| feline syncytial virus spontaneously detected in feline cell cultures. | | 1979 | 480769 |
| seroepizootiologic survey of feline syncytial virus infections in domestic cats. | | 1989 | 2548027 |
| latent infection with feline syncytial virus of cell cultures prepared from the kidneys of new-born kittens. | feline syncytial virus infection was detected in 4 out of 30 secondary or tertiary cultures of kidney cells from new-born kittens. such infection was not detected in any primary cell culture. the syncytia-forming virus was readily transmissible by infected cells. one strain was transmissible to heterologous (bovine and canine) secondary cells, but did not infect mdbk and pk-15 cell lines. based on biochemical, untrastructural and serological characteristics, the virus was designated a member of ... | 1988 | 3354195 |
| detection and prevalence of serotypes of feline syncytial spumaviruses. | three serotypes of feline syncytial virus (fsv) were detected by neutralisation tests: 906, a serotype of low prevalence and 702 and 951 which were serotypes of higher prevalence, between which a minor one-way antigenic difference was detected. serum antibody in naturally-infected cats in some cases neutralised 951 but not 702 or 906 which suggested that 951 could be considered as a major distinct serotype. an increase in prevalence of antibody to fsv in cats over a 5 year period from 1977-1981 ... | 1985 | 3918526 |
| feline syncytial virus. | | 1971 | 4325043 |
| [isolation and characterisation of a feline syncytial virus (author's transl)]. | | 1974 | 4421720 |
| feline respiratory virus carriers in clinically healthy cats. | in two surveys, feline calicivirus was cultured from 19.7% and 15% of 66 and 201 clinically healthy cats respectively. feline viral rhinotracheitis virus was cultured also from 1.5% of oropharyngeal swabs collected in both surveys. feline syncytial virus was isolated from 5.5% oropharyngeal swabs collected in the second survey. the use of serological examination and corticosteroid treatment to stimulate virus shedding demonstrated that 25.8% cats in the first survey were carriers of feline viral ... | 1981 | 6266382 |
| seroepidemiological survey of feline retrovirus infections in cats in taiwan in 1993 and 1994. | in order to investigate the prevalence of infections with three feline retroviruses feline immunodeficiency virus (fiv), feline leukemia virus (felv) and feline syncytial virus (fsv) in taiwan, we collected a total of 75 blood samples from cats from veterinary hospitals, a breeding cattery and a homeless shelter in 1993 and 1994. we examined the presences of anti-fiv and fsv antibodies and felv-p27 antigen in these samples by the indirect immunofluorescence and/or enzyme-linked immunosorbent ass ... | 1995 | 7756412 |
| establishment of carrier-state infection of a feline renal cell line with feline syncytial virus. | although feline syncytial virus (fsv) is normally highly cytopathogenic in crandell feline kidney cells, a non-cytopathic persistent infection was established in the cells after cocultivation of the initially infected cells with uninfected cells 4 times. more than 90% of the persistently infected cells were positive for fsv antigen, and electron microscopy showed that the culture produced morphologically normal fsv. virus from the carrier culture was infectious, however, the titer of the virus f ... | 1995 | 7756428 |
| characterization of the spliced pol transcript of feline foamy virus: the splice acceptor site of the pol transcript is located in gag of foamy viruses. | foamy viruses, or spumaviruses, are distinct members of the retroviridae. here we have characterized the long terminal repeat of the feline, or cat, foamy virus by determining the locations of the transcriptional start site and the poly(a) addition site. the splice donor and splice acceptor sites of the subgenomic mrna responsible for pro-pol protein expression were identified by nucleotide sequencing of the corresponding cdnas. the leader exon of the feline foamy virus is 57 nucleotides long. t ... | 1996 | 8971036 |
| replication of feline syncytial virus in feline t-lymphoblastoid cells and induction of apoptosis in the cells. | feline syncytial virus (fsv) was isolated from feline peripheral blood mononuclear cells of fsv-seropositive cats. when the susceptibility of feline t-lymphocytes to fsv was examined using three strains of fsv, fsv antigens were detected in the fsv-infected t-lymphoblastoid cells. further, a diversity of biological properties, including replication kinetics and syncytia formation, was noted among the strains, and condensation of chromatin and the fragmentation of cellular dna were observed in th ... | 1997 | 9194043 |
| characterization of the genome of feline foamy virus and its proteins shows distinct features different from those of primate spumaviruses. | the genome of the feline foamy virus (fefv) isolate fuv was characterized by molecular cloning and nucleotide sequence analysis of subgenomic proviral dna. the overall genetic organization of fefv and protein sequence comparisons of different fefv genes with their counterparts from other known foamy viruses confirm that fefv is a complex foamy virus. however, significant differences exist when fefv is compared with primate foamy viruses. the fefv gag protein is smaller than that of the primate s ... | 1997 | 9261397 |
| a rapid streptavidin-capture elisa specific for the detection of antibodies to feline foamy virus. | we report a simple procedure for the rapid development of an elisa with the potential for wide application to any defined protein antigen. the procedure involves the expression of protein encoded by a pcr product, using a commercially available t-vector that adds a biotin tag, and a single step purification by affinity for streptavidin for direct use in elisa. in our experiments, a recombinant protein from the nucleocapsid domain of the feline foamy virus gag gene was expressed as a fusion prote ... | 1997 | 9328588 |
