Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
intercellular adhesion molecule 3, a candidate human immunodeficiency virus type 1 co-receptor on lymphoid and monocytoid cells.the cd4 molecule serves as the principal cell surface receptor common to both the human and simian immunodeficiency viruses (hiv-1, hiv-2 and siv). since binding to cd4 is not sufficient to permit virus entry, hiv 'co-receptors' have been implicated in mediating the fusion of viral and cellular membranes necessary for completing the entry process. in order to identify candidate co-receptor molecules, a panel of monoclonal antibodies (mabs) directed against adhesion molecules was tested for the a ...19957540195
t cell receptor v beta repertoire in an acute infection of rhesus monkeys with simian immunodeficiency viruses and a chimeric simian-human immunodeficiency virus.changes in t cell receptor (tcr) v beta repertoire and their correlation with virologic events were investigated in rhesus monkeys after acute infection with the simian immunodeficiency virus (siv). 11 genetically defined rhesus monkeys were experimentally infected with sivmac or a chimeric simian-human immunodeficiency virus (shiv), and their peripheral blood lymphocytes (pbl) and lymph nodes were prospectively assessed for tcr v beta gene expression. pbl and lymph nodes of the acutely infected ...19957540651
sensitivity/resistance profile of a simian immunodeficiency virus containing the reverse transcriptase gene of human immunodeficiency virus type 1 (hiv-1) toward the hiv-1-specific non-nucleoside reverse transcriptase inhibitors.to develop an animal model for the therapy of aids with human immunodeficiency virus type 1 (hiv-1)-specific reverse transcriptase (rt) inhibitors, we recently constructed a hybrid simian immunodeficiency virus (siv)/hiv-1 in which the rt gene of siv was replaced by the rt gene of hiv-1. this chimaeric virus, designated rt-shiv, was found to be markedly sensitive to the inhibitory effects of both nucleoside (ddn) and non-nucleoside rt inhibitors (nnrtis). in contrast, siv was inhibited only by d ...19957541200
attachment of an oligopeptide epitope to the c-terminus of recombinant siv gp160 facilitates the construction of smaa complexes while preserving cd4 binding.a small 14 amino acid oligopeptide tag (termed sv5-pk) was fused onto the carboxy-terminus of simian immunodeficiency virus gp160 expressed from a recombinant baculovirus. the presence of the pk tag had no obvious effect on the expression and glycosylation of gp160 and did not interfere either with cd4 binding or with cleavage at its maturation site by the protease furin. the presence of the pk tag did, however, facilitate the simplified purification of full-length gp160 and its incorporation in ...19957543487
specificity and neutralizing capacity of three monoclonal antibodies produced against the envelope glycoprotein of simian immunodeficiency virus isolate 251.three mouse monoclonal antibodies (mab) were produced against soluble recombinant vaccinia virus gp140 from siv-mac251. two mabs (1b9 and 6c11) were mapped at the aa 411-430 sequence within the v4 domain, and the third mab (3c8) recognizes a conformation-dependent epitope on the external envelope glycoprotein. this was shown by its loss of reactivity in western blot and elisa with dithiothreitol-reduced gp140. mab 3c8, but not 1b9 and 6c11, cross-reacts well with gp140 and gp125 from hiv-2rod, i ...19957544048
animal model for the therapy of acquired immunodeficiency syndrome with reverse transcriptase inhibitors.the reverse transcriptase (rt) of the human immunodeficiency virus type 1 (hiv-1) is the major target for antiretroviral therapy of the acquired immunodeficiency syndrome (aids). while some inhibitors exhibit activity against most retroviral rts, others are specific for the hiv-1 enzyme. to develop an animal model for the therapy of the hiv-1 infection with rt inhibitors, the rt of the simian immunodeficiency virus (siv) was replaced by the rt of hiv-1. macaques infected with this siv/hiv-1 hybr ...19957545297
passive immunization of rhesus macaques against siv infection and disease.to evaluate the role of humoral immunity against simian immunodeficiency virus (siv), we tested whether passive immunization with plasma from sivmac251 vaccine-protected or healthy infected animals would protect rhesus monkeys against intravenous infection with ten 50% animal infectious doses of the cell-free homologous virus. the challenge dose of this sivmac251 virus stock had previously caused persistent infection in all (21 of 21) nonimmunized controls. a plasma pool was obtained from a dono ...19957546912
nucleotide sequence of the hiv-2 eho genome, a divergent hiv-2 isolate.the hiv-2 eho isolate from cote d'ivoire has been characterized as a highly cytopathic hiv-2 strain, which can be differentiated from other isolates by the smaller size of its external envelope glycoprotein. the entire nucleotide sequence (10,352 bp) of the hiv-2 eho genome is filed in the embl/genbank data libraries under accession no. u27200. despite its high degree of variability, the genetic organization of hiv-2 eho was found to be similar to other hiv-2 and simian immunodeficiency virus ...19957546916
the peri-kappa b site mediates human immunodeficiency virus type 2 enhancer activation in monocytes but not in t cells.human immunodeficiency virus type 2 (hiv-2), like hiv-1, causes aids and is associated with aids cases primarily in west africa. hiv-1 and hiv-2 display significant differences in nucleic acid sequence and in the natural history of clinical disease. consistent with these differences, we have previously demonstrated that the enhancer/promoter region of hiv-2 functions quite differently from that of hiv-1. whereas activation of the hiv-1 enhancer following t-cell stimulation is mediated largely th ...19957609053
repair and evolution of nef in vivo modulates simian immunodeficiency virus virulence.experimental evidence from the simian immunodeficiency virus (siv) model of aids has shown that the nef gene is critical in the pathogenesis of aids. consequently, nef is of considerable interest in both antiviral drug and vaccine development. preliminary findings in two rhesus macaques indicated that a deletion of only 12 bp found in the overlapping nef/3' long terminal repeat (ltr) region (9501 to 9512) of the sivmacc8 molecular clone was associated with reduced virus isolation frequency. we s ...19957609080
suppression of simian immunodeficiency virus replication by human immunodeficiency virus type 1 trans-dominant negative rev mutants.we demonstrate that trans-dominant negative rev mutants are able to suppress simian immunodeficiency virus provirus replication in both transient cotransfection assays and stably transduced hut 78 cells. these studies suggest that the efficacy of trans-dominant rev strategies in reducing viral burden may be evaluated in a simian immunodeficiency virus-rhesus macaque animal model.19957609088
effects of mutations in constant regions 3 and 4 of envelope of simian immunodeficiency virus.twenty-six mutant forms of simian immunodeficiency virus strain mac239 were constructed with changes in constant region 4 (c4) of env. twenty-four of these had a single amino acid change, one had changes in two amino acids, and one had a deletion of eight amino acids. the effects of these mutations on viral replication, gp160 processing, and binding of env protein to soluble cd4 receptor were analyzed. the c4 region was relatively sensitive to sequence changes since only 11 of the 26 mutants rep ...19957618279
