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activation of bovine immunodeficiency-like virus expression by bovine herpesvirus type 1.bovine immunodeficiency-like virus (biv) is a recently identified lentivirus that infects cattle. the virus has structural and genetic similarities to human hiv. the present study demonstrates that biv can be activated by bovine herpesvirus type 1 (bhv-1), a pathogen frequently associated with cattle diseases. activation of biv expression can be detected as increased biv reverse transcriptase activity, increased in the number of syncytia induced by biv, and increased in the steady state level of ...19921312280
analysis of the transcription pattern and mapping of the putative rev and env splice junctions of bovine immunodeficiency-like virus.the bovine immunodeficiency-like virus (biv) genome contains the obligatory structural genes of all retroviruses and, in addition, the complex central region of lentiviruses; this novel region may code for at least five nonstructural/regulatory genes in biv (k.j.garvey, m.s. oberste, j.e. elser, m.j. braun, and m.a. gonda, virology 175:391-409, 1990). as a prelude to determining the function of these novel open reading frames, the transcriptional pattern of biv was studied by northern analysis o ...19911645801
animal immunodeficiency viruses.feline immunodeficiency virus (fiv) has morphological, physical and biochemical characteristics similar to human immunodeficiency virus (hiv), the cause of aids in man. however, it is antigenically and genetically distinct from hiv; an antigenic relatedness with equine infectious anaemia virus has been demonstrated. fiv has been molecularly cloned and sequenced. diagnostic tests are commercially available and attempts at preparing inactivated, subunit and molecularly engineered vaccines are bein ...19921336243
detection of multiple retroviral infections in cattle and cross-reactivity of bovine immunodeficiency-like virus and human immunodeficiency virus type 1 proteins using bovine and human sera in a western blot assay.bovine antibovine immunodeficiency-like virus (biv) antibodies were detected by western blot analysis (wba) using a chemiluminescence protocol. bovine sera with anti-biv activity, obtained from cows in two dairy herds, had antibodies directed against a variety of biv-specific antigens indicating chronic infections. these sera were also tested for serological reactivity against bovine leukemia virus (blv) and bovine syncytial virus (bsv). cows most commonly had anti-bsv antibodies (12 of 39). evi ...19921335835
infection and dysfunction of monocytes induced by experimental inoculation of calves with bovine immunodeficiency-like virus.three calves were experimentally inoculated with bovine immunodeficiency-like virus (biv) to examine biv pathogenesis. inoculated calves produced specific antibody that could be detected from 3 to 5 weeks up to 1 year postinoculation (pi). virus was isolated from peripheral blood mononuclear cells (pbmc) 3-4 weeks pi by syncytia assay. thereafter, the virus could be continually isolated. biv could be isolated from monocytes but not from t cells. likewise, monocytes could be infected with biv in ...19921333528
identification and characterization of the bovine immunodeficiency-like virus tat gene.a cdna clone of the bovine immunodeficiency-like virus (biv) trans-activator gene (tat) was identified and characterized. the tat cdna clone was generated by splicing, and on the basis of sequence analysis, the tat protein was found to be encoded entirely by the first exon. it is 103 amino acids in size and shares sequence homology with the human immunodeficiency virus (hiv) tat. the biv tat clone can trans activate the biv promoter effectively, as measured by the expression of the bacterial chl ...19921321293
seroprevalence of bovine immunodeficiency-like virus and bovine leukemia virus in a dairy cattle herd.to determine the prevalence of single vs. dual infection with bovine immunodeficiency virus (biv) and bovine leukemia virus (blv), sera (n = 95) from a dairy cattle herd were analyzed for anti-biv and anti-blv antibodies by an enzyme linked immunosorbent assay. twenty-one percent (20/95) of samples were biv-seropositive, while 52% (49/95) of the same samples were blv-seropositive. a significantly greater percentage of biv-seronegative samples were blv-seropositive, 57% (43/75), than were biv-ser ...19921320785
persistent infection of rabbits with bovine immunodeficiency-like virus.chronic infection of rabbits was induced by a single intraperitoneal injection of bovine immunodeficiency-like virus (biv)-infected cells. ten biv-infected animals were monitored serologically for up to 2 years. results of serologic and virus rescue assays indicated that all animals became infected and demonstrated a rapid and sustained biv-specific humoral response. biv was rescued by cocultivation from spleen, lymph nodes, and peripheral blood leukocytes of infected animals. viral dna in immun ...19921318416
development of a monoclonal antibody-based p24 capsid antigen detection assay for htlv-i, htlv-ii, and stlv-i infection.a monoclonal antibody-based antigen capture enzyme-linked immunosorbent assay (elisa) was developed and employed to detect p24 capsid antigen from human t-cell lymphotropic viruses type i and ii (htlv-i, htlv-ii), simian t-cell lymphotropic virus type i (stlv-i)-infected cell lines, and from mononuclear cell cocultures of htlv-infected humans and stlv-i infected monkeys. a monoclonal antibody specific for htlv p24 and p53 capsid antigens was coated onto 96-well microtiter plates to capture htlv/ ...19921318063
examination of whether persistently indeterminate human immunodeficiency virus type 1 western immunoblot reactions are due to serological reactivity with bovine immunodeficiency-like virus.the bovine lentivirus, known as bovine immunodeficiency-like virus (biv), is genetically, structurally, and antigenically related to human immunodeficiency virus type 1 (hiv-1). it is not known whether sera from persons exposed to biv proteins would show either positive or indeterminate reactivity on hiv-1 antibody tests. we used a biv western blot (immunoblot) analysis to examine human sera characterized as hiv-1 antibody positive, hiv-1 antibody negative, hiv-1 persistently indeterminate, hiv- ...19921315332
bovine immunodeficiency-like virus encodes factors which trans activate the long terminal repeat.lentiviruses are known to encode factors which trans activate expression from the viral long terminal repeat (ltr); the primary trans activator is the tat gene product. one of the putative accessory genes (tat) of the bovine immunodeficiency-like virus (biv) bears sequence similarity to other lentivirus tat genes. this finding suggests that biv may encode a trans-activating protein capable of stimulating ltr-directed gene expression. to test this hypothesis in vitro, biv ltr-chloramphenicol acet ...19921313891
infection of rabbits with bovine immunodeficiency-like virus.new zealand white rabbits, which had been prepared for inoculation by intraperitoneal treatment with thioglycollate, were inoculated intraperitoneally with bovine immunodeficiency-like virus (biv). infected materials from various sources were used including cultured cells and culture fluids, peripheral blood leukocytes from infected cattle and spleen tissue from previously infected rabbits. virus isolations and serological responses detected by western blotting provided clear evidence that infec ...19921313619
