Vaccinia virus-encoded eIF-2 alpha homolog abrogates the antiviral effect of interferon.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to E Paoletti.
Explore the source record for details and available documents.
Recently, we have reported the complete nucleotide sequence of vaccinia virus (Goebel, S. J., Johnson, G. P., Perkus, M. E., Davis, S. W., Winslow, J. P., and Paoletti, E. 1990, Virology 179, 247-266). Approximately 2.2 kbp leftward of the large subunit of ribonucleotide reductase resides a 108-amino acid open reading frame, O2L (nt 62,851-62,528) with significant similarity to known glutaredoxins. The deduced amino acid sequence of open reading frame O2L is 28.7% identical to the yeast and Escherichia coli proteins and greater than 40% identical to various mammalian glutaredoxins. Similar patterns of hydrophobicity as well as alpha-helix and beta-sheet potentials suggest that O2L and the glutaredoxins share a similar secondary structure. Furthermore, a common function is inferred by the presence of a highly conserved redox-active site.
Immunization with recombinant vaccinia viruses that specified the synthesis of Japanese encephalitis virus (JEV) glycoproteins protected mice from a lethal intraperitoneal challenge with JEV. Recombinants which coexpressed the genes for the structural glycoproteins, prM and E, elicited high levels of neutralizing (NEUT) and hemagglutination inhibiting (HAI) antibodies in mice and protected mice from a lethal challenge by JEV. Recombinants expressing only the gene for the nonstructural glycoprotein, NS1, induced antibodies to NS1 but provided low levels of protection from a similar challenge dose of JEV. Antibodies to the NS3 protein in postchallenge sera, representing the degree of infection with challenge virus, were inversely correlated to NEUT and HAI titers and levels of protection. These results indicate that although vaccinia recombinants expressing NS1 can provide some protection from lethal JEV infection, recombinants expressing prM and E elicited higher levels of protective immunity.
Fowlpox virus (FPV) recombinants expressing influenza virus H5 haemagglutinin (HA), nucleoprotein (NP) or co-expressing both of these antigens were tested for vaccine efficacy in chickens. Immunization with the recombinant FPV-HA was highly efficacious but provided no cross protection between subtypes. Bursectomy established that immunity against the H5 subtype was antibody-mediated despite the presence of very low levels of antibody in the vaccinated birds. Immunization with the recombinant FPV expressing the cross-reactive NP antigen did not provide protective immunity despite hyperimmunization and provided no benefit above HA expressed alone. The results suggest that the kinetics of viral replication outpaces immunity induced by NP.
Recombinant avipox viruses have been developed expressing the rabies glycoprotein gene. A fowlpox-rabies recombinant has previously been shown to be protective against live rabies virus challenge in a number of non-avian species. This report describes the development of a canarypox-rabies recombinant. A comparison is made of the protective efficacy of this recombinant with other pox-rabies recombinants.
The bovine leukaemia virus (BLV) envelope gene encoding extracellular glycoprotein gp51 and transmembrane glycoprotein gp30 was cloned into the HA locus of vaccinia virus (Copenhagen strain), downstream of the vaccinia virus early-late promoter, H6, or a triple promoter element consisting of the promoter for the vaccinia virus H6 gene, the promoter for the cowpox virus A-type inclusion (ATI) gene and the promoter for the vaccinia virus HA gene. Inoculation of rabbits or sheep with the recombinant vaccinia virus coding for gp51 and gp30 or an uncleaved env precursor induced neutralizing antibodies to BLV. These antibodies competed with monoclonal antibodies directed against gp51 epitopes F, G, and H previously shown to be of crucial importance for BLV infection. Seven out of eight sheep vaccinated with the vaccinia recombinants resisted a drastic challenge (1.5 x 10(3) sheep infectious doses) with BLV-infected lymphocytes. These results show that vaccination with BLV env vaccinia recombinants protects sheep against infection with extremely high doses of BLV-infected heterologous lymphocytes.
