| use of major histocompatibility complex class i/peptide/beta2m tetramers to quantitate cd8(+) cytotoxic t lymphocytes specific for dominant and nondominant viral epitopes in simian-human immunodeficiency virus-infected rhesus monkeys. | to evaluate the impact of the diversity of antigen recognition by t lymphocytes on disease pathogenesis, we must be able to identify and analyze simultaneously cytotoxic t-lymphocyte (ctl) responses specific for multiple viral epitopes. many of the studies of the role of cd8(+) ctls in aids pathogenesis have been done with simian immunodeficiency virus (siv)- and simian-human immunodeficiency virus (shiv)-infected rhesus monkeys. these studies have frequently made use of the well-defined siv gag ... | 1999 | 10364294 |
| induction of aids in rhesus monkeys by a recombinant simian immunodeficiency virus expressing nef of human immunodeficiency virus type 1. | a nef gene is present in all primate lentiviruses, including human immunodeficiency virus type 1 (hiv-1) and simian immunodeficiency virus of macaque monkeys (sivmac). however, the nef genes of hiv-1 and sivmac exhibit minimal sequence identity, and not all properties are shared by the two. nef sequences of sivmac239 were replaced by four independent nef alleles of hiv-1 in a context that was optimal for expression. the sources of the hiv-1 nef sequences included nl 4-3, a variant nl 4-3 gene de ... | 1999 | 10364333 |
| persistent infection of rhesus macaques by the rev-independent nef(-) simian immunodeficiency virus sivmac239: replication kinetics and genomic stability. | we generated previously a nef(-), replication-competent clone of sivmac239 in which the rev protein and the rev-responsive element were replaced by the constitutive transport element (cte) of simian retrovirus type 1 (a. s. von gegerfelt and b. k. felber, virology 232:291-299, 1997). in the present report, we show that this virus was able to infect and replicate in rhesus macaques. the rev-independent nef(-) simian immunodeficiency virus induced a persistent humoral immune response in all monkey ... | 1999 | 10364376 |
| alterations in rantes gene expression and t-cell prevalence in intestinal mucosa during pathogenic or nonpathogenic simian immunodeficiency virus infection. | rantes, a beta-chemokine, can suppress human immunodeficiency virus (hiv) as well as simian immunodeficiency virus (siv) infections in t-lymphocyte cultures in vitro. however, the association of rantes levels in peripheral blood with viral loads and disease outcome in hiv infection has been inconclusive. siv-infected rhesus macaques were evaluated to determine whether rantes gene expression correlated with suppression of viral infection in intestinal lymphoid tissues. intestinal tissues were obt ... | 1999 | 10364494 |
| ethanol suppression of the functional state of polymorphonuclear leukocytes obtained from uninfected and simian immunodeficiency virus infected rhesus macaques. | human immunodeficiency virus (hiv) infection and alcohol abuse frequently coexist in the host and are known to suppress individually the host response to a variety of opportunistic infections. | 1999 | 10371409 |
| the relationship of personality dimensions in adult male rhesus macaques to progression of simian immunodeficiency virus disease. | studies of nonhuman primate personality have suggested that physiological correlates of relevant behavioral dimensions exist. the present study examined personality using techniques similar to those employed in human personality research. adult male rhesus monkeys were each rated on 25 adjectives while living in their natal groups. approximately 1.5 years later, 18 animals were inoculated with the simian immunodeficiency virus (siv) and exposed to socially stable or socially unstable conditions. ... | 1999 | 10373278 |
| threat to humans from virus infections of non-human primates. | several hundred distinct non human primate species are recognised, and they are likely to harbour a similar range of viruses to humans. simians such as cynomolgus and rhesus macaques, african green monkeys, and marmosets are widely used for biomedical research, but despite this extensive close contact very few simian viruses have been shown to pose a threat of infection or illness to humans. herpesvirus simiae is the best recognised zoonotic hazard of simians. it is an alphaherpes virus of asiat ... | 1997 | 10398488 |
| activated memory cd4(+) t helper cells repopulate the intestine early following antiretroviral therapy of simian immunodeficiency virus-infected rhesus macaques but exhibit a decreased potential to produce interleukin-2. | using the simian immunodeficiency virus (siv)-infected rhesus macaque model, we performed a longitudinal study to determine the effect of antiretroviral therapy on the phenotype and functional potential of cd4(+) t cells repopulating intestinal mucosa in human immunodeficiency virus infection. severe depletion of cd4(+) and cd4(+) cd8(+) t cells occurred in the intestinal mucosa during primary siv infection. the majority of these cells were of activated memory phenotype. phosphonate 9-[2-(phosph ... | 1999 | 10400763 |