role of the conserved dipeptide gly75 and cys76 on hiv-1 vpr function.vpr is one of the accessory proteins encoded by the hiv-1 genome. several interesting features associated with vpr include incorporation into virus particles, ability to oligomerize, localization in the nucleus, and positive effect on virus production and replication. in order to understand the structure-function relationship of vpr, we have analyzed the role of the gly75 and cys76 (gc) residues which are highly conserved in hiv-1 vpr and in vpr and vpx of hiv-2/siv. we have generated several su ...19957618286
mutational analysis of the conserved cysteine residues in the simian immunodeficiency virus matrix protein.the matrix protein (ma) of human and simian immunodeficiency viruses (hiv and siv) is encoded by the amino-terminal region of the gag precursor and has been suggested to be involved in different processes during the early and late stages of the virus life cycle. the ma protein of siv contains three cysteine residues at positions 57, 83, and 87, which are also highly conserved among hiv-2 isolates. in order to study the functional significance of these residues in virus morphogenesis, a series of ...19957618287
squamous epithelial proliferative lesions associated with rhesus epstein-barr virus in simian immunodeficiency virus-infected rhesus monkeys.proliferative lesions were found on the squamous epithelium of the tongue, esophagus, or penis or haired skin of the lip, hand, or thorax of 8 simian immunodeficiency virus-infected rhesus monkeys that died of simian aids. the lesions were focal and consisted of hyperkeratosis, parakeratosis, and acanthosis in the skin, with additional ballooning degeneration in the tongue, esophagus, and penis. the epithelial surfaces were frequently colonized by candida species or gram-positive cocci. intranuc ...19957622899
serial passage of microglial siv results in selection of homogeneous env quasispecies in the brain.the pathogenic effects of hiv include infection of the central nervous system (cns) which can result in cognitive and motor dysfunction. simian immunodeficiency virus (siv) infection of rhesus macaques provides an excellent model of hiv-induced disease. we have achieved a reproducible infection of the cns using a stock of virus obtained by serial passage of microglia-associated siv. since the envelope genes of both hiv and siv encode determinants important in viral pathogenesis, and the variabil ...19957571415
the pett series, a new class of potent nonnucleoside inhibitors of human immunodeficiency virus type 1 reverse transcriptase.to identify the minimal structural elements necessary for biological activity, the rigid tricyclic nucleus of the known human immunodeficiency virus type 1 (hiv-1) reverse transcriptase (rt) inhibitor tetrahydroimidazobenzodiazepinthione was subjected to systematic bond disconnection to obtain simpler structures. a rational selection and testing of modeled analogs containing these potential pharmacophoric moieties led to the discovery of a new series of nonnucleoside inhibitors of rt. the lead c ...19957574525
animal models recapitulate aspects of hiv/cns disease.neurobehavioral and pathological data indicate that the central nervous system (cns) becomes infected with hiv-1 soon after the virus enters the body. however, neuropathogenesis of hiv-1 infection is difficult to investigate because the brain parenchyma is not accessible to sampling during the course of aids. the second compartment of the cns, cerebrospinal fluid (csf), is accessible to sampling but how changes in the csf relate to the changes in the parenchyma is poorly understood. thus, knowle ...19957576936
a trimeric subdomain of the simian immunodeficiency virus envelope glycoprotein.previous attempts to define the oligomeric state of the hiv and siv envelope glycoproteins have yielded conflicting results. we have produced in escherichia coli a recombinant model for the ectodomain of the siv envelope protein gp41 and have identified a small, trimeric subdomain by proteolytic digestion of this gp41 fragment. the subdomain assembles from two peptide fragments, spanning residues 28-80 (n28-80) and residues 107-149 (c107-149) of siv gp41. each of these peptides contains a 4,3-hy ...19957578108
early appearance of antibodies to simian immunodeficiency virus in saliva and serum of infected macaques.simian immunodeficiency virus (siv) infection in macaques is an important animal model for human immunodeficiency virus infection in humans. this study evaluated the temporal development of antibodies to siv in the parotid saliva of macaques inoculated with the virus and compared these findings with the development of antibodies to siv in the animals' sera. three animals (ages, 14, 18, and 18 years) were inoculated with the macrophagetropic strain sivmac239. prior to inoculation and at consecuti ...19957583931
early suppression of siv replication by cd8+ nef-specific cytotoxic t cells in vaccinated macaques.in order to develop a successful subunit vaccine against infection with the human immunodeficiency virus (hiv), protective immune effector functions must be identified. until now, there has been only indirect evidence that hiv-specific cytotoxic t lymphocytes (ctls) fulfill this role. using the macaque simian immunodeficiency virus (siv) model, the protective potential of nef-specific ctls, stimulated by vaccination, was examined in animals challenged with a high intravenous dose of the pathogen ...19957584989
apoptosis occurs predominantly in bystander cells and not in productively infected cells of hiv- and siv-infected lymph nodes.although 13 years have passed since identification of human immunodeficiency virus-1 (hiv-1) as the cause of aids, we do not yet know how hiv kills its primary target, the t cell that carries the cd4 antigen. we and others have shown an increase in the percentage of apoptotic cells among circulating cd4+ (and cd8+) t cells of hiv-seropositive individuals and an increase in frequency of apoptosis with disease progression. however, it is not known if this apoptosis occurs in infected or uninfected ...19957585008
long-term protection against siv-induced disease in macaques vaccinated with a live attenuated hiv-2 vaccine.the aim of this study was to test the ability of a live attenuated human immunodeficiency virus type 2 (hiv-2) vaccine to protect cynomolgus monkeys against superinfection with a pathogenic simian immunodeficiency virus (sivsm). this report is an update on our previously reported observation period of nine months. the new data here show that three of four monkeys vaccinated with live hiv-2 were protected against immunosuppression and siv-induced disease during more than five years of follow-up. ...19957585217
gamma delta t cells in rhesus monkeys and their response to simian immunodeficiency virus (siv) infection.recent reports of the increase in peripheral blood gamma delta t cells in hiv+ patients prompted us to examine the gamma delta t cell system in rhesus monkeys (macaca mulatta) and the responses of these cells to siv infection. our results reveal differences in the gamma delta t cell subset composition and their expression of cd8 in the peripheral blood of monkeys and humans. the outgrowth of simian gamma delta t cells in response to daudi cells is similar to that in humans, but the exposure to i ...19957586674
the restricted igg1 antibody response to maedi visna virus is seen following infection but not following immunization with recombinant gag protein.maedi-visna (mvv) is a retrovirus of the subfamily lentivirinae which includes hiv, simian immunodeficiency virus (siv) and feline immunodeficiency virus (fiv). infection of its natural host, the sheep, does not cause overt immunodeficiency, but rather a chronic inflammatory disease. however, subtle immunological changes following infection have been reported including a sheep igg1 subclass-restricted mvv-neutralizing antibody. here we demonstrate by western blotting that there is no igg2 serum ...19957586678