The human cytomegalovirus (HCMV), Towne strain, glycoprotein B (gB) gene was cloned into a vaccinia vector (Copenhagen strain) under the control of the H6 early and late vaccinia promoters (Vac-gB recombinant). The gB protein was expressed in a high percentage of the Vac-gB-infected cells throughout the virus replication cycle. Cytosine-arabinoside (ara-C) did not influence the expression of the gB protein early after infection (5 h), but did inhibit it later in viral replication (7-29 h). The Vac-gB recombinant induced HCMV neutralizing antibodies in guinea-pigs. Cells infected with the Vac-gB recombinant absorbed 50-88% of neutralizing activity of human sera obtained from volunteers previously inoculated with the Towne or Toledo strains and from naturally seropositive individuals.
cDNA clones of the genes encoding either the hemagglutinin (HA) or fusion (F) proteins of the Edmonston strain of measles virus (MV) were expressed in vaccinia virus recombinants. Immunofluorescence analysis detected both proteins on the plasma membranes of unfixed cells as well as internally in fixed cells. Immunoprecipitation of metabolically radiolabeled infected-cell extracts by using specific sera demonstrated a 76-kDa HA polypeptide and gene products of 60, 44, and 23 kDa which correspond to a MV F precursor and cleavage products F0, F1, and F2, respectively. Neither recombinant induced cell fusion of Vero cells when inoculated individually, but efficient cell fusion was readily observed upon coinfection of cells with both recombinants. Inoculation of dogs with the vaccinia virus-MV F recombinant (VV-MVF) did not give rise to detectable MV-neutralizing antibody. Inoculation of dogs with the vaccinia virus-MV HA recombinant (VV-MVHA) or coinoculation with both recombinants (VV-MVF and VV-MVHA) induced significant MV-neutralizing titers that were increased following a booster inoculation. Inoculation of dogs with the vaccinia virus recombinants or with MV failed to induce canine distemper virus (CDV)-neutralizing antibodies. Upon challenge with a lethal dose of virulent CDV, signs of infection were observed in dogs inoculated with (VV-MVF). No symptoms of disease were observed in dogs that had been vaccinated with VV-MVHA or with VV-MVHA and VV-MVF and then challenged with CDV. All dogs vaccinated with the recombinant viruses as well as those inoculated with MV or a vaccine strain of CDV survived CDV challenge.
This study assessed the effect of recombinant human erythropoietin (r-HuEPO) on red cell membrane behaviour in patients undergoing hemodialysis (HD) and hemodiafiltration (HDF). We studied erythrocyte osmotic fragility (EOF), mechanical fragility (EMF) and deformability (ED) before and after r-HuEPO therapy in patients on conventional dialysis treatment with a cuprophan membrane and in subjects undergoing HDF with a polyacrylonitrile membrane. Non-uremic, non-anemic subjects were enrolled as controls. Red cell membrane defects were more evident in HD than in HDF; r-HuEPO seemed to improve deformability in both groups compared to controls (p less than 0.005) possibly through the great production of red cells during this therapy.
A recombinant fowlpox virus expressing the hemagglutinin-neuraminidase (HN) protein of Newcastle disease virus (NDV) strain Texas was generated. Immunoprecipitation with chicken anti-NDV serum confirmed authentic expression of the HN protein. Protection of chickens from infection with NDV was observed when birds were immunized with the recombinant HN fowlpox virus by the intramuscular route after one or two inoculations. Vaccination by the ocular route with a mixture of fowlpox recombinants expressing the fusion and HN proteins did not show added protection over that seen with the individual viruses.
The complete DNA sequence of the genome of vaccinia virus has been determined. The genome consisted of 191,636 bp with a base composition of 66.6% A + T. We have identified 198 "major" protein-coding regions and 65 overlapping "minor" regions, for a total of 263 potential genes. Genes encoded by the virus were located by examination of DNA sequence characteristics and compared with existing vaccinia virus mapping analyses, sequence data, and transcription data. These genes were found to be compactly organized along the genome with relatively few regions of noncoding sequences. Whereas several similarities to proteins of known function were discerned, the function of the majority of proteins encoded by these open reading frames is as yet undetermined.