| comparison of the complete sequence of feline spumavirus with those of the primate spumaviruses reveals a shorter gag gene. | the complete nucleotide sequence of the provirus of feline foamy virus (fefv), strain f-17, was determined, and compared to the available data for human and simian spumaviruses. in addition to the usual retroviral gag, pol and env genes, two open reading frames are present between the env gene and the 3'-ltr, as in the simian spumaviruses, the first being the putative transactivator. the gag gene is predicted to encode a precursor protein of only 53 kda compared to 70 kda for simian spumaviruses ... | 1997 | 9349476 |
| the nucleotide sequence and spliced pol mrna levels of the nonprimate spumavirus bovine foamy virus. | we have determined the complete nucleotide sequence of a replication-competent clone of bovine foamy virus (bfv) and have quantitated the amount of splice pol mrna processed early in infection. the 544-amino-acid gag protein precursor has little sequence similarity with its primate foamy virus homologs, but the putative nucleocapsid (nc) protein, like the primate ncs, contains the three glycine-arginine-rich regions that are postulated to bind genomic rna during virion assembly. the bfv gag and ... | 1998 | 9499074 |
| detection of subgenomic cdnas and mapping of feline foamy virus mrnas reveals complex patterns of transcription. | feline foamy virus (fefv) belongs to the group of spumaretroviruses that contain in addition to gag, pol, and env accessory genes collectively called bel genes. primate fvs have been shown to utilize internal promoters in addition to the 5' ltr promoters. in contrast to other known retroviruses, the fv pol genes are expressed via spliced transcripts. northern blot analysis and reverse transcription-coupled polymerase chain reactions (rt-pcr) were used to amplify, clone, and characterize cdnas ge ... | 1998 | 9601510 |
| detection and molecular characterisation of feline foamy virus serotypes in naturally infected cats. | the characterisation of two distinct feline foamy virus sequence groupings in the external surface portion of the viral env gene are reported. although amino acid identities in the gag nucleocapsid, pol protease, and env transmembrane domains were greater than 92% in the 12 proviral sequences examined, two distinct sequence groups were observed in the env surface (su) protein. only 57% amino acid identity was observed in the env su between the two groups designated fuv7-like or 951-like, while w ... | 1998 | 9705907 |
| nuclear localization of the functional bel 1 transactivator but not of the gag proteins of the feline foamy virus. | interactions between host cells and foamy or spumaretroviruses are different from those of other known retroviruses. previous work has suggested that the gag and high-affinity dna-binding bel 1 transactivator of human foamy virus are localized in the nuclei of infected cells. using two independent detection methods, we show here that the functionally active bel 1 transactivator protein of feline foamy virus is of nuclear localization. in contrast to that reported for the human foamy virus gag pr ... | 1998 | 9813199 |
| seroepidemiological survey of feline retrovirus infections in domestic and leopard cats in northern vietnam in 1997. | the prevalence of infections with three feline retroviruses (feline immunodeficiency virus (fiv), feline leukemia virus (felv) and feline syncytial virus (fsv)) was examined in northern vietnam in 1997. we collected a total of 77 blood samples from 69 domestic and 8 leopard cats, and examined the presence of anti-fiv and fsv antibodies and felv p27 antigen in the plasma samples by the indirect immunofluorescence and/or two commercial kits. none of the samples was positive for fiv and felv. the o ... | 1998 | 9853314 |
| feline viruses in wildcats from scotland. | few data are available on the prevalence of feline viruses in european wildcats (felis silvestris). previous surveys have indicated that wildcats may be infected with the common viruses of domestic cats, apart from feline immunodeficiency virus (fiv). in the present study, 50 wildcats trapped throughout scotland (uk) between august 1992 and january 1997 were tested for evidence of viral infection. all were negative for fiv by several serological or virological methods. by contrast, 10% of the ca ... | 1999 | 10073361 |
| epidemiology of feline foamy virus and feline immunodeficiency virus infections in domestic and feral cats: a seroepidemiological study. | although foamy viruses (spumaviruses) have repeatedly been isolated from both healthy and diseased cats, cattle, and primates, the primary mode of transmission of those common viruses remains undefined. a database of the feline foamy virus (fefv) and feline immunodeficiency virus (fiv) antibody status, age, and sex of 389 domestic cats presented to veterinarians was assembled. a similar database for 66 feral (wild) cats was also assembled. that fefv antibody status reflects infection was validat ... | 1999 | 10449463 |
| strategies of retrovirus survival in the cat. | retroviruses establish persistent infections in their hosts which often lead to serious and fatal diseases after a long incubation period. the molecular basis of this persistence is the integration of a copy of the viral genome into cellular chromosomal dna. at the level of the whole animal, however, each retrovirus genus has evolved a different strategy to ensure its survival. this variety is well illustrated in the cat. feline leukaemia virus, an oncovirus, has a simple genomic structure and s ... | 1999 | 10515277 |
| construction of infectious feline foamy virus genomes: cat antisera do not cross-neutralize feline foamy virus chimera with serotype-specific env sequences. | full-length genomes of the feline foamy virus (ffv or fefv) isolate fuv were constructed. dna clone pfefv-7 stably directed the expression of infectious ffv progeny virus indistinguishable from wild-type, uncloned ffv isolate fuv. the env and bel 1 genes of pfefv-7 were substituted for by corresponding sequences of the ffv serotype 951 since previous studies implicated a defined part of ffv env protein as responsible for serotype-specific differences in serum neutralization (i. g. winkler, r. m. ... | 2000 | 10612669 |
