bluuebunny/crossref_metadata_2025 huggingface dataset:
Inverse relationship between constitutive gamma interferon production and human T-cell lymphoma/leukemia virus expression in cultured T lymphocytes
Authors: Moore J L , Poiesz B J , Zamkoff K W , Merl S A , Hanna S , Gazdar A F , Comis R L
Published: January 2020

Particular interest in human T lymphocyte lymphoma/leukemia virus (HTLV) derives from the close association of HTLV with several types of human mature T lymphocyte malignancies and the strong possibility that HTLV is the causative agent of this group of leukemias and lymphomas. This is the first report to show that HTLV expression in T lymphocytes cultured in vitro is inversely proportional to constitutive gamma interferon production. Of 16 fresh T lymphocyte cultures established from patients with mature T lymphocyte neoplasias, 3 were grown continuously for over 3 years and 13 were grown for 2 to 8 months in culture. Of the 16 cultures, 9 were HTLVp19 positive and interferon negative, whereas the remaining 7 were HTLVp19 negative or weakly positive and also interferon positive (12 to 105 U/ml). The prototype HTLV-positive T-cell line (HUT102) was examined over a long-term culture and after selective cell cloning for high virus yield. Results indicate that early-passage, low-HTLV-producing HUT102 cells constitutively produced significant levels of gamma-immune interferon. In late-passage and cloned HUT102 cells, an increase in HTLV production was concordant with a decrease in constitutive interferon production and the loss of mature T lymphocyte antigens. Transformation of human umbilical cord blood lymphocytes by HTLV was possible only after cocultivation with the non-interferon, high virus-producing, cloned HUT102 T lymphocytes. The inverse relationship between interferon and HTLV production was also observed when normal human umbilical cord blood and adult T lymphocytes were transformed by HTLV and maintained in culture.
Sensitivity of arabinosyladenine-resistant mutants of herpes simplex virus to other antiviral drugs and mapping of drug hypersensitivity mutations to the DNA polymerase locus
Authors: Coen D M , Fleming H E , Leslie L K , Retondo M J
Published: January 2020

Seven herpes simplex virus mutants which have been previously shown to be resistant to arabinosyladenine were examined for their sensitivities to four types of antiviral drugs. These drugs were a pyrophosphate analog, four nucleoside analogs altered in their sugar moieties, two nucleoside analogs altered in their base moieties, and one altered in both. The seven mutants exhibited five distinct phenotypes based on their sensitivities to the drugs relative to wild-type strain KOS. All mutants exhibited resistance to acyclovir and arabinosylthymine, as well as marginal resistance to iododeoxyuridine, whereas all but one exhibited resistance to phosphonoformic acid. The mutants exhibited either sensitivity or hypersensitivity to other drugs tested--2'-nor-deoxyguanosine, 5-methyl-2'-fluoroarauracil, 5-iodo-2'-fluoroarauracil, and bromovinyldeoxyuridine--some of which differed only slightly from drugs to which the mutants were resistant. These results suggest ways to detect and treat arabinosyladenine-resistant isolates in the clinic. Antiviral hypersensitivity was a common phenotype. Mutations conferring hypersensitivity to 2'-nor-deoxyguanosine in mutant PAAr5 and to bromovinyldeoxyridine in mutant tsD9 were mapped to nonoverlapping regions of 1.1 and 0.8 kilobase pairs, respectively, within the herpes simplex virus DNA polymerase locus. Thus, viral DNA polymerase mediates sensitivity to these two drugs. However, we could not confirm reports of mutations in the DNA polymerase locus conferring resistance to these two drugs. All of the mutants exhibited altered sensitivity to two or more types of drugs, suggesting that single mutations affect recognition of the base, sugar, and triphosphate moieties of nucleoside triphosphates by viral polymerase.
Temperature-sensitive viral RNA expression in Moloney murine sarcoma virus ts110-infected cells
Authors: Hamelin R , Brizzard B L , Nash M A , Murphy E C , Arlinghaus R B
Published: January 2020

We examined the mos-specific intracellular RNA species in 6m2 cells, an NRK cell line nonproductively infected with the ts110 mutant of Moloney murine sarcoma virus. These cells present a normal phenotype at 39 degrees C and a transformed phenotype at 28 or 33 degrees C, expressing two viral proteins, termed P85gag-mos and P58gag, at 28 to 33 degrees C, whereas only P58gag is expressed at 39 degrees C. It has been previously shown that 6m2 cells contain two virus-specific RNA species, a 4.0-kilobase (kb) RNA coding for P58gag and a 3.5-kb RNA coding for P85gag-mos. Using both Northern blot and S1 nuclease analyses, we show here that the 3.5-kb RNA is the predominant viral RNA species in 6m2 cells grown at 28 degrees C, whereas only the 4.0-kb RNA is detected at 39 degrees C. During temperature shift experiments, the 3.5-kb RNA species disappears after a shift from 28 to 39 degrees C and is detected again after a shift back from 39 to 28 degrees C. By Southern blot analysis, we have detected only one ts110 proviral DNA in the 6m2 genome. This observation, as well as previously published heteroduplex and S1 nuclease analyses which showed that the 3.5-kb RNA species lacks about 430 bases found at the gag gene-mos gene junction in the 4.0-kb RNA, suggests that the 3.5-kb RNA is a splicing product of the 4.0-kb RNA. The absence of the 3.5-kb RNA when 6m2 cells are grown at 39 degrees C indicates that the splicing reaction is thermosensitive. The splicing defect of the ts110 Moloney murine sarcoma virus viral RNA in 6m2 cells cannot be complemented by acute Moloney murine leukemia virus superinfection, since no 3.5-kb ts110 RNA was detected in acutely superinfected 6m2 cells maintained at 39 degrees C. The spliced Moloney murine leukemia virus env mRNA, however, is found in acutely infected cells maintained at 39 degrees C, suggesting that the lack of ts110 viral RNA splicing at 39 degrees C is not due to an obvious host defect. In sharp contrast, however, 6m2 cells chronically superinfected with Moloney murine leukemia virus produce a 3.5-kb RNA species at 39 degrees C as well as at 28 degrees C and contain proviral DNAs corresponding to the two viral RNA species.(ABSTRACT TRUNCATED AT 400 WORDS)
Adenovirus 3 fiber polypeptide gene: implications for the structure of the fiber protein
Authors: Signäs C , Akusjärvi G , Pettersson U
Published: January 2020

