Hepatitis Virus Type Research Articles

Mouse hepatitis virus 3 pathogenicity expressed by a lytic viral infection in bone marrow 14.8+ mu+ B lymphocyte subpopulations.

Mouse hepatitis virus type 3 (MHV3) provides an excellent model for studying viral-B lymphocyte interaction in the immune system, which plays an important role in the outcome of an acute disease. Bone marrow B lymphocyte subpopulations, at various times postinfection, were studied in genetically C57BL/6 and resistant A/J mice, infected with pathogenic L2-MHV3 and its nonpathogenic variant, YAC-MHV3. B lineage cell subpopulations were identified by double immunofluorescence assays using mAb of terminal deoxynucleotidyl transferase, 14.8 and cytoplasmic (cu) or surface (su) Ig mu-chains. Results revealed diminished percentage and absolute number in the bone marrow 14.8+ mu+ B lymphocyte subpopulations, including pre-B (cu+ su-) and B (cu+ su+) cells of L2-MHV3-infected susceptible C57BL/6 mice; whereas, slight or no increase was evident in the cell subpopulations of L2-MHV3 infected resistant A/J mice or in YAC-MHV3 infected in both strains of mice. Abnormal large-sized forms of the 14.8+ mu+ cells occurred, at 48-h postinfection, in L2-MHV3-infected susceptible C57BL/6 mice only. In contrast, no change in the percentage and absolute number of precursor cells (terminal deoxynucleotidyl transferase positive) and pre pre-B cells (14.8+ mu-) were detected in all infected mice. In vitro L2-MHV3 infection of C57BL/6 bone marrow purified B lineage cell subpopulations showed that pre-B (cu+ su-) and B (cu+ su+) cells became abnormally large in size and depleted in number as a result of a productive and lytic viral replication. Low L2-MHV3 viral replication occurred in these cell subpopulations of A/J mice but no YAC-MHV3 virus was produced in the cells of both strains of mice. Pre pre-B (14.8+ mu-) cells in both strains were not permissive to L2-MHV3 or YAC-MHV3 viral replication. These results are discussed with regard to the role of humoral immunodeficiency in the pathogenic process.

A Major Role of Macrophage Activation by Interferon-Gamma during Mouse Hepatitis Virus Type 3 Infection. I. Genetically Dependent Resistance

Resistance of mice to mouse hepatitis virus type 3 (MHV3) infection is genetically determined. Normal adult A/J mice are resistant, and BALB/c mice are susceptible. Higher titers of virus and interferon (IFN) in vivo were found in MHV3-infected BALB/c mice compared with A/J mice. In vitro activation of macrophages (MФ) by lipopolysaccharide (LPS) delayed MHV3 replication only in cells that originated from A/J mice, although cell populations from both A/J, and BALB/c mice were able to synthesize comparable amounts of IFN-α/β. Using specific antibodies, we have shown that the delayed MHV3 replication in LPS-activated A/J MФ was due, in part, to IFN-α/β. A/J MФ were found to be more sensitive to IFN-γ than to IFN-α/β, and BALB/c MФ did not develop an antiviral state to either IFN. Cultured spleen cells from A/J mice synthesized more IFN-γ than BALB/c spleen cells after specific or non-specific stimulation. The results indicate that IFN-activated MФ may play a crucial role in the resistance to MHV3 infection. Since IFN-γ is produced in large amounts by A/J spleen cells after specific stimulation with MHV3 and is efficient in activating the A/J MФ, a T cell-dependent mechanism- is likely to be involved.