| contrastive prevalence of feline retrovirus infections between northern and southern vietnam. | the prevalence of infections with three feline retroviruses; feline leukemia virus (felv), feline immunodeficiency virus (fiv) and feline foamy virus (fefv), was examined in domestic cats (felis catus) and leopard cats (felis bengalensis) in southern vietnam in 1998. we then compared this data with our previous study in northern vietnam in 1997. none of the cats had felv antigens in both the northern and southern areas. in contrast, there is a great distinction in the seropositivity of fiv. twen ... | 2000 | 10993195 |
| characterization of the humoral immune response and virus replication in cats experimentally infected with feline foamy virus. | cats were experimentally infected with cell culture-adapted feline foamy virus (ffv, spumaretrovirinae) isolate fuv. ffv was consistently recovered from peripheral blood leukocytes and throat samples of ffv-infected cats starting 2 to 3 weeks postinfection (p. i.), indicative of the establishment of persistent ffv infections. viral persistence was established, even despite neutralizing antibodies that appeared early after infection. the humoral immune response toward ffv was quantitatively and q ... | 2000 | 11017797 |
| survey of veterinary conference attendees for evidence of zoonotic infection by feline retroviruses. | to examine exposure risks, possibility of zoonosis, and potential disease associations for feline retroviruses among a group of occupationally exposed individuals. | 2000 | 11128537 |
| reactivation of feline foamy virus from a chronically infected feline renal cell line by trichostatin a. | although acute infection of feline foamy virus (fefv) is normally highly cytopathogenic in crandell feline kidney (crfk) cells, a noncytopathic persistent infection was established in the cells after cocultivation of the initially infected cells with uninfected cells four times. to investigate reactivation of persistent infection, crfk cells chronically infected with fefv were treated with trichostatin a (ta), a histone deacetylase inhibitor. ta induced higher fefv production from the coleman st ... | 2001 | 11336556 |
| genetic analyses of feline foamy virus isolates from domestic and wild feline species in geographically distinct areas. | to know the genetic diversities and phylogenetic relationship among feline foamy virus (fefv) isolates from domestic cats (felis catus) and fefv-related viruses from the iriomote cats (felis iriomotensis) and leopard cats (felis bengalensis) in geographically distinct areas, we sequenced a partial gag-pol region of 17 strains and a partial env region of nine strains, and the u3 region of long terminal repeat of three strains of the viruses. fefv-related viruses from the feral cats were quite sim ... | 2001 | 11410316 |
| specific interaction of a novel foamy virus env leader protein with the n-terminal gag domain. | cryoelectron micrographs of purified human foamy virus (hfv) and feline foamy virus (ffv) particles revealed distinct radial arrangements of gag proteins. the capsids were surrounded by an internal gag layer that in turn was surrounded by, and separated from, the viral membrane. the width of this layer was about 8 nm for hfv and 3.8 nm for ffv. this difference in width is assumed to reflect the different sizes of the hfv and ffv ma domains: the hfv ma domain is about 130 residues longer than tha ... | 2001 | 11483744 |
| the bet gene of feline foamy virus is required for virus replication. | foamy viruses (fv) are complex retroviruses with additional bel genes located between env and the 3' long-terminal repeat. the functions of the bel 2 and bet genes are unknown and both are dispensable for replication of the prototypic human foamy virus in cell cultures. we examined the function(s) of bel 2 and bet of the distantly related feline foamy virus (ffv) in the proviral context. mutagenesis was used to alter the bel 2 and bet or to abrogate their expression. the bel 2/bet mutants showed ... | 2001 | 11531409 |
| isolation and sequencing of infectious clones of feline foamy virus and a human/feline foamy virus env chimera. | full-length dnas of the coleman and s7801 strains (psky3.0, psky5.0) of infectious feline foamy viruses (ffvs) were cloned and sequenced. parental viruses, designated sky3.0 and sky5.0, were secreted following transfection of crandell feline kidney (crfk) cells. production of the rescued parental viruses was enhanced in the presence of trichostatin a. amino acid sequence similarities between ffv and human foamy virus (hfv) are extremely low for the envelope protein and capsid antigen, as predict ... | 2001 | 11714976 |
| construction and functional characterization of feline foamy virus-based retroviral vectors. | replication-competent feline foamy or spuma virus (ffv) vectors were constructed and functionally tested. the unmodified ffv vector genome expressed by the strong human cytomegalovirus immediate early promoter encodes ffv particles that were replication-competent in cell cultures. virus derived from the cloned ffv dna replicated and persisted in experimentally infected cats similar to the ffv isolate fuv. a ffv vector partially deleted in the noncoding area of the u3 region was used to transduce ... | 2002 | 12359446 |
| establishment of a gfp-based indicator cell line to quantitate feline foamy virus. | to quantitate infectious feline foamy virus (fefv), crandell feline kidney (crfk) cells were transfected with the gfp gene under the control of the fefv long terminal repeat (ltr) for establishing an indicator cell line named ffg cells. the fefv activates promoter activity of the ltr to express green fluorescent protein (gfp) upon infection. the titers determined by gfp-positive ffg cells (gfp-based assay) were higher than those determined by the cytopathic effects-positive crfk cells (cpe-based ... | 2003 | 12711054 |
| features of the env leader protein and the n-terminal gag domain of feline foamy virus important for virus morphogenesis. | previous studies have shown that foamy virus (fv) particle budding, especially the involvement of the viral env glycoprotein is different from that of other (ortho) retroviruses: the n-terminal env leader protein elp is a constituent of released fv particles. a defined sequence in elp required for particle budding binds to the ma domain of gag. to extend these findings, we show that feline fv elp is a membrane-anchored protein with the n-terminus located inside the particle. thus, the internal/c ... | 2003 | 12781711 |