The nucleotide sequence of a 1,330-base-pair-long DNA segment located between map coordinates 88.5 and 92.3 in the adenovirus type 3 (Ad3) genome was determined. Transcripts from the r-strand of the region were mapped by S1 nuclease analysis and by in vitro translation of RNA, selected by filter hybridization. The results revealed that the sequenced region encodes the Ad3 fiber polypeptide with a molecular weight of 34,800. A comparison between the predicted amino acid sequences of the Ad3 and the Ad2 fiber polypeptides revealed that they have almost identical secondary structures, consisting of a tail, a shaft, and a knob. A striking difference between Ad2 and Ad3 fibers was that the shaft of the Ad3 fiber was significantly shorter, containing only 6 repeat units compared with 22 in the Ad2 fiber. The secondary structure suggests that the fiber is a dimeric structure, as proposed earlier (N.M. Green, N.G. Wrigley, W.C. Russell, S.R. Martin, and A.D. McLachlan, EMBO J. 2:1357-1365, 1983), with the size of the polypeptide determining the length of the fiber protein.
Response of a phage modification factor to enhanced production of its target molecule
Authors: Olson N J , Marchin G L
Published: January 2020

Escherichia coli cells with plasmids bearing the valS gene were constructed from the Clark-Carbon collection. Their increased valyl-tRNA synthetase (EC 6.1.1.9) activity was not matched by commensurate production of a modifying peptide during T4 infection. Thus, phage vs gene expression is set to modify the normal amount of valyl-tRNA synthetase activity.
Analysis of the major transcripts encoded by the long repeat of human cytomegalovirus strain AD169
Authors: McDonough S H , Staprans S I , Spector D H
Published: January 2020

In this report, we describe the size and kinetics of appearance of RNAs from the long repeat of human cytomegalovirus. The most abundant RNA from this region was a 2.7-kilobase (kb) species that was detected throughout the infection and was most abundant at 27 and 72 h after infection. The 2.7-kb RNA was the only major species detected with a probe that included the terminus of the long repeat and the heterogeneous L-S junction region. Other transcripts were detected with probes from the internal portion of the long repeat, including an immediate-early RNA of 1.3 kb, early and late RNAs of 1.2 kb, and minor late transcripts of 4.4, 3.6, 3.3, and 1.8 kb. S1 nuclease and exonuclease VII protection analyses of RNA from immediate-early, early, midpoint, and late times in the infection indicated that the major 2.7-kb RNA was not spliced and that the RNA mapped within the long repeat, 1.6 kb from the heterogeneous region. No evidence for temporally regulated changes in transcription initiation, splicing, or choice of 3' end of this RNA was observed. Nuclease protection analysis also demonstrated that the second most abundant late RNA from this region, the 1.2-kb species, was not spliced and had the same polarity as the 2.7-kb RNA. The 1.2-kb also mapped entirely within the long repeat, with its 3' terminus 1.7 kb upstream from the 5' terminus of the 2.7-kb RNA.
An adenovirus early region 1A protein is required for maximal viral DNA replication in growth-arrested human cells
Authors: Spindler K R , Eng C Y , Berk A J
Published: January 2020

Two closely related adenovirus early region 1A proteins are expressed in transformed cells. The smaller of these, which is 243 amino acids in length, is required for the transformation of primary rat cells and for the transformation of immortalized rat cells to anchorage-independent growth. This protein is not required for productive infection of exponentially growing HeLa cells but is required for maximal replication in growth (G0)-arrested human lung fibroblasts (WI-38 cells). To determine the function of this protein in viral replication in these G0-arrested cells, we compared viral early mRNA, early protein, and late protein synthesis after infection with wild type or a mutant which does not express the protein. No differences were found. However, viral DNA synthesis by the mutant was delayed and decreased to 20 to 30% that of wild type in these cells. Viral DNA synthesis was much less defective in growing WI-38 cells, and in the transformed human HeLa cell line it occurred at wild-type levels. Furthermore, the mutant which can express only the 243-amino-acid early region 1A protein induced cellular DNA synthesis in G0-arrested rat cells to the same level as wild-type virus. A mutant which can express only the 289-amino-acid early region 1A protein induced less cellular DNA synthesis in G0-arrested rat cells. We propose that the early region 1A 243-amino-acid protein alters the physiology of arrested permissive cells to allow maximal viral DNA replication. In nonpermissive rodent cells, the 243-amino-acid protein drives G0-arrested cells into S phase. This activity is probably important for the immortalization of primary cells.
Characterization of a porcine kidney cell line resistant to influenza virus infection
Authors: Kimura Y , Yokochi T , Miyadai T , Yoshida K , Yokoo J , Matsumoto K
Published: January 2020

