biochemical properties of a hamster syncytium-forming ("foamy") virus.a hamster syncytium-forming ("foamy") virus (hfv) was characterized. the hfv sedimented in isopyknic sucrose density gradients at 1.16-1.165 g/ml. it had rna but no dna, its replication was inhibited by actinomycin d, and it contained virion-associated, rna-dependent dna polymerase. analysis of the rna from purified virus showed several species: 62s, 40s, 28-30s, 18-20s, and 4-7s.197547398
the foamy viruses. 197551620
[induction, by 5-bromo-2'-deoxyuridine, of a "foamy" virus previously undetected in hamster cells transformed by sv40].tsv5 clone 2 cells in normal conditions of culture contain only an expressed rna virus (r-type virus). however, exposure of the cells to 5-bromo-2'-deoxyuridine with dexamethasone, induced synthesis of a syncitium-forming ("foamy") virus. in other hamster cell lines, the same treatment fails to induce a "foamy" virus. the origin of this "foamy" virus is discussed.197555314
virological studies of baboon (papio hamadryas) lymphoma: isolation and characterization of accordance with a memorandum of understanding in cancer research between scientists in the ussr and the usa, virological studies were performed on two baboons from the russian colony at the institute of experimental pathology and therapy at sukhumi where several cases of leukemia have been observed over the past few years. foamyvirus isolations were made from lymphoid cells of both of these monkeys, one of which had a confirmed case of lymphoma. the isolates were similar to each other serolog ...197658063
enhancement of ige-mediated histamine release from human basophils by viruses: role of interferon.human leukocytes maintained in culture are induced to release histamine when exposed to ragweed antigen e or anti-ige. leukocyte cultures incubated with virus (i.e. hsv-1, influenza a, and adeno-1) but not exposed to ragweed antigen e or anti-ige fail to release histamine. if, however, leukocyte cultures are first exposed to virus and then to ragweed antigen e or anti-ige, significant enhancement of histamine release occurs. both infectious and inactivated virus enhance histamine release and the ...197767173
reverse transcriptase of foamy virus. purification of the enzymes and immunological identification.reverse transcriptase from foamy virus, strain h4188 was estimated and purified. the enzyme has the following characteristics: 1. the reaction utilized preferentially oligo (dt) poly (ra) as a primer-template; however, the synthetic primer-template oligo (dt) poly (da) could also be used to some extent. 2. the reaction utilized oligo (dg) poly (rc) as a primer-template with very low efficiency. 3. the crude virus preparation had a detectable endogenous reaction using the four deoxyribonucleotide ...197774244
antigenic relationship of human foamy virus to the simian foamy viruses.a foamy virus isolated by achong et al. from a human nasopharyngeal carcinoma was studied to determine its antigenic relationship to the eight known simiam foamy viruses (sfv). using reciprocal cross-immunofluorescent and cross-neutralization techniques, we found the human isolate to be closely related to sfv type 6. in a seroepidemiological survey, neutralizing antibody to the human foamy virus was not detected in the sera of animal caretakers or laboratory personnel who routinely handled a wid ...197878897
isolation of foamy virus from patient with dialysis encephalopathy. 197880725
isolation of foamy virus from patients with de quervain thyroiditis. 197989378
attempt to isolate infectious agent from bone-marrow of patients with multiple sclerosis. 197989467
feline syncytium-forming virus: identification of a virion associated reverse transcriptase and electron microscopical observations of infected cells.the maturation of feline syncytium-forming virus (fsfv), a member of the foamy virus sub-family (spumavirinae), has been studied by electron microscopy of thin sections of infected feline embryo (fea) cells. the initial event observed was formation of crescent-shaped nucleoids at the plasma membrane. as budding progressed, the nucleoid became circular in outline with an electron-lucent centre in fully mature extracellular particles. these observations suggested that the maturation of fsfv in ful ...197990117
isolation of foamy viruses from baboon (papio cynocephalus) tissues.fourty per cent of baboon kidney cell cultures were found to contain foamy virus contaminants regardless of sex of the animal, source or time of year. the older the animal, however, the higher the incidence. fifty percent of placentas examined contained foamy virus, with first and second trimester specimens more likely to be positive. foamy virus isolates from baboon lymphocytes were also more frequent as the age of the animal increased. freezing and thawing these lymphocytes prevented foamy vir ...1975168767
pathogenesis of simian foamy virus infection in natural and experimental hosts.inoculation of simian foamy virus type 1 into new zealand white rabits resulted in an infection which was very similar to that observed in naturally infected nonhuman primates. both intraperitoneal and intranasal inculations were found to be efficient procedures for the establishment of the infection in rabbits. infection by the nasal route was found to be the best method, whereas no infection could be established by feeding virus in the drinking water. once infection was established, virus pers ...1975170201
isolation of foamy virus from rhesus, african green and cynomolgus monkey leukocytes.foamy virus (fv) was recovered regularly from the leukocyte of rhesus and cynomolgus monkeys and somewhat less often from african green monkey leukocytes. virus was found in virtually all organs of experimentally infected rhesus monkeys. no illness or pathologic abnormalities were noted in these animals or in any of the naturally infected animals in spite of the prolonged period of viral persistence in various organs and tissues.1975171409
