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D H Bishop

Publications and source records attributed to D H Bishop.

At least 55 records · Page 3Linked to original sources
PubMed1989

Identification of mutations in the M RNA of a candidate vaccine strain of Rift Valley fever virus.

The M RNA species of a candidate vaccine strain of Rift Valley fever virus (RVFV ZH-548M12), derived by consecutive high level mutagenesis using 5-fluorouracil (H. Caplen, C. J. Peters, and D. H. L. Bishop, J. Gen. Virol., 66, 2271-2277, 1985), has been cloned and the cDNA sequenced. The data have been compared to those obtained for the parent virus strain RVFV ZH-548 as well as the previously published data for RVFV ZH-501 (M. S. Collett, A. F. Purchio, K. Keegan, S. Frazier, W. Hays, D. K. Anderson, M. D. Parker, C. Schmaljohn, J. Schmidt, and J. M. Dalrymple, Virology, 144, 228-245, 1985). Some eight nucleotide and three amino acid differences were identified between the M RNAs of ZH-501 and ZH-548. Between the M RNAs of ZH-548 and that of the M12 mutant there were 12 nucleotide and 7 amino acid changes. Unique to the mutant virus is a new AUG codon upstream of that which initiates the open reading frame of the RVFV M gene product (the viral glycoprotein precursor). The significance of this and other differences in the mutant RNA with regard to the derivation and potential attenuation of the candidate vaccine is discussed.

Amino Acid Sequence↗
PubMed1989

Immunogenic and protective properties of rabies virus glycoprotein expressed by baculovirus vectors.

The gene encoding the glycoprotein of rabies virus (G protein, CVS strain) has been cloned and inserted into the baculovirus transfer vector pAcYM1 derived from the nuclear polyhedrosis virus of Autographa californica (AcNPV). The gene was placed under the control of the AcNPV polyhedrin promoter and expressed to high levels by the derived recombinant virus using a Spodoptera frugiperda cell line. It has been established that the antigenic characteristics of the protein were conserved by comparison with those of the native glycoprotein of rabies virions. The immunogenicity of the expressed product was also demonstrated. Intraperitoneal or intramuscular injection of G antigen conferred protection to mice and was associated with the induction of high titers of neutralizing antibodies. The availability of large quantities of antigenically and immunogenically reactive rabies G protein may make feasible crystallographic studies and the safe preparation of a low cost subunit vaccine for the disease.

Animals↗
PubMed1989

Sequence analyses of Thogoto viral RNA segment 3: evidence for a distant relationship between an arbovirus and members of the Orthomyxoviridae.

The genome of Thogoto (THO) virus, an unclassified tick-borne virus, comprises six segments of single-stranded RNA. The complete sequence of the third largest RNA segment has been determined from overlapping cDNA clones and by primer extension studies. Segment 3 RNA consists of 1865 nucleotides (approx. 6.2 x 10(5) Mr). It has a large open reading frame (ORF1;597 amino acids, 68.6K) in its virus-complementary sequence, confirming that the RNA has a negative-sense coding strategy. A transcription termination (polyadenylation) site located after the end of ORF1 has been identified. A second ORF (ORF2;98 amino acids in length), overlapping ORF1, is also present in the virus-complementary sequence although whether it is translated is not known. The 3' and 5' sequences of the segment 3 RNA are complementary and similar to those of the tick-borne Dhori (DHO) and the mammalian and avian influenza viruses. Protein database searches have identified regions of homology between the sequence of the THO ORF1 gene product and regions of the PA protein of influenza virus strain A/NT/60/68 (approx. 20% aligned homology) and the corresponding protein of influenza B/Sing/222/79 virus (approx. 15% aligned homology). Although the THO protein sequence is not as closely related to those of the influenza viruses as they are to each other (40% aligned homology), the indicated sequence data provide further evidence of relationships between the tick-borne THO and DHO viruses and the vertebrate orthomyxoviruses.

Amino Acid Sequence↗
PubMed1989

Synthesis of immunogenic, but non-infectious, poliovirus particles in insect cells by a baculovirus expression vector.