| application of chimeric feline foamy virus-based retroviral vectors for the induction of antiviral immunity in cats. | in order to define the potential and applicability of replication-competent foamy virus-based vaccine vectors, recombinant feline foamy virus (ffv) vectors encoding defined segments of the feline calicivirus (fcv) capsid protein e domain were constructed. in cell cultures, these ffv-fcv vectors efficiently transduced and expressed a hybrid fusion protein consisting of the essential ffv bet protein and the attached fcv e domains. the stability of the vectors in vitro was inversely correlated to t ... | 2003 | 12829823 |
| non-primate foamy viruses. | foamy viruses (pfvs), also called spumaviruses, are complex retroviruses inducing a characteristic cytopathic effect in cell culture, leading rapidly to cell lysis. these viruses have been isolated mostly in non-human primates, but three non primate pfvs were characterized, namely the bovine foamy virus, the feline foamy virus and more recently the equine foamy virus. in their hosts, pfvs seem to be apathogenic, mirroring an efficient control of virus replication in vivo. comparing the biology o ... | 2003 | 12908774 |
| feline foamy virus genome and replication strategy. | crucial aspects of the foamy virus (fv) replication strategy have so far only been investigated for the prototypic fv (pfv) isolate, which is supposed to be derived from nonhuman primates. to study whether the unusual features of this replication pathway also apply to more-distantly related fvs, we constructed feline fv (ffv) infectious molecular clones and vectors. it is shown by quantitative rna and dna pcr analysis that ffv virions contain more rna than dna. full-length linear dna was found i ... | 2003 | 14557618 |
| demonstration of feline foamy virus in experimentally infected cats by immunohistochemistry. | foamy viruses (fv) are complex retroviruses which are commonly isolated from cats, cattle and non-human primates. the infection is persistent and infected animals have a sustained antibody response. the role of fv in diseases remains unclear, in cats, a possible association with uncharacterized renal symptoms remains to be confirmed. to demonstrate feline fv (ffv) in tissues of experimentally infected cats three polyclonal monospecific antisera from rabbits against three different viral proteins ... | 2003 | 14633220 |
| comparative functional characterization of the feline foamy virus transactivator reveals its species specificity. | foamy virus (fv) bel1/tas transactivators act as key regulators of gene expression and directly bind dna bel1 response elements (bres) in both the internal (ip) and 5'ltr promoters. here, we report the mapping and the virus species specificity of the nonhomologous feline foamy virus (ffv) bres in both promoters. the data indicate that ffv bel1 did not bind the primate fv ip.bre and that primate fv bel1 was not capable of binding the ffv ip.bre. in addition, we show that the c-terminal activation ... | 2004 | 14972532 |
| kinetics and characteristics of replication-competent revertants derived from self-inactivating foamy virus vectors. | in this study, self-inactivating (sin) retroviral vectors based on feline foamy virus (ffv) were constructed and analysed. the ffv sin vectors were devoid of the core ffv long terminal repeat promoter plus upstream sequences but contained all structural and regulatory genes. this design allowed sensitive detection of replication-competent revertants (rcrs). the ffv sin vectors efficiently transduced the green fluorescence protein into recipient cells. however, rcrs appeared after serial passages ... | 2004 | 14973540 |
| fip: a novel approach to vaccination. proceedings from the 2nd international fcov/fip symposium, glasgow, 4-7 august 2002. | feline infectious peritonitis (fip) is a fatal disease of cats. early attempts at vaccination have been unsuccessful, some even serving to exacerbate the disease through antibody-dependent enhancement. replication-incompetent feline foamy virus (ffv) transducing vectors are being developed as potential vaccine agents, into which immunogenic fragments of feline coronavirus (fcov) proteins will be inserted. to use a recombinant viral vector to express fcov proteins, the agent chosen should be apat ... | 2004 | 15123157 |
| feline foamy virus tas protein is a dna-binding transactivator. | foamy viruses (fvs) harbour a transcriptional transactivator (tas) and two tas-responsive promoter regions, one in the 5' long terminal repeat (ltr) and the other an internal promoter (ip) in the envelope gene. to analyse the mechanism of transactivation of the fvs, the specificity of feline fv (ffv) tas protein, which is more distantly related to the respective proteins of non-human primate origin, were investigated. ffv tas has been shown specifically to activate gene expression from the cogna ... | 2004 | 15448355 |
| furin-mediated cleavage of the feline foamy virus env leader protein. | the molecular biology of spuma or foamy retroviruses is different from that of the other members of the retroviridae. among the distinguishing features, the n-terminal domain of the foamy virus env glycoprotein, the 16-kda env leader protein elp, is a component of released, infectious virions and is required for particle budding. the transmembrane protein elp specifically interacts with n-terminal gag sequences during morphogenesis. in this study, we investigate the mechanism of elp release from ... | 2004 | 15564468 |
| characterization of env antigenicity of feline foamy virus (fefv) using fefv-infected cat sera and a monoclonal antibody. | to characterize neutralizing antigenicity in relation to env genotypes of feline foamy virus (fefv), serological analyses were performed using fefv-infected cat sera and several field isolates including two env genotypes (f17- and fuv-types). since three cats from which fefv were isolated were found to have undetectable titers of virus neutralization (vn) antibodies, even to the homologous virus, vn antibodies were further examined with complement supplementation as an enhancement factor. with t ... | 2005 | 15778026 |