Biochemical and genetic analyses have been conducted to determine whether a vaccinia virus open reading frame (orf) with extensive homology to the Saccharomyces cerevisiae DNA ligase gene encodes a functional ligase activity. This orf in HindIII A, designated A50R, is capable of encoding a 552-amino-acid, 63.4-kDa polypeptide. Full-length A50R mRNA produced in vitro directed the synthesis of a polypeptide with an apparent molecular weight of 57 kDa. Significantly, translation reactions programmed with A50R mRNA were capable of ligating a 3-kb Notl restriction fragment into multimers. DNA ligase activity was not detectable when either truncated sense or full-length antisense mRNA was translated in vitro. In extracts prepared from cells infected with wt vaccinia virus, DNA ligase activity was detected as assayed by the formation of a 57 kDa ligase-AMP adduct which was expressed early in the viral replication cycle. In cells infected with a DNA ligase deletion mutant no equivalent AMP-labeled adduct was detected. Relative to wt virus, the DNA ligase deletion mutant exhibited no significant differences in homologous recombination. These results indicate that the vaccinia orf A50R encodes a functional DNA ligase expressed early in infection, but this DNA ligase is nonessential for either recombination or viral replication.
A gene encoding an 18-kDa polypeptide (ORF C7L) located in the vaccinia virus HindIII C fragment was shown to be functionally equivalent to previously described host range gene (ORF K1L) spanning the HindIII K/M fragment junction. Either C7L or K1L host range gene is necessary and sufficient by itself to allow replication of vaccinia virus on human cells. Deletion of both C7L and K1L genes from the wild-type vaccinia genome is required to derive a virus deficient for replication on human cells. Further, an ORF encoding a 77-kDa polypeptide derived from cowpox (CP77kDa) and previously shown to allow vaccinia to overcome the restriction for replication on Chinese hamster ovary cells could substitute for the vaccinia host range genes C7L and K1L in permitting replication of the virus on human cells. Additionally, the three unique host range genes C7L, K1L, and CP77kDa were functionally equivalent for vaccinia replication on pig kidney cells, but not on rabbit kidney cells.
The phosphorylation of the internal and integral membrane (M1) protein of influenza virus was studied. Four points can be made based on the data: (1) The M1 contains at least two moles of phosphate per mole of M1. (2) Phosphorylation of M1 is conserved between influenza A, B and C viruses. Other characteristics of the M1 are also conserved, such as solubility in organic solvent, heterogeneity and ability to partition into lipid vesicles. (3) M1 is phosphorylated in cells infected with a vaccinia recombinant (vP273) containing only the gene of M1, either as a result of a vaccinia virus associated kinase or a cellular one. (4) The phosphate is located within or in close proximity to the major stretch of neutral and hydrophobic amino acids found in M1, as determined by analyzing cyanogen bromide fragments.
Homologous recombination was measured in vaccinia-infected cells cotransfected with two plasmid recombination substrates. One plasmid contains a vaccinia protein lacZ coding region bearing a 1.1 kb 3' terminal deletion while the other plasmid contains a non-promoted lacZ coding region bearing a 1.1 kb 5' terminal deletion. Homologous recombination occurring between the 825 bp of lacZ common to both plasmids regenerates a functional lacZ gene from which B-galactosidase expression was measured. The entire 3 kb lacZ gene was used as a positive control. A panel of thermosensitive mutants was screened in cells either transfected with the positive control plasmid or cotransfected with the recombination substrates. A DNA - mutant, ts42, known to map to the viral DNA polymerase gene was found to be defective in recombination. Significantly, other DNA - mutants, ts17 or ts25, or other DNA polymerase mutants did not exhibit a defect in recombination similar to ts42. Inhibitors of viral DNA synthesis did not uniformly affect recombination. Cytosine arabinoside and aphidicolin inhibited B-galactosidase expression from the recombination substrates but not from the positive control plasmid, whereas hydroxyurea enhanced expression from both. Marker rescue with the cloned wildtype DNA polymerase gene repaired the defect in ts42. Southern and western analyses demonstrated that B-galactosidase activity was consistent with a recombined lacZ gene and unit size 116 kDa protein. Measurement of plasmid and viral DNA replication in cells infected with the different DNA - mutants indicated that recombination was independent of plasmid and viral DNA replication. Together these results suggest that the vaccinia DNA polymerase participates in homologous recombination at a level other than that of DNA replication.