Aetiology and outcome of acute viral hepatitis in pregnancy

The aetiologic types of sporadic acute viral hepatitis in 169 pregnant women were compared with those of 70 non-pregnant women and 287 adult men. The majority of pregnant women (87.6%) came with acute hepatitis in the last trimester of pregnancy. Non-A, non-B (NANB) hepatitis accounted for 81.6% of hepatitis during pregnancy in comparison with 48.6% in non-pregnant women and 57.1% in adult men. Hepatitis A was extremely uncommon during pregnancy. Hepatitis B infection accounted for 17% of all cases in pregnant women compared with 45% in controls. Acute viral hepatitis in pregnancy had a poor outcome as assessed by maternal and/or fetal mortality (28.5%). The outcome was equally bad in hepatitis NANB and hepatitis B. Pregnant women generally had significantly lower immunoglobulin levels in comparison with non-pregnant women. In acute NANB hepatitis during pregnancy, serum IgG and IgM levels were lower and higher, respectively, compared with those in non-pregnant women and pregnant women with acute hepatitis B. It is suggested that an immune suppression during pregnancy might be responsible for increased susceptibility to acute NANB viral hepatitis, which, by itself, seems to induce only a transient acute phase IgM response.

Mouse hepatitis virus 3 replication in T and B lymphocytes correlate with viral pathogenicity.

Viral pathogenicity may be regulated by host defense mechanisms at the virus-immune cell interaction level. The immune system plays an important role in the outcome of acute disease induced by the mouse hepatitis virus type 3 (MHV3) virus. The lymphoid cells act as effectors in the virus elimination as well as targets for viral replication. In order to demonstrate a correlation between MHV3 pathogenicity and viral replication in lymphocytes, genetically-determined resistant A/J and susceptible C57BL/6 mice were infected with pathogenic (L2-MHV3) or nonpathogenic (YAC-MHV3) viral strains. Pathogenicity and histopathologic studies have revealed that lymphoid organs such as thymus and spleen, showed injuries or atrophy in susceptible mice infected with L2-MHV3. No histopathologic lesions in the lymphoid organs occurred in C57BL/6 mice infected with YAC-MHV3 or A/J mice infected with both viruses. The mechanisms involved in the lymphoid injuries were studied regarding viral replication in the lymphoid organs and cells in infected mice. Results indicate that cell depletion in lymphoid organs is caused by a complete viral replication in lymphoid cells. Thy1.2+ and surface IgM+ lymphoid cells from susceptible C57BL/6 mice infected with L2-MHV3 were permissive to viral replication and to subsequent cell lysis. No cell lysis, however, occurred in lymphoid cells from C57BL/6 mice infected with YAC-MHV3 and A/J mice infected with both virus strains. In vitro studies, with purified T and B cell populations were performed to determine the mechanism effecting susceptibility or resistance to viral-induced cell lysis occurring in such cells. A blockade, probably occurring at the viral RNA polymerase activity level, prevents viral replication in resistant cells between the stages of fixation of the virus at the cell-surface receptor and the viral protein translation. These experiments indicate that an intrinsic virus-specific resistant mechanism occurs in lymphoid cells that plays a major role in the viral pathogenicity.

Detection of markers for transfusion transmitted viruses

Presently, serological markers distinguish at least four types of viral hepatitis: hepatitis A, hepatitis B, delta hepatitis and non-A, non-B (NANB) hepatitis. Hepatitis A, previously called infectious hepatitis, is caused by the RNA hepatitis A virus (HAV). l Worldwide it is the most prevalent type of hepatitis, occurring endemically in many underdeveloped countries and in sporadic outbreaks in areas of low prevalence. Hepatitis A is spread by fecal-oral routes, although rare cases resulting from exposures to contaminated blood components have been reported. The serological markers for HAV infection are antibodies to HAV; IgM class for acute or recent infection, IgG class for past infection and immunity.* Hepatitis B, formerly called serum hepatitis, is caused by the DNA hepatitis B virus (HBV, originally recognized as the “Dane” particle).3 HBV has an inner core that contains the hepatitis B core antigen (HBcAg). Double-stranded DNA, DNA polymerase, and hepatitis B e antigen (HBeAg) are also present in the inner core. This inner core is surrounded by a surface lipoprotein coat detectable as the

Host Cell Resistance to Mouse Hepatitis Virus Type 3 Is Expressed In Vitro in Macrophages and Lymphocytes

