Chiron Corporation

About: Chiron Corporation is a based out in . It is known for research contribution in the topics: Antigen & Hepatitis C virus. The organization has 1973 authors who have published 1969 publications receiving 172330 citations.

Hamster preproglucagon contains the sequence of glucagon and two related peptides

Abstract: Glucagon is a 29-amino acid polypeptide hormone synthesized by the A cells of the endocrine pancreas. Its primary site of action is the liver where it stimulates glycogenolysis, gluconeogenesis and ketogenesis. In mammals, biosynthetic studies have shown that glucagon is derived from a precursor of molecular weight (Mr) approximately 18,000 which is five to six times larger than glucagon. Glucagon-containing polypeptides and immunoreactants of various sizes have also been described from stomach, intestine, brain and salivary gland. Here, we have determined the structure of hamster pancreatic preproglucagon from the sequence of its cDNA. This 180-amino acid precursor contains the sequence of glucagon and two glucagon-like polypeptides arranged in tandem. The precursor also contains the sequences of several non-pancreatic glucagon-containing polypeptides which suggests that, in mammals, both pancreatic and non-pancreatic glucagon and glucagon-containing polypeptides may be derived from a common precursor by tissue-specific processing. We have tentatively identified each of the glucagon-like immunoreactants which have been described with respect to the sequence of proglucagon and have proposed a scheme for the processing of pancreatic proglucagon.

Structure, sequence and expression of the hepatitis delta ( δ ) viral genome

Abstract: Biochemical and electron microscopic data indicate that the human hepatitis δ viral agent contains a covalently closed circular and single-stranded RNA genome that has certain similarities with viroid-like agents from plants. The sequence of the viral genome (1,678 nucleotides) has been determined and an open reading frame within the complementary strand has been shown to encode an antigen that binds specifically to antisera from patients with chronic hepatitis δ viral infections.

Oligonucleotides with selectably cleavable and/or abasic sites

Abstract: A modified polynucleotide containing at least one cleavable or abasic site as shown below. ##STR1## DNA 1 is a first segment of DNA; DNA 2 is a second segment of DNA; and R m is C 1 to C 16 alkylene or an oxytheylene oligomer --(CH 2 CH 2 O) z -- where z is an interger in the range of 1 to 16 inclusive, and R n is selected from the group consisting of ##STR2## Such polynucleotides are useful in solid phase hybridizations because they permit the release of a label from the solid support after the hybridization reaction.

Vaccination of chimpanzees against infection by the hepatitis C virus.

Abstract: A high incidence of community-acquired hepatitis C virus infection that can lead to the progressive development of chronic active hepatitis, liver cirrhosis, and primary hepatocellular carcinoma occurs throughout the world. A vaccine to control the spread of this agent that represents a major cause of chronic liver disease is therefore needed. Seven chimpanzees (Pan troglodytes) have been immunized with both putative envelope glycoproteins [E1 (gp33) and E2 (gp72)] that were copurified from HeLa cells infected with a recombinant vaccinia virus expression vector. Despite the induction of a weak humoral immune response to these viral glycoproteins in experimentally infected chimpanzees, a strong humoral immune response was obtained in all vaccines. The five highest responders showed complete protection against an i.v. challenge with homologous hepatitis C virus 1. The remaining two vaccines became infected, but both infection and disease may have been ameliorated in comparison with four similarly challenged control chimpanzees, all of which developed acute hepatitis and chronic infections. These results provide considerable encouragement for the eventual control of hepatitis C virus infection by vaccination.

Induction of CD4-dependent cell fusion by the HTLV-III/LAV envelope glycoprotein.

Abstract: Formation of syncytia, with progression to cell death, is a characteristic feature of in vitro cultures of susceptible cells infected with human T-lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV)1–3. Viral antigen-positive multi-nucleated giant cells have also been observed in histological sections from infected individuals4,5. In vitro, formation of these multinucleated giant cells occurs through cell fusion which is dependent on cell-surface expression of the differentiation antigen CD4 (ref. 1). Utilizing a recombinant vaccinia virus containing the gene for the envelope glycoprotein of HTLV-III/LAV6, we demonstrate that cell-surface expression of this protein, in the absence of other HTLV-III/LAV structural or regulatory proteins, is sufficient to induce CD4-dependent cell fusion, leading to cell death, one of the characteristic manifestations of AIDS (acquired immune deficiency syndrome) virus cytopathology. This process may contribute to the loss of CD4+ T cells seen in AIDS.