constitutive expression of major histocompatibility complex class ii antigens on monocytes and b cells correlates with disease in simian immunodeficiency virus-infected rhesus macaques.constitutive host factors that influence progression to aids are understood poorly. in the macaque model for aids, 35 animals infected with simian immunodeficiency virus (siv) were analyzed for major histocompatibility complex class ii antigen expression on blood monocytes and b cells by immunostaining and flow cytometry. expression varied widely between animals but was constant with time. level of expression and the proportion of monocytes and b cells that expressed class ii were not affected b ...19957594662
early replication block of human immunodeficiency virus type 1 in monkey cells.the genetic and functional basis of the replication-defective nature of human immunodeficiency virus type 1 (hiv-1) in monkey cells was studied. by the generation and characterization of chimeras between hiv-1 and simian immunodeficiency virus, the sequence encompassing the 3' half of the long terminal repeat, gag and pol genes of hiv-1 was found to be responsible for the growth restriction. early and late phases of hiv-1 replication in monkey cells were analysed in detail using several assay sy ...19957595379
extracellular vpr protein increases cellular permissiveness to human immunodeficiency virus replication and reactivates virus from latency.the vpr gene product of human immunodeficiency virus (hiv) and simian immunodeficiency virus is a virion-associated regulatory protein that has been shown using vpr mutant viruses to increase virus replication, particularly in monocytes/macrophages. we have previously shown that vpr can directly inhibit cell proliferation and induce cell differentiation, events linked to the control of hiv replication, and also that the replication of a vpr mutant but not that of wild-type hiv type 1 (hiv-1) was ...19957815499
regions required for cd4 binding in the external glycoprotein gp120 of simian immunodeficiency virus.the external domain of the envelope glycoprotein, gp120, of simian immunodeficiency virus (siv) has been expressed as a mature secreted product using recombinant baculoviruses and the expressed protein, which has an observed molecular mass of 110 kda, was purified by monoclonal antibody (mab) affinity chromatography. n-terminal sequence analysis showed a signal sequence cleavage identity similar to that of the gp120s of both human immunodeficiency virus type 1 (hiv-1) and hiv type 2. the express ...19957815501
simian immunodeficiency virus sivmac chimeric virus whose env gene was derived from siv-encephalitic brain is macrophage-tropic but not neurovirulent.we inoculated four rhesus macaques with molecularly cloned simian immunodeficiency virus sivmac239/17e env, a chimeric virus whose env gene was derived from the brain of an siv-encephalitic macaque. blood and lymphoid tissues had high frequencies of infected cells. the virus was neuroinvasive, but productive virus replication did not occur in the brain, and animals did not develop encephalitis.19957815523
induction of aids by simian immunodeficiency virus from an african green monkey: species-specific variation in pathogenicity correlates with the extent of in vivo replication.previous studies suggested that simian immunodeficiency viruses isolated from african green monkeys (sivagm) are relatively nonpathogenic. the report describes the isolation and biologic and molecular characterization of a pathogenic sivagm strain derived from a naturally infected african green monkey. this virus induced an aids-like syndrome characterized by early viremia, frequent thrombocytopenia, severe lymphoid depletion, opportunistic infections, meningoencephalitis, and death of five of e ...19957815563
[virulence of human immunodeficiency virus].virulence is relative capacity of a virus, compared to other closely related viruses, to produce disease in a host. viral strains considered as virulent have been described in hiv-1 infected patients. they are characterized in vitro by enhanced cellular host range, rapid kinetic of replication and increased capacity of syncytium induction. some genetic modification of the v3 loop in the envelope gene have been associated with the emergence of these strains. but at aids diagnosis, and even at the ...19957754307
immunization with class i human histocompatibility leukocyte antigen can protect macaques against challenge infection with sivmac-32h.to evaluate the efficacy of immunopurified class i human histocompatibility leukocyte antigen (hla) to protect against siv infection.19957755909
b-cell lymphomagenesis in siv-immunosuppressed cynomolgus monkeys.b-cell lymphomas developed frequently (approx. 40%) in sivsm (smm3) immunosuppressed monkeys and were mostly extranodal, aggressive and all associated with an ebv-related simian herpes virus operationally designated herpes virus macaca fascicularis (hvmf-i). lymphoma tissues from 21 monkeys were studied by pcr and dna page for mono/oligoclonality of the vdj-rearranged igh genes. most lymphomas (n = 15) showed a monoclonal and approximately 1/3 (n = 6) an oligoclonal vdj rearrangement pattern. th ...19957759163
complementation of vif-defective human immunodeficiency virus type 1 by primate, but not nonprimate, lentivirus vif genes.the productive infection of many susceptible human cells, including lymphocytes and macrophages derived from peripheral blood, by the pathogenic lentivirus human immunodeficiency virus type 1 requires expression of the virally encoded vif (for virion infectivity factor) gene. interestingly, this gene appears to have been conserved among all of the lentiviruses of primates and almost all of the lentiviruses of nonprimates. using t cells constitutively expressing vif genes derived from diverse sou ...19957769676
rapid screening for mamu-a1-positive rhesus macaques using a sivmac gag peptide-specific cytotoxic t-lymphocyte assay.as part of an ongoing vaccine study using peptide immunogens designed to stimulate simian immunodeficiency virus (siv)mac-specific cytotoxic t lymphocytes (ctl) it was necessary to identify rhesus macaques within our colony bearing the mamu-a1 major histocompatibility complex (mhc) class i haplotype. peripheral blood mononuclear cells (pbmc) from individual monkeys were analysed by immunoelectrofocusing for the presence of a band corresponding to the mamu-a1 molecule. in addition, pbmc were puls ...19957751033
an attenuated vaccine for aids?one of the few bright prospects in aids research is the findings from a study of an attenuated siv vaccine in monkeys. the vaccine consists of siv with the nef region deleted (sivmac239). all 6 monkeys vaccinated with the nef-deleted virus were still healthy and alive 5 years after vaccination, while 11 of the 12 rhesus monkeys administered the virulent sivmac died. the case monkeys were challenged with virulent siv at 2.25 years and were completely protected. other researchers used an attenuate ...19957752750
protection by attenuated simian immunodeficiency virus in macaques against challenge with virus-infected cells.a vaccine against aids will probably have to protect against challenge both by viable virus-infected cells and by cell-free virus. eight cynomolgus macaques infected with attenuated simian immunodeficiency virus (siv) were challenged (four each) with cell-free and cell-associated siv. all were protected, whereas eight controls were all infected after challenge. these findings show that live-attenuated vaccine can confer protection against siv in macaques. extrapolation to human beings will requi ...19957752758
