Antigens of hepatitis delta virus in the liver and serum of humans and animals.
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Animals↗
Biomedical subjects
J L Gerin
Publications and source records attributed to J L Gerin.
Significance of IgM antibody to hepatitis B core antigen in a Greek population with chronic hepatitis B virus infection.
IgM antibody to hepatitis B core antigen (IgM anti-HBc) may indicate an active immune response to persistent infection with hepatitis B virus (HBV). We studied 186 Greek HBsAg carriers for IgM anti-HBc and attempted to correlate it with other HBV and hepatitis delta virus (HDV) markers. Overall, IgM anti-HBc was detected more frequently than HBV DNA in this population (50% vs 34, p less than 0.001); this was also true for the 149 of the 186 HBsAg carriers with antibody to hepatitis B e antigen (anti-HBe) (48% vs 22%, p less than 0.001). The opposite was found in the carriers positive for hepatitis B e antigen (HBeAg): HBV DNA was observed in 93% and IgM anti-HBc in 64% of the cases (p less than 0.05). The detection of these markers was independent of sex. Serum alanine aminotransferase (ALT) levels were significantly more elevated in patients with positive tests for IgM anti-HBc and HBV DNA than in patients positive only for HBV DNA (p less than 0.001) irrespective of their HBeAg or anti-HBe status. Moreover, the detection of elevated ALT was independent of the intensity of the HBV DNA hybridization signal. Antibodies to hepatitis delta antigen (HDAg) were only found in 4 (2.4%) of 167 patients tested.
Adult↗
Hepadnavirus infection of peripheral blood lymphocytes in vivo: woodchuck and chimpanzee models of viral hepatitis.
The peripheral blood lymphocytes (PBL) of five hepatitis B virus (HBV)-infected chimpanzees and 17 woodchuck hepatitis virus (WHV)-infected woodchucks were examined for the presence of viral DNA and RNA. HBV DNA was detected in the PBL of three of three chronically infected chimpanzees but in neither of two animals with acute HBV infection. WHV DNA was found in the PBL of 11 of 13 chronically infected woodchucks and in the PBL and bone marrow of 1 of 4 woodchucks with antibody to WHV surface antigen. Viral DNA in the PBL and bone marrow was episomal, primarily existing as multimers with some monomeric forms. Integrated HBV DNA was detected in the PBL of one chronically infected chimpanzee, but only for a brief period. Viral RNA was also detected in the PBL, although less frequently than was DNA. HBV RNA in chimpanzee PBL existed as 3.8- and 7.5-kilobase species, while 2.3- and 3.8-kilobase WHV RNA was found in woodchuck PBL. Subfractionation of PBL isolated from the chronically infected chimpanzees demonstrated that HBV DNA and RNA were located in B and T cells. No HBV DNA was detected in the macrophages. These results, along with the recent reports of HBV nucleic acids in the PBL of human patients, suggest that infection of PBL may be a general phenomenon associated with the pathology of hepadnaviruses.
Animals↗
Protection of chimpanzees from type B hepatitis by immunization with woodchuck hepatitis virus surface antigen.
Two chimpanzees immunized with woodchuck hepatitis virus (WHV) surface antigen (WHsAg) developed antibodies cross-reactive with hepatitis B virus (HBV) surface antigen (HBsAg). After challenge with HBV, one animal was completely protected and the other experienced a subclinical infection, without evidence of liver disease. Three woodchucks immunized with HBsAg developed antibodies to HBsAg which did not cross-react with WHsAg. After challenge with WHV, all three woodchucks developed typical acute infections with associated hepatic lesions. Serological studies with the cross-reactive antibodies raised in chimpanzees suggested that the protective epitopes of WHsAg were related to the group a specificity of HBsAg. These studies indicated that cross-protective epitopes are shared by HBV and WHV; however, the humoral response to these epitopes can vary among species.
Animals↗
Failure to detect polyalbumin-binding sites on the woodchuck hepatitis virus surface antigen: implications for the pathogenesis of hepatitis B virus in humans.
Binding sites for polymerized albumin on hepatitis B virus components were reported in human hepatitis B virus chronic carriers predominantly with active viral replication (HB e antigen positive). The presence of comparable albumin-binding sites in the woodchuck hepatitis virus (WHV) model was examined on WHV components obtained from woodchucks with active viral replication (DNA polymerase positive). Binding sites for polymerized woodchuck serum albumin were not detected on the intact WHV virion, on 22-nm woodchuck hepatitis surface antigen (WHsAg), or on WHsAg polypeptides. Woodchuck albumin was not detected in purified 22-nm WHsAg, and anti-albumin antibodies were not detected in WHV chronic-carrier woodchucks. Our results in the WHV model argue against a role for viral polyalbumin-binding sites in tissue- and host-specific virus infectivity.