A baculovirus expression vector (AcLeon) derived from Autographa californica nuclear polyhedrosis virus (AcNPV) was prepared containing the complete 6.6 kb coding region of the P3/Leon/37 strain of poliovirus type 3 placed under the control of the AcNPV polyhedrin promoter. The recombinant virus was used to infect Spodoptera frugiperda insect cells. As demonstrated by use of the appropriate antibodies, infected insect cells made poliovirus proteins that included the structural proteins VP0, VP1 and VP3. Poliovirus particles were recovered from extracts of the infected cells and demonstrated to be free from detectable levels of RNA and to be non-infectious in tissue culture. After particle purification by CsCl gradient centrifugation and immunization of outbred mice, antibodies to the structural proteins, including neutralizing antibodies, were obtained. Other recombinant baculoviruses, containing the majority of the capsid coding region of P3/Leon/37 (e.g. AcCAP21, nucleotide residues 742 to 3318), made an unprocessed precursor to the poliovirus structural proteins. These data suggested that processing of the poliovirus gene product by the AcLeon construct was catalysed by the poliovirus-encoded proteases. The results demonstrated that antigenic and immunogenic poliovirus proteins and empty particles can be made in insect cells by recombinant baculoviruses.

Animals↗
PubMed1989

Expression of glycoprotein D of herpes simplex virus type 1 in a recombinant baculovirus: protective responses and T cell recognition of the recombinant-infected cell extracts.

Recombinant baculoviruses expressing glycoprotein D (gD) of herpes simplex virus type 1 (HSV-1) have been generated. The proteins expressed from the recombinants have been characterized using monoclonal antibodies on Western blots and by immunoprecipitation. Partially glycosylated 48K polypeptides have been identified as products of the gD gene. Polyclonal sera from H-2k mice infected with HSV-1 recognized the same polypeptides. Furthermore, draining lymph node cells from H-2k mice infected with HSV-1 proliferated in vitro in response to recombinant-infected cell extracts. Immunization with such extracts generated high titre complement-dependent and -independent neutralizing antibody and the mice were protected against a challenge with HSV-1.

Animals↗
PubMed1989

The design and use of specific genetic probes to identify closely related bunyaviruses and to determine the genotype of their recombinants.

Viruses that are very closely related to each other at the genetic and gene product level can prove difficult to distinguish, although they may differ in phenotype (for example in their virulence or vector preferences). A chimeric genetic probe has been developed and tested to distinguish the S RNAs of two closely related bunyaviruses, snowshoe hare and La Crosse viruses. The technique is applicable to other RNA species of these two bunyaviruses.

Blotting, Northern↗
PubMed1989

Detection of La Crosse and snowshoe hare viral nucleic acids by in situ hybridization.

A molecular hybridization technique was developed to detect bunyavirus RNA in cells. Complementary DNAs (cDNAs) to the small (S) RNA segment of La Crosse (LAC) virus and to a portion of the middle (M) RNA segment of snowshoe hare (SSH) virus were used as probes to detect LAC or SSH viral RNA by in situ hybridization. Protocols were developed and standardized using radiolabeled DNA probes, and adapted for use with biotin labeled probes. The in situ hybridization procedure detected an estimated 3,600 copies of viral S RNA/cell at 24 hr postinfection. In growth curve studies, LAC nucleocapsid antigen was detectable slightly before S RNA. LAC S RNA synthesis was first seen about the nucleus. By 12 hr postinfection, hybridization signal was detected throughout the cytoplasm of the cell. The LAC S RNA probe was group-specific and cross-hybridized to 5 other California group viruses. The SSH M RNA probe was type-specific.

Animals↗
PubMed1988

Molecular and biochemical studies of the evolution, infection and transmission of insect bunyaviruses.

Members of the Bunyaviridae family of RNA viruses (bunyaviruses, hantaviruses, nairoviruses, phleboviruses and uukuviruses) have been studied at the molecular and genetic level to understand the basis of their evolution and infection in vertebrate and invertebrate (arthropod) hosts. With the exception of the hantaviruses, these viruses infect and are transmitted by a variety of blood-sucking arthropods (mosquitoes, phlebotomines, gnats, ticks, etc.). The viruses are responsible for infection of various vertebrate species, occasionally causing human disease, morbidity and mortality (e.g. Rift Valley fever, Crimean-Congo haemorrhagic fever, Korean haemorrhagic fever). Genetic and molecular analyses of bunyaviruses have established the coding assignments of the three viral RNA species and documented which viral gene products determine host range and virulence. Ecological studies, with molecular techniques, have provided evidence for bunyavirus evolution in nature through genetic drift (involving the accumulation of point mutations) and shift (RNA-segment reassortment).

Animals↗
PubMed1988

Intracellular accumulation of Punta Toro virus glycoproteins expressed from cloned cDNA.