viral spread in the presence of neutralizing antibody: mechanisms of persistence in foamy virus infection.several viruses were categorized on the basis of their ability to spread from cell to contiguous cell and form plaques in the presence of antiviral antibody. herpes simplex virus, cytomegalovirus, and vaccinia, measles, and foamy viruses were able to spread in the presence of neutralizing antibody, whereas coxsackievirus, encephalomyocarditis virus, vesicular stomatitis virus, mumps virus, and simian virus 5 failed to spread. a detailed study of one of these virus groups (simian foamy viruses) s ...1976185150
a haemagglutination assay for the primate syncytium-forming (foamy) viruses.preparations of highly concentrated simian foamy virus type 1 (sfv1)agglutinate guinea pig red blood cells. the agglutination occurs both at 22 degrees and 37 degrees c. it is inhibited by specific antisera against sfv1 but also by antisera prepared against several other types of simian foamy viruses.1977188979
isolation and characterization of lymphocyte associated foamy virus from a red uakari monkey (cacajao rubicundus).a syncytium-forming virus was isolated from the lymphocytes of a uakari monkey 70 days after establishing a lymphocyte/owl monkey kidney coculture in the wild. the morphology and morphogenesis of the virus, plus its physicochemical characteristics indicate that the agent is a foamy virus. an unusal cell alteration found in cultures infected with this foamy was the formation of eosinophilic intracytoplasmic inclusion in association with the syncytia. the agent was found to be antigenically distin ...1976191616
further biological properties of the human syncytial virus.some biological properties of the human syncytial virus have been examined. a 13-day plaque assay in whole human embryo fibroblasts (hef) has been developed using a liquid (growth medium) overlay. the plaques were 0.7-2 mm in diameter and often showed a clear central zone with irregular edges. pretreatment of hef monolayers with the polycation deae-dextran for either 30 min or 1 h was found to enhance plaque formation by a factor of from 2- to 7-fold. the plaque assay procedure required cell cul ...1977194865
infectious dna from cells infected with feline syncytium-forming virus (spumavirinae).dna isolated from cells infected with fsfv (a foamy virus) is infectious when tested on susceptible cells. the virus produced by this infectious dna is identical to the original infecting virus in terms of plaque and virion morphology and serology.1977199699
pelvic endometriosis and simian foamy virus infection in a pigtailed macaque.pelvic endometriosis and simian foamy virus infection occurred in a pigtailed macaque. diffuse omental, peritoneal, and intestinal implantation of endometrium resulted in massive adhesions between adjacent abdominal and pelvic viscera, with formation of a large mass in the right caudal quadrant of the abdomen. simian foamy virus type 1 was isolated from ectopic endometrium and from the uterine wall but was considered to be merely epiphenomenal.1977200594
establishment of cell substrates for nonhuman primates. 1976201524
human foamy virus: further characterization, seroepidemiology, and relationship to chimpanzee foamy viruses.a foamy virus present in human nasopharyngeal carcinoma tissue was studied for a number of biological properties, including range of cellular susceptibility, growth curve, evolution of cytopathic effect in relation to cellular fusion and intracellular viral distribution, reverse transcriptase activity, and buoyant density. the virus was also studied immunologically and found to be closely related to the chimpanzee foamy viruses, particularly simian foamy virus type 6, with which it shares common ...1978206631
[foamy viruses in baboons and macaques].the occurrence of foamy viruses among baboons and macaca monkeys in sukhumi monkey farm was investigate;. the monkeys were shown to be carriers mainly of foamy virus type ii. the frequency of virus isolation increased with the age of the animals and reached 88.8-100% in adult specimens. the virus behaviour in cell cultures is described. the morphological characteristics of the virus are based on electron microscopic examinations of ultrathin sections of primary and inoculated cell cultures.1978208305
[isolation of foamy virus type ii out of haematopoetic cells from baboons with haematoblastoses and from healthy animals (author's transl)].foamy virus type ii persists in the haematopoetic organs of 75 percent of baboons in the suchumi flock. a mixed infection with foamy virus types i and ii seems to be possible. foamy viruses are isolated as well from monkeys with haemoblastoses as from healthy animals. new information concerning the intrauterine transmission of foamy viruses were obtained.1978210734
possible role of infectious simian foamy virus dna in persistent infection.simian foamy virus type 7 (sfv-7) can persist in peripheral blood leukocytes of sfv-7-infected rabbits. rabbit peripheral blood leukoyctes cultured in vitro did not support the growth of sfv-7, but low titer of virus could be detected after 4 to 5 days incubation. the dna derived from sfv-7 infected primary rabbit kidney cells is infectious. the presence of sfv-7 dna provirus in infected rabbit kidney cells during replication may contribute one of the mechanisms of persistance.1977211013
antibody responses to herpesvirus papio antigens in baboons with epstein-barr virus-related herpesvirus, termed herpesvirus papio (hvp), was isolated from baboons (papio hamadryas) at the institute of experimental pathology and therapy, sukhumi, ussr, where there is a continuing outbreak of lymphoma. in the present study sera from diseased baboons and from age- and sex-matched control animals were examined for antibodies to hvp antigens. results showed that animals with lymphoid disease had antibodies to hvp virus capsid, early, soluble, and nuclear antige ...1979216640
some infectious diseases of wild vervet monkeys (cercopithecus aethiops pygerythrus) in south africa.our surveys indicate that nearly all batches of vervet monkeys arriving at the national institute for virology from various areas of south africa, are infected with foamy viruses and there is evidence that intra-urterine infection also occurs. monkeys from certain areas of south africa are apparently infected with the protozoal parasite entopolypoides macaci in a sub-clinical state which becomes active when the monkeys are splenectomised. serological studies indicate that infections with schisto ...1978218005