| the antiretroviral activity of apobec3 is inhibited by the foamy virus accessory bet protein. | genome hypermutation of different orthoretroviruses by cellular cytidine deaminases of the apobec3 family during reverse transcription has recently been observed. lentiviruses like hiv-1 have acquired proteins preventing genome editing in the newly infected cell. here we show that feline foamy virus (ffv), a typical member of the foamy retrovirus subfamily spumaretrovirinae, is also refractory to genome deamination. apobec3-like ffv genome editing in apobec3-positive feline crfk cells only occur ... | 2005 | 15911774 |
| evaluation of formalin-fixed paraffin-embedded tissues from feline vaccine site-associated sarcomas for feline foamy virus dna. | to evaluate a group of vaccine site-associated sarcomas (vss) for the presence of feline foamy virus (fefv) dna, using polymerase chain reaction (pcr) methods. | 2002 | 16206781 |
| antibodies against gag are diagnostic markers for feline foamy virus infections while env and bet reactivity is undetectable in a substantial fraction of infected cats. | spumaretroviruses or foamy viruses constitute a distinct subfamily of retroviruses. the biology of foamy viruses within the authentic host, their mode of transmission, and disease potential in the authentic host or after zoonotic transmission into human or other species are almost unknown. using feline foamy virus (ffv) as model system, we established modular enzyme-linked immunosorbent assays (elisa) suited to determine feline igg and igm antibody responses against structural and non-structural ... | 2006 | 16297422 |
| feline foamy virus-mediated marker gene transfer: identification of essential genetic elements and influence of truncated and chimeric proteins. | retroviral vectors derived from foamy or spumaretroviruses are considered promising tools for targeted gene delivery and vaccination purposes. in order to fully exploit this potential, we identified essential cis-acting sequences on the feline foamy virus (ffv) genome by constructing and analyzing a series of ffv-based replication-deficient vector genomes. cis-acting sequences essentially required for marker gene transfer were found to be localized at two sites on the ffv genome: (i) in the 5'-u ... | 2006 | 16443252 |
| construction and characterization of efficient, stable and safe replication-deficient foamy virus vectors. | as serious side effects affected recent virus-mediated gene transfer studies, novel vectors with improved safety profiles are urgently needed. in the present study, replication-deficient retroviral vectors based on feline foamy virus (ffv) were constructed and analyzed. the novel ffv vectors are devoid of almost the complete env gene plus the internal promoter - accessory bel gene cassette including the gene for the viral transcriptional transactivator bel1/tas. in these bel1/tas-independent vec ... | 2007 | 17203107 |
| functions, structure, and read-through alternative splicing of feline apobec3 genes. | over the past years a variety of host restriction genes have been identified in human and mammals that modulate retrovirus infectivity, replication, assembly, and/or cross-species transmission. among these host-encoded restriction factors, the apobec3 (a3; apolipoprotein b mrna-editing catalytic polypeptide 3) proteins are potent inhibitors of retroviruses and retrotransposons. while primates encode seven of these genes (a3a to a3h), rodents carry only a single a3 gene. | 2008 | 18315870 |
| is feline foamy virus really apathogenic? | feline foamy virus (ffv) is a retrovirus commonly found in cats. it is generally thought to be apathogenic, making it a suitable candidate as a gene therapy vector. however, there have been reports of association of ffv with chronic progressive arthritis and a cofactor effect with feline immunodeficiency virus. this study investigated experimental ffv infection and whether this was associated with signs of disease. eight young specific pathogen free cats were inoculated intramuscularly with ffv. ... | 2008 | 18342375 |
| importance of the major splice donor and redefinition of cis-acting sequences of gutless feline foamy virus vectors. | foamy virus vectors are potent alternatives to lenti- and gamma-retroviral vectors for gene therapy. to construct and optimize gutless feline foamy virus (ffv) replication-deficient (rd) vectors, viral elements essential for optimal efficient marker gene transduction were characterized and fine-mapped and packaging clones constructed. for these purposes, new gag and pol expression clones which allow efficient expression of packaging proteins and vectors carrying deletions in coding and non-codin ... | 2009 | 19775717 |
| characterization of biochemical properties of feline foamy virus integrase. | in order to study biochemical properties, the integrase (in) protein of feline foamy virus (ffv) was over-expressed from escherichia coli, purified by two-step chromatography; talon column and heparin column, and characterized in biochemical aspects. for the three enzymatic reactions of the 3' -processing, strand transfer, and disintegration activities, mn2+ ion was essentially required as a cofactor. interestingly, co2+ and zn2+ ions were found to act as effective cofactors, while other transit ... | 2010 | 20622493 |
| immunological properties of the transmembrane envelope protein of the feline foamy virus and its use for serological screening. | the transmembrane envelope (tm) proteins of retroviruses are used as antigen in diagnostic immunoassays and they represent a conserved target for neutralizing antibodies. to analyze the situation in infections with the feline foamy virus (ffv), its recombinant tm protein was produced and used for elisa and western blot analyses. screening sera from 404 german cats showed that 39% reacted against the tm protein, the same infection rate was determined using the gag protein. epitope mapping showed ... | 2011 | 21316070 |
| feline tetherin efficiently restricts release of feline immunodeficiency virus but not spreading of infection. | domestic cats endure infections by all three subfamilies of the retroviridae: lentiviruses (feline immunodeficiency virus [fiv]), gammaretroviruses (feline leukemia virus [felv]), and spumaretroviruses (feline foamy virus [ffv]). thus, cats present an insight into the evolution of the host-retrovirus relationship and the development of intrinsic/innate immune mechanisms. tetherin (bst-2) is an interferon-inducible transmembrane protein that inhibits the release of enveloped viruses from infected ... | 2011 | 21490095 |