The Punta Toro virus (PTV) middle size (M) RNA encodes two glycoproteins, G1 and G2, and possibly a nonstructural protein, NSM. A partial cDNA clone of the M segment which contains G1 and G2 glycoprotein coding sequences but lacks most of the NSM sequences was inserted into the genome of vaccinia virus under the control of an early vaccinia promoter. Cells infected with the recombinant virus were found to synthesize two polypeptides with molecular weights of 65,000 (G1) and 55,000 (G2) that reacted specifically with antibody against PTV. Studies using indirect immunofluorescence microscopy revealed that these proteins accumulated intracellularly in the perinuclear region. The results of endoglycosidase H digestion of these glycoproteins suggested that both G1 and G2 glycoproteins were transported from the RER to the Golgi complex. These proteins were not chased out from the Golgi region during a 6-hr incubation in the presence of cycloheximide. Surface immune precipitation and 125I-protein A binding assays also demonstrated that the majority of the G1 and G2 glycoproteins are retained intracellularly. These results indicate that the PTV glycoproteins contain the necessary information for retention in the Golgi apparatus.

Acetylglucosaminidase↗
PubMed1988

Expression of snowshoe hare bunyavirus S RNA coding proteins by recombinant baculoviruses.

Recombinant baculoviruses have been constructed that express the two snowshoe hare (SSH) bunyavirus proteins coded in overlapping reading frames of the SSH S viral-complementary RNA species (namely the nucleoprotein, N, and the nonstructural protein, NSS). The 26.5 kDa N protein, which is read from the first AUG of the mRNA containing the SSH S sequence, was expressed at a high level (estimated to be ca 40% of the stained cellular proteins in recombinant baculovirus-infected Spodoptera frugiperda cells). This level of expression was much higher than that of the 10.5 kDa NSS protein made at the same time (estimated to be less than 1% of the stained proteins), presumably due in part to lower levels of translation initiation from the second AUG (19 nucleotides downstream). Bal31 nuclease digestion was used to delete the first ATG of the SSH DNA sequence in the baculovirus transfer vector and BamHI was used to remove downstream N coding sequences. A second recombinant baculovirus was constructed from the products that only expressed the SSH NSS protein. The yield of NSS protein was estimated to be of the order of ca 2% of the stained cellular proteins. A third recombinant transfer vector made from the products of the Bal31 digestion, fortuitously possessed a new ATG 8-10 nucleotides upstream of the NSS ATG. A recombinant virus derived from this vector synthesized essentially similar quantities (ca 2% each) of both the NSS protein and a 16.7 kDa N-related product.

Amino Acid Sequence↗
PubMed1988

Bunyavirus-vector interactions.

Recent advances in the genetics and molecular biology of bunyaviruses have been applied to understanding bunyavirus-vector interactions. Such approaches have revealed which virus gene and gene products are important in establishing infections in vectors and in transmission of viruses. However, much more information is required to understand the molecular mechanisms of persistent infections of vectors which are lifelong but apparently exert no untoward effect. In fact, it seems remarkable that LAC viral antigen can be detected in almost every cell in an ovarian follicle, yet no untoward effect on fecundity and no teratology is seen. Similarly the lifelong infection of the vector would seem to provide ample opportunity for bunyavirus evolution by genetic drift and, under the appropriate circumstances, by segment reassortment. The potential for bunyavirus evolution by segment reassortment in vectors certainly exists. For example the Group C viruses in a small forest in Brazil seem to constitute a gene pool, with the 6 viruses related alternately by HI/NT and CF reactions, which assay respectively M RNA and S RNA gene products (Casals and Whitman, 1960; Shope and Causey, 1962). Direct evidence for naturally occurring reassortant bunyaviruses has also been obtained. Oligonucleotide fingerprint analyses of field isolates of LAC virus and members of the Patois serogroup of bunyaviruses have demonstrated that reassortment does occur in nature (El Said et al., 1979; Klimas et al., 1981; Ushijima et al., 1981). Determination of the genotypic frequencies of viruses selected by the biological interactions of viruses and vectors after dual infection and segment reassortment is an important issue. Should a virus result that efficiently interacts with alternate vector species, the virus could be expressed in different circumstances with serious epidemiologic consequences. Dual infection of vectors with different viruses is not unlikely, because many bunyaviruses are sympatric in nature. For example, the Ae. trivittatus-cottontail rabbit and the Ae. triseriatus-squirrel arbovirus cycles are sympatric in the ecotone between their respective grassland and forest ecosystems (LeDuc, 1979). Should a LaCrosse virus variant or reassortant evolve that was efficiently vectored by Ae. trivittatus mosquitoes, significantly more human infections with La Crosse virus would likely occur. Unlike Ae. triseriatus, Ae. trivittatus mosquitoes are not restricted to forested areas and consequently are more likely to encounter and to feed upon humans.(ABSTRACT TRUNCATED AT 400 WORDS)

Aedes↗
PubMed1988

Co-expression of the hepatitis B surface and core antigens using baculovirus multiple expression vectors.