conservation of amino-acid sequence motifs in lentivirus vif proteins.the nonstructural/regulatory genes of human immunodeficiency virus type 1 (hiv-1) and other lentiviruses are believed to play an important role in the replication and pathogenesis of these viruses. in hiv-1 and other lentiviruses, the vif (viral infectivity factor) open reading frame (orf) (also termed sor or q in some lentivirus genomes) is located in the central region, overlapping the 3' end of the pol orf, but in a different reading frame. among the lentiviruses, only equine infectious anemi ...19921312756
expression of bovine immunodeficiency-like virus envelope glycoproteins by a recombinant baculovirus in insect cells.the bovine immunodeficiency-like virus (biv) env open reading frame (orf) contains both sequences encoding env and sequences for exon 1 of the putative rev gene. recombinant baculoviruses incorporating biv env orf sequences were constructed to characterize the expression, processing, and immunogenicity of products of the biv env orf in insect cells and to develop reagents to study native biv env glycoproteins. a recombinant baculovirus containing the entire env orf synthesized a nonglycosylated, ...19921310184
characterization of early pathogenic effects after experimental infection of calves with bovine immunodeficiency-like virus.the early pathogenic effects of bovine immunodeficiency-like virus (biv) were studied in calves experimentally inoculated with biv. all animals inoculated with biv r29-infected cells seroconverted by 6 weeks postinoculation, and biv was recoverable from each animal at 2 weeks postinoculation. however, levels of biv replication in vivo appeared to be low. in situ hybridization studies indicated that during peak periods of viral replication in vivo, less than 0.03% of peripheral blood mononuclear ...19921309889
the polymerase chain reaction (pcr): a valuable method for retroviral detection.although the detection of antibodies to a specific pathogen is used initially as the assay of choice, direct detection of human retroviruses is difficult. first, only a small fraction of cells are infected in the peripheral blood and lymphatic tissue may serve as a reservoir for infection. second, infected cells may harbor only a small number of copies of the viral sequences. third, a latent infection marked by transcriptional dormancy is often established thereby obviating the use of proteins o ...19902170779
inhibitory effect of liposomes containing sulfatide or cholesterol sulfate on syncytium formation induced by bovine immunodeficiency virus-infected cells.the effect of galactocerebroside 3'-sulfate (sulfatide) or cholesterol sulfate on syncytium formation induced by bovine immunodeficiency virus (biv)-infected cells was investigated in vitro. sulfatide was purified from bovine brain and incorporated in liposomes which were composed of egg phosphatidylcholine (pc), cholesterol (chol), and dipalmitoylphosphatidic acid (dppa). either sulfatide- or cholesterol sulfate-containing liposomes effectively prevented syncytium formation induced by biv-infec ...19901963428
[bovine immunodeficiency virus: short review].a bovine visna-like virus was isolated by van der maaten et al (1972) but it did not draw attention since, at that time, most efforts were directed towards research on bovine leukemia virus. however, new interest was shown on the bovine visna-like virus after the isolation of the human immunodeficiency virus (hiv), because of the urgent need for developing animal models for the acquired immunodeficiency syndrome (aids). the purpose of this paper is to describe the different stages of the identif ...19901963056
lymphocyte transformation abnormalities in bovine immunodeficiency-like virus infected calves.bovine immunodeficiency-like virus (biv) is a lentiviral pathogen of cattle which is genetically and antigenically related to the human immunodeficiency virus (hiv-1). to determine the impact of biv infection on the bovine immune system we studied the lymphocyte transformation responses of male holstein calves inoculated with biv strain r-29 to three mitogens: pokeweed mitogen (pwm), concanavalin a (con a), and phytohemagglutinin (pha) at two and six months post-infection. by six months post-ino ...19911851137
a western blot assay for the detection of antibodies to bovine immunodeficiency-like virus in experimentally inoculated cattle, sheep, and goats.a cocultivation method was used to establish a cytocidal bovine immunodeficiency-like virus (biv) infection in primary fetal bovine lung (fbl) cell cultures. cultures were monitored for virus production using radial immunodiffusion and agar gel immunodiffusion. pelleted virus and detergent (chaps)-solubilized infected cell lysates from biv-infected cell cultures were compared as sources of antigen for western blots. pelleted virus preparations from fbl-biv cell cultures produced the best antigen ...19911848061
bovine immunodeficiency virus: immunochemical characterization and serological survey.bovine immunodeficiency virus (biv) was purified by isodensity centrifugation; viral activities were monitored in gradient fractions using the reverse transcriptase assay and a p26-specific monoclonal antibody elisa. in the coincident peak fractions (density about 1.17 g/ml) proteins with mr values of 26k, 17k, 53k, 14k and 100k (with decreasing intensity) were detected by western blotting using serum of a calf after experimental biv infection. when 957 randomly collected cattle sera from the ne ...19911722502
comparative evaluation of bovine immunodeficiency-like virus infection by reverse transcriptase and polymerase chain reaction.infection of embryonic bovine lung (ebl) cells by bovine immunodeficiency-like virus (biv) were monitored by reverse transcriptase (rt), syncytia formation and polymerase chain reaction (pcr). infection can be detected by pcr at 24 h while the presence of syncytia and rt were not detected until much later. the detection of biv rt can be optimized by changing the ph and salt conditions. the enzyme is very sensitive to changes in ph but can tolerate a wider range of salt and mgcl2 concentrations. ...19911713914
characterization of virus-like particles produced by a recombinant baculovirus containing the gag gene of the bovine immunodeficiency-like virus.the entire gag gene of the bovine immunodeficiency-like virus (biv) was inserted behind the strong polyhedron promoter of autographa californica nuclear polyhedrosis virus (acnpv). the resultant recombinant baculovirus (acnpv-bivgag) was used to infect insect cells in order to overexpress and characterize biv gag gene products. the infection resulted in the high-level expression of a protein similar in size to the predicted biv gag precursor (pr53gag). biv pr53gag was detected in acnpv-bivgag-in ...19901699349