| pattern of seroreactivity against feline foamy virus proteins in domestic cats from germany. | the prevalence of feline foamy virus (ffv, spumaretrovirinae) in naturally infected domestic cats ranges between 30 and 80% ffv positive animals depending on age, sex and geographical region analyzed. two serotypes have been reported for ffv designated fuv7-like and f17/951-like. serotype-specific neutralization has been shown to correlate with sequence divergence in the surface (su) domain of the envelope protein (env). we analyzed a serum collection of 262 domestic cat sera from germany using ... | 2011 | 21724269 |
| diffuse scattering resulting from macromolecular frustration. | distinctive diffuse scattering in the form of diffuse rings around bragg positions has been observed in the diffraction patterns of a crystal of the n-terminal fragment of the gag protein from feline foamy virus. it is shown that these are caused by geometric frustration as molecules try to pack on the triangular b-c mesh of the space group p6(1)22. in order to explain the strong diffuse scattering it is necessary for the crystal to contain occupational disorder such that each unit cell contains ... | 2011 | 22101541 |
| N-terminally myristoylated feline foamy virus gag allows env-independent budding of sub-viral particles. | Foamy viruses (FVs) are distinct retroviruses classified as Spumaretrovirinae in contrast to the other retroviruses, the Orthoretrovirinae. As a unique feature of FVs, Gag is not sufficient for sub-viral particle (SVP) release. In primate and feline FVs (PFV and FFV), particle budding completely depends on the cognate FV Env glycoproteins. It was recently shown that an artificially added N-terminal Gag myristoylation signal (myr-signal) overcomes this restriction in PFV inducing an Orthoretrovir ... | 2011 | 22163342 |
| Identification of a Cullin5-ElonginB-ElonginC E3 complex in degradation of feline immunodeficiency virus Vif-mediated feline APOBEC3 proteins. | Various feline APOBEC3 (fA3) proteins exhibit broad antiviral activities against a wide range of viruses, such as feline immunodeficiency virus (FIV), feline foamy virus (FFV), and feline leukemia virus (FeLV), as well as those of other species. This activity can be counteracted by the FIV Vif protein, but the mechanism by which FIV Vif suppresses fA3s is unknown. In the present study, we demonstrated that FIV Vif could act via a proteasome-dependent pathway to overcome fA3s. FIV Vif interacted ... | 2011 | 21957297 |
| optimisation of expression and purification of the feline and primate foamy virus transmembrane envelope proteins using a 96 deep well screen. | the production of recombinant transmembrane proteins is due to their biochemical properties often troublesome and time consuming. here the prokaryotic expression and purification of the transmembrane envelope proteins of the feline and primate foamy viruses using a screening assay for optimisation of expression in 96 deep well plates is described. testing simultaneously various bacterial strains, media, temperatures, inducer concentrations and different transformants, conditions for an about twe ... | 2012 | 21964437 |
| identification and functional characterization of bet protein as a negative regulator of bfv3026 replication. | foamy virus (fv) establishes persistent infection in the host without causing apparent disease. besides the transactivator tas protein, another auxiliary protein--bet--has been reported in prototype foamy virus, equine foamy virus, and feline foamy virus. here, we found the putative bbet gene in clone c74 from a cdna library of bovine foamy virus strain 3026 (bfv3026) by comparison of gene localization, composition, and splicing features with other known bet genes. subsequently, bbet protein was ... | 2014 | 24615636 |
| evolution of the retroviral restriction gene fv1: inhibition of non-mlv retroviruses. | fv1 is the prototypic restriction factor that protects against infection by the murine leukemia virus (mlv). it was first identified in cells that were derived from laboratory mice and was found to be homologous to the gag gene of an endogenous retrovirus (erv). to understand the evolution of the host restriction gene from its retroviral origins, fv1s from wild mice were isolated and characterized. most of these possess intact open reading frames but not all restricted n-, b-, nr-or nb-tropic ml ... | 2014 | 24603659 |
| epitope mapping of the antibody response against the envelope proteins of the feline foamy virus. | foamy viruses (fv) are retroviruses that infect several species without pathological signs, but induce substantial antibody responses in the infected host. in the case of feline fv (ffv), antibodies against gag, bet, and env have been used to indicate infection; however, it is unclear whether the response to specific epitopes correlates with immunity. here, we investigated the epitope specificity of antibodies targeting the env protein using peptide microarrays. sera from naturally and experimen ... | 2017 | 28355125 |
| mutagenesis of n-terminal residues of feline foamy virus gag reveals entirely distinct functions during capsid formation, particle assembly, gag processing and budding. | foamy viruses (fvs) of the spumaretrovirinae subfamily are distinct retroviruses, with many features of their molecular biology and replication strategy clearly different from those of the orthoretroviruses, such as human immunodeficiency, murine leukemia, and human t cell lymphotropic viruses. the fv gag n-terminal region is responsible for capsid formation and particle budding via interaction with env. however, the critical residues or motifs in this region and their functional interaction are ... | 2016 | 27549192 |
| expression levels of fv1: effects on retroviral restriction specificities. | the mouse protein fv1 is a factor that can confer resistance to retroviral infection. the two major fv1 alleles from laboratory mice, fv1 (n) and fv1 (b) , restrict infection by different murine leukaemia viruses (mlvs). fv1(n) restricts b-tropic mlv, but not n-tropic mlv or nb-tropic mlv. in cells expressing fv1(b) at natural levels, only n-mlv is restricted, however restriction of nb-mlv and partial restriction of b-mlv were observed when recombinant fv1(b) was expressed from an mlv promoter i ... | 2016 | 27342974 |