feline syncytium-forming virus: dna provirus size and infectious dna assay has been used to investigate the size and structure of the genome of feline syncytium-forming virus (fsfv). the dose response between dna extracted from fsfv-infected cells and plaque number on feline embryo cells followed two-hit kinetics and the mol. wt. of the proviral dna was estimated as approx. 6 x 10(6).1979227986
comparison of the antigens produced by foamy virus in a cytolytic and a persistent infection of hep2 cells.the antigens from cytolytic infections of hep2 cells by type i simian foamy virus produced two multicomponent precipitation lines when tested by immunodiffusion with the homologous hyperimmune rabbit antiserum. the antigens obtained from a non-productive infection of mk5 virus in hep2 cells produced only those precipitation lines which corresponded with the inner lines obtained from the cytolytic infection. similarly, hyperimmune rabbit antiserum against antigens extracted from the persistent in ...1979227994
simian foamy virus-induced immunosuppression in rabbits. 1979230289
isolation and characterization of a new simian foamy virus serotype from lymphocytes of a papio cynocephalus baboon.a new type of syncytium-forming (foamy) virus was isolated from peripheral lymphocytes of a papio cynocephalus baboon after cocultivation with a rhesus monkey cell line. the isolate was characterized by cytopathogenic effect, host range, electron microscopy, reverse transcriptase activity and physical and chemical properties. seroneutralization tests indicate that the new isolate is antigenically distinct from the other nine known simian foamy virus serotypes.1979231658
factors affecting the growth and titration by immunofluorescence of simian foamy virus.this paper presents some observations concerned with the growth of simian foamy virus and some modifications which should be introduced to the fluorescence assay of foamy virus. the modified procedure is the most sensitive method described for the titration of foamy virus. examination of the optimal conditions for the growth and titration by fluorescence assay of simian foamy virus showed that the virus was particularly sensitive to changes in virus and cell concentration. at the low cell concen ...1979231947
cis-acting regulatory regions in the long terminal repeat of simian foamy virus type 1.simian foamy virus type 1 (sfv-1), a member of the spumavirinae subfamily of retroviruses, encodes a transcriptional transactivator (taf) that strongly augments gene expression directed by the viral long terminal repeat (ltr) (a. mergia, k. e. s. shaw, e. pratt-lowe, p. a. barry, and p. a. luciw, j. virol. 65:2903-2909, 1991). this report describes cis-acting regulatory elements in the ltr that control viral gene expression. a series of ltr mutants and hybrid promoter constructs have been analyz ...19921309244
genomic organization and expression of simian foamy virus type 3 (sfv-3).the complete nucleotide sequence of simian foamy virus type 3 (sfv-3) strain lk-3, isolated from an african green monkey, was determined. in addition to translation frames representing the gag, pol, and env genes, two open reading frames are located in the region between the env gene and the 3' long terminal repeat (ltr). both sfv-3 and sfv-1 encode two open reading frames between env and the 3' ltr, whereas hfv encodes three open reading frames in this region. northern blot analysis of cell cul ...19921310187
sequence analysis of m2 mrna of bovine respiratory syncytial virus obtained from an f-m2 dicistronic mrna suggests structural homology with that of human respiratory syncytial virus.the nucleotide sequences of the f and m2 mrnas of strain a51908 of bovine respiratory syncytial virus (brsv) were determined by sequencing cdna of an intracellular dicistronic mrna. comparison of the f mrna sequence with those of other brsv strains showed that there was extensive sequence identity at both the nucleotide (95% identity) and amino acid (94% identity) levels. alignment of the nucleotide and encoded amino acid sequences of m2 mrna of brsv with those of human respiratory syncytial vir ...19921312130
absence of antibody to human spumaretrovirus in patients with chronic fatigue syndrome. 19921313314
bovine immunodeficiency-like virus encodes factors which trans activate the long terminal repeat.lentiviruses are known to encode factors which trans activate expression from the viral long terminal repeat (ltr); the primary trans activator is the tat gene product. one of the putative accessory genes (tat) of the bovine immunodeficiency-like virus (biv) bears sequence similarity to other lentivirus tat genes. this finding suggests that biv may encode a trans-activating protein capable of stimulating ltr-directed gene expression. to test this hypothesis in vitro, biv ltr-chloramphenicol acet ...19921313891
transactivation of human immunodeficiency virus type 1 long terminal repeat-directed gene expression by the human foamy virus bel1 protein requires a specific dna sequence.human foamy virus (hfv) encodes the transcriptional transactivator bel1. the bel1 protein transactivates hfv long terminal repeat (ltr)-directed gene expression by recognizing a region in u3. it also transactivates human immunodeficiency virus type 1 (hiv-1) ltr-directed gene expression in transient transfection assays. to identify the specific region in hiv-1 ltr responsible for bel1 action, we examined the effect of bel1 on chloramphenicol acetyltransferase (cat) gene expression in transfected ...19921313928
human spumavirus antibodies in sera from african patients.serum samples collected from patients with a wide variety of diseases from african and other countries were tested for antibodies to the human spumaretrovirus (hsrv). a spumaviral env-specific elisa was employed as screening test. out of 3020 human sera screened, 106 were found to be positive (3.2%). while the majority of patients' sera from europe (1581) were negative, 26 were positive (1.6%). sera from healthy adult blood donors (609), from patients with multiple sclerosis (48), graves' diseas ...19921314048