use of bacterial trpe fusion vectors to express and characterize the bovine immunodeficiency-like virus core protein.the gag coding region from bovine immunodeficiency-like virus (biv) was cloned into e. coli and expressed as a bacterial fusion protein. six different clones spanning various regions of the gag open reading frame were generated. the resulting fusion proteins were expressed at high concentrations and readily purified. a panel of bovine immune sera specifically recognized the recombinant gag proteins, as did immune sera from animals infected or immunized with lentiviruses related to biv, such as e ...19921372612
identification and evaluation of new primer sets for the detection of lentivirus proviral dna.we have developed sets of degenerate oligonucleotides designed to detect pol gene sequences from any member of the lentivirus subfamily when used as primers in amplification techniques such as the polymerase chain reaction (pcr). this pan-lentivirus-specific primer set (plsps) consists of primers, lv1, lv2, and lv3, based on conserved regions common to lentiviruses only. our protocol is based on primary amplification with lv1 and lv2 followed by secondary amplification with a nested primer set b ...19921337258
serological evidence for the presence of bovine lentivirus infection in cattle in australia. 19921337246
development of the bovine immunodeficiency-like virus as a model of lentivirus disease.the bovine immunodeficiency-like virus (biv) is morphologically, serologically, and genetically related to the lentivirus subfamily of retroviruses which includes human and simian immunodeficiency viruses and other lentiviruses causally associated with debilitating diseases of domestic animals. there are many parallels in the biology and pathologic characteristics of biv infections with those of hiv that make its development as a model of hiv-like infection and disease potentially attractive. in ...19902178134
nucleotide sequence and genome organization of biologically active proviruses of the bovine immunodeficiency-like virus.the complete nucleotide sequences and translations of major open reading frames (orf) of two distinct, infectious, proviral molecular clones (106 and 127) of the bovine immunodeficiency-like virus (biv), obtained from a single virus isolation, were determined and compared. the genomes of biv 127 and 106 are 8482 and 8391 nucleotides (nt), respectively, in the form predicted for the viral rna. the structural organization of the genomes of biv 127 and 106 are identical to one another and most simi ...19902183467
humoral immune response to the bovine immunodeficiency-like virus in experimentally and naturally infected cattle.calves inoculated with bovine immunodeficiency-like virus (biv) produced virus-specific antibodies that could be detected from 2 weeks to 2.5 years postinoculation by using both indirect fluorescent-antibody and western immunoblot assays. antibodies were primarily to p26. virus and biv-specific antibodies were isolated from calves given biv-infected blood. antibodies to biv proteins were found in sera from naturally infected cattle.19902191153
immunological characterization of the gag gene products of bovine immunodeficiency virus.the bovine immunodeficiency virus (biv) gag gene encodes a 53-kda precursor (pr53gag) that is involved in virus particle assembly and is further processed into the putative matrix (ma), capsid (ca), and nucleocapsid (nc) functional domains in the mature virus. gag determinants are also found in the gag-pol polyprotein precursor. to immunologically identify the major precursors and processed products of the biv gag gene, monospecific rabbit sera to recombinant biv ma protein and pr53gag and pepti ...19921331499
molecular cloning of biologically active proviruses of bovine immunodeficiency-like virus.a series of independent proviral molecular clones of bovine immunodeficiency-like virus (biv) obtained from a genomic library of biv-infected bovine cell dna were physically and biologically characterized. heteroduplex mapping shows that two of these biv clones (106 and 127) contain uninterrupted proviral sequences approximately 9.0 kb in length, flanked by nonhomologous bovine cellular sequences. microinjection of purified dna from biv clone 106 or 127 into susceptible bovine cells produces vir ...19882462309
replication of the bovine immunodeficiency-like virus in diploid and aneuploid cells: permanent, latent and virus-productive infections in vitro.bovine immunodeficiency-like virus (biv) is an infectious and leukotropic retrovirus, the sole lentivirus candidate which has been isolated from cattle. although biv has recently been shown to be related to the human immunodeficiency virus, there is very limited information on the replication and the pathogenesis of biv. it is reported here that biv can permanently infect diploid and aneuploid cells from four different species: bovine, canine, ferret and ovine. with the exceptions of a bovine di ...19892694251
animal models for hiv infection and aids: memorandum from a who meeting.the human immunodeficiency virus is a member of the lentivirus subfamily of the retrovirus family. retroviruses are rna viruses which code for an rna-dependent dna polymerase (reverse transcriptase), which transcribes the rna genome into a dna provirus which, on integration with the host dna, directs the synthesis of new virions. the rna genome consists of a gag gene, which codes for the viral core proteins, a pol gene, which codes for the reverse transcriptase, an env gene, which codes for th ...19882850118
characterization and molecular cloning of a bovine lentivirus related to human immunodeficiency virus.an infectious virus which causes persistent lymphocytosis, lymphadenopathy, lesions in the central nervous system (cns), progressive weakness and emaciation was previously isolated from the leukocytes of cattle. our present studies show that this virus encodes a reverse transcriptase (rt) with mg2+ cation preference, replicates and induces syncytia in a variety of embryonic bovine tissues in vitro, and has a morphology most similar to the human immunodeficiency virus (hiv). moreover, serologic a ...19873683555
effect of administration of serum thymic factor (fts) in calves and rabbits infected with bovine immunodeficiency-like virus.the effect of serum thymic factor (fts) administration in bovine immunodeficiency-like virus (biv)-infected calves and rabbits was examined. we previously found that some of the macrophage functions were depressed and humoral immune responses against foreign proteins were delayed in biv-infected calves compared to uninfected calves. after fts administration, however, no delay of antibody responses against foreign proteins was observed in biv-infected calves. though the chemiluminescence (cl) res ...19957492651
solution structure of a bovine immunodeficiency virus tat-tar peptide-rna complex.the tat protein of bovine immunodeficiency virus (biv) binds to its target rna, tar, and activates transcription. a 14-amino acid arginine-rich peptide corresponding to the rna-binding domain of biv tat binds specifically to biv tar, and biochemical and in vivo experiments have identified the amino acids and nucleotides required for binding. the solution structure of the rna-peptide complex has now been determined by nuclear magnetic resonance spectroscopy. tar forms a virtually continuous a-for ...19957502045