A mutant cell line of porcine kidney cells that resists the cytopathic effect of influenza virus has been obtained and characterized. These cells, designated ESK-R, were originally obtained by prolonged cultivation of cells surviving influenza B/Kanagawa/73 virus infection. No infectious virus was recovered from ESK-R cells, and no evidence for the presence of virus antigens in the cells was demonstrated by immunofluorescent staining. ESK-R cells also showed a distinct resistance to various other strains of both types A and B influenza viruses. The growth of mumps, Sendai, or Newcastle disease virus was considerably restricted, but the cell line normally supported the replication of vesicular stomatitis virus. ESK-R cells were found to lack specific receptors for influenza virus as determined by fluorescence-activated cell sorter analyses. The membrane barrier of ESK-R cells was successfully overcome by nonspecific endocytosis of calcium-coprecipitated virus particles followed by production of an appreciable amount of progeny virus.
Genetic analysis of the susceptibility of mouse cytomegalovirus to acyclovir
Authors: Sandford G R , Wingard J R , Simons J W , Staal S P , Saral R , Burns W H
Published: January 2020

Eight independently derived mouse cytomegalovirus (MCMV) mutants resistant to acyclovir (ACV) were obtained by the sequential plating of wild-type virus in increasing concentrations of ACV. Results of complementation studies among these eight mutants suggest that all had mutations within the same or closely associated genes. A ninth MCMV mutant resistant to phosphonoacetate (PAA) derived by plating wild-type virus in the presence of 100 micrograms of PAA per ml displayed coresistance to ACV and was unable to complement any of the ACV-derived mutants. Recombination experiments among all combinations of the nine MCMV mutants were performed and supported the complementation data in that no recombination could be detected. Seven of the eight ACV-resistant mutants demonstrated cross-resistance to PAA and hypersensitivity to aphidicolin. The one mutant not coresistant to PAA was more susceptible to PAA than was the parent virus. Only a few mutants demonstrated coresistance when the mutants were tested against 9-beta-D-arabinofuranosyladenine (ara-A). The ACV mutant that demonstrated increased susceptibility to PAA was 30-fold more susceptible to ara-A but remained unchanged in susceptibility to aphidicolin. Two of the parent-mutant combinations were selected for DNA synthesis analysis in the presence of ACV (5 microM). A significant decrease in DNA synthesis was demonstrated for both parent viruses, and there was little effect on mutant virus DNA synthesis at the same drug concentration. These results suggest that susceptibility of MCMV to ACV is confined to a product of a single gene and that a mutation of this gene can lead to an altered phenotype when compared with parent virus in susceptibility of DNA synthesis to PAA, ara-A, and aphidicolin, drugs that are known to inhibit DNA polymerase activity.
Detection and physical map of a omega tox+-related defective prophage in Corynebacterium diphtheriae Belfanti 1030(-)tox-
Authors: Rappuoli R , Ratti G , Perugini M , Murphy J R
Published: January 2020

A library of chromosomal DNA from Corynebacterium diphtheriae Belfanti 1030(-)tox- was cloned in the lambda phage vector EMBL4 and screened for sequences homologous to corynephage omega tox+ and the attB1-attB2 region of the C7(-)tox- chromosome. Two portions of the 1030(-)tox- chromosome, 35 and 30.5 kilobases long which contain, respectively, the entire region homologous to corynephage omega tox+ and the attB1-attB2 sites, were mapped with the restriction endonucleases BamHI and EcoRI. Chromosomal DNA from 1030(-)tox- was shown to contain a 15.5-kilobase region that was homologous to ca. 42% of the corynephage omega tox+ genome. These sequences were found to hybridize to three regions of the phage genome and do not contain either the diphtheria tox operon or the attP site. These sequences are distant from the chromosomal region that contains the attB1-attB2 sites. Moreover, unlike other known defective prophages, the physical map of this prophage starts at the cos site and is colinear with the vegetative phage map. The 30.5-kilobase region of the 1030(-)tox- chromosome, which contains the attB1-attB2 sites, has a central core region that is almost identical to the corresponding region of the C7(-)tox- chromosome; however, the flanking sequences in these two strains of C. diphtheriae are different.
A monoclonal antibody that neutralizes poliovirus by cross-linking virions
Authors: Thomas A A , Brioen P , Boeyé A
Published: January 2020

The neutralization of type 1 poliovirus by monoclonal antibody 35-1f4 was studied. The virions were rapidly linked by antibody into oligomers and larger aggregates, followed by slow redistribution of antibody between the immune complexes. The antibody content and infectivity of immune complexes were determined. Remaining single virions were fully infectious and free of antibody. The oligomers and larger aggregates did not significantly contribute to the residual infectivity, which therefore correlated with the number of remaining single virions. Papain digestion of neutralized poliovirus released fully infectious, antibody-free virions from the immune complexes. Anti-immunoglobulin antibodies reneutralized these virions. Polymerization was shown to occur even at virus concentrations of less than 10(3) PFU per ml.
High-frequency transduction of c-erbB in avian leukosis virus-induced erythroblastosis
Authors: Miles B D , Robinson H L
Published: January 2020