expression of human foamy virus is differentially regulated during development in transgenic mice.the human foamy virus (hfv) is a recently characterized member of the spumavirus family. although no diseases have been unequivocally associated with hfv infection, expression of hfv regulatory genes in transgenic mice induces a characteristic acute neurodegenerative disease and a myopathy. to better characterize the sequence of events leading to disease, and to gain a better understanding of the underlying pathogenetic mechanisms, we have analyzed in detail the transgene expression pattern duri ...19921316144
the bel-1 protein of human foamy virus activates human immunodeficiency virus type 1 gene expression via a novel dna target site.the bel-1 protein of human foamy virus can activate transcription directed by the long terminal repeat (ltr) promoter of human immunodeficiency virus type 1 (hiv-1). the target sequence for bel-1 is shown to lie within the hiv-1 ltr u3 region but does not coincide with any previously described factor-binding site. gene expression directed by an hiv-1 ltr lacking functional sites for the inducible cellular transcription factor nf-kappa b was activated over 100-fold by coexpression of bel-1. these ...19921316494
prevalence of feline immunodeficiency virus and other retroviral infections in sick cats in italy.two hundred and seventy-seven sick pet cats living in italy were tested for antibodies to feline immunodeficiency virus (fiv) and for feline leukemia virus (felv) antigen. overall, 24% of the cats resulted positive for anti-fiv antibody and 18% for felv antigen. fiv was isolated from the peripheral mononuclear blood cells of ten out of 15 seropositive cats examined and from one out of eight saliva samples. no fiv isolations were obtained from six serum samples cultured. feline syncytium forming ...19921317073
bacterial expression of the capsid antigen domain and identification of native gag proteins in spumavirus-infected cells.a bacterial expression plasmid containing the central part of the gag gene of the human spumaretrovirus (hsrv) was constructed and expressed in e. coli. the expected protein product consisting of the complete region of the hsrv capsid antigen and part of the matrix protein was expressed in relatively large amounts. polyclonal antisera raised against this recombinant protein were used to identify authentic gag precursors of 78 and 74 kda and processed gag proteins of 60, 58, and 33 kda in hsrv-in ...19921318626
bovine respiratory syncytial virus fusion protein gene: sequence analysis of cdna and expression using a baculovirus vector.the nucleotide sequence of bovine respiratory syncytial virus (rsv), atcc strain a51908 fusion (f) glycoprotein gene cdna was determined. the amino acid sequence deduced was then compared to those of two different isolates of bovine rsv, strains rb 94 and 391-2, and the a and b subtypes of human rsv, strains 18537 and a2. the bovine rsv f protein is highly conserved between the three isolates, a51908 has 97% amino acid identity to rb 94, and 99% identity to 391-2. the f proteins of both the a an ...19921318950
isolation of a spumavirus from a sheep. 19921320857
generation of macaque b lymphoblastoid cell lines with simian epstein-barr-like viruses: transformation procedure, characterization of the cell lines and occurrence of simian foamy virus.two simian epstein-barr-like viruses, a rhesus epstein-barr virus and herpesvirus papio, were used to transform b cells from rhesus or cynomolgus macaques. the resulting cell lines exhibited predominantly a b lymphocyte phenotype and expressed epstein-barr virus antigens. the majority of b lymphoblastoid cell lines from macaques, which were seropositive for simian foamy virus, developed giant cells in culture. the cytopathic agent was identified as a foamy virus and was transmissible to human em ...19921331148
human spumaretrovirus-related sequences in the dna of leukocytes from patients with graves disease.viruses, and more particularly retroviruses, have been postulated to play a role in the pathogenesis of autoimmune diseases. in a search for spumaretrovirus infection markers, we screened a group of 29 patients with graves disease and a representative healthy population (23 subjects) as a control. southern blot hybridization under stringent conditions, of patients' dna extracted from peripheral blood lymphocytes, with a spumaretrovirus-specific genomic probe derived from the human spumaretroviru ...19921332028
no evidence for spumavirus or oncovirus infection in relapsing-remitting multiple sclerosis.polymerase chain reaction analysis was used to investigate the possible role of human spumaretrovirus and oncoretroviruses (human t-cell lymphotropic virus types i [htlv-i] and ii [htlv-ii]) in multiple sclerosis. eleven patients with relapsing-remitting multiple sclerosis in exacerbation and 11 normal blood donors were included in the study. cerebrospinal fluid cells, peripheral blood mononuclear cells, and plasma were cocultured with allogeneic mononuclear cells for 6 weeks. cultured cells wer ...19921333176
no evidence of spumaretrovirus infection markers in 19 cases of de quervain's thyroiditis. 19921333778
human foamy virus antigens in thyroid tissue of graves' disease patients.human foamy virus (hfv) is a recently characterized member of the retrovirus subfamily spumaretrovirinae. hfv has a complex structure: it encodes the classical three retroviral structural genes gag, pol and env, but also possesses additional regulatory, so-called bel sequences. foamy viruses have been discussed occasionally as being possibly involved in the pathogenesis of autoimmune thyroiditis. by indirect immunofluorescence we were able to demonstrate the expression of hfv gag proteins on the ...19921336420