use of trpe fusion protein to identify antigenic domains within the biv envelope protein.nine different recombinant clones spanning various regions of the bovine immunodeficiency-like virus (biv) envelope gene open reading frame were generated. these clones span the entire external glycoprotein as well as the transmembrane glycoprotein region. these proteins were expressed as fusions to the trpe protein in e. coli. the levels of recombinant protein expressed varied, some clones expressed enough protein that can be detected in a coomassie blue-stained gel, whereas other proteins coul ...19947520916
identification of hypervariable and conserved regions in the surface envelope gene in the bovine lentivirus.the surface envelope (su) gene of nine different isolates of the bovine lentivirus (biv) were compared for nucleotide and deduced amino acid (aa) sequence diversity. analyses were done both on isolates derived from the original reference strain, r29, and on field isolates of biv. six conserved and six hypervariable regions were identified. many of the hypervariable regions were located in areas predicted to be on the surface of the su protein. the su gene comparison among all isolates showed up ...19957571444
bovine immunodeficiency virus in stud bull semen.bovine immunodeficiency virus (biv), a lentivirus, is prevalent in dairy and beef cattle in southeastern united states and may be associated with a lymphoproliferative disease. the mode(s) of biv transmission are undefined. because artificial insemination is a common practice in dairy production, contaminated stud semen could serve as an important source of infection if the virus is harbored in seminal fluids. to evaluate this possibility, we procured 11 cryopreserved semen specimens from a stud ...19957653885
improved early and long-term detection of bovine lentivirus by a nested polymerase chain reaction test in experimentally infected calves.a nested polymerase chain reaction (pcr) test was developed to examine infection with the bovine lentivirus, bovine immunodeficiency-like virus (biv), in cattle. primers were designed to amplify 2 separate regions of the pol and env segments of the biv genome. two calves were experimentally infected with an isolate derived from the original strain of biv, r29, or with a recent field isolate, fl491. serial blood samples were collected and examined by virus isolation, protein immunoblot, and neste ...19957661451
the bovine immunodeficiency-like virus (biv) is transcriptionally active in experimentally infected calves.we have studied the infection by the bovine immunodeficiency-like virus (biv) in three experimentally infected calves, by polymerase chain reaction (pcr) and reverse transcription-polymerase chain reaction (rt-pcr), from the peripheral blood mononuclear cells (pbmc). two primer pairs located in the gag and pol regions of the viral genome allowed to detect the viral genomic dna by pcr, as well as the unspliced genomic viral rna transcript, by rt-pcr. we also present the evidence of the presence i ...19957661697
characteristics of a retrovirus associated with jembrana disease in bali cattle.a virus causing jembrana disease in bali cattle (bos javanicus) was demonstrated to have characteristics of a retrovirus. reverse transcriptase activity was detected in virus purified by sucrose gradient centrifugation. electron microscopic examination of tissue from the affected cattle indicated that the virus matured by c-type budding through the plasma membrane and into intracytoplasmic vacuoles of cells in lymphoid tissue, with the formation of circular enveloped virus particles ranging in d ...19937690840
in vitro detection of bovine immunodeficiency-like virus using monoclonal antibodies generated to a recombinant gag fusion protein.an escherichia coli recombinant fusion protein containing the major core protein of bovine immunodeficiency-like virus (biv) was used to immunize mice for generation of monoclonal antibodies to biv p26. eight hybridomas specific for biv p26 were identified and two antibodies, designated 104 and 142, were further characterized. both 104 and 142 antibodies were isotyped as igg1; they reacted specifically with both biv p26 and the recombinant fusion protein in western immunoblot analyses. however, ...19937693743
haematological and lymphocyte subset analyses in sheep inoculated with bovine immunodeficiency-like virus.bovine immunodeficiency-like virus (biv) was passaged in vivo by intraperitoneal transfusion of ovine whole blood. prior to transfusion, the recipient sheep were given sodium thioglycolate intraperitoneally to induce mild non-suppurative inflammation. the anti-biv antibody response, haematology, and peripheral blood lymphocyte subsets (b, gamma delta, cd2+, cd4+ and cd8+) of recipient sheep were assessed for one year following transfusion. passaging was successful since serum anti-biv antibody r ...19947701785
alteration of immune responses of rabbits infected with bovine immunodeficiency-like virus.nine 3-month-old rabbits were inoculated with bovine immunodeficiency-like virus (biv) to study the pathogenesis of biv and alteration of the immune responses in experimentally infected rabbits. biv proviral dna and anti-biv antibodies were detected from all rabbits inoculated with biv-infected bovine embryo spleen (besp) cells. rabbits inoculated with spleen cells of the biv-infected rabbit also converted to proviral dna-positive and biv-antibody-positive. the blastogenic responses to concanava ...19947723687
a peptide interaction in the major groove of rna resembles protein interactions in the minor groove of dna.a 17-amino acid arginine-rich peptide from the bovine immunodeficiency virus tat protein has been shown to bind with high affinity and specificity to bovine immunodeficiency virus transactivation response element (tar) rna, making contacts in the rna major groove near a bulge. we show that, as in other peptide-rna complexes, arginine and threonine side chains make important contributions to binding but, unexpectedly, that one isoleucine and three glycine residues also are critical. the isoleucin ...19957761451
cis-acting regulatory elements in the bovine immunodeficiency virus long terminal repeat.functional cis-acting regulatory elements in the bovine immunodeficiency virus (biv) long terminal repeat (ltr) were identified by deletion mapping and nuclear protein gel shift analysis using three biv-infectible cell lines, cf2th, blac-20, and erep. deletion mapping studies indicated that putative nf-kappa b, gre, ap-4, ap-1, caat, and atf/cre transcription factor elements positively contribute to ltr-directed gene expression in each cell line both in the presence and absence of the viral tran ...19957778292
detection of bovine immunodeficiency virus in blood and milk-derived leukocytes by use of polymerase chain reaction.bovine immunodeficiency virus (biv) is prevalent in beef and dairy cattle, yet the mode(s) of biv transmission are undefined. using polymerase chain reaction, which specifically targeted a 235-bp, highly conserved region of the biv pol gene, biv-infected leukocytes were detected in the blood and milk of biv-seropositive cows. these data confirm the presence of biv in milk and identify the potential for lactogenic transmission of this virus.19957785819