| replication-competent foamy virus vaccine vectors as novel epitope scaffolds for immunotherapy. | the use of whole viruses as antigen scaffolds is a recent development in vaccination that improves immunogenicity without the need for additional adjuvants. previous studies highlighted the potential of foamy viruses (fvs) in prophylactic vaccination and gene therapy. replication-competent fvs can trigger immune signaling and integrate into the host genome, resulting in persistent antigen expression and a robust immune response. here, we explored feline foamy virus (ffv) proteins as scaffolds fo ... | 2015 | 26397953 |
| feline foamy virus adversely affects feline mesenchymal stem cell culture and expansion: implications for animal model development. | mesenchymal stem cells (mscs) are a promising therapeutic option for various immune-mediated and inflammatory disorders due to their potent immunomodulatory and trophic properties. naturally occurring diseases in large animal species may serve as surrogate animal models of human disease, as they may better reflect the complex genetic, environmental, and physiologic variation present in outbred populations. we work with naturally occurring diseases in large animal species to better understand how ... | 2015 | 25404388 |
| construction and characterisation of replicating foamy viral vectors expressing hiv-1 epitopes recognised by broadly neutralising antibodies. | with the aim to develop a replicating vector system for the delivery of hiv-1 antigens on the basis of an apathogenic foamy virus we recently showed that immunisation with purified recombinant hybrid antigens composed of the feline foamy virus bet protein and parts of the transmembrane envelope protein of hiv-1 induced antibodies with an epitope specificity identical to that of the broadly neutralising antibody 2f5 (mühle et al., immunol res., 2013, 56:61-72). here we set out to further improve ... | 2013 | 24055836 |
| identification of the feline foamy virus bet domain essential for apobec3 counteraction. | apobec3 (a3) proteins restrict viral replication by cytidine deamination of viral dna genomes and impairing reverse transcription and integration. to escape this restriction, lentiviruses have evolved the viral infectivity factor (vif), which binds a3 proteins and targets them for proteolytic degradation. in contrast, foamy viruses (fvs) encode bet proteins that allow replication in the presence of a3, apparently by a3 binding and/or sequestration, thus preventing a3 packaging into virions and s ... | 2013 | 23880220 |
| feline foamy virus-based vectors: advantages of an authentic animal model. | new-generation retroviral vectors have potential applications in vaccination and gene therapy. foamy viruses are particularly interesting as vectors, because they are not associated to any disease. vector research is mainly based on primate foamy viruses (pfv), but cats are an alternative animal model, due to their smaller size and the existence of a cognate feline foamy virus (ffv). the potential of replication-competent (rc) ffv vectors for vaccination and replication-deficient (rd) ffv-based ... | 2013 | 23857307 |
| biochemical characteristics of functional domains using feline foamy virus integrase mutants. | we constructed deletion mutants and seven point mutants by polymerase chain reaction to investigate the specificity of feline foamy virus integrase functional domains. complementation reactions were performed for three enzymatic activities such as 3'-end processing, strand transfer, and disintegration. the complementation reactions with deletion mutants showed several activities for 3'-end processing and strand transfer. the conserved central domain and the combination of the n-terminal or c-ter ... | 2013 | 23351385 |
| immunising with the transmembrane envelope proteins of different retroviruses including hiv-1: a comparative study. | the induction of neutralizing antibodies is a promising way to prevent retrovirus infections. neutralizing antibodies are mainly directed against the envelope proteins, which consist of two molecules, the surface envelope (su) protein and the transmembrane envelope (tm) protein. antibodies broadly neutralizing the human immunodeficiencvy virus-1 (hiv-1) and binding to the tm protein gp41 of the virus have been isolated from infected individuals. their epitopes are located in the membrane proxima ... | 2013 | 23249763 |
| molecular and functional interactions of cat apobec3 and feline foamy and immunodeficiency virus proteins: different ways to counteract host-encoded restriction. | defined host-encoded feline apobec3 (fea3) cytidine deaminases efficiently restrict the replication and spread of exogenous retroviruses like feline immunodeficiency virus (fiv) and feline foamy virus (ffv) which developed different fea3 counter-acting strategies. here we characterize the molecular interaction of ffv proteins with the diverse fea3 proteins. the ffv accessory protein bet is the virus-encoded defense factor which is shown here to bind all fea3 proteins independent of whether they ... | 2012 | 22265237 |
| frequent cross-species transmissions of foamy virus between domestic and wild felids. | emerging viral outbreaks resulting from host switching is an area of continued scientific interest. such events can result in disease epidemics or in some cases, clinically silent outcomes. these occurrences are likely relatively common and can serve as tools to better understand disease dynamics, and may result in changes in behavior, fecundity, and, ultimately survival of the host. feline foamy virus (ffv) is a common retrovirus infecting domestic cats globally, which has also been documented ... | 2020 | 31942245 |
| a virome sequencing approach to feline oral squamous cell carcinoma to evaluate viral causative factors. | feline oral squamous cell carcinoma (foscc) may be the best naturally-occurring model of human head and neck squamous cell carcinoma (hnscc). hnscc can be broadly divided into human papillomavirus (hpv)-negative cancers and hpv-positive cancers where hpv is the causative agent. previous studies in foscc have used both species-specific and species-nonspecific pcr primers that may be insensitive to the detection of pvs and other viruses that may be divergent from known sequences. virocap is a targ ... | 2020 | 31902496 |