Phenotypic expression of in vivo sensitivity to mouse hepatitis virus type 3 (MHV3) was studied in vitro in macrophages and lymphocytes. MHV3 infections were induced in peritoneal exudate (PE), nonadherent spleen (NAS) and thymus (THY) cells from resistant A/J, susceptible C57BL/6 or semisusceptible (C57BL/6xA/J)F1 mice. Differences in cytopathic effect, cell viability and virus titers were found only at 48 hrs postinfection (p.i.). "Carrier state" infections were performed at 48 hrs p.i. by transfer of supernatants of infected cells to newly collected cells originating from the same strain of mice. A passage-dependent restriction of viral replication was detected in vitro and was expressed in PE, NAS and THY cells as a recessive phenotype. No defective-interfering viral particles were involved in the restriction of viral replication. Results obtained with crossed infections and determination of the number of productively infected cells demonstrated that restriction of viral replication in macrophages and lymphoid cells from resistant A/J mice is controlled by a genetically-determined intrinsic cellular mechanism acting principally on the level of production of infectious viral particles by the infected cell.

Effect of sensitized T cell transfer on mouse hepatitis virus type 4 infection in athymic nude mice.

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Incidence and types of acute viral hepatitis in Newcastle upon Tyne.

The incidence and types of viral hepatitis in the city of Newcastle upon Tyne have been studied by serological analysis of (a) all blood samples sent to the virological laboratory for hepatitis testing and (b) all blood samples sent by general practitioners to the biochemical laboratory for liver function testing. The annual detection rate of acute viral hepatitis was found to be 31.5 cases/100,000 population, of which 9.1 were hepatitis B. Only three sporadic cases of non-A non-B hepatitis were identified. The incidence of hepatitis is at least four-fold greater than suggested by notification rates and may be substantially higher as general practitioners rarely requested laboratory confirmation of household contacts of index cases.

In vivo and in vitro models of demyelinating disease: efficiency of virus spread and formation of infectious centers among glial cells is genetically determined by the murine host.

Resistance or susceptibility of various mouse strains to central nervous system disease caused by different strains of coronavirus is well known. Data from the present study draw attention to an additional, genetically determined mechanism controlling CV infections. The resistance to A59 and JHM virus (JHMV) associated with SJL mice was maintained in explanted glial cultures which, by contrast, fully supported a productive infection by the serorelated mouse hepatitis virus type 3. A comparative analysis of the infectious process in glial cell explants from SJL and CD.1 mice helped to define the stage at which restriction is manifested. Cultures of oligodendrocytes and astrocytes from these strains of mice were challenged with JHMV or mouse hepatitis virus type 3, and cell-virus interactions were monitored, including adsorption, uptake of inoculum, transcription, and cell-to-cell dissemination. The sequence of early events from adsorption to genome activation occurred with about equal efficiency with both viruses and genetically different cells, indicating that SJL resistance is not due to any deficiency in specific receptors or penetration of the inoculum or general expression of viral functions. However, intercellular spread of the infection was restricted in SJL glial cells owing to an as yet undefined component. Since cells from (SJL x CD.1)F1 mice were fully susceptible to JHMV, resistance to virus spread must be due to a deficiency in some factor, perhaps a proteolytic activity necessary for dissemination.

Temperature-sensitive mutants of mouse hepatitis virus type 3 (MHV-3): isolation, biochemical and genetic characterization.

SummaryMouse hepatitis virus 3 (MHV-3) is highly hepatotropic in sensitive mice. Temperature-sensitive mutants (ts mutants) induced by N-methyl-N′-nitrosoguanidine and 5-fluorouracil were isolated. Twelve mutants which were able to induce the formation of syncytia at 33°C but not at the restrictive temperature (39.5°C) were selected for detailed study. No viral RNA synthesis was detected after infection at the restrictive temperature with six of the mutants (RNA−) whereas six others were RNA+, although they displayed RNA synthesis which was generally reduced. No differences have been detected in the size of the genome or the viral-intracellular RNA species found in wild type virus or ts mutant infected cells at permissive temperature. The pattern of virus-induced proteins analyzed after immunoprecipitation by SDS-PAGE was similar in wild type virus and RNA+ mutant infected cells at 39.5°C. Complementation experiments between ts mutants enabled us to distinguish five groups. Three of the groups contained RNA− mutants and two of them RNA+. Plaques made by mutants in one group displayed characteristic features that distinguished them from the wild type.