prevention of siv infection in macaques by (r)-9-(2-phosphonylmethoxypropyl)adenine.the efficacy of pre- and postexposure treatment with the antiviral compound (r)-9-(2-phosphonylmethoxypropyl)adenine (pmpa) was tested against simian immunodeficiency virus (siv) in macaques as a model for human immunodeficiency virus (hiv). pmpa was administered subcutaneously once daily beginning either 48 hours before, 4 hours after, or 24 hours after virus inoculation. treatment continued for 4 weeks and the virologic, immunologic, and clinical status of the macaques was monitored for up to ...19957502044
recombination in aids viruses.recombination contributes to the generation of genetic diversity in human immunodeficiency viruses (hiv) but can only occur between viruses replicating within the same cell. since individuals have not been found to be simultaneously coinfected with multiple divergent strains of hiv-1 or hiv-2, recombination events have been thought to be restricted to the rather closely related members of the quasispecies that evolves during the course of hiv infection. here we describe examples of both hiv-1 an ...19957723052
concurrent central nervous system toxoplasmosis and simian immunodeficiency virus-induced aids encephalomyelitis in a barbary macaque (macaca sylvana). 19957725605
antiviral properties of aminodiol inhibitors against human immunodeficiency virus and protease.a series of aminodiol inhibitors of human immunodeficiency virus type 1 (hiv-1) protease were identified by using an in vitro peptide cleavage assay. bms 182,193, bms 186,318, and bms 187,071 protected cells against hiv-1, hiv-2, and simian immunodeficiency virus infections, with 50% effective doses ranging from 0.05 to 0.33 microm, while having no inhibitory effect on cells infected with unrelated viruses. these compounds were also effective in inhibiting p24 production in peripheral blood mono ...19957726501
rapid screening of open reading frames by protein synthesis with an in vitro transcription and translation assay.the analysis of open reading frames (orfs) to predict full-length or truncated proteins in genes is conventionally achieved by dna sequencing. this method becomes labor-intensive when a large number of specimens or when large genes are to be examined. to circumvent this problem, we used an in vitro transcription and translation (tt) assay to identify full-length or truncated proteins in pcr-amplified genes. a total of 47 nef genes from the simian immunodeficiency virus (siv) were cloned from 13 ...19957727125
cross-protective immune responses induced in rhesus macaques by immunization with attenuated macrophage-tropic simian immunodeficiency virus.the simian immunodeficiency virus (siv) macaque model of aids has provided a valuable system with which to investigate vaccine approaches for protection against human immunodeficiency virus type 1 (hiv-1) infection. in particular, the ability of macaques persistently infected with attenuated infectious molecular clones of siv to resist challenge with the pathogenic parental swarm has conclusively demonstrated that protective immunity can be achieved by immunization prior to exposure. the breadth ...19957707496
macaques immunized with hla-dr are protected from challenge with simian immunodeficiency virus.macaques immunized with uninfected human cells have been shown to be protected from challenge with simian immunodeficiency virus (siv) propagated in human cells. to identify the potential antigens involved in this protection, macaques were immunized with uninfected human cells, sucrose density gradient-purified culture fluid from uninfected human cells (mock virus), beta-2 microglobulin (beta 2m), immunoaffinity-purified hla class i and class ii proteins from these human cells, and adjuvant. alt ...19957707540
apparent lack of vertical transmission of simian immunodeficiency virus (siv) in naturally infected african green monkeys, cercopithecus aethiops. 19957495371
mutagenesis of the putative alpha-helical domain of the vpr protein of human immunodeficiency virus type 1: effect on stability and virion incorporation.vpr is one of the auxiliary genes of human immunodeficiency virus type 1 (hiv-1) and is conserved in the related hiv-2/simian immunodeficiency virus lentiviruses. the unique feature of vpr is that it is the only nonstructural protein incorporated into the virus particle. secondary structural analysis predicted an amphipathic alpha-helical domain in the amino terminus of vpr (residues 17-34) which contains five acidic and four leucine residues. to evaluate the role of specific residues of the hel ...19957731985
identification and properties of the largest subunit of the dna-dependent rna polymerase of fish lymphocystis disease virus: dramatic difference in the domain organization in the family iridoviridae.cytoplasmic dna viruses encode a dna-dependent rna polymerase (ddrp) that is essential for transcription of viral genes. the amino acid sequences of the known largest subunits of ddrps from different species contain highly conserved regions. oligonucleotide primers, deduced from two conserved domains (rqp[t/s]lh and nadfdgde) were used for detecting the corresponding gene of fish lymphocystis disease virus (flcdv), a member of the family iridoviridae, which replicates in the cytoplasm of infecte ...19957730795
the development of pcr based assays for the detection and differentiation of simian immunodeficiency virus in vivo.polymerase chain reaction based assays, which amplify a region of the gag gene, have been developed for the direct detection of simian immunodeficiency virus (siv) dna sequences in the blood of experimentally infected cynomolgus macaques. in macaques infected with a characterised virus pool (11/88 pool sivmac 32h), an assay employing a single round of amplification was found to be highly sensitive and specific. however, in animals infected with the siv molecular clones j5 and c8 (rud et al., j. ...19957738143
targeting foreign proteins to human immunodeficiency virus particles via fusion with vpr and vpx.the human immunodeficiency virus type 1 (hiv-1) and hiv-2 vpr and vpx proteins are packaged into virions through virus type-specific interactions with the gag polyprotein precursor. to examine whether hiv-1 vpr (vpr1) and hiv-2 vpx (vpx2) could be used to target foreign proteins to the hiv particle, their open reading frames were fused in frame with genes encoding the bacterial staphylococcal nuclease (sn), an enzymatically inactive mutant of sn (sn*), and chloramphenicol acetyltransferase (cat) ...19957745685
early intrathecal events in rhesus macaques (macaca mulatta) infected with pathogenic or nonpathogenic molecular clones of simian immunodeficiency virus.encephalitis is a common and devastating sequela of hiv infection in humans and of simian immunodeficiency virus (siv) infection in rhesus macaques. we used the siv-infected rhesus macaque model to study early intrathecal events in the pathogenesis of lentiviral encephalitis.19957745949