Twenty-one cases of Rous-associated virus type 1-induced erythroblastosis have been analyzed for novel restriction endonuclease fragments of c-erbB. Twenty of the erythroleukemias contained novel c-erbB fragments; 10 of these were found to contain a proviral insertion in c-erbB, and 10 were found to have a new transduction of c-erbB. Each of the proviral insertions was in the same transcriptional orientation as c-erbB, and most appeared to have retained both long terminal repeats as well as 5' viral sequences that signal packaging of RNA into virions. Each of the new c-erbB transducing viruses had a characteristic EcoRI fragment that contained a spliced form of c-erbB sequences. When inoculated into 1-week-old chickens, the new transducing viruses caused rapid-onset erythroblastosis.
A 1.6-kilobase-pair fragment in the genome of the ts1 mutant of Moloney murine leukemia virus TB that is associated with temperature sensitivity, nonprocessing of Pr80env, and paralytogenesis
Authors: Yuen P H , Malehorn D , Knupp C , Wong P K
Published: January 2020

ts1 and ts7, two temperature-sensitive mutants of Moloney murine leukemia virus strain TB induce hind-limb paralysis in 100% of CFW/D mice injected. These two paralytogenic mutants also share a defect in their inability to process the env precursor protein, Pr80env, at the restrictive temperature. To identify the mutation(s) in the genomes of the paralytogenic mutants which cause the inability to process Pr80env efficiently and confer the ability to cause hind-limb paralysis instead of lymphoma, we constructed chimeric genomes between ts1 and Moloney murine leukemia virus or the TB strain of the virus. We identified a 3.9-kilobase-pair HindIII-PstI sequence from nucleotides 4895 through 8264 and 1 through 567 of ts1, comprising the 3' end of the pol and all of the env genes, the long terminal repeat, and the 5' noncoding sequence, as being responsible for the temperature sensitivity, the inefficiency in processing Pr80env, and the induction of paralysis. We extended these findings by demonstrating that the 1.6-kilobase-pair pol-gp70 HindIII-BamHI DNA sequence from nucleotides 4895 through 6537 of ts1 within the 3.9-kilobase-pair HindIII-PstI fragment is necessary for ts1 to induce paralysis. In addition, we showed that this 1.6-kilobase-pair fragment also controls the processing of Pr80env and the temperature sensitivity of ts1.
Simian agent 12 is a BK virus-like papovavirus which replicates in monkey cells
Authors: Cunningham T P , Pipas J M
Published: January 2020

We have begun to characterize the genomic structure and replication of the baboon papovavirus simian agent 12 (SA12). We have defined a wild-type clone of SA12 (SA12 wt100) by plaque purification from a heterogeneous stock. The functional map of SA12 wt100 can be aligned with those of the other primate papovaviruses by assigning one of the two EcoRI sites as 0/1.0 map units. The origin of bidirectional viral DNA replication maps near 0.67 map units, consistent with the limits of sequences homologous to origin sequences in the other papovaviruses. DNA sequence analysis shows that the organization of the SA12 genome is similar to that of the other primate papovaviruses studied. The arrangement and sequence of functional elements in the origin of replication region, as well as the sequences of the N-terminal regions of early protein products, indicate that SA12 is most closely related to the human virus BK, next most closely related to JC virus, and less closely related to simian virus 40. Unlike BK virus, SA12 is capable of productive infection of African green monkey kidney cells.
Human rhinovirus 14 infection of HeLa cells results in the proteolytic cleavage of the p220 cap-binding complex subunit and inactivates globin mRNA translation in vitro
Authors: Etchison D , Fout S
Published: January 2020

One of the characteristics of picornavirus infection of cells in tissue culture is a specific inhibition of utilization of host cell mRNA for protein synthesis. In this study we show that human rhinovirus 14 is similar to poliovirus in that the inhibition of host cell translation that occurs during infection correlates with the proteolytic cleavage of an Mr 220,000 subunit of the cap-binding protein complex.
Intracellular synthesis of human parainfluenza type 3 virus-specified polypeptides
Authors: Wechsler S L , Lambert D M , Galinski M S , Pons M W
Published: January 2020

The intracellular synthesis of human parainfluenza type 3 virus-specified polypeptides was examined by polyacrylamide gel electrophoresis of [35S]methionine-labeled cell extracts under reducing conditions. All of the virion structural proteins were detected in cell extracts, including: L, 180,000 molecular weight (180K); P, 83K; HN, 69K; NP, 66K; F0, 60K; F1, 51K; and M, 38K. P and NP were phosphorylated. HN and F were glycosylated. The kinetics of intracellular viral protein synthesis did not detect any early or late proteins. Pulse-chase experiments failed to detect any precursor-product relationships. No nonstructural proteins were detected.
Nucleotide sequence of a full-length human endogenous retroviral segment
Authors: Repaske R , Steele P E , O'Neill R R , Rabson A B , Martin M A
Published: January 2020

The nucleotide sequence of a full-length (8.8-kilobase) endogenous C-type human retroviral DNA (clone 4-1) is presented and compared with that of Moloney murine leukemia virus (MoMuLV) DNA. Colinearity of deduced amino acids of clone 4-1 with MoMuLV in the gag and pol regions was clearly evident, and overall amino acid homology in these regions was about 40%. Identification of the putative N terminus of gag and p30, the gag-pol junction, and the C terminus of pol could be established on the basis of sequence homology with MoMuLV. Unique characteristics of the endogenous human retroviral DNA included a tRNA Glu primer binding site separated from the 5' long terminal repeat by a pentanucleotide and a putative env sequence which does not appear to overlap the C terminus of pol and has virtually no homology with the env gene of known infectious retroviruses. Clone 4-1 represents a defective prototype of a human C-type retrovirus which integrated into the germ line some time in the distant past.
DNA sequence of the leftward junction in the adenovirus-simian virus 40 hybrid Ad2+D2 and determination of the structure of the D2-T antigen
Authors: Baumann E A , Baur C P , Baack M , Beck S
Published: January 2020

