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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
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
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
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
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
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
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
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
detection and characterization of infectious dna intermediates of a primary foamy virus.dna from human t-lymphoid (molt-4) and hamster kidney (bhk-21) cells infected with the t-lymphotropic simian foamy virus lk-3 was shown to be infectious, when assayed by transfection of bhk-21 cells. the proviral genome was further characterized by blot hybridization to a specific cdna probe, which had been prepared by reverse transcription in vitro using viral rna and rna-dependent dna polymerase present in cytoplasmic extracts of infected bhk-21 cells. this probe hybridized to a dna species of ...19863018132
purification and characterization of simian foamy virus type i structural core polypeptides.the present study concerns the purification and partial characterization of simian foamy virus type 1 (sfv 1) structural core polypeptides. the obtention of sfv 1 cores separated from envelope components after viral disrupture was verified by electron microscopy (em), density gradient, and polyacrylamide gel electrophoresis (page). multistep purification by column chromatography, verified by page, enabled us to separate the structural core polypeptides from the 80,000 molecular weight reverse tr ...19863942506
isolation of a new simian foamy virus from a spider monkey brain culture.a syncytium-forming (foamy) virus was isolated from a spider monkey brain cell culture. cytopathic effect was observed both in the brain culture and in human embryonic kidney cells. neutralizing antibody was present in the sera of the spider monkey from whom the isolation was made. the virus was inhibited by 5-bromo-2-deoxyuridine (20 mug/ml), contained a ribonucleic acid-dependent deoxyribonucleic acid polymerase, and had an infectivity peak at 1.15 g/cm(3) in a sucrose density gradient. the vi ...19734201323
replication of simian foamy virus in monkey kidney cells.the structure of foamy virus, its mode of maturation, and the origin of vacuoles in monkey kidney cells are described.19694976561
carrier cultures of simian foamy virus.the production of cultures of hep-2 and bhk-21 cells persistently infected with a type 1 simian foamy virus is described. after infection, hep-2 cells showed no structural changes, whereas bhk-21 cells lost their normal spindle shape and showed mitochondrial damage, and some cells contained many lysosomes. thin sections also showed that a few bhk-21 cells contained virus particles in low concentration, and infectious virus could be isolated from both the cells and the supernatant fluid. no virus ...19704986851
syncytium-forming virus of common marmosets (callithrix jacchus jacchus).this communication describes the isolation and characterization of a new syncytium-forming virus of common marmosets (callithrix jacchus jacchus). the virus, isolated from skin explants and peripheral leukocytes of healthy animals, induced syncytia and subsequent cytolysis of several human, simian, and rodent fibroblastic cultures and induced a carrier state in mixed fibroblastic-epithelial or epithelial cell lines. cytoplasmic and nuclear viral antigen was demonstrated in infected cells by indi ...19816164648
persistent asymptomatic infection of the laboratory mouse by simian foamy virus type 6: a new model of retrovirus latency.simian foamy virus (sfv) type 6, originally isolated from the kidney of a kuru-inoculated chimpanzee, has been adapted to produce an asymptomatic infection in swiss-webster white mice, with virus detected in the kidney and spleen for up to 10 months after intra-peritoneal inoculation, and the presence in some animals of complement-fixing, but not neutralizing, serum antibody. this first successful experimental infection of the laboratory mouse by a representative of the foamy virus group has spe ...19826285859
characterization of a simian foamy virus isolated from a spontaneous primate lymphoma.examination of tissues from a stump-tailed monkey (macaca arctoides) with a spontaneous lymphoid malignancy by light and electron microscopy confirmed the presence of a diffuse lymphoma of intermediate cell type. membranes showed positivity with anti-ia-like antisera and negativity with all other markers. in vitro cocultivation of affected tissues resulted in the isolation of an agent found to have properties idenitical to those described for simian foamy virus type 1. there was no evidence for ...19817345142
cell cycle dependence of foamy retrovirus infection.in common with oncoviruses but unlike the lentivirus human immunodeficiency virus type 1, foamy (spuma) viruses require host cell proliferation for productive infection. we show that human immunodeficiency virus type 1 replicates in rd-cd4 cells regardless of the growth arrest condition of the cells, while murine leukemia virus is unable to infect growth-arrested rd-cd4 cells or cells progressing through a partial cell cycle that includes s phase but not mitosis. human foamy virus, like murine l ...19957474157