Spontaneous production of interleukin-2 and interleukin-3 by spleen cells from mice infected with mouse hepatitis virus type 4.

Spleen cells from mice, 4 to 60 days after infection with mouse hepatitis virus type 4, produced interleukin-2, as well as interleukin-3, in the absence of exogenous stimulants in vitro. This unique lymphokine production by mouse hepatitis virus type 4 infection was controlled by host genes.

Hepatic cytoprotection by prostaglandins: theories unlimited.

16,16 Dimethyl prostaglandin E2 (dmPGE2), a known cytoprotective agent, was examined for its ability to alter the course of fulminant hepatitis in an experimental model of fulminant viral hepatitis, murine hepatitis virus type 3 (MHV-3). Fully susceptible BALB/cJ mice, infected with 100 50% lethal doses (LD50) of MHV-3 developed histologic and biochemical evidence of fulminant hepatitis, as evidenced by massive hepatic necrosis with hypoglycemia, metabolic acidosis, and a markedly elevated serum alanine aminotransferase (ALT) (mean, 1,402 ± 619 IU/liter). In contrast, animals treated with dmPGE2 either before or after infection (up to 48 h) demonstrated a marked reduction in both histologic and biochemical evidence of liver damage as characterized by normal blood glucose, total CO2, and ALT determinations (mean ALT, 63 ± 40 IU/liter). Treatment of infected mice with PGF2 demonstrated no cytoprotective effects. High titers of infectious virus were recovered from the livers of both dmPGE2-treated and -untreated animals throughout the course of infection. In a parallel in vitro study, dmPGE2 (10−4-10−8 M) demonstrated a similar cytoprotective effect on monolayers of isolated cultured hepatocytes from fully susceptible BALB/cJ mice infected at a multiplicity of infection of 0.1, 1.0, and 10.0. In addition, splenic macrophages recovered from infected and untreated BALB/cJ mice demonstrated a marked augmentation in procoagulant activity (PCA) from a basal 10 ± 5 mU/106 splenic macrophages to a maximum of 615 ± 102 mU/106 splenic macrophages, whereas no increase in macrophage PCA was detected in infected animals treated with dmPGE2. These results suggest that dmPGE2, without detectably altering viral replication or infectivity in vivo, confers a marked cytoprotective effect on hepatocytes both in vivo and in vitro, and prevents the induction of macrophage PCA in vivo in fully susceptible BALB/cJ mice after murine hepatitis virus type 3 infection.

Duck viral hepatitis type 1 vaccination: Monitoring of the immune response with a microneutralisation test in pekin duck embryo kidney cell cultures

A microneutralisation test in Pekin duck embryo kidney cell cultures with attenuated duck hepatitis virus (DHV) type 1 is described for monitoring and evaluating the immune response following vaccination of Pekin ducks against duck hepatitis type 1. Serum samples from 19 flocks of commercial fattening ducks 7 to 8 weeks of age had no detectable antibodies. Breeding ducks experienced exposure to DHV type 1 during the growing period as evidenced by some positive reactions in the VN test. Two consecutive subcutaneous vaccinations prior to the first breeding season resulted in high, and in most cases, uniform titres against DHV with small standard deviations and mostly narrow 95% confidence limits of the respective mean values. Additional vaccinations prior to further breeding seasons did not result in augmentation of the humoral immune response.

16, 16 Dimethyl prostaglandin E2 prevents the development of fulminant hepatitis and blocks the induction of monocyte/macrophage procoagulant activity after murine hepatitis virus strain 3 infection.