mo-mulv nucleotide sequence exhibits three levels of oligomeric repetitions, suggesting a stepwise molecular exhaustive computer-assisted analysis of the moloney murine leukemia virus nucleotide sequence shows numerous deviations in the oligomeric distribution, suggesting three overlapping levels of a stepwise duplicative evolution. (1) the sequence fits the universal rule of tg/ct excess which has been proposed as the construction principle of all sequences, and maintains some degree of symmetry between the two complementary strands. (2) oligomeric repeating units share a core consensus regularly s ...19921336800
human foamy virus: an underestimated neuropathogen?human foamy virus (hfv) is a recently characterized retrovirus which was originally isolated from patients with various neoplastic and degenerative diseases. however, until today it has not been possible to identify hfv as the causative agent of any disease and little is known about its prevalence in human populations. like htlv and hiv, hfv encodes the three structural retroviral genes, gag, pol and env, and an additional region containing three open reading frames, bel-1 to bel-3. bel-1 activa ...19921341948
[basic understanding of retroviruses].retroviruses contain a reverse transcriptase in the virion that converts viral genomic rna to proviral dna. retroviruses are divided into three groups; oncovirus, lentivirus, and spumavirus. the oncovirus group contains htlv-1, which causes adult t-cell leukemia, encephalomyeloneuropathy, arthritis, and alveolo-bronchopathy. the lentivirus groups contains hiv, which causes acquired immunodeficiency syndrome and dementia. the genomic structures and functions of htlv-1 and hiv have been demonstrat ...19921630036
sequence analysis of the simian foamy virus type 1 genome.we have cloned the simian foamy virus type 1 genome (sfv1) and determined its nucleotide sequence. analysis of this genome reveals, in addition to the usual genes encoding retroviral capsid, reverse transcriptase, and envelope protein (respectively, gag, pol, and env), two open reading frames (orfs) between env and the long terminal repeat with partial homology to the human foamy virus (hfv) bel1 and bel2 genes. the first orf could code for a polypeptide of 312 amino acids (aa) showing 40% homol ...19911647358
distinct cis-acting regions in u3 regulate trans-activation of the human spumaretrovirus long terminal repeat by the viral bel1 gene product.the human spumaretrovirus (hsrv) genome contains, in addition to coding information for the structural proteins, open reading frames (orfs) for at least three additional genes termed bel1, bel2 and bel3. we report here the localization of the transcriptional activator of hsrv to the bel1 orf. in reporter-based transient expression assays in cos cells utilizing the bacterial cat gene linked to hsrv ltr sequences between -710 and +309 with respect to the transcriptional initiation site, co-express ...19911649456
spumaviruses: a group of complex retroviruses. 19911649916
progressive encephalopathy and myopathy in transgenic mice expressing human foamy virus genes.transgenic mice carrying the bel region of human foamy retrovirus (hfv) under transcriptional control of its own long terminal repeat expressed the transgene in their central nervous systems and in smooth and striated muscle tissues. the animals developed a progressive degenerative disease of the central nervous system and of the striated muscle. because expression of the transgene was closely correlated with the appearance of structural damage and inflammatory reactions were scanty, the disease ...19911650034
construction of an infectious dna clone of the full-length human spumaretrovirus genome and mutagenesis of the bel 1 infectious and full-length molecular clone of genomic human spumaretrovirus (hsrv) dna was constructed. the infectivity of the phsrv13 clone was demonstrated after transfection into susceptible cells by passage of hsrv-specific cytopathic effects as a cell-free culture supernatant, by electron microscopy of hsrv particles in phsrv13 dna-transfected cells, by detection of hsrv transcripts, and by identification of hsrv-encoded proteins with env- and bel-specific antisera in indirect immunofluo ...19911651600
replication and regulation of primate foamy viruses. 19911653483
transcription factor ap-1 modulates the activity of the human foamy virus long terminal repeat.the human foamy virus (hfv) contains within the u3 region of its long terminal repeat (ltr) three perfect consensus sequences for the binding of the inducible transcription factor ap-1. results of dnase i footprint protection and gel retardation assays demonstrated that proteins in extracts of hela and bhk-21 cells as well as bacterially expressed jun and fos proteins bind to these ap-1 sites. by conducting transient expression assays using chloramphenicol acetyltransferase plasmids carrying ltr ...19911656100
[yearling flu]. 19911656545
structure and transcriptional status of bovine syncytial virus in cytopathic infections.the genomic structure of bovine syncytial virus (bsv), a virus commonly infecting cattle, was examined in order to gain insights into the nature of viral dna (vdna) intermediates and the transcriptional status of the virus in cytopathic infections. in dog cf2th cells, the dna intermediate of bsv was found to exist predominantly as linear unintegrated vdna (uvd) molecules. the uvd molecules were cloned directly from total cellular dna by addition of ecori linkers and subsequent ligation into the ...19911657718
depression of lymphocyte responses to phytohaemagglutinin in lambs experimentally infected with bovine respiratory syncytial virus.eight lambs were experimentally infected with bovine respiratory syncytial virus (brsv) and the responses of their peripheral blood lymphocytes to the mitogen phytohaemagglutinin and brsv antigen compared with that of control lambs injected with tissue culture fluid. the lymphocyte transformation responses to phytohaemagglutinin were significantly reduced five and 10 days after experimental infection with brsv (p less than 0.05). it appears that these reductions were associated with cd4+ lymphoc ...19911674620
