Biophysical and biochemical properties of purified preparations of hepatitis B surface antigen (HBS Ag)

Gr, Dreesman; Fb, Hollinger; Jl, Melnick

doi:10.1097/00000441-197507000-00018

Cited by 43 publications

(27 citation statements)

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“…1 Much of the work on HB5Ag has been directed towards investigating infective properties, and the infectious virus is believed to be the 42 nm Dane particle (Dane, Cameron and Briggs, 1970), the component which, in some cases, contains DNA of 1-6 x 106 daltons (Robinson, Clayton and Greenman, 1974). Genetic material of 'this size can code for the synthesis of about 3 polypeptides, whereas HB,Ag is more complex (Howard and Zuckerman, 1974;Dreesman, Hollinger and Melnick, 1975) and Zuckerman (1974) has suggested that HBV may be classified among the viroids. Nevertheless there is extensive evidence which also indicates that although HBsAg has characteristics of infectivity, in many respects the antigen shares features suggestive of protein polymorphism.…”

Section: Methodsmentioning

confidence: 99%

Tumour-initiating activities on mouse skin of dihydrodiols derived from benzo[a]pyrene

Chouroulinkov¹,

Gentil²,

Grover³

et al. 1976

Br J Cancer

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Three dihydrodiols that are metabolites of benzo[a]pyrene and benzo[a]-pyrene itself have been tested in a comparative experiment for their activities as initiators of tumours in mouse skin. A single application (25 mug) of 4,5-dihydro-4,5-dihydroxybenzo[a]pyrene, of 7,8-dihydro-7,8-dihydroxybenzo[a]pyrene, of 9,10-dihydro-9,10-dihydroxybenzo[a]pyrene, or of benzo[a]pyrene was made to the shaved dorsal skin of adult female CDI mice; this was followed 2 weeks later by multiple thrice-or twice-weekly applications (1 mug) of 12-O-tetradecanoyl-phorbol-13-acetate as promoting agent. A control group of 30 mice received the promoting agent alone. The experiments were terminated 52 weeks after initiation. At this stage, all the groups contained mice bearing skin papillomas, some of which had progressed to malignancy. Quantitatively the results show that the 7,8-dihydrodiol is almost as active an initiator of mouse skin tumours as benzo[a]pyrene itself; the 4,5- and 9,10-dihydrodiols were significantly less active. The significance of these results is discussed in relation to the hypothesis that diol-epoxides are important in the metabolic activation of polycyclic hydrocarbons like benzo[a]pyrene. Images Fig. 1 Fig. 2 Fig. 3

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Section: Methodsmentioning

confidence: 99%

Tumour-initiating activities on mouse skin of dihydrodiols derived from benzo[a]pyrene

Chouroulinkov¹,

Gentil²,

Grover³

et al. 1976

Br J Cancer

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“…29 The high concentrations of HBsAg contained in fractions nine to twelve most likely represent HBsAg filaments and spheres which have been reported to migrate to these densities. 31 …”

Section: Gradient Analysis Of Extracellular Hbv Particles Produced Bymentioning

confidence: 99%

Hepatitis B virus replication in human HepG2 cells mediated by hepatitis B virus recombinant baculovirus