phylogenetic analysis of primate foamy viruses by comparison of pol sequences.the relationship between primate foamy viruses was determined by comparing a 425-bp dna segment obtained by pcr using primers homologous to highly conserved portions of the pol gene. the phylogenetic tree of 14 foamy viruses investigated reflects the relationship between their host species: a cluster of asian old world monkey foamy viruses including simian foamy virus (sfv) prototypes 1 and 2 (isolated from macaca cyclopsis) is separated from african old world foamy viruses including prototype s ...19957886963
efficient isolation of endogenous rhesus retrovirus from trophoblast.an examination of various rhesus monkey (macaca mulatta) organs has shown a preference for type c viral antigen expression in the placenta. separate cocultivations of isolated trophoblasts from 10 rhesus monkey placentas with cell lines from heterologous mammalian species led to rapid isolation of type c rhesus retrovirus in 4 of 10 cases. these four retrovirus isolates have been designated mmc-2 through mmc-5. five of the remaining six sets of cocultivations grew simian foamy virus and were dis ...19836310872
simian foamy virus pseudotypes of vesicular stomatitis virus: production and use in sero-epidemiological investigations.simian foamy virus (sfv) pseudotypes of vesicular stomatitis virus have been successfully produced and their host range characterized. the availability of these pseudotypes has permitted the development of a rapid, quantitative assay to measure neutralizing antibody titres to sfv that has proved useful in a sero-epidemiological study.19826279771
biochemical characterization of simian foamy virus type i.simian syncitium-forming ("foamy") virus type i (sfv1) was characterized biochemically. rna was extracted from purified virus either with 0.1 per cent sds or by the standard phenol-chloroform method. by both techniques a main component of 65-70s was found. denaturation of the 65-70s rna by heat resulted in a shift of the sedimentation coefficient mainly to a 30-35s component. electrophoresis on a composite polyacrylamide gel demonstrated the existence of three minor rna's: 8s, 5s and 4s respecti ...19816268018
transcriptional trans activators of human and simian foamy viruses contain a small, highly conserved activation domain.the bel-1 protein of human foamy virus is a potent transcriptional trans activator of its homologous long terminal repeat promoter element. here, we demonstrate that bel-1 can also efficiently activate gene expression when targeted to a heterologous promoter by fusion to the dna-binding motif of the yeast gal4 protein. analysis of a series of deletion mutants of bel-1 generated in this hybrid protein context suggests the presence of a single transcription activation domain that is fully containe ...19938411385
electron microscopic observations on the mechanisms of entry of simian foamy virus in hep-2 cells. 19734360628
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
simultaneous isolation of simian foamy virus and htlv-iii/lav from chimpanzee lymphocytes following htlv-iii or lav inoculation.re-isolation 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
cell tropism of the simian foamy virus type 1 (sfv-1).several cell lines representing different species and cell types were tested for simian foamy virus type 1 (sfv-1) infection. sfv-1 infections were monitored by polymerase chain reaction, reverse transcriptase, cytopathology, and immunofluorescent assays. all cells tested were permissive for sfv-1, demonstrating that sfv-1 has a broad host range with respect to species and cell types. infected fibroblasts, epithelial cells, and neural cells all showed extensive cytopathology that is characterist ...19968740945
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
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 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
simian foamy virus isolated from an accidentally infected human individual.evidence for natural foamy virus (fv) infections in humans is still lacking. however, accidental infections of humans with simian fv have been demonstrated by serology and pcr, but all previous attempts to recover infectious virus in such cases have failed. here we describe the isolation of a simian fv from peripheral blood mononuclear cells (pbmc) of a healthy animal caretaker, who acquired the virus 20 years ago from an african green monkey (agm) bite. properties of the human isolate such as h ...19979151878
simian foamy virus type 1 (sfv-1) induces apoptosis.foamy virus infection causes cytopathology in several cell types from different species. the mechanism of cell killing by foamy viruses is not known. in this report, the mechanism of cell death induced by simian foamy virus type 1 (sfv-1) infection was investigated in fibroblast and lymphoid derived cells lines. infected l-929 (fibroblast) and raji (b cell) cells showed chromatin condensation, chromatin cleavage into nucleosome oligomers, and ultrastructural changes consistent with apoptosis. th ...19979282778
characterization of provirus clones of simian foamy virus type 1.we have cloned proviral dna of simian foamy virus type 1 (sfv-1) from linear unintegrated dna (psfv-1). transfection of psfv-1 induces cytopathology in several cell lines with supernatants from the transfected cell culture containing infectious viral particles. electron microscopy of the transfected cells revealed foamy virus particles. deletion analysis of psfv-1 indicated that the transcriptional transactivator (tas) gene located between env and the long terminal repeat is critical for virus r ...19989420293
