycoprotein gene of coronaVirus mouse Hepatitis Virus
Journal of Virology, 2000Co-Authors: Jayasri Das Sarma, Susan R. Weiss, Jean Tsai, Ehud LaviAbstract:Demyelination is the pathologic hallmark of the human immune-mediated neurologic disease multiple sclerosis, which may be triggered or exacerbated by viral infections. Several experimental animal models have been developed to study the mechanism of Virus-induced demyelination, including coronaVirus mouse Hepatitis Virus (MHV) infection in mice. The envelope spike (S) glycoprotein of MHV contains determinants of properties essential for Virus-host interactions. However, the molecular determinants of MHV-induced demyelination are still unknown. To investigate the mechanism of MHV-induced demyelination, we examined whether the S gene of MHV contains determinants of demyelination and whether demyelination is linked to viral persistence. Using targeted RNA recombination, we replaced the S gene of a demyelinating Virus (MHV-A59) with the S gene of a closely related, nondemyelinating Virus (MHV-2). Recombinant Viruses containing an S gene derived from MHV-2 in an MHV-A59 background (Penn98-1 and Penn98-2) exhibited a persistence-positive, demyelination-negative phenotype. Thus, determinants of demyelination map to the S gene of MHV. Furthermore, viral persistence is insufficient to induce demyelination, although it may be a prerequisite for the development of demyelination.
Taiki Higashimoto - One of the best experts on this subject based on the ideXlab platform.
-
the woodchuck Hepatitis Virus post transcriptional regulatory element reduces readthrough transcription from retroviral vectors
Gene Therapy, 2007Co-Authors: Taiki Higashimoto, Fabrizia Urbinati, Ajay Perumbeti, A Zarzuela, Lung Ji Chang, Donald B Kohn, G Jiang, Punam MalikAbstract:The woodchuck Hepatitis Virus post-transcriptional regulatory element reduces readthrough transcription from retroviral vectors
William E. Hornbuckle - One of the best experts on this subject based on the ideXlab platform.
-
antiviral activities of oral 1 o hexadecylpropanediol 3 phosphoacyclovir and acyclovir in woodchucks with chronic woodchuck Hepatitis Virus infection
Antimicrobial Agents and Chemotherapy, 2000Co-Authors: Karl Y. Hostetler, William E. Hornbuckle, John L Gerin, James R Beadle, Christine A Bellezza, Ilia A Tochkov, Paul J. Cote, Brent E KorbaAbstract:Acyclovir triphosphate is a potent inhibitor of Hepatitis B Virus DNA polymerase, but acyclovir treatment provides no benefit in patients with Hepatitis B Virus infection. This is due in part to the fact that Hepatitis B Virus, unlike herpes simplex Virus, does not code for a viral thymidine kinase which catalyzes the initial phosphorylation of acyclovir. We synthesized 1-O-octadecyl-sn-glycero-3-phospho (3-P)-acyclovir and found that it was highly active in reducing Hepatitis B Virus replication in 2.2.15 cells, while acyclovir was inactive. The greater antiviral activity of 1-O-octadecyl-sn-glycero-3-P-acyclovir appeared to be due to liver cell metabolism of the compound to acyclovir monophosphate (K. Y. Hostetler et al., Biochem. Pharmacol. 53:1815–1822, 1997). However, a closely related compound without a hydroxyl group at the sn-2 position of glycerol, 1-O-hexadecylpropanediol-3-P-acyclovir, was more active and selective in 2.2.15 cells in vitro. In this study, we treated woodchucks chronically infected with woodchuck Hepatitis Virus with increasing oral doses of 1-O-hexadecylpropanediol-3-P-acyclovir and assessed the response to therapy versus acyclovir or a placebo. At a dosage of 10 mg/kg of body weight twice a day, the test compound significantly inhibited viral replication in vivo, as indicated by a 95% reduction in serum woodchuck Hepatitis Virus DNA levels and by a 54% reduction in levels of woodchuck Hepatitis Virus replicative intermediates in the liver. Higher doses were somewhat less effective. In contrast, 20 mg of acyclovir/kg twice daily, a 5.3-fold-higher molar dosage, had no demonstrable activity against woodchuck Hepatitis Virus. Oral 1-O-hexadecylpropanediol-3-P-acyclovir appeared to be safe and effective in chronic woodchuck Hepatitis Virus infection.