The nucleotide sequence of the junction between the simian virus 40 early region and the adenovirus type 2 late region L4 in the hybrid virus Ad2+D2 was determined. The deduced amino acid sequence suggests that the D2-T antigen is a chimeric protein sharing 594 amino acids with the C-terminal end of the simian virus 40 T antigen and 104 amino acids with the N terminus of the adenovirus type 2 33,000-molecular-weight protein. The predicted structure of the D2-T antigen was confirmed by an immunoprecipitation analysis.
Tissue-specific expression of the newly acquired ecotropic Emv-18 provirus in Fv-2 congenic mice
Authors: Robson I B , Mowat M , Bernstein A
Published: January 2020

Expression of endogenous retroviral sequences in Fv-2 congenic mouse strains was examined by Northern blot analysis. Endogenous ecotropic virus transcripts were observed in total spleen RNA of B6.S (Fv-2ss) mice. Endogenous ecotropic transcripts were not detected in spleen RNA of C57BL/6, the Fv-2rr congenic partner of B6.S, nor in spleens of the C57BL/10 (Fv-2rr) and B10.C (Fv-2ss) congenic strains. Mendelian segregation analysis revealed that only backcross mice segregating the newly acquired Fv-2-linked endogenous ecotropic provirus had endogenous ecotropic transcripts in spleen RNA. Examination of different tissues of B6.S mice showed that Emv-18 transcription was highest in spleen and bone marrow, tissues in which Fv-2 has been shown to function. These results support the conclusion that chromosomal location is an important factor controlling Emv-18 expression in B6.S mice. We also report the presence in the spleen of a novel xenotropic virus transcript detectable only in B6.S mice.
Transformation by Epstein-Barr virus requires DNA sequences in the region of BamHI fragments Y and H
Authors: Skare J , Farley J , Strominger J L , Fresen K O , Cho M S , zur Hausen H
Published: January 2020

Eight independent recombinant Epstein-Barr virus genomes, each of which was a transforming strain, were made by superinfecting cell lines containing Epstein-Barr virus DNA (Raji or B95-8 strain) with a nontransforming virus (P3HR1 strain). A knowledge of the constitution of each transforming recombinant allowed the localization of the defect in the genome of the nontransforming parent to a 12-megadalton sequence within the EcoRI A fragment. Within this region, the nontransforming virus has a deletion of the BamHI Y fragment and about half of the sequences in the adjacent BamHI H fragment. The present data suggest that this deletion is responsible for the nontransforming phenotype. Furthermore, mapping a deletion in one of the recombinant genomes allowed the conclusion that a sequence (comprising about 20% of the Epstein-Barr virus genome) from the center of BamHI-D to BamHI-I' is not necessary for the maintenance of transformation by Epstein-Barr virus.
Cloning and sequence of DNA encoding structural proteins of the autonomous parvovirus feline panleukopenia virus
Authors: Carlson J , Rushlow K , Maxwell I , Maxwell F , Winston S , Hahn W
Published: January 2020

Approximately 80% of the genome of feline panleukopenia virus was cloned into pBR322. This DNA included the transcription unit for the major viral mRNA species. The nucleotide sequence of the cloned portion of the genome was determined. Comparison of the feline panleukopenia virus sequence with the sequences of the parvoviruses minute virus of mice and H-1 revealed considerable homology between the three viruses on both the nucleic acid and protein levels. Based on this homology, a model for the generation of the two size classes of viral structural proteins (VP1 and VP2') is proposed.
Role of complement and the Fc portion of immunoglobulin G in immunity to Venezuelan equine encephalomyelitis virus infection with glycoprotein-specific monoclonal antibodies
Authors: Mathews J H , Roehrig J T , Trent D W
Published: January 2020

We have previously characterized with monoclonal antibodies (MAbs) seven unique epitopes on the two envelope glycoproteins of Venezuelan equine encephalomyelitis (VEE) virus vaccine strain TC-83. The epitopes important in protection from VEE virus infection were determined in passive antibody transfer studies, with virulent VEE (Trinidad donkey) virus as the challenge virus. Selected high-avidity MAbs to the three major protective epitopes (E2c, E1b, and E1d) were assayed for in vitro complement activity. All three fixed murine complement to high titer. Limited pepsin digestion of the anti-E2c in the presence of cysteine resulted in a rapid decrease and complete loss of complement-fixing ability by 2 h, but the majority of mice, except at the lowest dilution of MAb, were protected until the Fc termini were cleaved at 3 h. Anti-E2c F(ab')2 would neutralize VEE (Trinidad donkey) virus more efficiently than either Fab' or Fab; none of the fragments would fix complement or was effective in passive protection. C5-deficient mice and mice depleted of C3 with cobra venom factor were still protected from VEE (Trinidad donkey) virus challenge after passive transfer of either anti-E2c or anti-E1b MAb. The results show that the anti-E2c MAb mediates neutralization through bivalent binding at a critical site on the virion and that Fc effector functions, other than complement, are necessary for protection. Although the ability of the anti-E2c MAb to fix complement was associated with its ability to protect in vivo, no direct cause-and-effect relationship was found. Since the epitope defined by the anti-E1d antibody is found on the cell membrane, but is not expressed on the infectious virion, protection in mice was most likely mediated at the cellular level, possibly by inhibition of the final stages of virion maturation.
Golgi-derived membranes that contain an acylated viral polypeptide are used for vaccinia virus envelopment
Authors: Hiller G , Weber K
Published: January 2020