protection of macaques against simian immunodeficiency virus infection with inactivated vaccines: comparison of adjuvants, doses and challenge viruses. the european concerted action on 'macaque models for aids research'.nine european laboratories contributed a total of 98 macaques towards a collaborative trial to study the ability of formaldehyde-inactivated or subunit siv vaccines to protect immunized animals against live virus challenges. four adjuvants, three dose levels and two immunization schedules were compared. fifty-two of 61 (85%) immunized animals were protected against infection after challenge with either homologous or heterologous virus strains grown in human cells. optimum protection required a h ...19957631516
neutralizing monoclonal antibody against a external envelope glycoprotein (gp110) of sivmac251.three monoclonal antibodies (m318t, m56s and m815) against an external envelope glycoprotein (gp110) of simian immunodeficiency virus (siv) mac251 were obtained by immunizing balb/c mice with recombinant gp110 (rgp110). all three monoclonal antibodies reacted with the surface of cells infected with sivmac251 but not with that of uninfected counterparts. the binding activity of these monoclonal antibodies against native gp110 was confirmed by means of western blotting. one of them, m318t neutrali ...19957632464
in vivo administration of cd4-specific monoclonal antibody: effect on provirus load in rhesus monkeys chronically infected with the simian immunodeficiency virus of macaques.since monoclonal antibodies (mab) specific for cd4 are potent inhibitors of hiv and siv replication in vitro, we explored their potential usefulness in vivo as an aids therapy. the anti-cd4 mab 5a8 binds to domain 2 of the cd4 molecule and inhibits virus replication and virus-induced cell fusion at a postvirus binding step. administration of this mab to normal rhesus monkeys coats all circulating and lymph node cd4 cells and induces neither cd4 cell clearance nor measurable immunosuppression. in ...19957632466
a macaque adherent cell line that expresses human cd4 is susceptible to siv: utility for assessing neutralizing antibody.a macaque cd4 + adherent cell line was generated by stable expression of the human cd4 gene in a rhesus macaque mammary tumor cell line, cmmt. the resulting cell line cmmt/cd4 expressed surface cd4 and was sensitive to infection by a wide range of isolates of simian immunodeficiency virus (siv) of different subgroups, but was not susceptible to infection with hiv-1. the cmmt/cd4 cell line was used to develop a microassay for measurement of neutralizing antibody in plasma of siv-infected or immun ...19957635923
a single amino acid change in the cytoplasmic domain of the simian immunodeficiency virus transmembrane molecule increases envelope glycoprotein expression on infected cells.we have described a virus termed cp-mac, derived from the bk28 molecular clone of simian immunodeficiency virus, that was remarkable for its ability to infect sup-t1 cells with rapid kinetics, cell fusion, and cd4 down-modulation (c. c. labranche, m. m. sauter, b. s. haggarty, p. j. vance, j. romano, t. k. hart, p. j. bugelski, and j. a. hoxie, j. virol. 68:5509-5522, 1994 [erratum 68:7665-7667]). compared with bk28, cp-mac exhibited a number of changes in its envelope glycoproteins, including a ...19957636963
persistent infection of rhesus macaques with t-cell-line-tropic and macrophage-tropic clones of simian/human immunodeficiency viruses (shiv).to elucidate the functions of human immunodeficiency virus type 1 (hiv-1) genes in a nonhuman primate model, we have constructed infectious recombinant viruses (chimeras) between the pathogenic molecular clone of simian immunodeficiency virus (siv) sivmac239 and molecular clones of hiv-1 that differ in phenotypic properties controlled by the env gene. hiv-1sf33 is a t-cell-line-tropic virus which induces syncytia, and hiv-1sf162 is a macrophage-tropic virus that does not induce syncytia. a dna f ...19957638218
a simplified general method for determination of recombinant retrovirus titers.to construct recombinant retroviruses with only a single active promoter, we introduced point mutations into the tata box region of the 3'-ltr, and successfully obtained high-titer virus with sufficient self-inactivating activity. however, the viral titer could not be determined by the number of g418 resistant colonies since the neomycin resistance gene was under 5'-ltr control, because of inactivation of the selection marker in target glioma cells. to overcome this problem, we constructed pcr p ...19957641300
simian immunodeficiency virus infection of macaque primary placental cells.we have characterized the ability of a simian immunodeficiency virus, sivmne strain e11s, to infect macaque placental trophoblast and hofbauer cells. these primary placental cells were permissive to sivmne infection, regardless of gestational age. virus production by the infected cells was determined as time-dependent viral core antigen p27 production, followed by verification of the proviral gag/ltr dna sequences in the infected cells using a polymerase chain reaction assay. of more than six pl ...19957492442
studies of complement-activating antibodies in the siv/macaque model of acute primary infection and vaccine protection.questions regarding the potential impact of complement-activating antibodies on lentivirus pathogenesis and vaccine development were addressed in the siv/macaque model by evaluating sera for activity related to complement-mediated, antibody-dependent enhancement (c'-ade) of siv infection in vitro. c'-ade activity in sera obtained during acute primary infection in macaques inoculated with sivmac251 appeared before neutralizing antibodies and coincided with the initial peak and decline of plasma a ...19957492443
morphological changes in lymph nodes and expression of vcam1 and cytokines at the late stages of siv-induced disease in rhesus monkeys.four patterns of structural alterations were found in lymph nodes (lns) from rhesus monkeys 17 to 34 months after infection with simian immunodeficiency virus (siv-mac251). siv p27gag antigen and viral particles were localized either between the processes of follicular dendritic cells (fdcs) or in the cytoplasm of macrophages. in hyperplastic follicles, enlarged germinal centres contained numerous ki67+ proliferating centroblasts which were rather rare in light zones occupied by the cd23+ fdc ne ...19957481091
identification of v3 mutations that can compensate for inactivating mutations in c4 of simian immunodeficiency virus.a valine to isoleucine substitution at position 322 within variable region 3 (v3) of envelope of simian immunodeficiency virus was previously shown to compensate for an inactivating valine to glycine mutation at position 448 in constant region 4 (c4) (morrison et al., virology 195, 167-174, 1993). cloned dna fragments with inactivating c4 mutations were combined with complex mixtures of mutant v3 sequences, and full length genomes were transfected into cos-1 cells. by cocultivating transfected c ...19957483261
infection of baboons with simian/human immunodeficiency viruses.baboons were evaluated for their utility to serve as a model for testing envelope-based vaccines against human immunodeficiency virus type 1 (hiv-1). the ability of hiv-1 strains iiib, rf, and sf2 to infect baboons was compared with that of simian/human immunodeficiency virus (shiv) recombinant viruses comprised of either hxb2 or sf2 env, tat, rev, and vpu genes inserted into the sivmac239 backbone. both shiv recombinants replicated in baboon pbmc in vitro, while no evidence of replication was n ...19957627620
the tendency of lentiviral open reading frames to become a-rich: constraints imposed by viral genome organization and cellular trna availability.human immunodeficiency virus type 1 (hiv-1) and other lentiviridae demonstrate a strong preference for the a-nucleotide, which can account for up to 40% of the viral rna genome. the biological mechanism responsible for this nucleotide bias is currently unknown. the increased a-content of these viral genomes corresponds to the typical use of synonymous codons by all members of the lentiviral family (hiv, siv, biv, fiv, caev, eiav, visna) and the human spuma retrovirus, but not by other retrovirus ...19957666442