Animals↗
Hepatitis delta virus disease.
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Antigens, Viral↗
A final report on safety and immunogenicity of a bivalent aqueous subunit HBV vaccine.
The bivalent form of an aqueous formalin-inactivated hepatitis B vaccine was evaluated for safety and immunogenicity in chimpanzees. To evaluate safety five animals were inoculated intravenously with vaccine containing 500 micrograms HBsAg and two animals with 50 micrograms. None of these animals developed hepatitis or any serologic marker indicative of the presence of residual live virus in the vaccine. Twenty-four animals were used to evaluate immunogenicity and protective efficacy. Seven of these immunized animals produced weak or no anti-HBs responses. Two doses of 50 micrograms HBsAg given subcutaneously 1 month apart protected each of four animals that were challenged with 10(3.5) CID50 HBV at 6 and 12 months after immunization and protected three of four animals challenged at 24 months against development of hepatitis or HBsAg. Three of 4 animals in each group immunized with two doses of 20, 10, or 5 micrograms HBsAg were similarly protected when challenged 6 months after immunization. Thirteen of 20 immunized animals that did not develop HBsAg after challenge with HBV developed anamnestic anti-HBs or anti-HBc responses between 2 and 18 months after challenge, indicating minimal replication of challenge virus. The time of onset and frequency of occurrence of these delayed responses was related to the titer of anti-HBs at the time of challenge. False positive Ausab test results were observed in quarantined chimpanzees. These were neither preceded by appearance of HBsAg nor accompanied by development of anti-HBc. In most cases these reactions were due to a reactant having a sedimentation coefficient and an electrophoretic mobility resembling that of IgM. This reactant generally did not appear to confer resistance to challenge with HBV. The humoral immune response was characterized as being entirely of the IgM class 2 weeks after immunization and switched entirely into the IgG class by 10-12 weeks after vaccine administration. At the time of challenge all animals with antibody had anti-HBs of subtype a.
Animals↗
Frequency and significance of delta antibody in acute and chronic hepatitis B. A United States experience.
Of 560 hepatitis B surface antigen-positive patients who were tested for antibody to hepatitis delta-antigen by blocking radioimmunoassay, 29 (5%) were seropositive. Patients with chronic active hepatitis had a greater frequency of seropositivity than those with chronic persistent hepatitis (26% vs. 0%, p less than 0.05), and patients with symptomatic chronic disease harbored the antibody more commonly than asymptomatic counterparts (14% vs. 2%, p less than 0.01) or patients with acute hepatitis (14% vs. 1%, p less than 0.02). Of 8 patients with acute fulminant hepatitis, including 6 who died of liver failure, none were seropositive. Antibody was detected in drug users, dialysis patients, hemophiliacs, and transfusion recipients; in 17 patients, however, including 3 homosexuals, it occurred sporadically. Samples harvested in 1969 contained delta-antibody. Antibody was found in most ethnic groups, including Orientals, where it occurred only in relocated Vietnamese. We conclude that delta-antibody is detected infrequently in a diverse referral population within the United States. Seropositivity is associated with symptomatic chronic disease and histologic findings of chronic active hepatitis. Homosexuals and resettled Vietnamese are susceptible to sporadic delta-infection.
Acute Disease↗
Radioimmunoassay and characterization of woodchuck hepatitis virus core antigen and antibody.
Solid-phase radioimmunoassays for woodchuck hepatitis virus core antigen (WHcAg) and antibody (anti-WHc) were developed. WHcAg in woodchuck liver homogenates was characterized by ultracentrifugation in CsCl gradients; both heavy (1.35 g/cm3) and light (1.31 g/cm3) cores were obtained from the liver of an animal during acute WHV infection, which is consistent with observations in hepatitis B virus infection in man. Endpoint titers of anti-WHc were higher in chronic WHV carriers than in animals recovered from acute infections. Both IgM and IgG anti-WHc antibodies were produced by infected woodchucks. A survey of colony woodchucks demonstrated that 88/89 animals having one or more markers of past or ongoing WHV infection were positive for anti-WHc. Thus, serum anti-WHc appears to be a sensitive marker of WHV infection.
Animals↗
Kinetics of synthesis of respiratory syncytial virus glycoproteins.