A 37,000-dalton polypeptide (p37K) present on purified extracellular vaccinia virus but absent from intracellular virus particles of classical morphology (G. Hiller et al., J. Virol. 39:903-913, 1981; L. G. Payne, J. Virol. 27:28-37, 1978) was further characterized. The polypeptide was only expressed in infected cells after onset of viral DNA replication. Phase partition experiments showed that it is relatively hydrophobic. Although p37K apparently is not a glycoprotein, in vivo radioisotope labeling detected tightly associated palmitic acid. Antibodies to p37K were used to monitor its distribution within infected cells at the light and electron microscopic levels. After synthesis p37K first accumulated in the Golgi region due to a tight membrane association. During progressing infection p37K-carrying membranes were used to form double-walled envelopes around brick-shaped vaccinia particles. Within these specialized vesicles vaccinia particles were moved through the cytoplasm toward the cell's surface, presumably along cellular routes for certain secretory products. Finally, single enveloped viruses were released into the extracellular space by an exocytotic process.
Genetic mapping of lymphocytic choriomeningitis virus pathogenicity: virulence in guinea pigs is associated with the L RNA segment
Authors: Riviere Y , Ahmed R , Southern P J , Buchmeier M J , Oldstone M B
Published: January 2020

The Armstrong CA 1371 (ARM) and WE strains of lymphocytic choriomeningitis virus (LCMV) differ in the ability to produce disease in adult guinea pigs. Infection with the ARM strain is not lethal, even at high virus doses (greater than 10,000 PFU), whereas the WE strain causes 100% mortality even at low doses (less than 10 PFU). To determine the genetic basis of this virulence, intertypic reassortants were made between the ARM and WE strains of LCMV. The two reassortants with the genotypes WE/ARM (L segment of WE and S segment of ARM) and ARM/WE (L segment of ARM and S segment of WE) were tested for their pathogenicity in guinea pigs. The ARM/WE reassortant was avirulent like the ARM/ARM parental strain. Minimal viral replication was observed in organs of guinea pigs inoculated with 10(2) or 10(5) PFU of ARM/ARM or ARM/WE, and all animals survived. In contrast, the WE/ARM reassortant was highly virulent like the WE/WE parental strain and killed all of the infected animals. High levels of viral replication were observed in guinea pigs infected with the latter two strains. In contrast to these in vivo observations, both the parental strains and the ARM/WE or WE/ARM reassortants had similar growth potential in cultured guinea pig fibroblasts. Thus, the L RNA segment of LCMV WE is important for viral replication in vivo and is associated with fatal acute disease after infection of adult guinea pigs.
Binding of complement component C3b to glycoprotein C is modulated by sialic acid on herpes simplex virus type 1-infected cells
Authors: Smiley M L , Friedman H M
Published: January 2020

Neuraminidase treatment of cells infected with herpes simplex virus type 1 (HSV-1) markedly enhanced the binding of complement component C3b to HSV 1 glycoprotein C (gC). When HSV-1 was grown in BHK RicR14 cells in which glycoproteins had reduced amounts of N-linked complex oligosaccharides, including sialic acid, the binding of C3b to gC was markedly enhanced. We used neuraminidase treatment to demonstrate that cloning the gC gene from the HSV-1 F strain into an HSV-1 mutant which fails to express gC converted the mutant virus from C3b receptor negative to receptor positive. These results further support a role for gC as a C3b receptor and indicate that sialic acid modifies receptor activity.
Formation of a cruciform structure at the simian virus 40 replication origin abolishes T-antigen binding to the origin in vitro
Authors: Tenen D G , Haines L L , Hansen U M , Martin R G , Livingston D M
Published: January 2020

Heteroduplex DNA molecules were formed by annealing an intact simian virus replication origin-containing fragment to a mutant derivative lacking the indigenous wild-type 27-base-pair (bp) inverted repeat within this structure and containing a nonhomologous 26-bp inverted repeat sequence in its place. Results of restriction enzyme and S1 endonuclease cleavage analyses strongly suggested that a 13-bp stem-loop structure formed at the site of nonhomology between these two DNAs. This structure lies within the boundary of simian virus 40 T-antigen-binding site 2, and its presence inhibited T-antigen binding to that sequence but not to an adjacent higher-affinity binding site (site 1). Therefore, the conformation of sequences within an otherwise intact T-antigen-binding site can have major effects upon T-antigen binding there.
Specificity of Fc receptors induced by herpes simplex virus type 1: comparison of immunoglobulin G from different animal species
Authors: Johansson P J , Myhre E B , Blomberg J
Published: January 2020

Cells infected with herpes simplex virus type 1 (HSV-1) express a cell surface receptor able to bind the Fc portion of immunoglobulin G (IgG). Of the four human IgG subclasses, the HSV-1 Fc receptor, like staphylococcal protein A, binds to all except IgG3. In this paper, we describe the binding of a number of animal IgG and IgG subclass molecules to HSV-1-infected cells and compare this binding to that of protein A. Although only few representatives from each animal order were tested, we found that IgG from Carnivora and Rodentia did not bind or bound only slightly to the HSV-1 receptor, whereas IgG from Primates, Lagomorpha, and Artiodactyla bound well. This pattern was clearly different from the species spectrum of IgG binding of protein A. Differences between the two receptors were also found when animal IgG subclasses were tested. The pronounced differences in affinity for the HSV-1 Fc receptor between immunoglobulins from, for example, mouse and rabbit may influence the interpretation of animal studies with this virus.
Transcription mapping of the varicella-zoster virus genome
Authors: Ostrove J M , Reinhold W , Fan C M , Zorn S , Hay J , Straus S E
Published: January 2020

