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A R Carroll

Publications and source records attributed to A R Carroll.

30 records · Page 2Linked to original sources
PubMed1983

Synthetic peptides mimic subtype specificity of foot-and-mouth disease virus.

The major immunogen of foot-and-mouth disease virus (FMDV) is located between amino acids 141-160 of the capsid protein VP1. Synthetic peptides corresponding to the major immunogenic region give good neutralising antibody responses and protection in guinea pigs. To define more precisely the immunogenic site of the virus, we have examined serological differences between subtypes of the A serotype using synthetic peptides covering the 141-160 region. We show that these synthetic peptides carry determinants which mimic the subtype specificity of the virus. The correlation between these results and predictive structural models, based on the amino acid sequence, is discussed.

Amino Acid Sequence↗
PubMed1979

Adenosine-5'-O-(3-thiotriphosphate) as an affinity probe for studying leader RNA's transcribed by vesicular stomatitis virus.

The ATP required for in vitro transcription by vesicular stomatitis virus can be replaced by the analogue adenosine-5'-O-(3-thiotriphosphate) without affecting the rate of transcription or the nature of the mRNA products. RNA chains (less than 5 S) initiated with adenosine-5'-O-(3-thiotriphosphate) can be isolated by affinity chromatography on mercury-agarose columns used in these experiments. At least 80% of the leader RNA synthesized in vitro by infectious B virions and 70% of the leader RNA synthesized by defective-interfering particles of vesicular stomatitis virus contained a 5'-terminal triphosphate as judged by binding to mercury-agarose of leader RNA synthesized in the presence of the 5'-thiotriphosphate adenosine analogue.

Adenosine Triphosphate↗
PubMed1979

Role of the membrane (M) protein in endogenous inhibition of in vitro transcription by vesicular stomatitis virus.

An endogenous transcriptase inhibitor active at high concentrations of vesicular stomatitis (VS) virus was present in trypsinized whole virions but was absent from ribonucleoprotein cores containing only the L, N, and NS proteins. Poly(L-glutamic acid) effectively reversed the transcriptase inhibition. Transcription under noninhibited, inhibited, and poly(L-glutamic acid)-reversed conditions did not appear to greatly affect the nature of the RNA transcription product. The VS virion matrix (M) protein was purified to greater than 98% homogeneity and was found to have an isoelectric point of approximately 9.0. Purified M protein inhibited transcription by ribonucleoprotein cores, an effect that was partially reversed by poly(L-glutamic acid). Two group III temperature-sensitive (ts) mutants of VS virus (tsO23 and ts G31) with lesions in the M protein exhibited little or no endogenous inhibitor activity compared with two wild-type strains and a group V mutant (tsO45) with a lesion in the G protein. The data presented strongly suggest that the virion M protein is responsible for the endogenous inhibition of in vitro RNA synthesis seen at high concentrations of VS virus.

Isoelectric Point↗
PubMed1979

Use of UV irradiation to identify the genetic information of vesicular stomatitis virus responsible for shutting off cellular RNA synthesis.

UV irradiation of infectious vesicular stomatitis virus was employed to study the relationship between the expression of certain viral gene functions and viral inhibition of RNA synthesis in mouse myeloma (MPC-11) cells. Viral infectivity, protein synthesis, and viral mRNA synthesis were all highly susceptible to inactivation by UV radiation; however, low levels of viral transcriptase activity were detected in vitro in virus preparations subjected to large doses of UV radiation. In sharp contrast, the capacity of vesicular stomatitis virus to shut off cellular transcription was quite resistant to UV radiation. The data presented here indicate that viral transcription is essential to inhibit host RNA metabolism, even though synthesis of viral polypeptides in the inhibited cells could not be detected. At those levels of UV radiation that inactivated all viral gene functions, except viral inhibition of cellular RNA synthesis, the only viral product detected was non-adenylated, low-molecular-weight RNA species.

Animals↗
PubMed1978

Reversal by certain polyanions of an endogenous inhibitor of the vesicular stomatitis virus-associated transcriptase.

The RNA-dependent RNA polymerase associated with vesicular stomatitis virus has been found to be markedly inhibited at high concentrations of virus. This endogenous inhibitor of the virion transcriptase was completely reversed by the action of two negatively charged polyamino acids: poly(L-glutamic acid) and pepsin (EC 3.4.23.1). Two other polyanions, heparin and polyethylene sulfonate, strongly inhibited the activity of the virion transcriptase even at low virus concentrations. Poly (L-glutamic acid) rapidly released the block in transcription of concentrated vesicular stomatitis virus, possibly owing to competition for binding sites of the inhibitor on the virion nucleocapsid transcription complex.