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
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
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
simian foamy virus-induced immunosuppression in rabbits. 1979230289
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
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
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
the carboxy-terminal transcription enhancement region of the human spumaretrovirus transactivator contains discrete determinants of the activator function.the bel1 gene of human spumaretrovirus (hsrv) encodes a 300-amino-acid nuclear protein termed bel1 that is a potent activator of transcription from the cognate long terminal repeat (ltr). bel1 can also efficiently activate the human immunodeficiency virus type 1 (hiv-1) ltr. we have previously shown that the amino-terminal 227-residue region (minimal activator region) of bel1 can activate the hsrv ltr at low levels and that two distinct domains within the carboxy-terminal 73 residues, from resid ...19938389909
simian foamy virus type 3 (sfv-3) in latently infected vero cells: reactivation by demethylation of proviral dna.cell cultures latently infected with simian foamy virus type 3 (sfv-3) were established by suppressing lytic infection in vero cells with 3'-azido-3'-deoxythymidine (azt) and homologous antibodies (african green monkey serum immune to sfv-3). the resulting cell line, designated vero-l, was shown to contain at least one copy per cell of sfv-3 dna stably integrated at a defined site of the host cell genome. sequencing of 669 bp at the integration site did not identify a coding region and revealed ...19938380669
simian foamy virus type 1 contains a second promoter located at the 3' end of the env gene.simian foamy virus type 1 (sfv-1) is a member of a distinct subfamily of retroviruses that possess a complex genome organization as well as complex means of regulating gene expression. this virus encodes a transcriptional transactivator (taf) that dramatically increases gene expression directed by the viral long terminal repeat. in this report, the identification of a second promoter which is significantly transactivated by sfv-1 taf is described. the second promoter is located at the 3' end of ...19948116246
high throughput detection of retrovirus-associated reverse transcriptase using an improved fluorescent product enhanced reverse transcriptase assay and its comparison to conventional detection methods.the development and application of a novel, sensitive taqman fluorescent probe-based product enhanced rt test (f-pert) for the detection of retrovirus are described. the assay allows discrimination between the amplification signals generated by genuine positive signals that result from retroviral rt activity and the rt-like activity from dna polymerases. the rt-like activity from dna polymerases was suppressed by the addition of activated calf-thymus dna with no reduction in the rt activity. a l ...199910894635
isolation of a new foamy retrovirus from orangutans.we have isolated a new foamy virus from blood samples taken from two apparently healthy orangutans (pongo pygmaeus). the older orangutan has since died with encephalopathy after a brief acute illness, while the younger one, his grandson, remains well. these animals and 12 other orangutans had specific antibodies to foamy virus as measured by immunofluorescence. the new foamy virus and the antisera showed strong and specific neutralization, with only weak cross-reaction with other simian foamy vi ...19947933094
phylogenesis and genetic complexity of the nonhuman primate retroviridae.the three known groups of nonhuman primate retroviruses (simian immunodeficiency virus, simian t cell lymphotropic/leukemic virus type i, and simian foamy virus) are thought to have equivalent human counterparts. this is clearly the case with human immunodeficiency virus types 1 and 2, the causative agents of acquired immunodeficiency syndrome, and with human t cell lymphotropic/leukemia virus type i (htlv-i), which causes t cell leukemia and a progressive form of myelopathy (tropical spastic pa ...19947826692
regulatory elements in the long terminal repeat (ltr) of simian foamy virus type 3 (sfv-3).simian foamy virus type 3 (sfv-3) is a retrovirus that has a complex genome organization and encodes two open reading frames (orf-1 and orf-2) in addition to the genes coding for gag, pol, and env. in this report, we demonstrate that orf-1 of sfv-3 encodes a transcriptional transactivator designated taf (transactivator of foamy virus) which augments gene expression directed by the viral long terminal repeat (ltr). the taf responsive elements have been mapped to the u3 region of the ltr, between ...19938390763
functional domains of the simian foamy virus type 1 transcriptional transactivator (taf).the genome of simian foamy virus type 1 encodes a transcriptional transactivator (taf) that dramatically elevates gene expression directed by the viral long terminal repeat. in this report, we describe the functional domains of simian foamy virus type 1 taf. several taf mutants and fusion proteins of taf and the dna-binding domain of the saccharomyces cerevisiae transcriptional transactivator gal4 were used in this study. taf contains two potent activation domains. one of the activation domains ...19938392601