vaccine-induced virus-neutralizing antibodies and cytotoxic t cells do not protect macaques from experimental infection with simian immunodeficiency virus sivmac32h (j5).to gain further insight into the ability of subunit vaccines to protect monkeys from experimental infection with simian immunodeficiency virus (siv), two groups of cynomolgus macaques were immunized with either recombinant sivmac32h-derived envelope glycoproteins (env) incorporated into immune-stimulating complexes (iscoms) (group a) or with these siv env iscoms in combination with p27gag iscoms and three nef lipopeptides (group b). four monkeys immunized with recombinant feline immunodeficiency ...19957666529
an infectious chimeric human immunodeficiency virus type 2 (hiv-2) expressing the hiv-1 principal neutralizing determinant.the human immunodeficiency virus type 1 strain mn (hiv-1mn) principal neutralizing determinant (pnd, v3 loop) was introduced into infectious molecular clones hiv-2kr and simian immunodeficiency virus mm239 (sivmm239) by hybridization pcr, replacing the corresponding hiv-2 or siv envelope cysteine loops with the hiv-1 coding sequence. the hiv-2 chimera (hiv-2kr-mnv3) was found to be capable of infecting a number of t-cell lymphoblastic cell lines as well as primary peripheral blood mononuclear ce ...19957666543
mycobacterium avium complex in macaques with aids is associated with a specific strain of simian immunodeficiency virus and prolonged survival after primary infection.mycobacterium avium complex (mac) in simian immunodeficiency virus (siv)-infected macaques is a frequent opportunistic infection that shares many features with the condition in human aids patients. a retrospective analysis of necropsies on 135 macaques with siv-induced simian aids that received neither antiretroviral nor antimicrobial therapy revealed that 17% (23/135) were infected with mac. mac developed in 31.3% (21/67) of the animals inoculated with uncloned sivmac251 versus 1.9% (1/53) and ...19957561201
functional analysis of the vpx, vpr, and nef genes of simian immunodeficiency virus.the role of the vpx, vpr, and nef genes in the replication of simian immunodeficiency virus (siv) was investigated using point and deletion mutations in these genes. the effects on replication kinetics of single or combined mutants--vpx, vpr, vpx-vpr, vpx-nef, vpr-nef, and vpx-vpr-nef--in established lymphoid cemx174 and mt-4 cells were negligible, except that the postinfection appearance of vpx-nef, vpr-nef, and vpx-vpr-nef progeny virus was slightly delayed in mt-4 cells. the vpx, but not the ...19957882097
presence of virion protein x (vpx) of simian immunodeficiency virus sivmac 251 in target cells in vivo.localization of virion-associated protein x (vpx) of sivmac 251 was studied in lymph nodes and liver of six sivmac-infected monkeys. vpx was found associated with the network of follicular dendritic cells and macrophages in lymph nodes and/or livers from five out of six animals by immunohistochemistry. although the humoral response to vpx occurs in only 50% of the animals, the presence of vpx in target cell or antibodies to vpx in all the monkeys studied, suggests that vpx may be necessary for v ...19957563009
cellular immune response of rhesus monkeys infected with a partially attenuated nef deletion mutant of the simian immunodeficiency virus.to date the vaccines most successful in the simian immunodeficiency virus (siv) model of aids are live attenuated viruses. however, the virus-specific immune response induced after infection of monkeys with attenuated siv has not been described comprehensively. therefore, we investigated the cellular immune response of eight rhesus macaques infected with a nef deletion mutant of sivmac32h (pc8). in contrast to monkeys infected with pathogenic siv, pc8-infected macaques developed a virus-specific ...19957571408
progression to aids in the absence of a gene for vpr or vpx.rhesus monkeys (macaca mulatta) were experimentally infected with strains of simian immunodeficiency virus (siv) derived from sivmac239 lacking vpr, vpx, or both vpr and vpx genes. these auxiliary genes are not required for virus replication in cultured cells but are consistently conserved within the sivmac/human immunodeficiency virus type 2/sivsm group of primate lentiviruses. all four rhesus monkeys infected with the vpr deletion mutant showed an early spike in plasma antigenemia, maintained ...19957884883
mode of action of sdz nim 811, a nonimmunosuppressive cyclosporin a analog with activity against human immunodeficiency virus (hiv) type 1: interference with hiv protein-cyclophilin a interactions.cyclosporins, in particular the nonimmunosuppressive derivative sdz nim 811, exhibit potent anti-human immunodeficiency virus type 1 (hiv-1) activity in vitro. sdz nim 811 interferes at two stages of the viral replication cycle: (i) translocation of the preintegration complex to the nucleus and (ii) production of infectious virus particles. immunosuppressive activity is not correlated with anti-hiv-1 activity of cyclosporins. however, binding to cyclophilin a, the major cellular receptor protein ...19957884893
chimeric macaque/human fab molecules neutralize simian immunodeficiency virus.a collection of simian immunodeficiency virus (siv) neutralizing recombinant fab fragments was generated using the combinatorial antibody library approach. functional antibody fragments efficiently expressed in escherichia coli were identified only in the form of chimeric macaque heavy chain gamma 1 and human light chain kappa. the gamma 1 and kappa chains were derived from a clinically healthy long-term surviving sivsm-infected cynomolgus macaque and from an asymptomatic hiv-2 seropositive indi ...19957886953
progression to aids in macaques is associated with changes in the replication, tropism, and cytopathic properties of the simian immunodeficiency virus variant population.human immunodeficiency virus type 1 (hiv-1) typically evolves from a macrophage-tropic, noncytopathic virus at early asymptomatic stages of infection to a t-cell-tropic, cytopathic, and syncytia-inducing virus population as humans progress to aids. this suggests that changes in virus phenotype may influence disease. because simian immunodeficiency virus (siv) infection in macaques is a common model system for hiv-1 pathogenesis, we determined whether siv infection in macaques that develop simian ...19957886956
vpr deletion mutant of simian immunodeficiency virus induces aids in rhesus monkeys.in previous experiments, animals infected with sivmac239 containing a point mutation in the vpr and nef genes developed aids-like symptoms after early reversion of the vpr and nef genes. here we show that two animals in which the nef gene but not the vpr gene had reverted in the first few months did not develop disease during a 3-year observation period even after reversion to a functional vpr gene 70 weeks postinfection. to study the influence of a stable vpr mutation on virus load and pathogen ...19957609047
a conserved domain and membrane targeting of nef from hiv and siv are required for association with a cellular serine kinase activity.among the primate lentiviruses (human immunodeficiency virus (hiv) -1, hiv-2, and simian immunodeficiency virus (siv), the nef gene is highly conserved and encodes a myristylated protein of approximately 27 kda (hiv-1) or approximately 34 kda (hiv-2, siv). previously, we found nef expressed either as a cd8-nef fusion protein or as a native protein in virally infected t cell lines associates with a cellular serine kinase. this kinase activity phosphorylated two proteins of 62 and 72 kda that coim ...19957797518