Anions↗
PubMed1978

Inhibition of transcription by immunoglobulins directed against the ribonucleoprotein of homotypic and heterotypic vesicular stomatitis viruses.

Specific antisera were raised by immunization of rabbits with purified nucleocapsids containing only RNA and N protein (ribonucleoprotein, RNP) obtained from vesicular stomatitis (VS) virions of the Indiana (VSInd) and the New Jersey (VSNJ) serotypes. The specificity of anti-RNPInd serum was demonstrated by selective precipitation of homotypic RNPInd devoid of L and NS proteins; anti-RNPInd serum also selectively precipitated soluble N protein present in cytoplasm of infected cells, but co-precipitated a limited amount of contaminating soluble NS protein. Immunoglobulins prepared from each homotypic antiserum markedly inhibited in vitro transcription of VSInd and VSNJ virions. Anti-RNPInd and anti-RNPNJ immunoglobulins also exhibited cross-reactivity by inhibiting transcription of heterotypic virions, but only to a much lesser degree than in the homotypic reaction. Anti-RNPInd immunoglobulin did not inhibit transcription of the antigenically unrelated Chandipura rhabdovirus, but anti-RNPNJ immunoglobulin did to a very limited extent. The transcription inhibitory activity of anti-RNPInd immunoglobulin was not dependent on RNP immunoprecipitation activity, which could be diluted out well before loss of antitranscriptase activity. Anti-RNPind immunoglobulin appeared to exert its effect on transcription by blocking elongation rather than initiation or reinitiation of RNA transcripts.

Animals↗
PubMedDate not supplied

Synthesis and secretion of a functional antibody in a vaccinia virus expression system.

A humanized rat monoclonal antibody (Campath 1H) has been expressed in HeLa cells using recombinant vaccinia viruses. Heavy and light chain recombinant viruses were constructed separately and when grown independently produced proteins of the expected molecular weights. Expressed heavy chain was entirely intracellular but light chain was mainly excreted and processed. When cells were infected at high multiplicity with both heavy and light chain recombinants a proportion of the heavy chain was then found in the extracellular medium. This secreted heavy chain was shown to be associated with light chain as judged by co-electrophoresis in non-reducing SDS polyacrylamide gels and by co-purification on protein-A sepharose. The secreted heavy and light chain complexes were functionally active as an antibody, with activity comparable to authentic Campath 1H antibody as assessed by ELISA, T-cell binding and antigen binding assays. Production of antibody in this system was achieved in the absence of serum, which is an important consideration in the production of monoclonal antibodies (MAbs). The amount of antibody produced was 0.2-0.4 micrograms/10(6) cells without optimization of expression levels. The wide host cell range of vaccinia virus together with the recently developed methods for increasing expression levels make this an attractive candidate as a flexible general vehicle for producing MAbs.

Animals↗
PubMedDate not supplied

Chemical basis of antigenic variation in foot-and-mouth disease virus.

One of the difficulties in controlling foot and mouth disease by vaccination is the occurrence of the virus as seven distinct serotypes because immunity conferred by vaccination against one serotype leaves the animals susceptible to infection by the other six. Moreover, the antigenic variation, even within a serotype, can be so great that immunity against the homologous strain of virus need not necessarily ensure protection against infection by other viruses within that serotype. Here we report the separation of three natural antigenic variants, distinguishable in cross-neutralization tests from an isolate of foot-and-mouth disease virus (FMDV). The serological differences could also be demonstrated by antisera elicited by synthetic peptides corresponding to residues 141-160 of the capsid polypeptide VP1, showing that this region contains a major immunogenic site of the virus. The results have practical implications for the choice of viruses for vaccine production.

Amino Acid Sequence↗
PubMedDate not supplied

Improved immunogenicity of a peptide epitope after fusion to hepatitis B core protein.

Synthetic vaccines for viral diseases can use defined regions of viral proteins as immunogens: the peptide sequence of amino acids 141-160 of the VP1 protein of foot and mouth disease virus (FMDV) elicits virus-neutralizing antibodies to protect guinea pigs, cattle and pigs either when coupled to a carrier protein or when administered in liposomes or in incomplete Freund's adjuvant. The immune response to these peptides is much lower than that to complete virus particles and the same sequence fused to the N terminus of beta-galactosidase did not produce a more potent immunogen than synthetic peptide alone. We report here an expression system for immunogenic epitopes linked to a carrier protein, hepatitis B core antigen, to form part of a virus-like complex which can present these epitopes to the immune system at high density. The immunogenicity of these structures approaches that of FMDV particles.

Animals↗