16, 16 Dimethyl prostaglandin E2 (dmPGE2), a known cytoprotective agent, was examined for its ability to alter the course of fulminant hepatitis in an experimental model of fulminant viral hepatitis, murine hepatitis murine hepatitis type 3 (MHV-3). Fully susceptible BALB/cJ mice, infected with 100 50% lethal doses (LD50) of MHV-3 developed histologic and biochemical evidence of fulminant hepatitis, as evidenced by massive hepatic necrosis with hypoglycemia, metabolic acidosis, and a markedly elevated serum alanine aminotransferase (ALT) (mean, 1,402 +/- 619 IU/liter). In contrast, animals treated with dmPGE2 either before or after infection (up to 48 h) demonstrated a marked reduction in both histologic and biochemical evidence of liver damage as characterized by normal blood glucose, total CO2, and ALT determinations (mean ALT, 63 +/- 40 IU/liter). Treatment of infected mice with PGF2 alpha demonstrated no cytoprotective effects. High titers of infectious virus were recovered from the livers of both dmPGE2-treated and -untreated animals throughout the course of infection. In a parallel in vitro study, dmPGE2 (10(-4)-10(-8) M) demonstrated a similar cytoprotective effect on monolayers of isolated cultured hepatocytes from fully susceptible BALB/cJ mice infected at a multiplicity of infection of 0.1, 1.0, and 10.0. In addition, splenic macrophages recovered from infected and untreated BALB/cJ mice demonstrated a marked augmentation in procoagulant activity (PCA) from a basal 10 +/- 5 mU/10(6) splenic macrophages to a maximum of 615 +/- 102 mU/10(6) splenic macrophages, whereas no increase in macrophage PCA was detected in infected animals treated with dmPGE2. These results suggest that dmPGE2, without detectably altering viral replication or infectivity in vivo, confers a marked cytoprotective effect on hepatocytes both in vivo and in vitro, and prevents the induction of macrophage PCA in vivo in fully susceptible BALB/cJ mice after murine hepatitis virus type 3 infection.

Protection from mouse hepatitis virus type 3-induced acute disease by an anti-nucleoprotein monoclonal antibody. Brief report.

SummaryFusion of MHV-3-immune splenocytes from MHV-3-resistant A/J murine strain, with NS myeloma cells produced several hybridomas. Among eight hybridoma clones, the 1E7A4H1 clone secreted kappa IgG2a apparently directed against the nucleoprotein of the MHV-3 virion. The monoclonal antibody was able to neutralize the in vitro cytopathic effect of MHV-3 on cultured L2 cells, and was detected by indirect immuno-fluorescence on MHV-3-infected cultured YAC cells. In addition, it conferred a significant protection against MHV-3-induced acute disease, if injected intraperitoneally to C57BL/6 mice before inoculation with MHV-3.

The duck fatty kidney syndrome — An aspect of duck viral hepatitis

The duck fatty kidney syndrome accounted for mortalities of up to 30% on certain duck rearing farms in Britain from 1978 to 1983 and affected two distinct age groups of 1 to 2 and 4 to 6 weeks of age. Post mortem examinations revealed pale swollen kidneys and swollen mottled spleens. Histological examination of tissues suggested mild duck viral hepatitis, even though the birds were vaccinated against duck hepatitis virus type I and the older group was beyond the age at which age immunity to that disease usually develops. Studies on the pathogenesis of duck viral hepatitis suggested that the duck fatty kidney syndrome was a manifestation of that disease.

Characterization of a non-pathogenic MHV3 variant derived from a persistently infected lymphoid cell line.