effects of human recombinant alpha and gamma and of highly purified natural beta interferons on simian spumavirinae prototype (simian foamy virus 1) multiplication in human cells.the present study demonstrates the inhibitory effect of human recombinant interferons (r-hu-ifn) alpha and gamma, and that of highly purified natural human interferon beta on the replication of simian foamy virus type 1 (sfv1) in human av3-cell cultures. all ifn led to strong inhibition of the sfv1 cytopathic effect. electron microscopy showed a 70 to 95% decrease in viral particles. significant inhibition of virus-associated reverse transcriptase activity was found in supernatant fluids of infe ...19901691523
molecular differences between two immunologically related spumaretroviruses: the human prototype hsrv and the chimpanzee isolate sfv6.a comparative study at the genomic and protein level was performed between two immunologically related spumaretroviruses, the human hsrv and the simian sfv6. cross immunoprecipitation analysis with specific polyclonal and monoclonal antisera indicates shared antigenic determinants. however, restriction analysis of the viral dnas and thermal stability of the hybrids demonstrate that hsrv and sfv6 are two different isolates.19901697180
analysis of splicing patterns of human spumaretrovirus by polymerase chain reaction reveals complex rna structures.mapping of transcripts of the human foamy virus genome was carried out in permissive human embryonic fibroblast cells by northern blot hybridization and s1 nuclease analysis. since several splice sites that are localized within a relatively narrow genomic region were detected, the polymerase chain reaction (pcr) was employed, and cloning and sequencing of the splice site junctions of the corresponding viral cdnas were subsequently performed. all spumavirus transcripts have a common but relativel ...19911846194
the transcriptional transactivator of human foamy virus maps to the bel 1 genomic region.the human foamy virus (hfv) genome possesses three open reading frames (bel 1, 2, and 3) located between env and the 3' long terminal repeat. by analogy to other human retroviruses this region was selected as the most likely candidate to encode the viral transactivator. results presented here confirmed this and showed further that a deletion introduced only into the bel 1 open reading frame of a plasmid derived from an infectious molecular clone of hfv abolished transactivation. in contrast, del ...19911846970
the role of passive immunity in bovine respiratory syncytial virus-infected calves.the role of passive immunity in bovine respiratory syncytial virus (brsv) infections in neonatal calves was evaluated. calves were divided into groups as follows: colostrum-deprived, sham-inoculated; colostrum-deprived, brsv-inoculated; and colostrum-fed, brsv-inoculated. calves were inoculated with a low-passage field isolate of brsv for 4 consecutive days by a combined respiratory tract route and were euthanized 6 days after receiving the last inoculation. arterial oxygen tension (pao2) decrea ...19911847400
further characterization of the gapped dna intermediates of human spumavirus: evidence for a dual initiation of plus-strand dna synthesis.we recently reported the presence of linear duplex dna intermediates with a gap in the middle of the molecules in the replicative cycle of human (hsrv) and simian (sfv1) spumaviruses. the polypurine tract (ppt), at the 5' boundary of the 3' long terminal repeat, was found to be duplicated in the gap region. by molecular analysis of hsrv proviral dna with region- and strand-specific probes, we have now determined that the gap is located on plus-strand dna and that it is 120 bases long with the 3' ...19911848594
characterization of the transcriptional trans activator of human foamy retrovirus.the human foamy viruses, or spumaviruses, a distinct subfamily of complex human retroviruses, remain poorly understood both in terms of their pathogenic potential and in terms of the regulatory mechanisms that govern their replication. here, we demonstrate that the human spumaretrovirus shares with other complex human retroviruses the property of encoding a transcriptional trans activator of the homologous viral long terminal repeat. this regulatory protein is encoded by the viral bel-1 open rea ...19911850032
identification of the simian foamy virus transcriptional transactivator gene (taf).simian foamy virus type 1 (sfv-1), a member of spumavirus subfamily of retroviruses, encodes a transcriptional transactivator that functions to strongly augment gene expression directed by the viral long terminal repeat (ltr). the objective of this study was to identify the viral gene responsible for transactivation. nucleotide sequences between the env gene and the ltr of sfv-1 were determined. the predicted amino acid sequence revealed two large open reading frames (orfs), designated orf-1 (31 ...19911851862
effects of recombinant human alpha a interferon in gnotobiotic calves challenged with respiratory syncytial virus.the effects of recombinant human alpha a interferon were studied in gnotobiotic calves challenged with respiratory syncytial virus (rsv). gnotobiotic calves given doses of interferon by intramuscular injection over five days showed a marked, dose-related, rise in rectal temperature and depression of circulating leucocytes. differential counts showed decreases in both lymphocytes and neutrophils. no significant pathological differences were found between treated and untreated calves, nor could an ...19911852059
relationship of the env genes and the endonuclease domain of the pol genes of simian foamy virus type 1 and human foamy virus.we have molecularly cloned and sequenced a portion of the simian foamy virus type 1 (sfv-1); open reading frames representing the endonuclease domain of the polymerase (pol) and the envelope (env) genes were identified by comparison with the human foamy virus (hfv). unlike the hfv genomic organization, the sfv-1 pol gene overlaps the env gene; thus, the open reading frames reported for hfv between pol and env is not present in sfv-1. comparisons of predicted amino acid sequences of hfv and sfv-1 ...19902152825