-
titration of recombinant woodchuck Hepatitis Virus dna in adult woodchucks
Journal of Medical Virology, 1998Co-Authors: Hongshu Chen, William E. Hornbuckle, Paul J. Cote, John L GerinAbstract:In vivo transfection of Eastern woodchucks (Marmota monax) with recombinant woodchuck Hepatitis Virus (WHV) DNA is effective in inducing Virus infection for the study of replication, pathogenicity, and oncogenicity of wild-type and mutated WHV. The one drawback to this procedure is the need for preparation of large amounts of WHV DNA. Reduction of the amount of WHV DNA in the transfection protocol necessary to induce infection would save considerable time and resources. Therefore, we conducted a titration of WHV DNA, ranging from 50 μg to 50 pg of DNA, in adult woodchucks to determine the minimum infectious dose of recombinant WHV DNA. As little as 50 ng of transfected WHV DNA induced productive infection in adult woodchucks. Thus, transfection with large amounts of recombinant WHV DNA appears to be unnecessary. J. Med. Virol. 54:92–94, 1998. © 1998 Wiley-Liss,Inc.
-
Titration of recombinant woodchuck Hepatitis Virus DNA in adult woodchucks
Journal of medical virology, 1998Co-Authors: Hongshu Chen, William E. Hornbuckle, Paul J. Cote, John L GerinAbstract:In vivo transfection of Eastern woodchucks (Marmota monax) with recombinant woodchuck Hepatitis Virus (WHV) DNA is effective in inducing Virus infection for the study of replication, pathogenicity, and oncogenicity of wild-type and mutated WHV. The one drawback to this procedure is the need for preparation of large amounts of WHV DNA. Reduction of the amount of WHV DNA in the transfection protocol necessary to induce infection would save considerable time and resources. Therefore, we conducted a titration of WHV DNA, ranging from 50 micrograms to 50 pg of DNA, in adult woodchucks to determine the minimum infectious dose of recombinant WHV DNA. As little as 50 ng of transfected WHV DNA induced productive infection in adult woodchucks. Thus, transfection with large amounts of recombinant WHV DNA appears to be unnecessary.
-
Immunopathology of glomerulonephritis associated with chronic woodchuck Hepatitis Virus infection in woodchucks (Marmota monax).
American Journal of Pathology, 1992Co-Authors: D. N. Peters, William E. Hornbuckle, H Steinberg, Gerin Jl, Wayne I Anderson, Paul J. Cote, R.m. LewisAbstract:Abstract Retrospective analysis of necropsy findings of 705 woodchucks was performed to determine the prevalence and morphology of immune-mediated glomerulonephritis, its relationship to woodchuck Hepatitis Virus (WHV) infection, and the presence of major WHV antigens. Twenty-six woodchucks had glomerular lesions. Renal tissue of the 26 animals was evaluated histologically and immunohistochemically for immune-mediated glomerulonephritis. Of these 26 animals, immune-mediated glomerulonephritis was diagnosed in six, all of which were chronic WHV carriers. Membranous glomerulonephritis was identified in three animals, two of which also had mesangial proliferation. Host immunoglobulin was present within the mesangium and along capillary loops in all three. Woodchuck Hepatitis Virus core antigen (WHcAg) was present along capillary loops of two of these animals, one membranous and one mixed, and in the mesangium of all three. Woodchuck Hepatitis Virus surface antigen (WHsAg) deposition was similar to WHcAg deposition but was only present along capillaries in those animals with mixed nephritis. The remaining three animals had mesangial proliferation. WHsAg and host immunoglobulin deposition were predominately mesangial; WHcAg was not detected. Transmission electron microscopy showed thickening of the capillary loop basement membranes and subepithelial electron-dense deposits in animal one, and deposits in the mesangium in animal six.