the transcriptional transactivator of simian foamy virus 1 binds to a dna target element in the viral internal promoter.the transcriptional transactivator (tas) of simian foamy virus type 1 strongly augments gene expression directed by both the promoter in the viral long terminal repeat and the newly discovered internal promoter located within the env gene. a region of 121 bp, located immediately 5' to the tata box in the internal promoter, is required for transactivation by tas. the present study aimed to identify the precise tas-responsive target(s) in this region and to determine the role of tas in transcripti ...19968552631
simian foamy virus vectors. preparation and use. 200211987786
characterization of rnase h activity associated with reverse transcriptase in simian foamy virus type 1.spumavirinae or foamy viruses have been shown to have a characteristic rna-dependent dna polymerase activity. we demonstrate here the existence of an rnase h activity that copurifies with the 81-kilodalton monomeric polypeptide, which carries the rna-dependent dna polymerase activity of simian foamy virus type 1. rnase h degrades rna hybrid substrates; however, it does not solubilize single-stranded rnas. inactivation assays with heat, high levels of bivalent cations, ethidium bromide, and sodiu ...19836191042
cross-species retroviral transmission from macaques to human beings.cross-species transmission of simian foamy virus (sfv) to human beings from chimpanzees, baboons, and african green monkeys has been described. although macaques are the non-human primate most often handled in research, human infection with sfv from macaques has not been reported. two of 46 primate-facility workers tested positive for antibodies that reacted with an immunoblot that contained macaque foamy virus antigens. phylogenetic assessment of a 96-bp fragment of amplified proviral dna isola ...200212241782
infectious proviral clones of chimpanzee foamy virus (sfvcpz) generated by long pcr reveal close functional relatedness to human foamy virus.infectious proviral clones of simian foamy virus isolated from chimpanzee (sfvcpz) were generated by long pcr. two overlapping fragments representing the complete provirus were amplified from genomic dna of infected cells. four 8.8-kbp amplimers extending from base 1 of the provirus into the env gene and five 4.45-kbp amplimers reaching from env to the end of the 3'-ltr were cloned into pcr ii. subsequently, the proviral fragments were combined in a chessboard manner to generate 20 plasmids cont ...19958553577
transduction of umbilical cord blood cd34+ nod/scid-repopulating cells by simian foamy virus type 1 (sfv-1) vector.foamy viruses are nonpathogenic retroviruses that offer unique opportunities for gene transfer into various cell types including hematopoietic stem cells. we used a simian foamy virus type 1 vector (sfv-1) containing a lacz reporter gene with a titer of 1-5 x 10(6) viral particles/ml that was free of replication-competent retrovirus to transduce human umbilical cord blood cd34+ cells. transduced cd34+ cord blood cells were transplanted into nod/scid mice and plated in serum-free methylcellulose ...200212441067
a minimal genome simian foamy virus type 1 vector system with efficient gene transfer.foamy viruses have several inherent features for the opportunity to develop efficient and versatile vectors for gene therapy. we have constructed a series of vectors and helper plasmids based on simian foamy virus type 1 (sfv-1) to establish the minimum vector genome required for efficient gene transduction. to characterize the efficiency of gene transduction by these vectors, the green fluorescent protein (gfp) coding sequence is linked to the human cytomegalovirus immediate gene promoter. seve ...200212441068
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
derivation and functional characterization of a consensus dna binding sequence for the tas transcriptional activator of simian foamy virus type 1.although dna binding sites specific for the bel-1 and tas transcriptional activators, encoded, respectively, by the human and simian foamy viruses, have been mutationally defined, they show little evident sequence identity. as a result, the sequence determinants for dna binding by both bel-1 and tas have remained unclear. here, we report the use of a novel in vivo randomization and selection strategy to identify a tas dna binding site consensus. this approach takes advantage of the fact that tas ...19989621006
amplification of simian retroviral sequences from human recipients of baboon liver transplants.investigations into the use of baboons as organ donors for human transplant recipients, a procedure called xenotransplantation, have raised the specter of transmitting baboon viruses to humans and possibly establishing new human infectious diseases. retrospective analysis of tissues from two human transplant recipients with end-stage hepatic disease who died 70 and 27 days after the transplantation of baboon livers revealed the presence of two simian retroviruses of baboon origin, simian foamy v ...19989671210
packaging cell lines for simian foamy virus type 1 vectors.foamy viruses are nonpathogenic retroviruses that offer several unique opportunities for gene transfer in various cell types from different species. we have previously demonstrated the utility of simian foamy virus type 1 (sfv-1) as a vector system by transient expression assay (m. wu et al., j. virol. 72:3451-3454, 1998). in this report, we describe the first stable packaging cell lines for foamy virus vectors based on sfv-1. we developed two packaging cell lines in which the helper dna is plac ...199910196355