evaluation of hiv type 1 western blot-indeterminate blood donors for the presence of human or bovine retroviruses.from 1985 through 1990, 1100 of 500,000 human blood donations in syracuse, new york were repeatedly reactive by elisa for antibodies to the human immunodeficiency virus type 1 (hiv-1). nine hundred of the elisa-reactive samples were confirmed as negative by western blot (wb), 40 were confirmed as positive, and the remaining 160 sera were indeterminate, reacting mainly with hiv-1 gag gene products. twenty donors with the most reactive indeterminate wb were selected for follow-up studies. four of ...19957786586
dual infection with bovine immunodeficiency virus and bovine leukaemia virus in mississippi dairy cattle. 19957793023
genomic sequence analysis identifies jembrana disease virus as a new bovine lentivirus.jembrana disease virus, the cause of an acute, severe disease in bali (bos javanicus) cattle in indonesia was recently identified as a retrovirus, and possibly a lentivirus. we have produced sequence data representing 598 bp of the pol gene, amplified by pcr from viral cdna using broadly reactive universal primers for retroviruses and more specific genus-reactive primers for lentiviruses. when the sequence data were compared with that of known lentiviruses and other bovine retroviruses, the clos ...19957844531
bovine immunodeficiency virus: incidence of infection in mississippi dairy cattle.bovine immunodeficiency virus (biv), a lentivirus, was originally derived from a holstein cow with persistent lymphocytosis and severe wasting. the virus is known to occur sporadically throughout the united states and perhaps across the globe, but epidemiological data concerning the incidence of biv are meager and the virus was previously unreported in mississippi animals. this study examined the seroepidemiology of biv infection from two mississippi dairy herds (coastal plains and msu). serolog ...19947886931
amino acid sequence analysis of the proteolytic cleavage products of the bovine immunodeficiency virus gag precursor polypeptide.bovine immunodeficiency virus gag proteins were purified from virions, and their amino acid sequences and molecular masses were determined. the matrix, capsid, and nucleocapsid (ma, ca, and nc, respectively) and three smaller proteins (p2l, p3, and p2) were found to have molecular masses of 14.6, 24.6, and 7.3 and 2.5, 2.7, and 1.9 kda, respectively. the order of these six proteins in the gag precursor, pr53gag, is nh2-ma-p2l-ca-p3-nc-p2-cooh. in contrast to other retroviral ma proteins, the bov ...19947933153
cell-mediated and humoral immunity in sheep exposed to bovine immunodeficiency-like virus.six sheep were transfused intraperitoneally with whole blood from two sheep chronically infected with the bovine immunodeficiency-like virus (biv). five sheep were transfused intraperitoneally (i.p.) with normal ovine whole blood and served as controls. five of six biv-inoculated sheep seroconverted; four were transiently seropositive while one remained seropositive for the duration of the experiment. tests for nonspecific lymphocyte reactivity to mitogens were performed monthly for one year. at ...19948004932
bovine immunodeficiency-like virus--a potential cause of disease in cattle? 19948009785
spectre of aids haunts reports of sick cows. 19948107834
an rna-binding peptide from bovine immunodeficiency virus tat protein recognizes an unusual rna structure.the human immunodeficiency virus (hiv) tat protein binds specifically to an rna hairpin, tar, located at the 5' end of its mrna. tat uses a single arginine residue within a short region of basic amino acids to recognize a bulge region in tar. here we show that a 17 amino acid arginine-rich peptide from the bovine immunodeficiency virus (biv) tat protein also binds to an rna hairpin at the 5' end of its mrna (biv tar), but recognizes different structural features of the rna. mutagenesis, rnase ma ...19948117736
a serological survey for bovine immunodeficiency-like virus in ontario dairy cattle and associations between test results, production records and management practices.a chemiluminescence western blot analysis (wba) for detecting antibovine immunodeficiency-like virus (biv) antibodies, had good repeatability. the test was subsequently applied to a bank of serum samples from 928 adult cows from 265 herds in ontario; the number of cows sampled within each herd ranged from 1 to 13. the overall prevalence of anti-biv antibodies among cows was 5.5% with a 95% confidence interval of 4.2% to 7.2%. in contrast, 18.1% of herds had at least one reactor among cows tested ...19948143251
serological evidence of bovine immunodeficiency-like virus infection in a sheep.a six month-old sheep was entered into a control group in an experiment designed to study the effects of exposure to the bovine immunodeficiency-like virus (biv). anti-biv antibodies were detected in the serum of this sheep prior to the start of the study; these antibodies persisted for 12 months at which time the animal was destroyed. the sheep was normal clinically and was grossly normal at postmortem examination. blood from this sheep was inoculated into a recipient sheep which subsequently s ...19938269371
seroprevalence of bovine immunodeficiency-virus (biv) antibodies in the cattle population in germany.serum samples from 380 cattle were analysed for the presence of bovine immunodeficiency-virus (biv) antibodies by focus immunoassay (cell-elisa) and immunofluorescence assay (ifa). all specimens originated from dairy farms in the eastern part of germany, which had been randomly collected during the period 1989-1991. the cattle were clinically healthy and free of bovine leukaemia virus (blv) and bovine-virus diarrhoea-virus (bvdv) antibodies. infection of cell lines with biv was monitored by sync ...19947597862
monocyte function in cattle experimentally infected with bovine immunodeficiency-like virus.the effects of bovine immunodeficiency-like virus (biv) on monocyte function were examined in experimentally infected cattle and in monocytes infected in vitro. infection with the r29 isolate of biv appeared to have relatively little effect on monocyte function in cattle during the first 2 years postinfection (pi). for the first 4 to 8 months post infection, monocyte phagocytosis of staphylococcus aureus tended to be lower (p = 0.06) in biv infected calves than in control animals. after 8 months ...19957604536
identification of transactivation-response sequences in the long terminal repeat of bovine immunodeficiency-like virus.transient expression assays using the reporter gene that encodes chloramphenicol acetyltransferase were used to identify cis-acting sequences necessary for bovine immunodeficiency-like virus (biv) transactivation. computer analyses identified two rna stem-loop structures located immediately downstream of the transcription start site in the long terminal repeat. deletion analysis of the long terminal repeat indicated that sequences containing the proximal stem-loop structure located between +4 an ...19938389937
thermal inactivation of bovine immunodeficiency virus.cell-associated bovine immunodeficiency virus (biv) and cell-free biv were subjected to increasing temperatures, including pasteurization conditions. to determine the effect of heat treatment on biv viability, reverse transcriptase activity and infectivity of the heat-treated virus were assessed. biv was inactivated by heating to 47 degrees c for 30 min and by low- and high-temperature pasteurization conditions.19968900024