| isolation and partial characterization of a lentivirus from talapoin monkeys (myopithecus talapoin). | we have identified a novel lentivirus prevalent in talapoin monkeys (myopithecus talapoin), extending previous observations of human immunodeficiency virus-1 cross-reactive antibodies in the serum of these monkeys. we obtained a virus isolate from one of three seropositive monkeys initially available to us. the virus was tentatively named simian immunodeficiency virus from talapoin monkeys (sivtal). despite the difficulty of isolating this virus, it was readily passed between monkeys in captivit ... | 1999 | 10405363 |
| increased expression of nitric oxide synthase and dendritic injury in simian immunodeficiency virus encephalitis. | widespread dendritic injury may be one mechanism involved in the neurologic impairment that occurs in hiv-1 infection. the objectives of this study were to quantitate the extent of dendritic injury in a primate model of central nervous system (cns) infection, investigate the role of nitric oxide (no) as a mediator of neuropathologic changes, and evaluate the relation of these changes to cognitive and motor function. | 1999 | 10413365 |
| motor evoked potentials in a rhesus macaque model of neuro-aids. | previous work using bone marrow passaged sivmac239 (simian immunodeficiency virus) has shown that macrophage tropic strains of this virus enter the rhesus macaque brain early following inoculation (sharma et al, 1992; desrosiers et al, 1991; zhu et al, 1995; and narayan et al, 1997). as part of an effort to more fully characterize the extent of neurologic impairment associated with siv infection of the brain, we used transcranial electrical stimulation of motor cortex and the spinal cord to evok ... | 1999 | 10414512 |
| induction of mucosal antibody responses by microsphere-encapsulated formalin-inactivated simian immunodeficiency virus in a male urethral challenge model. | male rhesus macaques were immunized mucosally with microsphere-encapsulated formalin-inactivated simian immunodeficiency virus (siv) particles in a test of immunogenicity and protection against mucosal siv challenge. tracheal boosting of animals that had been primed intramuscularly resulted in strong serum elisa titers to siv, and evidence of local iga responses in broncho-alveolar washes. the bulk of the antibody response was against non-envelope epitopes. no neutralizing antibody was observed, ... | 1999 | 10438051 |
| factors associated with slow disease progression in macaques immunized with an adenovirus-simian immunodeficiency virus (siv) envelope priming-gp120 boosting regimen and challenged vaginally with sivmac251. | rhesus macaques were immunized with a combination vaccine regimen consisting of adenovirus type 5 host range mutant-simian immunodeficiency virus envelope (ad5hr-sivenv) recombinant priming and boosting with native siv gp120. upon intravaginal challenge with sivmac251, both persistently and transiently viremic animals were observed (s. l. buge, e. richardson, s. alipanah, p. markham, s. cheng, n. kalyan, c. j. miller, m. lubeck, s. udem, j. eldridge, and m. robert-guroff, j. virol. 71:8531-8541, ... | 1999 | 10438833 |
| effective induction of simian immunodeficiency virus-specific cytotoxic t lymphocytes in macaques by using a multiepitope gene and dna prime-modified vaccinia virus ankara boost vaccination regimen. | dna and modified vaccinia virus ankara (mva) are vaccine vehicles suitable and safe for use in humans. here, by using a multicytotoxic t-lymphocyte (ctl) epitope gene and a dna prime-mva boost vaccination regimen, high levels of ctls specific for a single simian immunodeficiency virus (siv) gag-derived epitope were elicited in rhesus macaques. these vaccine-induced ctls were capable of killing siv-infected cells in vitro. fluorescence-activated cell sorter analysis using soluble tetrameric major ... | 1999 | 10438842 |
| induction of inhibitory antibodies to the ccr5 chemokine receptor and their complementary role in preventing siv infection in macaques. | the seven-transmembrane g-protein-linked ccr5 molecule functions as a major coreceptor for hiv or simian immunodeficiency virus (siv) infection. antibodies to ccr5 were studied in rhesus macaques immunized with siv grown in human cd4(+) t cells. these macaques were completely protected against i.v. challenge with live siv. sera from the protected macaques showed significantly greater inhibition of siv replication (p < 0.001) and macrophage inflammatory protein-1beta-generated ccr5-dependent chem ... | 1999 | 10458756 |
| combined systemic and mucosal immunization with microsphere-encapsulated inactivated simian immunodeficiency virus elicits serum, vaginal, and tracheal antibody responses in female rhesus macaques. | we determined the efficacy of immunization with microsphere-encapsulated whole inactivated simian immunodeficiency virus (siv) by combined systemic and mucosal administration to protect female rhesus macaques against vaginal challenge with homologous rhesus pbmc-grown sivmac251. animals in one group were primed and boosted intramuscularly. two groups were primed intramuscularly and boosted either intratracheally or orally. a final group was primed by vaccinia/rgp140 scarification and subdivided ... | 1999 | 10461832 |