zidovudine treatment prolongs survival and decreases virus load in the central nervous system of rhesus macaques infected perinatally with simian immunodeficiency virus.to assess the potential therapeutic effects of zidovudine, rhesus macaques were inoculated with simian immunodeficiency virus (siv) strain smm/b670 at birth and infused either continuously or intermittently with zidovudine for 6-7 months. zidovudine did not prevent infection but did significantly increase survival time, which was associated with lower serum p26 viral core antigen levels, a lower virus burden in the cerebrospinal fluid (csf), and lower csf quinolinic acid levels than in untreated ...19957797947
induction of resistance to 1-beta-d-arabinofuranosylcytosine in human h9 cell line by simian immunodeficiency virus.we examined drug sensitivity of human t cell acute lymphoblastic leukemia h9 cells chronically infected with simian immunodeficiency virus (sivmac) and found that the retrovirus-infected h9 cells showed 8.2-fold resistance to 1-beta-d-arabinofuranosylcytosine (ara-c). in the infected cells, ara-ctp levels decreased to 20% of that found in uninfected h9 cells after 3 h incubation at ara-c concentration of 1 microm, and 8.1-fold increase of cytidine deaminase activity was observed in the infected ...19957826366
prior infection with a nonpathogenic chimeric simian-human immunodeficiency virus does not efficiently protect macaques against challenge with simian immunodeficiency virus.prior infection with a nef-deleted simian immunodeficiency virus (siv) protects macaques not only against a homologous pathogenic siv challenge but also against challenge with a chimeric siv expressing a human immunodeficiency virus type 1 env gene (shiv). since this shiv is itself nonpathogenic, we sought to explore the use of a nonpathogenic shiv as a live, attenuated aids virus vaccine. four cynomolgus monkeys infected for greater than 600 days with a chimeric virus composed of sivmac 239 exp ...19957769725
repeated exposure of rhesus macaques to low doses of simian immunodeficiency virus (siv) did not protect them against the consequences of a high-dose siv challenge.as part of an in vivo titration study of the macaque simian immunodeficiency virus (sivmac) strain 251/spl, macaques were inoculated intravenously with various dilutions of this infectious sivmac. seven animals received dilutions from 10(-3) to 10(-6) of sivmac251/spl. two monkeys infected with the 10(-3) dilution of sivmac exhibited a productive infection as indicated by seroconversion, detection of genomic rna and proviral dna and positive virus isolation. these animals showed a cytotoxic t ce ...19957782761
reactivation of human immunodeficiency virus type 2 in macaques after simian immunodeficiency virus sivmac superinfection.by superinfection of human immunodeficiency virus type 2 (hiv-2) strain hiv-2ben-infected macaques with simian immunodeficiency virus (siv) strain sivmac, we investigated the mutual influences of an apathogenic and a pathogenic virus in vivo. four rhesus and two cynomolgus monkeys were infected with hiv-2ben in 1988 and 1989, respectively. virus could be reisolated from five of six animals 6 weeks after infection. the monkeys remained healthy over the next 2 to 3 years. pcr for viral rna became ...19957853490
the central globular domain of the nucleocapsid protein of human immunodeficiency virus type 1 is critical for virion structure and infectivity.the nucleocapsid protein ncp7 of human immunodeficiency virus type 1 (hiv-1) is a 72-amino-acid peptide containing two cchc-type zinc fingers linked by a short basic sequence, 29raprkkg35, which is conserved in hiv-1 and simian immunodeficiency virus. the complete three-dimensional structure of ncp7 has been determined by 1h-nuclear magnetic resonance spectroscopy (n. morellet, h. de rocquigny, y. mely, n. jullian, h. demene, m. ottmann, d. gerard, j. l. darlix, m. c. fournié-zaluski, and b. p. ...19957853517
proline-rich (pxxp) motifs in hiv-1 nef bind to sh3 domains of a subset of src kinases and are required for the enhanced growth of nef+ viruses but not for down-regulation of cd4.human immunodeficiency virus (hiv) and simian immunodeficiency virus nef proteins contain a conserved motif with the minimal consensus (pxxp) site for src homology region 3 (sh3)-mediated protein-protein interactions. nef pxxp motifs show specific binding to biotinylated sh3 domains of hck and lyn, but not to those of other tested src family kinases or less related proteins. a unique cooperative role of a distant proline is also observed. endogenous hck of monocytic u937 cells can be specificall ...19957859737
inactivation of simian immunodeficiency virus by hydrostatic pressure.the inactivation of the simian immunodeficiency viruses sivmac251 and sivagm by pressures of 150 and 250 mpa was determined. the extent of inactivation depended on the time that the virus was subjected to compression as well as the level of the pressure and at 150 mpa reached 5 log10 dilution units after approximately 10 hr. the inactivations, which were uniformly carried out at room temperature, were independent of the concentration of the virus. possible applications of pressure inactivation f ...19957624347
antibodies to the putative siv infection-enhancing domain diminish beneficial effects of an siv gp160 vaccine in rhesus macaques.to demonstrate that antibodies against amino acids (aa) 603-622 of the siv gp41 transmembrane glycoprotein enhance infection of siv in vivo.19957893438
bone marrow monocyte/macrophages are an early cellular target of pathogenic and nonpathogenic isolates of simian immunodeficiency virus (sivmac) in rhesus macaques.hematopoietic abnormalities are a common complication of human immunodeficiency virus infection in humans. however, the pathogenesis of these abnormalities remains unclear. simian immunodeficiency virus (siv) infection of rhesus macaques is a well-recognized animal model for acquired immunodeficiency syndrome. our previous studies have determined that in early siv infection, rhesus macaques develop peripheral blood and bone marrow pathologic changes within the first 14 days after intravenous ino ...19957898051
formation of simian immunodeficiency virus long terminal repeat circles in resting t cells requires both t cell receptor- and il-2-dependent activation.although immunodeficiency viruses can enter resting cd4+ t lymphocytes, activation of t cells is required for complete viral cdna synthesis and transport of double-stranded viral dna to the nucleus. cross-linking t cell receptors (tcrs) on resting cd4+ t cells induces reverse transcription of full-length simian immunodeficiency virus (siv) genomes, but tcr engagement alone is insufficient to stimulate siv dna to move to the nucleus and form long terminal repeat (ltr) circles. neither ligation of ...19957629519
the activation domain of simian immunodeficiency virus sivmac239 rev protein is structurally and functionally analogous to the hiv-1 rev activation domain.the rev proteins of primate immunodeficiency viruses are essential transactivators for the switch from early to late phase in the viral replication cycle. by mutational analysis, a putative activation domain (ad) has been assigned to the carboxy-terminus. this leucine-rich stretch of amino acids proved to be essential for the transactivating properties of hiv-1 rev. some mutants in the ad transdominantly inhibit the function of wild-type rev protein very efficiently. we identified a similar doma ...19957645223