detection of bovine immunodeficiency-like virus by the polymerase chain reaction.this report describes a test for the bovine lentivirus, bovine immunodeficiency-like virus, in which polymerase chain reaction (pcr) technology is employed. two pairs of oligonucleotide primers directed to sequences within the coding regions of the gag and pol genes generated the expected pcr products from molecular biv clones and from dna of biv-infected cell cultures but not from dna of uninfected cultures. data indicating the specificity and sensitivity of these pcrs for biv detection and the ...19938390477
from essential to beneficial: glycoprotein d loses importance for replication of bovine herpesvirus 1 in cell culture.glycoprotein d (gd) of bovine herpesvirus 1 (bhv-1) has been shown to be an essential component of virions involved in virus entry. gd expression in infected cells is also required for direct cell-to-cell spread. therefore, bhv-1 gd functions are identical in these aspects to those of herpes simplex virus 1 (hsv-1) gd. in contrast, the gd homolog of pseudorabies virus (prv), although essential for penetration, is not necessary for direct cell-to-cell spread. cocultivation of cells infected with ...19978985319
isolation and characterization of new wild-type isolates of bovine lentivirus.two new isolates of bovine lentivirus, also known as bovine immunodeficiency-like virus (biv), were obtained from a seropositive cattle herd in florida. this is the first report of new isolates of biv since the original biv strain, r29, was isolated in 1969. the two new biv isolates were derived from blood buffy coat cells cocultivated in vitro with fetal bovine lung cell cultures. the new isolates differed in vitro from the original r29 isolate in replication and syncytium formation in fetal bo ...19938392629
[the bovine immunodeficiency virus: 1990-1992 update].substantial progress has been shown on the bovine immunodeficiency-like virus (biv) in 1990-1991 and up to mid-1992. the genomic sequences of biv were analysed in detail and several subgenomic rnas were identified. nucleic acid molecular probes, pcr (polymerase chain reaction) amplification and a novel western blotting procedure have been of great assistance for the experimental diagnosis of biv. antibody response after biv infection has shown that antibodies to p26 antigen were always present i ...19938393724
characterization of bovine immunodeficiency virus rev cdnas and identification and subcellular localization of the rev protein.one of the six putative accessory genes of bovine immunodeficiency virus (biv) is similar to those identified as rev in the human immunodeficiency virus and visna virus genomes. to further analyze the biv rev gene locus, protein, and function, rev cdnas were cloned and characterized. biv rev mrna is derived from the full-length transcript by multiple splicing events and consists of three exons, including the untranslated leader sequence and two coding exons. biv rev cdna was expressed in bacteri ...19938411341
recent advances in the understanding of jembrana disease.jembrana disease is a severe and acute clinical disease in bali (bos javanicus) cattle with a case fatality rate of about 20%, and a mild sometimes subclinical disease in other cattle types and buffalo. the aetiological agent has been identified as a lentivirus, designated as jembrana disease virus (jdv). preliminary sequence analysis has confirmed the identity of jdv as a lentivirus and has shown that it is distinguishable from biv. there is antigenic cross-reactivity between the capsid protein ...19958545963
loss of gag-specific antibody reactivity in cattle experimentally infected with bovine immunodeficiency-like virus.the development and persistence of virus-specific antibodies were investigated in eight cattle experimentally infected with the r29 isolate of bovine immunodeficiency-like virus (biv). by 4 weeks postinoculation (p.i.), antibodies reactive to biv gag- and env-encoded recombinant fusion proteins were detectable by immunoblotting in all animals. by 40 weeks p.i., seven of eight cattle had dramatically decreased gag-specific antibodies, and anti-gag reactivity remained very low or undetectable thro ...19958546802
a serological survey of bovine syncytial virus in ontario: associations with bovine leukemia and immunodeficiency-like viruses, production records, and management practices.of the 920 cows tested, 56.7% showed antiretroviral serological reactivity. prevalence rates (95% confidence interval) of antiretroviral antibodies among individual dairy cows in ontario were: biv 5.5% (4.0-7.0), blv 25.7% (22.9-28.6), and bsv 39.6% (36.4-42.8). the following percentages of cows showed serological reactivity against the specified retroviruses: biv 2.3%, blv 14.0%, bsv 27.5%, biv and bsv 1.3%, biv and blv 0.9%, blv and bsv 9.9%, biv and blv and bsv 0.9%. these rates of sero-posit ...19958548688
detection and isolation of bovine immunodeficiency-like virus (biv) in dairy herds of costa rica.serological (western blot) detection of bovine immunodeficiency-like virus (biv) in holstein dairy herds is reported in costa rica for the first time, as well as the isolation of the virus, from a seropositive bovine, by cocultivation of peripheral blood mononuclear cells (pbmc) with embryonic rabbit epithelial (erep) cells. the isolated strain, bivcr1, reacted similarly in western blot as the reference strain biv r29 and is clearly distinguishable from bovine leukaemia virus (blv). the data sug ...19958553709
possible role of bovine immunodeficiency virus in bovine paraplegic syndrome: evidence from immunochemical, virological and seroprevalence studies.bovine paraplegic syndrome (bps) is a debilitating cattle disease of unknown origin that is characterized by leukocytosis, lymphocytopenia and monocytopenia. the major clinical signs are difficulties in locomotion affecting hind limbs, hypoalgesia in the hind quarters, posterior paralysis and death within 72 to 96 hours after recumbency. to investigate the aetiological basis of bps, we examined a possible association of the syndrome with infection by bovine immunodeficiency virus (biv), a lentiv ...19958578005
two retroviral infections of periparturient holstein cattle: a phenotypic and genetic study.environmental and genetic factors affecting prevalences of antibodies to bovine leukosis virus and bovine immunodeficiency-like virus were studied on 137 periparturient holstein cows selected for milk production. environmental effects were obtained by logistic regression, and genetic parameters were determined using threshold animal models. cows selected for high predicted transmitting ability for kilograms of milk fat plus protein had the highest prevalence of antibodies to bovine immunodeficie ...19958598412
serologic evidence for bovine immunodeficiency virus infection in france.we report herein on the first serologic detection of antibodies to bovine immunodeficiency virus (biv) in france. serum samples from dairy and beef cattle from southwestern and western france (landes and vendée) were tested using a western blot assay with a recombinant 53 kda gag precursor derived from the louisiana biv r29 isolate. we performed our study on the oldest animals from 37 different herds that were under serologic follow up for previous bovine leukemia virus infection. overall, 398 s ...19968701572