Pollen germination and tube growth are among the most sensitive responses to atmospheric pollution. Both these are inhibited by the acidity of the growth medium. Pollen grains from two species (Pinus cembra L. and Sambucus nigra L.) were germinated in media over a range of pHs (5.0, 4.5, 4.0, 3.5, 3.0 and 2.5) and six types of acidity (H(2)SO(4), HNO(3), H(2)SO(4): HNO(3) in 1:1, 2:1, 3:1 and 5:1 ratio). Pollen of the Gymnosperm is shown to be more resistant to acidity in the medium. Sulphuric acid alone and the ratio 2:1 with nitric acid are demonstrated to be the more harmful for P. cembra and S. nigra, respectively. The latter species was sensitive to all mixtures, particularly in respect to germination percentage.
The nucleotide sequence of a 6.4 kbp portion of the 10.6 kbp BamHI fragment D contained in the unique short region of the equine herpesvirus type 1 (EHV-1) genome has been determined. Analysis of this sequence revealed five open reading frames (ORFs), four complete and one incomplete, which were encoded by the same sense strand. Comparison of the EHV-1 DNA sequence with that encoding glycoproteins of other alphaherpesviruses has revealed no significant homologies. Comparison at the amino acid level, however, has demonstrated regions of significant sequence similarity between the three complete EHV-1 ORFs 2, 3 and 4, and the herpes simplex virus type 1 (HSV-1) glycoprotein gD encoded by the US6 gene, the HSV-1 glycoprotein gI encoded by the US7 gene and the HSV-1 glycoprotein gE encoded by the US8 gene, respectively. The interrupted ORF 5 was found to display partial homology with the HSV-1 US9-encoded protein, but no homology was found between the protein encoded by ORF 1 and other proteins. The three collinear EHV-1 ORFs encoding putative glycoproteins with homology to the HSV-1 glycoproteins were therefore designated EHV-1 gD, gI and gE, respectively. Moreover, further similarities were found between EHV-1 gD and pseudorabies virus (PRV) gp50, between EHV-1 gI and PRV gp63 and varicellazoster virus (VZV) gpIV, and between EHV-1 gE and PRV gI and VZV gpI. It is concluded that EHV-1, PRV, HSV-1 and VZV encode homologous glycoprotein genes in the small unique components of their genomes and that the genetic organization of these regions is conserved.
A nucleoprotein (NP) preparation purified from the chorioallantoic membrane of chicken eggs infected with fowl plague virus (A/FPV/Rostock/34, H7N1) yielded, in addition to the commonly known 56K protein, a 42K component that could not be detected in virus particles. After testing with a series of NP-specific monoclonal antibodies it was found that some reacted with both proteins and others were bound only by the 56K protein. Among both types of NP-specific monoclonal antibodies only a limited number were bound to infected murine cells. Some antibodies bound to cells infected with a given subtype failed to react with the surface of cells infected with a different subtype. Binding was demonstrated by cellular ELISA, radioimmunoassay and immunofluorescence. The results indicate that only restricted antigenic domains of the native NP and perhaps NP fragments are exposed at the surface of infected murine cells. Additionally, the purified NP preparation was used to immunize mice in order to determine the protective capacity of cell-associated NP. In parallel, and as a relevant control, mice were immunized with a vaccinia virus recombinant containing the gene for NP prior to challenge with infectious virus. High levels of monospecific antibodies and a cytotoxic T cell activity was found in mice immunized with purified NP or infected with the vaccinia recombinant after secondary restimulation in vitro. After treatment with specific antibodies the cytotoxic cells were shown to be classical CD8+ cytotoxic T lymphocytes. Despite the elicitation of a humoral and a cellular immune response by the forms of NP employed mice were not protected from influenza virus infection.