RNA was isolated from varicella-zoster virus-infected Flow 5000 cells (diploid fibroblasts) at late times after infection. With the use of overlapping DNA probes representing all regions of the varicella-zoster genome, an extensive Northern blot analysis of the RNA was carried out. The analysis revealed at least 58 discrete transcripts ranging in size from approximately 0.8 to 6.5 kilobases. RNAs were found to be homologous to all probes used except for those mapping at approximately map unit 0.3, where no RNA transcripts could be detected. Comparison of the sizes and locations of RNA transcripts mapping in the right-hand ends of the varicella-zoster virus and the herpes simplex virus DNAs shows a number of striking analogies, suggesting their similar genomic organization.
Map of DNA homology between the genomes of Salmonella bacteriophages P22 and L
Authors: Wiggins B A , Hilliker S
Published: January 2020

The genomes of temperate Salmonella typhimurium phages P22 and L share approximately 69% homology, as measured by DNA heteroduplex analysis. Alignment of the P22/L heteroduplex molecules with a P22 physical map places most of this homology between the capsid genes and genes in the vicinity of the prophage attachment sites. The degree of genetic relatedness between these phages and the lambdoid phages is also discussed.
Human cytomegalovirus-induced DNA polymerase and its interaction with the triphosphates of 1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)-5-methyluracil, -5-iodocytosine, and -5-methylcytosine
Authors: Mar E C , Chiou J F , Cheng Y C , Huang E S
Published: January 2020

Human cytomegalovirus-induced DNA polymerase and cellular DNA polymerase alpha were purified by successive chromatography on DEAE-cellulose, phosphocellulose, heparin agarose, and single-stranded DNA agarose columns. The purified virus-induced DNA polymerase was resolved to consist of two polypeptides corresponding to molecular weights of 140,000 and 58,000, as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Virus-induced DNA polymerase and cellular alpha polymerase were examined for their sensitivities to the triphosphates of 1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)-5-methyluracil (FMAUTP), -5-iodocytosine (FIACTP), and -5-methylcytosine (FMACTP). The inhibitive effects of these triphosphates on the DNA polymerases were competitive with regard to the natural substrates; thus FMAUTP competes with dTTP, and FIACTP and FMACTP compete with dCTP. The inhibition constants (Ki) for FMAUTP, FIACTP, and FMACTP of virus-induced DNA polymerase are 0.06, 0.30, and 0.47 microM, respectively. Cellular DNA polymerase alpha is much less sensitive to these inhibitors, and its Ki values for FMAUTP, FIACTP, and FMACTP are 0.45, 3.10, and 2.90 microM, respectively. In addition, human cytomegalovirus-induced DNA polymerase, but not cellular DNA polymerase alpha, can utilize these analog triphosphates as alternate substrates for their corresponding natural deoxyribonucleoside triphosphates in in vitro DNA synthesis.
Proteolytic cleavage of the E2 glycoprotein of murine coronavirus: host-dependent differences in proteolytic cleavage and cell fusion
Authors: Frana M F , Behnke J N , Sturman L S , Holmes K V
Published: January 2020

Cell fusion induced by infection with mouse hepatitis virus strain A59 (MHV-A59) varied markedly in extent and time course in four different murine cell lines. When inoculated at a multiplicity of 3 to 5 PFU per cell, the Sac-, L2, and DBT cell lines began to fuse by 7 h, were fused into confluent syncytia by 9 to 12 h, and peeled from the substrate by 10 to 14 h. These virulent virus-cell interactions were in striking contrast to the moderate interaction of MHV-A59 with the 17 Cl 1 cell line, in which only small syncytia were observed 18 h postinoculation, and greater than 50% of the cells remained unfused by 24 h. The yield of infectious virus produced by 17 Cl 1 cells was 10-fold higher than the yields from the other three cell lines. The processing of the nucleocapsid protein, the membrane glycoprotein E1, and the peplomeric glycoprotein E2 were found to differ significantly in the four cell lines. Since the E2 glycoprotein is responsible for virus-induced cell fusion, we attempted to correlate differences in cellular processing of E2 with differences in fusion of infected cells. The predominant intracellular form of E2 in all cell lines was the 180K species. Pulse-chase experiments showed that a small portion of the 17 Cl 1 cell-associated 180K E2 was cleaved by 1 h after synthesis to yield 90K E2, shown in the preceding paper to consist of two different glycoproteins called 90A and 90B (L. S. Sturman, C. S. Ricard, and K. V. Holmes, J. Virol. 56:904-911, 1985). This cleavage occurred shortly before the release of virions from cells, as shown by pulse-chase experiments. After budding at intracellular membranes, virions released into the medium by the four cell lines contained different ratios of 180K to 90K E2. Virions from Sac- cells, which contained 100% 90K E2, fused L2 cells rapidly without requiring virus replication, whereas virions from 17 Cl 1 cells, which had 50% 90K E2, required trypsin activation to induce rapid fusion (Sturman et al., J. Virol. 56:904-911, 1985). The addition of protease inhibitors to the medium markedly delayed L2 cell fusion induced by MHV infection. The extent of coronavirus-induced cell fusion does not depend solely upon the percent cleavage of the E2 glycoprotein by cellular proteases, since extensive fusion was induced by infection of L2 and DBT cells but not 17 Cl 1 cells, although all three cell lines cleaved E2 to the same extent.(ABSTRACT TRUNCATED AT 400 WORDS)
Development of a helper-independent human adenovirus vector and its use in the transfer of the herpes simplex virus thymidine kinase gene
Authors: Haj-Ahmad Y , Graham F L
Published: January 2020