a second immunologic type of simian foamy virus: monkey throat infections and unmasking by both types. 196113790382
comparison of simian foamy virus strains including a new serological type. 196414154020
sites of simian foamy virus persistence in naturally infected african green monkeys: latent provirus is ubiquitous, whereas viral replication is restricted to the oral mucosa.foamy viruses (fv), retroviruses of the genus spumavirus, are able to infect a wide variety of animal species and replicate in nearly all types of cultured cells. to identify the cells targeted by fv in the natural host and define the sites of viral replication, multiple organs of four african green monkeys naturally infected with simian fv type 3 were investigated for the presence of fv proviral dna and viral transcripts. all organs contained significant amounts of fv proviral dna. in addition ...199910208915
naturally acquired simian retrovirus infections in central african hunters.hunting and butchering of wild non-human primates infected with simian immunodeficiency virus (siv) is thought to have sparked the hiv pandemic. although siv and other primate retroviruses infect laboratory workers and zoo workers, zoonotic retrovirus transmission has not been documented in natural settings. we investigated zoonotic infection in individuals living in central africa.200415043960
natural simian foamy virus infection in wild-caught gorillas, mandrills and drills from cameroon and gabon.a survey for the presence of simian foamy retroviruses (sfvs) was performed in 44 wild-caught apes and monkeys, including 27 gorillas, 11 mandrills and six drills, originating from south cameroon or gabon. combined serological and/or nested-pcr assays indicated sfv infection among five gorilla gorilla gorilla, seven mandrillus sphinx and two mandrillus leucophaeus. sequences of a 425 bp fragment of the integrase gene were obtained for 11 animals. phylogenetic studies indicated that strains from ...200415483245
strain fv-21 of simian foamy virus type 1 was cloned and sequenced after isolation from the taiwan monkey macaca cyclopsis. 200010806968
differential susceptibility of retroviruses to nucleoside analogues.retroviruses may cause diseases in their vertebrate hosts. they are distinguished by their common means of replication involving reverse transcription, a process inhibited by nucleoside reverse transcriptase inhibitors (nrtis) and other compounds used in antiretroviral chemotherapy. previous work on nrtis has been limited to their effect on human immunodeficiency virus (hiv) (for review see ho & hitchcock, 1989; weller, 1999) and little information exists regarding the efficacy and therapeutic p ...200111527046
mucosal and systemic antibody responses in humans infected with simian foamy virus.simian foamy virus (sfv) infection and the subsequent immune response are not well characterized. blood plasma, saliva, and urine were obtained from four humans and nine chimpanzees persistently infected with chimpanzee-type sfv for an unknown length of time. sfv-specific immunoglobulin g (igg) antibodies, but not iga antibodies, against the gag and bet proteins were detected, by western blotting, in all sample types from infected humans and chimpanzees. overall, chimpanzee samples had higher an ...200516189020
simian retrovirus infections: potential confounding variables in primate toxicology studies.various species of nonhuman primates are natural hosts for 6 exogenous retroviruses, including gibbon-ape leukemia virus (galv), simian sarcoma virus, simian t-lymphotropic virus (stlv), simian immunodeficiency virus (siv), simian type d retrovirus (srv), and simian foamy virus (sfv). these viruses establish persistent infections with a broad spectrum of pathogenic potential, ranging from highly pathogenic to nonpathogenic, depending on various host, virus, and environmental factors. latent or s ...200312597437
transactivation of the two promoters of sfv-3 by different mechanisms.simian foamy virus type 3 (sfv-3), a member of the spumavirus genus of retroviruses, has a complex genome organization and encodes two open reading frames (orfs), in addition to the structural genes gag, pol, and env. orf-1 encodes a viral transcriptional transactivator designated taf (transactivator of foamy viruses) which augments transcription from the viral long terminal repeat (ltr). it was recently shown that human foamy virus, as well as the simian viruses sfv-1 and sfv-3, contains a seco ...19968661448
simultaneous detection of antibodies to six nonhuman-primate viruses by multiplex microbead immunoassay.to maintain healthy nonhuman primates for use in biomedical research, animals are routinely screened for several infectious agents at most facilities. commonly, monkey serum samples are tested by conventional immunoassays, such as enzyme-linked immunosorbent assays (elisas) or western blotting, for antibodies to specific infectious agents. for testing for antibodies against multiple agents in each sample, conventional immunoassays are laborious and time-consuming. more efficient immunoassays are ...200616425999
the simian foamy virus type 1 transcriptional transactivator (tas) binds and activates an enhancer element in the gag gene.simian and human foamy viruses (sfv and hfv) encode a transcriptional transactivator, tas, which governs the levels of viral transcripts initiated by both the promoter in the long terminal repeat (ltr) and the internal promoter (ip) located within the env gene of these viruses. tas-responsive target elements,(tre) ltr in the ltr and (tre) ip in the env gene, are located 5' of the tata box in both viral promoters and function as orientation- and position-independent enhancers. we have identified ...19968794326