transacting transcriptional activation of human spumaretrovirus ltr in infected cells.the long terminal repeat (ltr) of the human spumaretrovirus (hsrv) was examined with respect to its ability to function as transcriptional promotor in virus-infected and uninfected cells. transient transfections using a plasmid in which the 3' ltr of hsrv was coupled to the bacterial chloramphenicol acetyltransferase (cat) gene revealed that the level of hsrv ltr-directed cat gene expression was markedly increased in hsrv-infected cells compared to uninfected cells. northern blot analysis of cat ...19902158186
identification of the major immunogenic structural proteins of human foamy virus.we have identified the major immunogenic structural proteins of the human foamy virus (hfv), a distinct member of the foamy virus subfamily of retroviridae. radiolabelled viral proteins were immunoprecipitated from hfv-infected cells by foamy virus antisera of human and non-human primate origin. precipitated viral proteins were in the range of 31k to 170k. labelling of proteins with [14c]glucosamine or with [35s]methionine in the presence of tunicamycin, as well as endo-beta-n-acetylglycosaminid ...19902161055
retroviral infections of the cns of nonhuman primates. 19902162289
existence of feline immunodeficiency virus infection in japanese cat population since 1968. 19902168001
feline retroviruses: a brief review.representatives of all three retrovirus subfamilies are recognized in the cat: feline leukaemia virus (an oncovirus), feline syncytium-forming virus (a spumavirus) and feline immunodeficiency virus (a lentivirus). each of these is briefly reviewed.19902169669
specific enzyme-linked immunosorbent assay for the detection of antibodies to the human spumavirus.recombinant plasmid clones were constructed harbouring the central domains of the outer membrane protein and the transmembrane protein of the env gene of human spumaretrovirus (hsrv). the corresponding fusion proteins were expressed in e. coli, purified and used subsequently to produce antibodies against the hsrv env proteins in rabbits. the authenticity of the bacterially produced domain of the hsrv env proteins was shown by radioimmunoprecipitation of the viral env glycoprotein from hsrv-infec ...19902170434
pulmonary lesions induced by 3-methylindole and bovine respiratory syncytial virus in calves.our objectives were to describe the ultrastructural morphogenesis of pulmonary lesions induced by 3-methylindole in 30- to 45-day-old holstein calves and to determine whether toxic exposure to 3-methylindole exacerbates pulmonary lesions induced by bovine respiratory syncytial virus. administration of 3-methylindole (0.25 g/kg) to calves resulted in interstitial edema and ultrastructural swelling of type-i alveolar epithelial cells and nonciliated bronchiolar epithelial cells as early as 4 to 6 ...19902173450
feline retrovirus infections. 19902178110
simian foamy virus type 1 is a retrovirus which encodes a transcriptional transactivator.simian foamy viruses, members of the spumavirus subfamily of retroviruses, are found in a variety of nonhuman primates and, as yet, remain to be characterized with respect to genetic structure and regulation of viral gene expression. the genome of simian foamy virus type 1 (sfv-1), an isolate from rhesus macaques, has been molecularly cloned, and the role of the viral long terminal repeat (ltr) in transcriptional control has been investigated. the sfv-1 ltr is 1,621 base pairs long, and sequence ...19902370676
purification and characterization of the major envelope glycoprotein of simian foamy virus type 1.simian foamy virus type 1 (sfv-1), the prototype of the spumavirinae, was subjected to disruption and serial purification procedures. separation of sfv-1 envelope components from viral cores was verified by electron microscopy, density gradient centrifugation and polyacrylamide gel electrophoresis. after affinity chromatography of the envelope polypeptides on a concanavalin a-sepharose column, a highly purified 70 000 mol. wt. protein was recovered. glycosylation of this gp70 was confirmed by gl ...19852410554
simultaneous isolation of simian foamy virus and htlv-iii/lav from chimpanzee lymphocytes following htlv-iii or lav of virus from htlv-iii b and lav-infected chimpanzee also yielded a simian foamy virus. this virus, replicated in htlv-iii b and lav-producing h 9 cells, had identical reverse transcriptase activity and caused similar cytopathic effects in h 9 cells.19872432853
enhanced production of a human spumavirus (retroviridae) in semi-permissive cell cultures after treatment with 5-azacytidine.infection by a human spumavirus of human foetal diploid lung (hfdl) cells was found to be productive with virus titres ranging from 10(3) to 10(5) p.f.u./ml. in contrast, infection of recovered amnion (ra) aneuploid cells resulted in a persistent infection with less than 100 p.f.u./ml infectious virus produced. the decreased sensitivity of ra cells to the spumavirus was not due to the failure of virus to penetrate into the cell since infectious virus was not produced even after transfection of i ...19872437243
[pathological findings in lentivirus infected cats].this report describes the necropsy findings in 3 cats with a natural t-lymphotropic lentivirus (ftlv) infection. the changes are compared with the "immunodeficiency syndrome" of humans and monkeys. furthermore, the pathogenicity of the ftlv and the significance of a dual infection with ftlv and spumavirus is discussed.19892537529
seroepizootiologic survey of feline syncytial virus infections in domestic cats. 19892548027
serological detection of multiple retroviral infections in cattle: bovine leukemia virus, bovine syncytial virus and bovine visna virus.individual experimental animals used in our studies on bovine leukemia virus (blv) are routinely screened for the presence of antibodies to the three bovine lymphotropic retroviruses. we utilized these screening methods to examine frozen sera from eight herds for antibodies to blv, bovine visna virus (bvv) and bovine syncytial virus (bsv). serum samples from 235 animals in four dairy and four beef herds were analyzed. detection methods used included indirect fluorescent antibody tests of virus-i ...19892549686