1998

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Hepatitis B virus (HBV) is a small, double-stranded DNA virus and is the prototype of the hepadnavirus family. HBV is a human pathogen capable of causing both acute and chronic hepatitis. The World Health Organization currently estimates that 350 million people are chronically infected with HBV. Persistent HBV infection is also associated with an increased risk of cirrhosis and hepatocellular carcinoma. 1 Although a tremendous amount is known about HBV, our knowledge of the virus is by no means complete. Historically, major obstacles in the study of HBV have been the inability of the virus to infect cells in vitro, and the lack of animal model systems due to a strict virus-host range. Thus, many aspects of HBV biology have been unraveled by studying related hepadnaviruses, such as the duck hepatitis virus which is capable of in vitro infection, 2 and the woodchuck hepatitis virus which allows for the in vivo study in an animal model system. 3 The duck hepatitis virus and woodchuck hepatitis virus systems were instrumental in developing an understanding of the hepadnavirus lifecycle and remain valuable models for HBV infection. However, many significant differences exist between animal hepadnaviruses and HBV. For example, avian hepatitis viruses do not encode the X gene, 4 and major transcriptional differences between woodchuck hepatitis virus and HBV have been reported. 5 Within the last decade, several HBV expressing cell lines have been established by transfecting viral DNA into liverderived human cell lines and by selecting novel cell lines containing stably integrated HBV genomes. [6][7][8] The most widely used are the HepG2 2.2.15 cell line (2.2.15) derived from the HepG2 hepatoblastoma cell line and HB611 derived from the HuH6 hepatoma cell line. These and other cell lines have led to considerable progress in the study of HBV in vitro. However, there are some inherent drawbacks which preclude the use of these cell lines in studying some aspects of HBV biology. (1) Many HBV expressing cell lines were created using constructs containing strong heterologous promoters proximal to the HBV genome. The effect those promoters have on HBV transcription and replication is unclear but could differ substantially from what occurs in a natural infection in vivo in which HBV gene expression is driven solely by endogenous HBV promoters. (2) Cell lines commonly used to study HBV contain multiple copies of integrated HBV DNA. Unlike retroviruses, which integrate viral DNA into the host genome, hepadnavirus genomes are not integrated routinely but, instead, are maintained in the nucleus of infected cells in vivo as a pool of episomal covalently closed circular (CCC) DNA molecules. 9 Although the integration of HBV DNA in human liver has been reported, 10 it is not an obligatory part of the HBV lifecycle. HBV does not encode any machinery for integration into the host genome, and integration is not required for HBV replication. In addition, when integrated HBV DNA is found,

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“…HBsAg, when disrupted under reducing conditions, has been shown to consist of two major polypeptides ofmol, wt. 20000 to 25 000 (P24) and 25 000 to 30000 (GP28) and several minor polypeptides of higher molecular weight (Peterson, 1981 ;Zuckerman & Howard, 1979;Dreesman et al, 1975). These two polypeptides have the same primary amino acid sequence and represent non-glycosylated and glycosylated forms of the basic peptide of HBsAg (Peterson, 1981).…”

Section: Introductionmentioning

confidence: 99%

Virus-neutralizing Antibodies to Hepatitis B Virus: The Nature of an Immunogenic Epitope on the S Gene Peptide

Waters

Pignatelli

Galpin

et al. 1986

Journal of General Virology

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SUMMARYUsing a murine monoclonal antibody (RF-HBs-1) which has been shown to be capable of neutralizing both ad and ay subtypes of hepatitis B virus (HBV), we have devised a competitive inhibition assay to measure the presence of virus-neutralizing antibodies in the sera of patients who have recovered from acute type B hepatitis. The majority of patients have this antibody in their serum. We also show that this antibody inhibits the binding of polymerized human serum albumin (pHSA) to the pHSA receptor site of the HBV particle, which has been proposed as an important site for the entry of HBV into liver cells. We have demonstrated that the epitope recognized by this antibody is dependent on the linkage of 24000 and 28 000 mol. wt. polypeptides via a disulphide bond. This conformational determinant in the coat of the virus which is part of or near to the pHSA binding site is important in evoking a virus-neutralizing response.

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Biophysical and biochemical properties of purified preparations of hepatitis B surface antigen (HBS Ag)

Cited by 43 publications

References 0 publications

Tumour-initiating activities on mouse skin of dihydrodiols derived from benzo[a]pyrene

Tumour-initiating activities on mouse skin of dihydrodiols derived from benzo[a]pyrene

Hepatitis B virus replication in human HepG2 cells mediated by hepatitis B virus recombinant baculovirus

Virus-neutralizing Antibodies to Hepatitis B Virus: The Nature of an Immunogenic Epitope on the S Gene Peptide

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