an early increase in somatostatin mrna expression in the frontal cortex of rhesus monkeys infected with simian immunodeficiency virus.motor and cognitive impairment is common in human immunodeficiency virus disease in humans and simian immunodeficiency virus (siv) disease in rhesus monkeys. we have examined peptide neurotransmitter expression in the frontal cortex of siv-infected rhesus monkeys to identify alterations in cortical neurons that might explain this impairment. a 2-fold higher number of preprosomatostatin (srif) mrna-positive interneurons was observed in layer iv of frontal cortex in two separate cohorts of siv-inf ...19957877985
simian immunodeficiency virus (human hiv-ii) transmission in allograft bone procedures.infection of rhesus monkeys (macaca mulatta) with simian immunodeficiency virus (siv, hiv-ii) was used to study disease transmission in allograft bone. four allograft bone processing techniques--fresh, fresh frozen, double freeze-thaw, and double freeze-thaw with chemical decontamination--were evaluated.19957676330
immediate zidovudine treatment protects simian immunodeficiency virus-infected newborn macaques against rapid onset of aids.simian immunodeficiency virus (siv) infection of newborn rhesus macaques is a practical animal model of pediatric aids. intravenous inoculation of rhesus newborns with uncloned sivmac resulted in a high virus load, no antiviral immune responses, severe immunodeficiency, and a high mortality rate within 3 months. in contrast, immediate oral zidovudine (azt) treatment of siv-inoculated rhesus newborns either prevented infection or resulted in reduced virus load, enhanced antiviral immune responses ...19957695293
transfer of neuropathogenic simian immunodeficiency virus with naturally infected microglia.the central nervous system (cns) is a target for human immunodeficiency virus infection, and, in individuals with acquired immune deficiency syndrome, this can lead to a devastating dementia. only certain viral variants appear capable of invading the cns and infecting microglia and brain macrophages. to determine whether the virus entering the brain may be particularly pathogenic to the cns, we isolated microglia from the brains of simian immunodeficiency virus-infected rhesus monkeys. serial tr ...19957717458
the proteins of lymphocyte- and macrophage-tropic strains of simian immunodeficiency virus are processed differently in macrophages.since the pathogenesis of sivmac disease complex is thought to be explained by the tropism of the infecting virus for either cd4+ t-lymphocytes or macrophages or both types of cells, we compared the infection in primary macaque macrophages with molecularly cloned, lymphocyte-tropic sivmac239 and a cloned, macrophage-tropic chimeric virus (sivmac239/17e) whose env gene was derived from brain of a macaque (17e) dying from siv-induced encephalopathy. sivmac239/17e caused a productive, syncytial cyt ...19957831808
the u3 promoter region of the acutely lethal simian immunodeficiency virus clone smmpbj1.9 confers related biological activity on the apathogenic clone agm3mc.infection with the acutely pathogenic molecular virus clone sivsmmpbj1.9, cloned from isolate pbj14 of simian immunodeficiency virus (siv) from sooty mangabey monkeys (cercocebus atys), leads to acute viral and often lethal disease within days or weeks. sivsmmpbj1.9 has the unique property of replicating in nonstimulated peripheral blood mononuclear cells from pig-tailed macaques. in contrast, molecular virus clone sivagm3mc of siv from african green monkeys (cercopithecus aethiops), which is ap ...19957877983
characterization of nef sequences in long-term survivors of human immunodeficiency virus type 1 infection.studies with the simian immunodeficiency virus have shown that nef deletion results in a low level of viremia and a lack of disease progression in monkeys. given the similarity of this clinical profile to that observed in long-term survivors of human immunodeficiency virus type 1 (hiv-1) infection, we sought to examine the nef gene in 10 patients who are clinically healthy and immunologically normal despite 12 to 15 years of infection. pcr and dna sequencing were used to determine nef sequences ...19957983771
viral factors determine progression to aids in simian immunodeficiency virus-infected newborn rhesus macaques.to evaluate how viral variants may affect disease progression in human pediatric aids, we studied the potential of three simian immunodeficiency virus (siv) isolates to induce simian aids in newborn rhesus macaques. the three virus isolates were previously shown to range from pathogenic (sivmac251 and sivmac239) to nonpathogenic (sivmac1a11) when inoculated intravenously into juvenile and adult rhesus macaques. six newborn macaques inoculated with pathogenic, uncloned sivmac251 developed persist ...19957769679
effects of viral virulence on intrauterine growth in siv-infected fetal rhesus macaques (macaca mulatta).studies with a simian immunodeficiency virus (siv)-infected fetal monkey model were conducted with a focus on fetal growth and viral pathogenesis. twenty-six fetuses were inoculated in utero via ultrasound guidance with an uncloned pathogenic strain of siv or vehicle during the second or third trimesters [gestational day (gd) 65, 110, or 130], sonographically monitored weekly (biometrics, blood flow), then necropsied at incremental time points postinfection. peripheral blood hematologic (complet ...19957552476
simian immunodeficiency virus (siv)-specific ctl in cerebrospinal fluid and brains of siv-infected rhesus macaques.simian immunodeficiency virus (siv)-specific cd8+ ctl were isolated from blood, cerebrospinal fluid, and brains of rhesus macaques infected i.v. with siv. ctl were found as early as 1 wk postinfection and their appearance correlated with a decrease of viral ag (p27) found in the blood. ctl isolated from cerebrospinal fluid and/or brain often recognized different viral proteins than ctl isolated from blood, suggesting either a unique migratory pattern to the central nervous system or a difference ...19957730657
permissiveness of kupffer cells for simian immunodeficiency virus (siv) and morphological changes in the liver of rhesus monkeys at different periods of siv infection.the pathogenesis of liver injury, which remains unclear in the course of human immunodeficiency virus infection, can be investigated in simian immunodeficiency virus-infected macaques, which develop an immunodeficiency disease resembling human acquired immune deficiency syndrome (aids). we studied the livers of 21 monkeys infected with simian immunodeficiency virus (sivmac251) for 4 days to 39 months and detected viral antigens in kupffer cells, macrophages, and lymphocytes in 65% of the livers ...19957737626
the tempo and mode of siv quasispecies development in vivo calls for massive viral replication and clearance.simian immunodeficiency virus (siv) quasispecies development was followed in four monkeys (macacca fascicularis) infected by intramuscular inoculation of phage lambda-sivmac239 dna. rooted phylogenetic trees were reconstructed and used to interpret the data. the rate of fixation of base substitutions varied within and between animals reaching 3.3 x 10(-2) per site per year. these data suggest that the tempo of quasispecies development requires both massive viral replication and efficient clearan ...19957747436
Refresh
firstprev
12345678910...
nextlast
Displaying items 901 - 1000 of 6211