histopathological changes in the lymphoid tissues of sheep exposed to the bovine immunodeficiency-like virus.six yearling sheep were inoculated intraperitoneally with peripheral blood from two sheep infected with the bovine immunodeficiency-like virus (biv) strain r29. an additional five sheep served as sham-inoculated controls. of the six sheep given biv, five seroconverted, one of them remaining seropositive for the duration of the study. the polymerase chain reaction demonstrated biv provirus in three of the five serologically positive animals. at necropsy, 1 year after inoculation, histological cha ...19968729077
detection of antibodies against bovine immunodeficiency-like virus in daily cattle in hokkaido.serological survey of bovine immunodeficiency-like virus (biv) infection was performed in cattle of 3 different farms in hokkaido, where a relatively high seroprevalence was recorded for bovine leukemia virus (blv). about a half of 120 cattle tested were seropositive for blv, while 7.5% of the cattle were seropositive for biv. though increased numbers of leukocytes were frequently observed in blv-seropositive cows, no such changes were observed in biv-positive but blv-negative cows. no correlati ...19968741608
lymphoproliferation assays in cattle naturally infected with bovine leukaemia virus (blv) and bovine immunodeficiency-like virus (biv).experiments were designed to evaluate the effect of blv on mitogen-stimulated peripheral blood mononuclear cells (pbmc) from naturally infected cattle. biv was also taken into consideration due to a recent report showing that in costa rica, most of the blv-infected animals are also seropositive for biv. the methodology was based on a non-radioactive technique to determine lymphoproliferation. a colorimetric assay using xtt (formazan salt) to measure cell multiplication was adapted for bovine pbm ...19968794694
getting into the major groove. protein-rna interactions.the solution structure of the complex between a peptide derived from the bovine immunodeficiency virus tat protein and the tar rna to which it binds reveals a new motif in protein-rna interactions.19968805260
how tat targets tar: structure of the biv peptide-rna complex.two new nmr structures describing the complex formed by a peptide from the biv tat protein with the tar rna provide a significant advance in our understanding of the ways in which peptides interact with specific sites in the major groove of their rna targets.19968805518
molecular recognition in the bovine immunodeficiency virus tat peptide-tar rna complex.in lentiviruses such as human immunodeficiency virus (hiv) and bovine immunodeficiency virus (biv), the tat (trans-activating) protein enhances transcription of the viral rna by complexing to the 5'-end of the transcribed mrna, at a region known as tar (the trans-activation response element). identification of the determinants that account for specific molecular recognition requires a high resolution structure of the tat peptide-tar rna complex.19958807816
new features in rna recognition: a tat-tar complex.the structure of a peptide from the biv tat protein bound to its cognate tar rna has been solved. this structure reveals a beta-hairpin motif for the protein, bound at a widened bulge site in the major groove of the rna.19968807823
encephalitis, lymphoid tissue depletion and secondary diseases associated with bovine immunodeficiency virus in a dairy herd.encephalitis, lymphoid tissue depletion and secondary infections occurred over a 5-yr-period in holstein cows infected with bovine immunodeficiency virus (biv). there were 59 cattle studied, the majority during 1991, when a severe environmental stress occurred, each with one or more primary causes of death, natural or by euthanasia, and most with several secondary diseases. the encephalitis was characterized by meningeal, perivascular and parenchymal infiltration with lymphocytes, occasional pla ...19968814974
suppressive effect of liposomes containing dna coding for diphtheria toxin a-chain on cells transformed with bovine leukemia virus.a recombinant plasmid which contained a gene for diphtheria toxin a-chain (dt-a) under the control of the long terminal repeat (ltr) of bovine leukemia virus (blv) (blv-ltr) was constructed to test a novel application of liposomes as antiviral agents. the promoter activity of blv-ltr was estimated by the chloramphenicol acetyltransferase (cat) assay using a plasmid which contains the coding sequence of cat under the control of blv-ltr (pblvcat). when blv-infected cells were transfected with pblv ...19938271974
effect of bovine immunodeficiency-like virus infection on immune function in experimentally infected cattle.bovine immunodeficiency-like virus (biv) is a bovine lentivirus that has antigenic and genetic homology with the human immunodeficiency virus. little work has been reported on the effect of biv infection on bovine immune function. this study was designed to evaluate lymphocyte blastogenesis, mononuclear cell subset numbers, neutrophil function, hematology, and clinical signs in three groups of cattle. these groups were evaluated at 0-2 months post inoculation (pi, group 1), 4-5 months pi (group ...19938386411
inhibition of bovine immunodeficiency virus by anti-hiv-1 compounds in a cell culture-based assay.the bovine immunodeficiency virus (biv) and human immunodeficiency virus types 1 and 2 (hiv-1 and -2) are members of the lentivirus genus of retroviruses. although dna sequences of these viruses have diverged considerably, the biv genome organization, function of structural and regulatory genes, and replication cycle are very similar to that of hiv-1, making biv a potentially useful model to study compounds with anti-hiv-1 activity. a cell culture-based antiviral assay was developed to test comp ...19968955850
bovine lentivirus induces early transient b-cell proliferation in experimentally inoculated cattle and appears to be pantropic.bovine immunodeficiency-like virus (biv) was first isolated in 1972 (m. j. vandermaaten et al., j. natl. cancer inst. 49:1649-1657, 1972). much work has been done on the molecular characterization of biv in studies using the original biv r29 isolate; however, r29 is believed to be attenuated since it no longer causes either mononuclear cell number increases or detectable enlargement of lymphatic nodules in experimentally infected cattle. the host cell tropism and changes in host peripheral blood ...19978985394
enhancement of monocyte migration and phagocytosis by the bovine immunodeficiency-like virus gag proteins.supernatants from bovine immunodeficiency-like virus (biv)-infected cells have been previously shown to affect monocyte random migration, chemotaxis, phagocytosis, and antibody-dependent cell-mediated cytotoxicity (adcc) in vitro. the experiments in this report demonstrate that the biv gag (core) proteins can enhance monocyte random migration, chemotaxis, and phagocytosis. supernatants from biv-infected cells contained 10-30 and 30-50 kda proteins, which significantly (p < 0.05) increased monocy ...19978989206