Mouse hepatitis virus type 3 infection leads to various types of evolution according to strain, age and immune status of animals-1, 2. Three types of viral sensitivity were observed: resistance, full susceptibility and semisusceptibility. The latter is characterized by a chronic disease with occurrence of paralysis, immunodepression, and viral persistency since MHV3 can be recovered during the first three months postinfection in most animals from brain, liver, spleen and lymph nodes1. During the first four days of infection, virus was recovered from the liver of resistant as well as susceptible strain mice. In resistant A/J strain mice, viral titers were consistently low whereas titers greater than 104 were always found in susceptible C57BL/6 animals. In the resistant mouse strain, virus was cleared from liver, brain and serum within seven days. In contrast, virus continued to replicate until death in susceptible animals. Immunosuppressive treatment, however, can abogate the resistance displayed by adult A/J mice, leading to an acute disease and to death. Protection of susceptible newborn mice against MHV3 infection requires the transfer of several cell populations originating from syngenic adult donors: adherent spleen cells, T lymphocytes and a third population present in the non-adherent spleen cell fraction as well as in peritoneal exudate and in bone marrow cells2, 3. Resistance to the acute disease was also correlated with viral replication in hepatocytes4, in embryonic fibroblasts5 and in peritoneal exudate cells2, 6, 7. Recent work suggested that at least two complementary mechanisms were required to confer resistance to MHV3: resistance genes operating at the macrophage level and cells capable to elicit an efficient immune response8.

Prostaglandin E2 (PGE2) alters the pathogenesis of MHV-3 infection in susceptible BALB/cJ mice.

Murine hepatitis virus type 3 (MHV-3) produces a strain dependent pattern of disease in inbred strains of mice. Balb/cJ mice develop fulminant hepatitis following MHV-3 infection.1. Direct viral cytopathic effects do not account for the full spectrum of the disease and it appears that host immune factors are important in the pathogenesis of the disease. We have previously demonstrated that the induction of a specific macrophage protease (procoagulant activity (PCA)) correlates directly with susceptibility to disease and that it is responsible for disturbances in the microcirculation characterized by microthrombi, vasculitis, thrombosis and cellular necrosis.2. Little attention has been devoted to the effects of prostaglandins on viral infections. These studies were undertaken to examine the effect of 16, 16 dimethyl prostaglandin E2 on an experimental animal model of viral hepatitis.KeywordsHepatitis VirusInbred StrainCytopathic EffectProcoagulant ActivityMount Sinai HospitalThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Association of human hepatocellular membrane fusions with non-A, non-B hepatitis.

Liver biopsies from patients with alcoholic hepatitis, chemical hepatitis, or viral hepatitis types A, B, or non-A, non-B were examined by electron microscopy. Circular, fused, cytoplasmic membranes were observed in hepatocytes of 17% of patients with hepatitis type B and 92% of patients with hepatitis type non-A, non-B. The membrane alterations were not observed in hepatocytes of patients with the other types of hepatitis. The greater frequency of altered cytoplasmic membranes in hepatocytes of patients with non-A, non-B hepatitis was shown to be statistically significant (p less than 0.05) when compared to that in patients with viral hepatitis type B.

A histological study of hepatitis delta virus liver disease.

The histopathology of hepatitis delta virus disease was studied in carriers of HBsAg with chronic hepatitis delta antigen-positive hepatitis and in serial biopsies of patients with acute hepatitis delta virus hepatitis that progressed to chronicity. There was no histologic feature distinctive of hepatitis delta virus from other types of viral hepatitis. Biopsy specimens of patients with chronic disease exhibited portal and periportal inflammation with piecemeal necrosis, conforming to a picture of aggressive hepatitis often accompanied by cirrhosis. Characteristic was a marked intralobular infiltration by mononuclear cells and a degenerative eosinophilic change of the hepatocytic cytoplasms conducive to the formation of acidophilic bodies. Liver specimens from patients with hepatitis delta virus hepatitis exhibited aspects of focal, confluent and bridging necrosis. The disease progressed to chronicity irrespective of the original histological features. The expression of intrahepatic hepatitis delta antigen was reduced in the phase of the acute hepatitis but increased in parallel with the development of chronic active liver disease. In late-stage cirrhosis, expression of hepatitis delta antigen was usually low.