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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The relationships among the core antigen polypeptides of hepatitis B virus (HBV) and ground squirrel hepatitis virus (GSHV) were studied using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and tryptic peptide mapping. The major core antigen polypeptides of liver-derived HBV (p22) and GSHV (p20.5) shared 56% of the spots in their peptide maps. Comparison of hepatitis B core antigen (HBcAg) p19 or ground squirrel hepatitis core antigen (GSHcAg) p16.5 with their respective major polypeptides indicated that these components probably resulted from cleavage of the major polypeptide of each virus. Other polypeptides smaller than the major component of each virus were often faint on polyacrylamide gels and probably resulted from the cleavage or degradation of components larger than p22 of HBcAg or p20.5 of GSHcAg, since their peptide maps contained spots unique to these high-molecular-weight components. p26 of GSHcAg and p27.5 of HBcAg shared approximately two-thirds of the spots on their peptide maps with those of their respective major core polypeptides. Furthermore, p37.5 of GSHcAg and p40 of HBcAg shared about 60% homology with their respective major polypeptides, and also shared many of the spots that were unique to p26 of GSHcAg or p27.5 of HBcAg but were not found in the peptide map of their respective core antigen polypeptides. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis bands larger than 40,000 daltons were variably present, and peptide mapping indicated that these were aggregates of various smaller core antigen-associated polypeptides. The results suggest that p40 of HBcAg and p37.5 of GSHcAg are the largest unique polypeptides in these core particles, and that they are encoded for by the genome of each virus. That a subset of the spots unique to p40 or p37.5 was also found in p27.5 of HBcAg or p26 of GSHcAg, respectively, as compared to the major core polypeptides, also suggests that p27.5 and p26 are unique proteins encoded by the genome of each virus. It is proposed that the core antigen gene of each virus is larger than that which would encode the major polypeptide of each virus, and that the genetic organizations of the core genes of HBV and GSHV are very similar.
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PMID:Core particles of hepatitis B virus and ground squirrel hepatitis virus. I. Relationship between hepatitis B core antigen- and ground squirrel hepatitis core antigen-associated polypeptides by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and tryptic peptide mapping. 710 37

The recently described protein kinase activity in hepatitis B virus core antigen particles (Albin and Robinson, J. Virol. 34:297-302, 1980) has been demonstrated here in the liver-derived core particles of ground squirrel hepatitis virus. Both protein kinase activities were initially associated with DNA polymerase-positive heavy core particles in CsCl density equilibrium gradients and shifted to polymerase-negative cores during the course of purification. The major core-associated polypeptide of each virus was the dominant species labeled. A variable number of other polypeptide species were also labeled by this reaction. Tryptic peptide mapping of both major and minor phosphorylated polypeptides of each virus resulted in similar patterns, suggesting that many of the sites of phosphorylation were the same in the components of each core particle. Hydrolysis of these phosphorylated core particles revealed a major phosphoamino acid as serine and a minor phosphoamino acid as threonine. The products of the protein kinase reaction in both human hepatitis B and ground squirrel hepatitis virus core particles, then, share many characteristics. The possible function(s) of this protein kinase activity is discussed in the light of similarly characterized activities in other animal viruses.
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PMID:Core particles of hepatitis B virus and ground squirrel hepatitis virus. II. Characterization of the protein kinase reaction associated with ground squirrel hepatitis virus and hepatitis B virus. 710 41

Previous studies established that the purified polypeptides derived from the 22-nm particles associated with hepatitis B surface antigen (HBsAg) produce both humoral and cellular immunity against HBsAg in guinea pigs. Therefore, the two major polypeptides with molecular weights of 22,000 and 25,000 (P22 and P25, respectively) were isolated, adsorbed to an alum adjuvant, and used to immunize four nonimmune chimpanzees. A vigorous anti-HBs response was observed in all four animals after one inoculation of an alum-adsorbed polypeptide vaccine containing 40 micrograms of protein. After one to two booster inoculations, anti-HBs switched from being predominantly immunoglobulin M to the immunoglobin G class, indicating the establishment of immunological memory. Challenge of the vaccinated chimpanzees with 30,000 chimpanzee infectious doses of hepatitis B virus provided evidence for the efficacy of this vaccine. None of the four animals developed serological markers associated with an active hepatitis B infection, and no biochemical or histopathological changes of hepatitis were observed. A nonvaccinated control chimpanzee that was inoculated with the same hepatitis B virus material developed hepatitis B infection, confirming infectivity of the challenge inoculum.
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PMID:Immunization of chimpanzees with hepatitis B virus-derived polypeptides. 721 95