latent simian foamy virus. 19892552596
structural analysis of proviral dna in simian foamy virus (lk-3)-infected cells.proviral dna of the t-cell lymphotropic simian foamy virus strain lk-3 was characterized. in infected cells, multiple copies of unintegrated linear duplex viral dna of about 13 kbp length are present. nuclease s1 treatment of the dna generated two fragments of 6.5 and 6.0 kbp length that were cloned in phage and plasmid vectors. the proviral dna contains a single-stranded gap of 109 nucleotides. a dna fragment spanning the gap was cloned after completing the double strand by dna synthesis in vit ...19892558626
nucleotide sequence analysis of the env gene and its flanking regions of the human spumaretrovirus reveals two novel genes.recombinant clones that represent the 3' part of the genome of the human spumaretrovirus (foamy virus) were established from viral dna and from dna complementary to viral rna. the recombinant clones were characterized by blot hybridizations and nucleotide sequence analysis. the deduced protein sequence of the clones at their 5' ends was found to be homologous to the 3' domain of retroviral reverse transcriptases. downstream of a small intergenic pol-env region a long open reading frame of 985 am ...19872820721
characterization of a human lymphoblastoid cell line permanently modified by simian foamy virus type 10.simian spumavirinae serotype, sfv10, of a papio cynocephalus baboon, was used to infect a human lymphoblastoid cell line, lv2. permanent growth and morphological alterations of infected cells occurred, even though no viral particles were detected. evidence for the presence of viral genomes in the modified cell line is provided indirectly from immunological studies and induction experiments followed by coculture procedures. the permanently modified cell line obtained (lv2-fb10) is an interesting ...19872826791
molecular cloning of the genome of human spumaretrovirus.dna of human spumaretrovirus (hsrv) was cloned from both cdna and from viral dna into phage lambda and bacterial plasmid vectors. the recombinant plasmids harboring viral dna were characterized by southern blot hybridization and restriction mapping. physical maps were constructed from cdna and found to be colinear with the restriction maps obtained from viral dna. the recombinant clones isolated contained viral dna inserts which range in size from 2.2 kb to 15.4 kb. the recombinant clones allowe ...19872830164
epidemiological studies of bovine spumavirus.bovine spumavirus (bsv) infection is shown to be endemic in some herds in north queensland. the virus was readily isolated from leucocytes of the majority of mature cattle which were bsv antibody positive (bsv reactors) in the agar gel precipitin test (agpt). calves born to dams which were bsv reactors showed no bsv antibody or circulatory leucocyte-associated bsv (clab) at birth, but became bsv reactors following ingestion of colostrum, and maintained such evidence of passive immunity until 3-5 ...19882833003
detection of immunological tolerance to bovine spumavirus (bsv) with evidence for salivary excretion and spread of bsv from the tolerant animal.a group of 17 friesian-holstein steers held in individual pens was examined for evidence of infection with bovine spumavirus (bsv). serum was examined for specific antibody by 2 serological procedures, and circulatory leucocytes and throat swabs were examined for the presence of circulatory leucocyte-associated bsv (clab) and saliva-associated bsv (sab). initial tests showed that 7 of the 17 steers had specific antibody to bsv by both serological procedures, and a further steer developed such an ...19882833004
heterogeneity of primate foamy virus genomes. brief report.dna of the t-lymphotropic simian foamy virus (sfv) lk-3 was cloned in a plasmid vector and used as a probe in comparative dna:dna hybridization studies with primate foamy viruses (sfv serotypes 1, 2, 3, 5, 6, 7, 8, fresh sfv isolates from 12 african green monkeys and one rhesus monkey, as well as human syncytium forming virus). all freshly isolated viruses seemed to be variants of sfv types 2 and 3. especially lk-3 appeared to be closely related to sfv type 3. no hybridization of the lk-3 clone ...19882833201
foamy retroviruses. a virus in search of a disease. 19882836735
evidence for a gapped linear duplex dna intermediate in the replicative cycle of human and simian spumaviruses.two forms of linear dnas have been found in simian (sfv1) and human (hsrv) spumaviruses: a linear duplex unsensitive to nuclease s1 and a sensitive structure with a single-stranded gap. two nuclease s1 sensitive sites, mapping at the same position for both viruses, have been identified in the gapped structure. using different molecular subgenomic clones of hsrv as probes in southern blot analysis, one s1 site was localized in the 3'ltr and the other near the middle of the molecule at about 6.5 k ...19882847117
animal models for hiv infection and aids: memorandum from a who meeting.the human immunodeficiency virus is a member of the lentivirus subfamily of the retrovirus family. retroviruses are rna viruses which code for an rna-dependent dna polymerase (reverse transcriptase), which transcribes the rna genome into a dna provirus which, on integration with the host dna, directs the synthesis of new virions. the rna genome consists of a gag gene, which codes for the viral core proteins, a pol gene, which codes for the reverse transcriptase, an env gene, which codes for th ...19882850118
isolation of a retrovirus and a herpesvirus from a captive california sea lion.a non-oncogenic retrovirus was isolated from an explanted skin biopsy from a captive california sea lion (zalophus californianus) with a history of recurring skin lesions. the morphology of the viral particles in electron photomicrographs was characteristic of a foamy virus, a retrovirus in the subfamily spumavirinae. viral cytopathic effects consistent with foamy virus infection were observed in subsequent explants of skin and lymph nodes and co-cultivated peripheral blood leukocytes. the sea l ...19863012127
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