The synthesis of the two respiratory syncytial (RS) virus glycoproteins (VP66 and VP84) was examined under standard conditions and after treatment with tunicamycin and monensin. The protein backbone for VP66, the fusion protein (F1,2) is cotranslationally glycosylated to form F0, which is cleaved to form F1,2 by 20 min of chase. Monensin treatment inhibited the cleavage of F0 over an 80 min chase period, indicating that this occurred late in the transit of F0 through the Golgi apparatus or after exit from the Golgi apparatus. Tunicamycin treatment resulted in the synthesis of a 50K to 55K unglycosylated F0 which is cleaved to a 40K protein. VP84, the large glycoprotein, contains a protein backbone of only 26K to 30K which is modified by N-linked and probable O-linked glycosylation. Tunicamycin treatment results in the synthesis of a 70K protein (p70) which incorporates [3H]glucosamine and [3H]fucose but not [3H]mannose. Glycosylated precursors varying in mol. wt. from 29K to 45K (p45) are found in infected cells at regular 2K to 3K intervals, producing a 'ladder' effect. The step from p45 to VP84 is severely delayed by monensin treatment thereby enhancing the 'ladder' effect of the precursors.
Electrophoresis, Polyacrylamide Gel↗
Activation of human peripheral blood B cells following immunization with hepatitis B surface antigen vaccine.
To further evaluate the human immune response to hepatitis B surface antigen (HBsAg), we used an enzyme-linked immunosorbent assay to measure the in vitro production of antibody to HBsAg in normal individuals following booster immunization with the HBsAg vaccine. Following booster immunization, cells spontaneously secreting antibody to HBsAg were present in the peripheral blood. The specific antibody production was first detectable 4 days after booster immunization. The peak of specific antibody production was on Day 6, with resolution of the response by Day 9. The presence of these spontaneously secreting cells in the peripheral blood precedes the rise in serum antibody levels to HBsAg. The antibody secretion does not require the presence of accessory cells and is not enhanced by pokeweed mitogen, suggesting that these cells are quite advanced in the B-cell maturation sequence. The significance of these observations is discussed. Understanding the human immune response to HBsAg vaccine should provide insights into the immune regulatory abnormalities associated with disease states characterized by chronic hepatitis B antigenemia, including cryoglobulinemia, polyarteritis nodosa, and chronic hepatitis.
Adult↗
Expression of hepatitis B virus surface and e antigen genes cloned in bovine papillomavirus vectors.
Sequences of the hepatitis B virus (HBV) genome coding for the surface antigen (HBsAg), but lacking the regulatory (preS) sequences, were cloned into a bovine papillomavirus (BPV) vector consisting of the transforming 69% of the BPV genome (BPV 69T), and transformed into mouse c127 cells. Clones carrying HBV and BPV sequences in the same transcriptional orientation did not produce immunologically active HBsAg, while those with the opposite orientation produced and secreted HBsAg. RNA species of an HBsAg producer were 3400, 9600, 11000 and 18000 nucleotides long and hybridized with both HBV and BPV probes. Mouse cells (c127) transformed with the whole BPV genome (BPV-1) carrying both the HBsAg-coding sequences and the regulatory preS sequences of HBV DNA were stable and produced and secreted HBsAg 22 nm particles. These yielded 11500 and 12500 nucleotide RNA transcripts which also hybridized with both BPV and HBV DNA probes. BPV-1 carrying whole HBV DNA monomer or dimer genomes yielded transformants which initially produced HBsAg as well as HBV e antigen (HBeAg), but these were not stable. The hybrid genomes, with the exception of those carrying the HBV dimers, existed as multicopy plasmids (50-100 copies per cell) and often acquired new sequences.
Animals↗
Hepatitis delta virus infection of the liver.
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Animals↗
Transmission of the hepatitis B virus-associated delta agent to the eastern woodchuck.
delta agent of human origin was inoculated into four woodchucks chronically infected with woodchuck hepatitis virus (WHV). The animals developed delta infections with serologic patterns similar to those previously observed in human and chimpanzee infections. delta antigen was detected transiently in serum and liver and was followed by seroconversion to anti-delta antibody. Analogous to the chimpanzee model of delta infection, serum and hepatocyte markers of WHV were suppressed in the woodchuck during acute delta infection. The suppression of WHV DNA in serum was evident only during the time of delta-antigen positivity, while the inhibition of other WHV markers was more protracted. The delta antigen in woodchuck sera circulated as an internal component of a particle similar in size to the human delta particle (36-nm diameter) and was encapsidated by the woodchuck hepatitis virus surface antigen; delta antigen from infected woodchuck and chimpanzee livers had similar biophysical properties. Histologic analysis showed that experimental delta infection is associated with a transient acute hepatitis in woodchucks and loss of hepatocytes carrying WHV antigens. The lesions differed from the conspicuous hepatitis associated with reappearance of WHV replication. Hepatitis B-like viruses, therefore, appear to provide the requisite helper functions for delta replication and the woodchuck represents a useful model for study of the virology and pathology of the delta agent.