Several physical, chemical, and serological properties of surface antigen particles from ground squirrel hepatitis virus (GSHsAg) and human hepatitis B virus (HBsAg) were compared. GSHsAg and HBsAg particles were purified from positive sera by gel chromatography and isopycnic centrifugation. Both antigens consisted mainly of spherical particles with an average diameter of approximately 20 nm and a buoyant density in CsCl of approximately 1.19 g/ml. Their UV absorption spectra indicated the presence of more tryptophane than tyrosine and the absence of detectable nucleic acid. GSHsAg was found to contain two major polypeptides of approximately 23,000 and 27,000 daltons, with electrophoretic migration rates distinctly faster than those of the two major polypeptides of HBsAg particles. After radiolabeling of purified antigen preparations with Bolton-Hunter reagent, the two major polypeptides of GSHsAg showed almost identical tryptic peptide maps. The tryptic peptide map of the major polypeptide from GSHsAg contained 13 of 37 spots also present in the map of the major HBsAg polypeptide, and 13 of 27 spots in the map of the major HBsAg polypeptide were also present in the map of the major GSHsAg polypeptide. This suggests considerable sequence homology between the major surface antigen polypeptides of the two viruses. However, there was only a weak serological cross-reactivity between antigens of the two viruses. Using an anti-HBs-containing serum with a relatively strong cross-reactivity, GSHsAg was found to consist of at least two antigenically different subspecies. The more strongly cross-reacting from had a slightly higher buoyant density than the other antigenic form.
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PMID:Structural relationships between the surface antigens of ground squirrel hepatitis virus and human hepatitis B virus. 746 56

Liver cytosol specific antibody type 1 (anti-LC1) was first described in a proportion of patients with liver/kidney microsomal antibody type 1 (anti-LKM1)-positive autoimmune hepatitis (AIH) and is routinely evaluated by immunodiffusion (ID). Using human liver cytosol as the source of antigen, we have used ID, counterimmunoelectrophoresis (CIE) and immunoblotting (IB), to test sera from 167 patients with documented chronic liver diseases of different etiology. 15 patients had antinuclear antibody (ANA) and/or smooth muscle antibody (SMA)-positive AIH, 13 had anti-LKM1-positive AIH, four had ANA/SMA/anti-LKM1-negative AIH, 76 had anti-LKM1-positive hepatitis C (recently renamed unclassified chronic hepatitis-UCH), 40 had chronic hepatitis C, 15 had chronic hepatitis B, and 4 had chronic hepatitis D. A precipitin line of identity with an anti-LC1 reference serum was detected both by ID and CIE in 16 patients: six with anti-LKM1-positive 'definite' AIH, four with ANA/SMA/anti-LKM1-negative 'definite' AIH, and six with anti-LKM1-positive UCH. By IB, 14 out of the 16 anti-LC1-positive sera (87.5%) reacted with a 58 kDa human liver cytosolic polypeptide, whereas three out of 16 (19%) recognised an additional 60 kDa band. Compared to ID, CIE is more economical in terms of both time and reagents and provides more clear-cut results. The 58 kDa reactivity by IB was detectable in nearly all CIE/ID anti-LC1-positive patients, was not found among CIE/ID anti-LC1-negative patients. In conclusion, CIE is the ideal screening test for the detection of anti-LC1, an autoantibody that can be regarded as an additional serological marker of AIH and is especially useful in ANA/SMA/anti-LKM1 negative cases.
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PMID:Detection of anti-liver cytosol antibody type 1 (anti-LC1) by immunodiffusion, counterimmunoelectrophoresis and immunoblotting: comparison of different techniques. 749 85

Hepatitis C virus is a positive single-strand RNA virus distantly related to flaviviruses. Therefore RNA replicase, an RNA-dependent RNA polymerase, may be essential for the replication of hepatitis C virus, as well as other RNA viruses. In this study we synthesized the recombinant polypeptide (HCV-NS5 antigen) with a 576 bp cDNA encoding a part of the NS5 region of the HCV genome that has the Gly-Asp-Asp motif. The antibody against this polypeptide was obtained from rabbit serum. In Western-blot analysis with NS5 IgG HCV antibody, an 84-kD protein was clearly detected as a single band in the microsomal fraction but not in the nuclear and mitochondrial fractions or in the cytosol fraction. Immunohistochemically, HCV-NS5 antigen was clearly stained in the cytoplasm of hepatocytes but not in the nucleus or cell membrane. Moreover, as determined on immunoelectron microscopy, HCV-NS5 antigen was demonstrated with fine granular distribution along the endoplasmic reticulum but not in other organelles, including the nucleus and mitochondria. Immunoreaction in other cell types was negative. These results indicate that replication of HCV may occur only in hepatocytes and that HCV-NS5 may be produced in the endoplasmic reticulum of these cells. HCV-NS5 antigen was stained only in the livers of hepatitis C virus-positive patients but not in sections from patients with chronic type B hepatitis or alcoholic fibrosis. In chronic type C liver disease, the overall detection rate of HCV-NS5 antigen was 56% (33% in chronic persistent hepatitis, 52% in chronic active hepatitis and 86% in cirrhosis).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Detection of antigens related to hepatitis C virus RNA encoding the NS5 region in the livers of patients with chronic type C hepatitis. 750 61