comparison of growth and differentiation of fetal and adult rhesus monkey mesenchymal stem cells.the goal of this study was to compare the growth and differentiation potential of fetal and adult rhesus monkey (macaca mulatta) mesenchymal stem cells (rhmscs). rhmscs were obtained from healthy early third-trimester fetal (n = 3) and adult (n = 3) rhesus monkey bone marrow. fetal rhmscs were plated at 10, 50, 100, or 1,000 cells/cm(2) in medium containing 10% or 20% infant monkey serum (ims) or fetal bovine serum (fbs). fetal rhmscs grown at 1,000 cells/cm(2) in 20% fbs showed faster growth ra ...200616646667
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
risk assessment: a model for predicting cross-species transmission of simian foamy virus from macaques (m. fascicularis) to humans at a monkey temple in bali, indonesia.contact between humans and nonhuman primates (nhps) frequently occurs at monkey temples (religious sites that have become associated with free-ranging populations of nhps) in asia, creating the potential for nhp-human disease transmission. in march 2003 a multidisciplinary panel of experts participated in a workshop designed to model the risk of nhp-human pathogen transmission. the panel developed a risk assessment model to describe the likelihood of cross-species transmission of simian foamy vi ...200616900504
isolation and characterization of infectious full-length dna clones of chimpanzee foamy viruses sfv6 and sfv7: evidence for a taf-dependent internal promoter.we have cloned complete viral genomes directly from hirt supernatant dnas of simian foamy virus types 6 and 7 (sfv6 and sfv7) -infected cells. these clones were shown to be infectious by transfection into cells and subsequent infection of susceptible cells either by cocultivation or by passage of cell-free supernatants. the presence of virus particles, suggested by a typical cytopathic effect, was confirmed by electron microscopy. these viruses were characterized at different levels of the repli ...19968882337
generation of herpes virus saimiri-transformed t-cell lines from macaques is restricted by reactivation of simian spuma viruses.herpes virus saimiri (hvs) transforms human t-cells in vitro to stable growth. these t-cell lines retain their immunological characteristics of the parent cells and do not release infectious virus. recently, lymphocytes of old world monkeys were efficiently transformed by hvs. in parallel to these studies we initiated transformation experiments by infecting peripheral blood cell cultures of 45 monkeys, 35 rhesus and 10 cynomolgus macaques. in only three cases, we obtained transformed t-cell line ...19979123851
implications of simian retroviruses for captive primate population management and the occupational safety of primate handlers.nonhuman primates can be naturally infected with a plethora of viruses with zoonotic potential, including retroviruses. these simian viruses present risks to both captive nonhuman primate populations and persons exposed to nonhuman primates. simian retroviruses, including simian immunodeficiency virus, simian type d retrovirus, simian t-lymphotropic virus, and gibbon ape leukemia virus, have been shown to cause clinical disease in nonhuman primates. in contrast, simian foamy virus, a retrovirus ...200617319119
cis-acting sequences required for simian foamy virus type 1 vectors.we have constructed a series of vectors based on simian foamy virus type 1 (sfv-1) to define the minimum cis-acting elements required for gene transfer. to characterize these vectors, we inserted the coding sequence of the bacterial lacz gene linked to the cytomegalovirus immediate-early gene promoter. introduction of a deletion mutation in the leader region between the 5' long terminal repeat and the start of the gag gene at position 1659 to 1694 completely abrogated gene transfer by the sfv-1 ...19989525680
threat to humans from virus infections of non-human primates.several hundred distinct non human primate species are recognised, and they are likely to harbour a similar range of viruses to humans. simians such as cynomolgus and rhesus macaques, african green monkeys, and marmosets are widely used for biomedical research, but despite this extensive close contact very few simian viruses have been shown to pose a threat of infection or illness to humans. herpesvirus simiae is the best recognised zoonotic hazard of simians. it is an alphaherpes virus of asiat ...199710398488
genetic stability of foamy viruses: long-term study in an african green monkey population.the genetic variability of the envelope surface domain (su) of simian foamy virus (fv) of african green monkeys was studied. to assess the interindividual diversity of fv, isolates were obtained from 19 animals living together in a monkey house. the monkeys had been imported from kenya prior to being placed in long-term housing in the research institute. in addition, a simian fv isolate and proviral dna were obtained from an animal caretaker infected in this setting. dna of the complete su (1779 ...199910516034
azt-resistant foamy virus.azidothymidine (azt) is a reverse transcriptase (rt) inhibitor that efficiently blocks the replication of spumaretroviruses or foamy viruses (fvs). to more precisely elucidate the mechanism of action of the fv rt enzyme, we generated an azt-resistant fv in cell culture. biologically resistant virus was obtained for simian foamy virus from macaque (sfvmac), which was insensitive to azt concentrations of 1 mm, but not for fvs derived from chimpanzees. nucleotide sequencing revealed four non-silent ...200817904181