immunomodulative effects of bovine immunodeficiency-like virus (biv)-infection and mixed infection of biv and bovine leukemia virus on sheep.experimental bovine immunodeficiency-like virus (biv)-infection and mixed infection of biv and bovine leukemia virus (blv) were performed on sheep. biv proviral dna and anti-biv antibodies were persistently detected in all biv-inoculated sheep. a slight increase in lymphocyte counts was observed in biv-infected sheep, but the percentages of cd4+ and cd8+ cells in sheep peripheral blood mononuclear cells (pbmcs) were not significantly changed. a transient decrease in lymphocyte blastogenic respon ...19968997876
size variation within the second hypervariable region of the surface envelope gene of the bovine lentivirus biv in experimentally and naturally infected cattle.the bovine lentivirus also known as the bovine immunodeficiency-like virus (biv) has conserved and hypervariable regions in the surface envelope (su) gene. size variation between isolates can be as large as 200 bp, mostly occurring in the second hypervariable (v2) gene region of the su gene. the v2 region was cloned and sequenced from both experimentally and naturally infected cattle. temporal evaluation of provirus from an experimentally inoculated cow showed two different-sized variants that a ...19979032387
nucleotide sequence analysis of jembrana disease virus: a bovine lentivirus associated with an acute disease syndrome.the complete nucleotide sequence of the rna genome of jembrana disease virus (jdv), a lentivirus that causes an acute disease syndrome in bali cattle (bos javanicus), is reported. in addition to the gag, pol and env genes and flanking long terminal repeats (ltrs) that characterize all retroviruses, a number of accessory genes represented by small multiply spliced orfs in the central and 3'-terminal regions of the genome, including tat and rev that are typical of lentiviruses, were identified. th ...19959049370
immune suppression in calves with bovine immunodeficiency virus.the present study was designed to evaluate the effect of bovine immunodeficiency virus (biv) infection on immune functions and possible interactions between biv and other bovine viruses in calves. ten calves were inoculated intravenously with biv, and five served as controls. an increased lymphocyte proliferation to biv gag protein was demonstrated 2 to 6 weeks after biv inoculation (p < 0.05). lymphocyte subset differentiation revealed a decreased cd4/cd8 ratio (p < 0.05) during weeks 2 to 7, s ...19979067663
laboratory diagnostic tests for retroviral infections in dairy and beef cattle.detection of bovine retroviruses stretches our diagnostic creativity to its limits. the nucleic acid-based, pcr-amplified assays are finding increased clinical use as the veterinary and livestock industry seek earlier detection of infection for eventual corrective management decisions. we are evolving from a point of disease diagnosis by tumor identification through conventional histopathology, to molecular diagnostics for early identification of retroviral nucleic acid (provirus). the clinical ...19979071748
natural and experimental bovine immunodeficiency virus infection in cattle.since 1989, the lsu dairy herd, with its high seroprevalence of biv, was recognized to have a high incidence of common diseases that reduced the economic viability of the dairy. the herd had a high percentage of cows with encephalitis associated with depression and stupor, alteration of the immune system associated with secondary bacterial infections, and chronic inflammatory lesions of the feet and legs. the occurrence of disease problems was associated with the stresses of parturition and earl ...19979071752
food animal and poultry retroviruses and human health.in summary, studies reported to date have largely failed to demonstrate human infection with animal and poultry retroviruses or an association between human diseases and these viruses. a number of studies, most of them serologic, have attempted to demonstrate human infection with these viruses. the lack of antibodies in apparently exposed groups of persons suggests an absence of infection. however, another possible explanation is that humans may be immunologically unresponsive to infection with ...19979071753
a docking and modelling strategy for peptide-rna complexes: applications to biv tat-tar and hiv rev-rbe.in spite of the great interest in the interaction between rnas and proteins, no general protocol for modelling these complexes is presently available. this methodological vacuum is particularly acute because the structure of few such complexes is known.19969080192
bovine immunodeficiency-like virus: inactivation in milk by pasteurisation.bioassay was used to determine whether bovine immunodeficiency-like virus (biv) in milk was inactivated by pasteurisation. three groups of three calves were inoculated with virus (biv isolate fl112), milk seeded with virus and milk seeded with virus that had been pasteurised before inoculation, respectively. seroconversion to biv was monitored for 12 months by an indirect immunofluorescence assay. the presence of biv proviral dna in peripheral blood was determined by a nested polymerase chain re ...19979090033
bovine immunodeficiency virus tat gene: cloning of two distinct cdnas and identification, characterization, and immunolocalization of the tat gene products.cdnas encoding the bovine immunodeficiency virus (biv) transactivator gene (tat) were cloned from virally infected cells and characterized. biv expresses two distinct tat mrnas composed of three exons that are derived by alternative splicing. the biv tat mrna splice variants encode tat proteins of 103 (tat103) and 108 (tat108) amino acids. the tat103 coding region is specified only by exon 2, while that of tat108 is specified by a truncated exon 2 and the first 30 nt of exon 3. thus, the first 9 ...19979217057
longitudinal studies of immune function in cattle experimentally infected with bovine immunodeficiency-like virus and/or bovine leukemia virus.the effects of single or dual infection with bovine immunodeficiency-like virus (biv) and/or, bovine leukemia virus (blv) on bovine immune function were examined over a 4 year period. holstein calves were infected with biv (four calves), blv (five calves), biv and blv (five calves), or sham inoculated (three calves). lymphocyte blastogenesis to mitogens, seven tests of neutrophil function, and mononuclear cell subset analysis by flow cytometry (bocd4, bocd8, bocd2, bowc1, sigm+, and monocytes) w ...19979220578
targeting the tat-binding site of bovine immunodeficiency virus tar rna with a shape-selective rhodium complex.the tat-binding site of the bovine immunodeficiency virus tar rna hairpin has been targeted by rh(phen)2phi3+ (phen = phenanthroline, phi = 9,10-phenanthrenequinone diimine), a photochemical probe of rna tertiary structure. the primary site cleaved by the rhodium complex, upon photoactivation, is u24, a base which participates in the novel base triple (with bases a13 and u10) characteristic of this folded rna. delta-rh(phen)2phi3+ binds to this site with an affinity of 2 x 10(6) m-1. upon mutati ...19979222507
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