A staphylococcus aureus protein A co-operated ELISA (SPA-ELISA) for the detection of anti-HCV-IgM has been established using HCV antigenic polypeptide, SPA-bearing germs and horseradish peroxidase labelled anti-human IgM. The specificity of SPA-ELISA has been confirmed by some substitution tests, blocking tests and destroying test with 2-mercaptoethanol. The results showed that the rate of anti-HCV-IgG in a group of patients with acute hepatitis and there were significant difference in anti-HCV-IgM was higher than that of anti-HCV-IgM detected rates between patients with acute hepatitis and those with chronic hepatitis (32.26%, P < 0.01). On the other hand, the positive rates of anti-HCV-IgM were 53.66% and 63.41% in transfusion associated hepatitis, 38.10% and 42.86% in sporadic hepatitis, 6.11% and 16.33% in people who have had active social activities, 40.00% and 10.00% in a group of blood donors respectively. Furthermore, taking into account the characteristics of HCV polypeptide used, its easiness of manipulation, and elimination of the interference of anti-HCV-IgG in sera, the new SPA-ELISA is believed to be of practical value in clinical and epidemiological studies of hepatitis C.
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PMID:Establishment and application of SPA-co-operated ELISA for detection of anti-HCV-IgM. 751 50

Until 1988 the putative agent of non-A/non-B (NANB) hepatitis had not been found. Research workers of the Chiron Corporation (California, USA) then identified, by "blind expression cloning", polypeptides which specifically bound antibodies present in sera of NANB-patients. A fusion polypeptide (C-100) was expressed in yeast. With the C-100 antigen prototype RIA and ELISA antibody tests were developed. Subsequently more polypeptides (C-200, C33c, C22) of the HCV-genome were added to the test system, resulting in second generation anti-HCV tests with increased sensitivity. For confirmation of HCV ELISA reactive samples, recombinant immunoblot (RIBA-2, Ortho; Innolia, Innogenetics) and dot immunoblot assays (Matrix, Abbott) were developed. Detection of HCV antigens has been hampered by the low virus titres in serum and the absence of free circulating viral antigen(s). However, with cDNA-PCR, applying primers of the highly (> 93% nucleotide homology) conserved 5' untranslated (5'UTR) region of the HCV genome, HCV-RNA in serum as well as in liver tissue can be detected. cDNA-PCR, although not yet commercially available, is useful to confirm HCV-viremia in patients. When chronic hepatitic C patients are treated with anti-viral drugs, the disappearance of HCV-RNA, as detected by PCR, is a measure of therapy response.
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PMID:Testing for HCV markers. 751 61

Hepadnaviruses encode a single core (C) protein which assembles into a nucleocapsid containing the polymerase (P) protein and pregenomic RNA during viral replication in hepatocytes. We examined the ability of heterologous hepadnavirus C proteins to cross-oligomerize. Using a two-hybrid assay in HepG2 cells, we observed cross-oligomerization among the core proteins from hepatitis B virus (HBV), woodchuck hepatitis virus, and ground squirrel hepatitis virus. When expressed in Xenopus oocytes, in which hepadnavirus C proteins form capsids, the C polypeptides from woodchuck hepatitis virus and ground squirrel hepatitis virus, but not duck hepatitis B virus, can efficiently coassemble with an epitope-tagged HBV core polypeptide to form mixed capsids. However, when two different core mRNAs are coexpressed in oocytes the core monomers show a strong preference for forming homodimers rather than heterodimers. This holds true even for coexpression of two HBV C proteins differing only by an epitope tag, suggesting that core monomers are not free to diffuse and associate with other monomers. Thus, mixed capsids result from aggregation of different species of homodimers.
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PMID:Phenotypic mixing between different hepadnavirus nucleocapsid proteins reveals C protein dimerization to be cis preferential. 751 33

Sequence analysis of the mouse hepatitis virus, strain A59 (MHV-A59) genome predicts the presence of two papain-like proteinases encoded within the first open reading frame (ORF 1a) of the replicase gene. The more 5' of these domains, the leader papain-like proteinase, is responsible for the cleavage of the amino terminal protein, p28. The core of this proteinase domain was defined to between amino acids 1084 and 1316 from the beginning of ORF 1a. Through the use of deletion analysis coupled with in vitro expression, we studied the role of the coding region between p28 and the leader papain-like proteinase on the cleavage of p28 itself. Expression of a series of deletion mutants showed processing of p28, albeit at lower levels. Reduced p28 production resulting from a 0.4-kb deletion positioned between p28 and the proteinase domain suggests an involvement of this region in catalytic processing. Some mutants displayed cleavage patterns indicative of a second cleavage site. Interestingly, this new cleavage site identified in vitro maps to a position similar to the expected cleavage site of a p65 polypeptide detected in MHV-A59-infected cells. Mutagenesis of the catalytic His1272 residue demonstrates that both cleavages observed are mediated by the leader papain-like proteinase encoded in ORF 1a.
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PMID:Characterization of the leader papain-like proteinase of MHV-A59: identification of a new in vitro cleavage site. 753 70


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