persistent zoonotic infection of a human with simian foamy virus in the absence of an intact orf-2 accessory gene.although foamy viruses (fvs) are endemic among nonhuman primates, fv infection among humans is rare. recently, simian foamy virus (sfv) infection was reported in 4 of 231 individuals occupationally exposed to primates (1.8%). secondary transmission to spouses has not been seen, suggesting that while fv is readily zoonotic, humans may represent dead-end hosts. among different simian species, sfv demonstrates significant sequence diversity within the u3 region of the long terminal repeat (ltr) and ...199910516073
inhibition of simian immunodeficiency virus by foamy virus vectors expressing sirnas.viral vectors available for gene therapy are either inefficient or suffer from safety concerns for human applications. foamy viruses are non-pathogenic retroviruses that offer several unique opportunities for gene transfer in various cell types from different species. in this report, we describe the use of simian foamy virus type 1 (sfv-1) vector to examine the efficacy of therapeutic genes. hairpin short-interfering rna (sirna) that targets the simian immunodeficiency virus (siv) rev/env was pl ...200516181654
simian foamy virus infections in a baboon breeding colony.the prevalence, transmission, and variation of simian foamy viruses (sfvs) in baboons was investigated. over 95% of adult baboons in the breeding colony as well as recently imported adult animals had high titers of anti-sfv serum igg. maternal antibody was detectable in infants' serum up to 6 months of age. approximately 30% of infants in breeding harems experienced sfv infections by 1 year of age. shedding of sfv in oral secretions was common, with 13% of samples from normal adult animals and 3 ...200011112493
the efficiency of simian foamy virus vector type-1 (sfv-1) in nondividing cells and in human pbls.current retroviral vectors based on murine leukemia virus (mulv) are unable to efficiently transduce nondividing cells. lentiviruses, such as the human immunodeficiency virus 1 (hiv-1) are efficient at transducing nondividing, growth-arrested, and post-mitotic cells, but due to complex safety considerations, they may have limited potential for human clinical gene transfer. for this reason, alternatives to mulv and hiv-1 vectors need to be explored. in this paper, we have found that simian foamy ...200111162838
a rapid and quantitative assay for measuring neighboring gene activation by vector proviruses.a simple, quantitative assay for measuring the oncogenic potential of integrating vectors is needed in order to improve vector design and safety. in this study, we have developed a transient plasmid-based assay to measure the activation of a reporter gene by an adjacent vector provirus. plasmid pact contains a luciferase cassette driven by a minimal, enhancerless promoter, into which vector proviruses are inserted upstream for evaluation by luciferase assays and northern blots. in a comparison o ...200818209733
identification of a conserved residue of foamy virus gag required for intracellular capsid assembly.in contrast to all retroviruses but similar to the hepatitis b virus, foamy viruses (fv) require expression of the envelope protein for budding of intracellular capsids from the cell, suggesting a specific interaction between the gag and env proteins. capsid assembly occurs in the cytoplasm of infected cells in a manner similar to that for the b- and d-type viruses; however, in contrast to these retroviruses, fv gag lacks an n-terminal myristylation signal and capsids are not targeted to the pla ...200111435565
prevalence of enzootic simian viruses among urban performance monkeys in indonesia.animal reservoirs are the most important sources of emerging infectious diseases that threaten human populations. global travel and tourism bring ever-increasing numbers of humans into contact with animals, increasing the likelihood of cross species transmission of infectious agents. non-human primates come into contact with humans in a variety of contexts and may harbor infectious agents with zoonotic potential. we investigated the prevalence of infection with enzootic simian viruses among 20 u ...200516359412
simian foamy virus infection in a blood donor.infections with simian foamy virus (sfv) are widely prevalent in nonhuman primates. sfv infection was confirmed in a worker, occupationally exposed to nonhuman primates, who donated blood after the retrospectively documented date of infection. human-to-human transmission of sfv through transfusion and its pathogenicity have not been studied.200212375661
screening for simian foamy virus infection by using a combined antigen western blot assay: evidence for a wide distribution among old world primates and identification of four new divergent viruses.simian foamy viruses (sfvs) belong to a genetically and antigenically diverse class of retroviruses that naturally infect a wide range of nonhuman primates (nhps) and can also be transmitted to humans occupationally exposed to nhps. current serologic detection of sfv infection requires separate western blot (wb) testing by using two different sfv antigens [sfv(agm) (african green monkey) and sfv(cpz) (chimpanzee)]. however, this method is labor intensive and validation is limited to only small n ...200312758172