The hepatitis B (HB) virus DNA sequences coding for the pre-core (preC) or C antigens (HBpcAg, HBcAg) have been inserted into the baculovirus plasmid transfer vector, pAcYM1, such that the HB viral sequences are under the control of the polyhedrin promoter of Autographa californica nuclear polyhedrosis virus (AcNPV). Spodoptera frugiperda cells infected with either of the derived recombinant plasmids in the presence of infectious AcNPV DNA yielded recombinant, polyhedrin-negative viruses that expressed high levels of the respective HBpcAg or HBcAg (representing approx. 5 to 10% and approx. 40% of the stained cellular proteins, respectively). The particulate 27 nm HBcAgs have been purified to homogeneity from infected cell extracts by density gradient centrifugation. Dual expression transfer vectors containing the HBcAg gene sequences and the coding sequences of the HB viral S antigen (HBsAg), each gene under the control of its own copy of the polyhedrin promoter, have also been constructed and used to derive recombinant viruses. The recombinant with the HB C and S genes expressed high levels of the HBcAg (approx. 40% of the cellular proteins) and low levels of the HBsAg (approx. 2% of the stained cellular proteins). Dual expression, occluded, recombinant baculoviruses that make HBsAg, as well as the AcNPV polyhedrin protein, have been prepared that are highly infectious for Trichoplusia ni caterpillars, allowing reproducible preparation of the antigen in larvae. Using radioimmunoassays (RIAs) and ELISAs, the recombinant HBcAg (RIA) and HBsAg (ELISA) have been used to identify human antibodies to HB virus with results that compare favourably with the data obtained with non-recombinant antigens.

Amino Acid Sequence↗
PubMed1988

Baculovirus expression of the small genome segment of Hantaan virus and potential use of the expressed nucleocapsid protein as a diagnostic antigen.

Autographa californica nuclear polyhedrosis virus (AcNPV) was used as an expression vector for the nucleocapsid protein gene of Hantaan virus. Two different cDNA clones representing the small genome segment of Hantaan virus were inserted into the transfer vector pAcYM1, and recombinants were generated by replacement of a portion of the baculovirus polyhedrin gene with the foreign, Hantaan virus gene. Recombinants containing both the first and second ATG initiation codons of the Hantaan virus gene produced nucleocapsid protein, while those containing only the second codon did not. The expressed nucleocapsid protein was evaluated as a potential diagnostic antigen with a variety of hantavirus-immune sera. The high levels of expression obtained, specific serological reactivity with immune sera and the low level of biological containment required for production of this protein all suggest a significant advantage over authentic viral antigen for diagnosis of hantavirus infection.

Antigens, Viral↗
PubMed1987

Identification of the N and NSS proteins coded by the ambisense S RNA of Punta Toro phlebovirus using monospecific antisera raised to baculovirus expressed N and NSS proteins.

An essentially complete DNA copy of the ambisense S RNA species of Punta Toro (PT) phlebovirus (T. Ihara, H. Akashi, and D.H.L. Bishop, 1984, Virology 136, 293-306) has been inserted in either orientation into Autographa californica nuclear polyhedrosis baculovirus (AcNPV) in lieu of the 5' coding region of the AcNPV polyhedrin gene (G.E. Smith, M.D. Summers, and M.J. Fraser, 1983, Mol. Cell. Biol. 3, 2156-2165). The two types of recombinant viruses were used to infect Spodoptera frugiperda cells and the expressed PT viral proteins characterized. Recombinant AcNPV having the S DNA in one orientation expressed PT virus N protein in amounts estimated to represent some 50% of the infected cell extracts, whereas recombinants with the S DNA in the other orientation expressed the putative PT virus NSS protein in lower quantities. Antisera that were monospecific with respect to each of the two PT proteins virus were raised in mice using the corresponding S. frugiperda infected cell extracts and were employed to identify N and NSS proteins in PT virus-infected Vero cells.

Animals↗