Animal Diseases↗
Delta hepatitis agent: structural and antigenic properties of the delta-associated particle.
Delta agent (delta) was serially passaged to a second and third hepatitis B surface antigen (HBsAg) carrier chimpanzee, using as inoculum the peak delta antigen (delta Ag) serum of an animal previously infected with human serum. The characteristics of serially transmitted delta Ag were similar to those described in first-passage animals. It was consistently detected before the development of anti-delta, in association with a 35- to 37-nm subpopulation of HBsAg particles and a unique low-molecular-weight (5.5 X 10(5)) RNA. RNase susceptibility of the delta-associated RNA and release of delta Ag activity upon treatment of delta-associated particles with detergent revealed that this particle is organized into a virion-like form with the RNA and delta Ag as internal components within a coat of HBsAg. Surface determinants of the delta-associated particle other than HBsAg were not detected by radioimmunoprecipitation experiments, using sera of humans and chimpanzees convalescent from delta hepatitis. The HBsAg-associated particle is the "candidate agent" of delta hepatitis.
Animals↗
Antigenic analysis of woodchuck hepatitis virus surface antigen with site-specific radioimmunoassays.
Monoclonal antibodies to five nonoverlapping antigenic domains of woodchuck hepatitis virus surface antigen (WHsAg) were used to develop site-specific radioimmunoassays. The assays were based on the solid-phase sandwich principle in which different combinations of individual domain-specific antibodies were used as immunoadsorbents and radioiodinated probes. Over 85% of the combinations tested were able to detect serum WHsAg, including those using the same antibody as immunoadsorbent and probe. The limits for antigen detection in one site-specific system ranged between 16 and 80 ng of WHsAg per ml. The antigenic similarity of serum WHsAg from 13 colony woodchucks was shown with several combination assay systems. WHsAg was equally immunoreactive in these assay systems whether obtained by immunoaffinity chromatography or standard rate zone centrifugation methods. Further site-specific analysis demonstrated that Formalin treatment of purified antigen did not affect the immunoreactivity of these WHsAg sites.
Animals↗
Core antigen and antibody in woodchucks after infection with woodchuck hepatitis virus.
The woodchuck hepatitis virus is a naturally occurring hepatitis B-like virus that infects the eastern woodchuck. Direct immunofluorescence staining for woodchuck hepatitis virus core antigen in liver biopsies demonstrated the presence of this antigen in 14 of 17 chronically infected woodchucks, and in 8 of 10 woodchucks undergoing acute infections. Fluorescent localization of woodchuck hepatitis virus core antigen was typically cytoplasmic, and this was confirmed further by electron microscopy. Experimental infection with woodchuck hepatitis virus was achieved in four of four woodchucks inoculated with serum from chronic carrier woodchucks. All infected animals developed a self-limited disease characterized by seroconversion to antibodies against the major viral antigens (core and surface antigens); naturally acquired acute infection demonstrated a similar course. A chimpanzee seronegative for all markers of hepatitis B virus developed a subclinical infection after inoculation with woodchuck hepatitis virus.
Animals↗
In vitro antigen-induced antibody responses to hepatitis B surface antigen in man. Kinetic and cellular requirements.
In this report we define the parameters of the human immune response after immunization with hepatitis B vaccine. 2 wk after booster immunization, there is significant spontaneous secretion of antibody to hepatitis B surface antigen (anti-HBs IgG), which is not further augmented by stimulation with antigen or pokeweed mitogen (PWM). By 4 wk there is little spontaneous secretion of specific antibody, and low doses of antigen or PWM produce significant increases in the amount of anti-HBs IgG produced. By 8 wk the peripheral blood mononuclear cells are refractory to stimulation by antigen, but anti-HBs IgG is produced in response to PWM. 0.5 yr or more after the last immunization, some individuals will manifest an antigen-induced specific antibody response. This induction of anti-HBs IgG by hepatitis B surface antigen (HBsAg) is monocyte- and T cell-dependent. Note that there is a dichotomy in the T cell response to HBsAg. The specific antibody response is clearly T cell dependent, but no in vitro T cell proliferative response to HBsAG could be demonstrated in the immunized individuals. Although the precise reason for the absent proliferative response to HBsAg despite well-established humoral immunity has not been determined, there was no evidence to suggest nonspecific suppression by HBsAg or the presence of an adherent suppressor cell population. The ability to evaluate antigen-induced, antigen-specific responses to HBsAg will be useful in defining the unique interaction between the human immune response and this clinically important viral agent.
Adult↗