simian foamy virus infection by whole-blood transfer in rhesus macaques: potential for transfusion transmission in humans.cross-species infection of humans with simian foamy virus (sfv) has been reported in european and north american nonhuman primate (nhp) handlers, primarily due to wound injuries involving infected animals in research centers and zoos. additionally, african hunters have been found to be infected with sfv by exposure to body fluids, blood, or tissues of infected nhps in the wild. the persistence of infectious virus in peripheral blood mononuclear cells (pbmnc) and the recent identification of some ...200616934071
unique pattern of enzootic primate viruses in gibraltar macaques.because gibraltar's macaques (macaca sylvanus) have frequent contact with humans, we assayed 79 macaques for antibodies to enzootic primate viruses. all macaques were seronegative for herpesvirus b, simian t-cell lymphotropic virus, simian retrovirus, simian immunodeficiency virus, and rhesus cytomegalovirus. seroprevalence of simian foamy virus reached 88% among adult animals.200818598634
molecular ecology and natural history of simian foamy virus infection in wild-living chimpanzees.identifying microbial pathogens with zoonotic potential in wild-living primates can be important to human health, as evidenced by human immunodeficiency viruses types 1 and 2 (hiv-1 and hiv-2) and ebola virus. simian foamy viruses (sfvs) are ancient retroviruses that infect old and new world monkeys and apes. although not known to cause disease, these viruses are of public health interest because they have the potential to infect humans and thus provide a more general indication of zoonotic expo ...200818604273
characterization of blood-borne transmission of simian foamy virus.simian foamy virus (sfv) is an endemic, nonhuman primate (nhp) retrovirus that is transmitted to individuals who work with or hunt nhps. the cross-species transmission of simian retroviruses is believed to be the etiology of human immunodeficiency virus and human t-lymphotropic virus infections in humans. although sfv is not pathogenic in the native host, the shared ancestry with other simian retroviruses has brought into question the potential for acquired pathogenicity after cross-species tran ...200717207245
structural and evolutionary analysis of an orangutan foamy virus.the full-length proviral genome of a foamy virus infecting a bornean orangutan was amplified, and its sequence was analyzed. although the genome showed a clear resemblance to other published foamy virus genomes from apes and monkeys, phylogenetic analysis revealed that simian foamy virus sfvora was evolutionarily equidistant from foamy viruses from other hominoids and from those from old world monkeys. this finding suggests an independent evolution within its host over a long period of time.200312857929
human infection with foamy viruses.virtually all nonhuman primate species investigated thus far including prosimians, new world and old world monkeys and apes all harbor distinct and species-specific clades of simian foamy virus (sfv). however, evidence supporting the existence of a human-specific foamy virus (fv) is not yet available. early reports describing widespread infection of healthy and sick humans with fv could not be confirmed. in contrast, all fv infections documented in humans are of zoonotic origin and are identifie ...200312908773
simian foamy virus infection among zoo keepers.we investigated 322 north american zoo workers in an anonymous serosurvey for antibodies to simian foamy viruses to establish the potential risk of zoonotic transmission by these retroviruses. 4 of 133 (3%) individuals who worked specifically with mammals including primates were seropositive, primarily with chimp-like viruses, indicating the importance of work practices to reduce exposure to these agents.200010683011
azt resistance of simian foamy virus reverse transcriptase is based on the excision of aztmp in the presence of atp.azidothymidine (azt, zidovudine) is one of the few nucleoside inhibitors known to inhibit foamy virus replication. we have shown previously that up to four mutations in the reverse transcriptase gene of simian foamy virus from macaque (sfvmac) are necessary to confer high resistance against azt. to characterize the mechanism of azt resistance we expressed two recombinant reverse transcriptases of highly azt-resistant sfvmac in escherichia coli harboring three (k211i, s345t, e350k) or four mutati ...200818096624
hepatitis b virus infection in non-human primates.hepatitis b viruses (hbvs) represent a serious public health problem affecting 350 to 400 million hbv carriers worldwide. the virus does not exclusively infect humans, but can also be found in non-human primates as in the families hominidae (chimpanzee, gorilla, orangutan) and hylobatidae (gibbon), which are distributed over africa (chimpanzee and gorilla) and southeast asia (orangutan and gibbon), the endemic areas of human hbv. the prevalence of asymptomatic hbv carriers reaches in gibbons 23- ...200919537907
sequence-specific (1)h, (13)c and (15)n resonance assignments and secondary structure of a truncated protease from simian foamy virus.the backbone and side chain assignments of the retroviral aspartate protease from simian foamy virus from macaques (sfvmac) have been determined by triple resonance nmr techniques.200719636858
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