| first report on the prevalence and genetic relatedness of feline foamy virus (ffv) from turkish domestic cats. | feline foamy virus (ffv) is an important retroviral agent affecting domestic cats in turkey that has been studied less intensively than feline immunodeficiency virus (fiv) and feline leukemia virus (felv). accordingly, we aimed to investigate the presence and prevalence of ffv among domestic cats by molecular techniques. pcr was used to amplify the gag-pol gene overlap in order to detect the presence of ffv. the gene encoding bet, an important accessory gene, was also characterized. molecular ch ... | 2019 | 31562905 |
| feline foamy virus seroprevalence and demographic risk factors in stray domestic cat populations in colorado, southern california and florida, usa. | our study aim was to document the seroprevalence and associated risk factors of feline foamy virus (ffv) infection in domestic cat populations presented to animal shelters located in southern california, colorado and florida, usa. | 2020 | 31555460 |
| feline foamy virus infection: characterization of experimental infection and prevalence of natural infection in domestic cats with and without chronic kidney disease. | foamy viruses (fvs) are globally prevalent retroviruses that establish apparently apathogenic lifelong infections. feline fv (ffv) has been isolated from domestic cats with concurrent diseases, including urinary syndromes. we experimentally infected five cats with ffv to study viral kinetics and tropism, peripheral blood mononuclear cell (pbmc) phenotype, urinary parameters, and histopathology. a persistent infection of primarily lymphoid tropism was detected with no evidence of immunological or ... | 2019 | 31330990 |
| feline foamy virus is highly prevalent in free-ranging puma concolor from colorado, florida and southern california. | feline foamy virus (ffv) is a retrovirus that has been detected in multiple feline species, including domestic cats (felis catus) and pumas (puma concolor). ffv results in persistent infection but is generally thought to be apathogenic. sero-prevalence in domestic cat populations has been documented in several countries, but the extent of viral infections in nondomestic felids has not been reported. in this study, we screened sera from 348 individual pumas from colorado, southern california and ... | 2019 | 31010173 |
| feline leukemia virus (felv) disease outcomes in a domestic cat breeding colony: relationship to endogenous felv and other chronic viral infections. | exogenous feline leukemia virus (felv) is a feline gammaretrovirus that results in a variety of disease outcomes. endogenous felv (enfelv) is a replication-defective provirus found in species belonging to the felis genus, which includes the domestic cat (felis catus). there have been few studies examining interaction between enfelv genotype and felv progression. we examined point-in-time enfelv and felv viral loads, as well as occurrence of felv/enfelv recombinants (felv-b), to determine factors ... | 2018 | 29976676 |
| replacement of feline foamy virus bet by feline immunodeficiency virus vif yields replicative virus with novel vaccine candidate potential. | hosts are able to restrict viral replication to contain virus spread before adaptive immunity is fully initiated. many viruses have acquired genes directly counteracting intrinsic restriction mechanisms. this phenomenon has led to a co-evolutionary signature for both the virus and host which often provides a barrier against interspecies transmission events. through different mechanisms of action, but with similar consequences, spumaviral feline foamy virus (ffv) bet and lentiviral feline immunod ... | 2018 | 29769087 |
| serosurvey of mountain lions in southern arizona. | an understanding of the prevalence of diseases in free-ranging populations of felids is limited, and there is even less known about the overall health and diseases of wild felids that inhabit or utilize urban areas. we collected serum samples from 9 radiocollared mountain lions (puma concolor) in the mountains surrounding tucson, arizona, usa, from august 2005 to august 2008. we tested serum samples for evidence of exposure to 10 feline viruses: feline calicivirus (fcv), feline herpesvirus, feli ... | 2012 | 32327861 |
| diagnostic uncertainty and the epidemiology of feline foamy virus in pumas (puma concolor). | feline foamy virus (ffv) is a contact-dependent retrovirus forming chronic, largely apathogenic, infections in domestic and wild felid populations worldwide. given there is no current 'gold standard' diagnostic test for ffv, efforts to elucidate the ecology and epidemiology of the virus may be complicated by unknown sensitivity and specificity of diagnostic tests. using bayesian latent class analysis, we estimated the sensitivity and specificity of the only two ffv diagnostic tests available-eli ... | 2020 | 32005906 |
| use of unbiased metagenomic and transcriptomic analyses to investigate the association between feline calicivirus and feline chronic gingivostomatitis in domestic cats. | to identify associations between microbes and host genes in cats with feline chronic gingivostomatitis (fcgs), a debilitating inflammatory oral mucosal disease with no known cause, compared with healthy cats and cats with periodontitis (control cats). | 2021 | 33904799 |
| serum samples from co-infected and domestic cat field isolates nonspecifically bind fiv and other antigens in enzyme-linked immunosorbent assays. | we evaluated enzyme-linked immunosorbent assay (elisa) specificity for measuring seroantibody responses to two types of retroviral infections in domestic cats: feline immunodeficiency virus (fiv) and feline foamy virus (ffv). we compared the seroreactivity of specific pathogen-free (spf) cat sera, sera from spf cats inoculated with either fiv or ffv, and field isolates (e.g., shelter or privately owned cats). sera from spf cats experimentally infected with the cognate virus had significantly low ... | 2021 | 34071706 |