Approximately 2 kilobases (kb) of additional DNA can be packaged into wild-type virions of human adenovirus type 5 (Ad5). To extend this limit, a helper independent Ad5 cloning vector was constructed by deleting most of early region 3 (E3) from map coordinates 78.5 to 84.7 and essentially all of early region 1 (E1) from coordinates 1.0 to 10.6. E3 is nonessential for adenovirus replication in cultured cells, and E1 is nonessential when the virus is propagated in 293 cells which constitutively express the E1 gene products. The resulting new virus, dlE1,3 is about 5.5 kb shorter than wild-type Ad5 and therefore should be able to accept up to 7.5 kb in foreign DNA. To test the usefulness of this vector, the herpes simplex virus type 1 (HSV-1) thymidine kinase gene (tk) along with its regulatory sequences was inserted into the unique XbaI site of dlE1,3 (at map position 78.5/84.7). The resulting recombinant virus, Adtk, expressed the HSV tk at a low level (as compared with HSV-1) in infected cells; however, tk expression was markedly enhanced when Adtk-infected cells were superinfected with a tk- mutant of HSV. Furthermore, the Adtk virus efficiently transformed tk- mouse cells (line LTA) to the tk+ phenotype. At a low efficiency, it was also possible to transform tk- human cells (line 143), and tk+ transformants of both mouse and human origin have been established as permanent lines.
Isolation and characterization of a novel human papillomavirus type 6 DNA from an invasive vulvar carcinoma
Authors: Rando R F , Groff D E , Chirikjian J G , Lancaster W D
Published: January 2020

Human papillomavirus type 6 (HPV-6) DNA was detected in a rapidly growing vulvar verrucous carcinoma and two recurrent tumor samples. The viral DNA (HPV-6vc) was molecularly cloned and found to have a high degree of DNA sequence homology to HPV-6b DNA. Comparison of restriction endonuclease cleavage patterns between HPV-6b and HPV-6vc genomes and DNA sequencing analysis demonstrated an additional 106 bases in the HPV-6vc genome. These additional nucleotides were located in the noncoding region of the viral genome which contains the putative viral DNA replication and early gene transcriptional control elements. Seventy-four of the additional 106 nucleotides were found as one insert in the purine-thymidine-rich region 3' to the end of the L1 open reading frame. This 74-base-pair addition had homology with viral sequences immediately upstream to it and to poly(dG-dT) sequences found in the human genome including the conserved repeated sequences in human DNA (EC1) and in the human cardiac muscle actin gene. Two smaller inserts, 19 and 15 nucleotides, were found upstream from the transcriptional control elements and demonstrate homology with regions of human alpha and gamma interferon genes.
Construction of recombinant murine retroviruses that express the human T-cell leukemia virus type II and human T-cell lymphotropic virus type III trans activator genes
Authors: Rosen C A , Sodroski J G , Campbell K , Haseltine W A
Published: January 2020

Recombinant retroviruses containing the trans activator genes of human T-cell leukemia virus (HTLV) type II and human T-cell lymphotropic virus type III were constructed. The trans activator genes tat II and tat III were inserted into the murine retroviral vector pZIPNEOSV(X)1. Recombinant plasmids were transfected into the psi 2 and psi AM packaging cell lines that produce murine leukemia virions containing no retroviral RNA. Functional tat II and tat III gene products were expressed as demonstrated by trans activation of HTLV type I and II and human T-cell lymphotropic virus type III long terminal repeat-directed gene expression in the respective infected cells. Use of these recombinant vectors permits high-efficiency gene transfer into a wide variety of cells, thereby providing the opportunity to study the biochemical effects associated with tat II and tat III gene expression.
Isolation of a monoclonal antibody that blocks attachment of the major group of human rhinoviruses
Authors: Colonno R J , Callahan P L , Long W J
Published: January 2020

Reciprocal competition binding assays have previously demonstrated that 20 of 24 human rhinovirus serotypes tested compete for a single cellular receptor. These studies suggested that the vast majority of rhinovirus serotypes utilize a single cellular receptor. With HeLa cells as an immunogen, a mouse monoclonal antibody was isolated which had the precise specificity predicted by the competition binding study. The receptor antibody was shown to protect HeLa cells from infection by 78 of 88 human rhinovirus serotypes assayed. In addition, the receptor antibody protects HeLa cells from infection by three coxsackievirus A serotypes. The receptor antibody was unable to protect cells from infection by a wide range of other RNA and DNA viruses. Using the receptor antibody and human rhinovirus type 15, we determined that the cellular receptor utilized by the vast number of human rhinovirus serotypes is present only on cells of human origin, with the exception of chimpanzee-derived cells. The receptor antibody has a strong affinity for the cellular receptor as evidenced by its rapid binding kinetics and ability to displace previously bound human rhinovirus virions from receptors. No viral variants were identified which could bypass the receptor blockage.