| neutralizing antibody responses in africa green monkeys naturally infected with simian immunodeficiency virus (sivagm). | this study assessed the magnitude and cross-reactivity of the neutralizing antibody response generated by natural siv infection in wild-caught african green monkeys. neutralizing antibodies of variable potency, sometimes exceeding a titer of 1:1,000, were detected in 20 of 20 siv-seropositive african green monkeys in kenya. detection of those neutralizing antibodies was dependent on the strain of virus and the cells used for assay, where the most sensitive detection was made with sivagm1532 in s ... | 1999 | 10475110 |
| motor skill impairment in siv-infected rhesus macaques with rapidly and slowly progressing disease. | a number of studies have shown that simian immunodeficiency virus (siv) infection in rhesus macaques parallels many aspects of hiv disease in humans. the purpose of this study was to further characterize the rhesus macaque infected with neurovirulent siv as a model of neuroaids. using a motor skill task, our objective was to detect siv-related movement impairments in behaviorally trained macaques. the motor skill task required retrieval of a food pellet from a cup in a rotating turntable across ... | 1999 | 10475111 |
| the simian immunodeficiency virus envelope glycoprotein contains two epitopes presented by the mamu-a*01 class i molecule. | cytotoxic t lymphocyte (ctl) responses against the simian immunodeficiency virus (siv) envelope and gag proteins were monitored in a mamu-a*01-positive rhesus macaque infected with sivsme660. peripheral blood mononuclear cells (pbmc) cultured with synthetic peptides spanning the entire gp160 and gag coding region recognized a total of three epitopes. one located in gag was identified as the previously described mamu-a*01-restricted p11cc-->m epitope (ctpydinqm). the other two epitopes, designate ... | 1999 | 10482552 |
| the human immunodeficiency virus type 1 nef gene can to a large extent replace simian immunodeficiency virus nef in vivo. | the nef gene of the pathogenic simian immunodeficiency virus (siv) 239 clone was replaced with primary human immunodeficiency virus type 1 (hiv-1) nef alleles to investigate whether hiv-1 nef can substitute for siv nef in vivo. initially, two rhesus macaques were infected with the chimeric viruses (nef-shivs). most of the nef alleles obtained from both animals predicted intact open reading frames. furthermore, forms containing upstream nucleotide substitutions that enhanced expression of the ins ... | 1999 | 10482588 |
| nodular pneumocystis carinii pneumonia in siv-infected macaques. | pneumocystis carinii (pc) pneumonia is a frequent manifestation of the acquired immunodeficiency syndrome (aids) in humans and macaques. an unusual nodular type of pc pneumonia was observed in two simian immunodeficiency virus (siv)-inoculated rhesus macaques (macaca mulatta). these animals developed clinical signs of simian aids, including anorexia, weight loss, dyspnea, and collapse. grossly, both animals had multifocal tan-white nodules 1-10 mm in diameter scattered throughout the lungs. one ... | 1999 | 10490219 |
| induction of b cell hyperplasia in simian immunodeficiency virus-infected rhesus macaques with the simian homologue of kaposi's sarcoma-associated herpesvirus. | a simian homologue of kaposi's sarcoma-associated herpesvirus (kshv), the eighth human herpesvirus (hhv8), was isolated from a simian immunodeficiency virus (siv)-infected rhesus macaque (macaca mulatta) that developed a multicentric lymphoproliferative disorder (lpd). this simian rhadinovirus is genetically similar to a recently described rhesus rhadinovirus (rrv) (desrosiers, r.c., v.g. sasseville, s.c. czajak, x. zhang, k.g. mansfield, a. kaur, r.p. johnson, a.a. lackner, and j.u. jung. 1997. ... | 1999 | 10499921 |
| neuropathogenesis of simian immunodeficiency virus in neonatal rhesus macaques. | neonatal human immunodeficiency virus (hiv) infection usually occurs intrapartum or postpartum and results in a higher incidence of neurological dysfunction than is seen in adults. to explore the neuropathogenesis of neonatal hiv infection, we infected neonatal macaques with simian immunodeficiency virus (siv) and followed the course of infection focusing on early time points. infected neonates had decreased brain growth and mild histological changes in brain that resembled those seen in pediatr ... | 1999 | 10514404 |
| co-receptor usage of bob/gpr15 in addition to ccr5 has no significant effect on replication of simian immunodeficiency virus in vivo. | human immunodeficiency virus type 2 (hiv-2) and the closely related simian immunodeficiency viruses (sivs) frequently use the orphan receptor bob/gpr15 in addition to the chemokine receptor ccr5 for efficient entry and replication. however, the role of bob/gpr15 in replication and pathogenesis of hiv-2 and siv in vivo is unclear. this study shows that a single amino acid substitution in the v3 loop of the pathogenic sivmac239 clone, 321p-->s, impaired the ability to use bob/gpr15 for entry and r ... | 1999 | 10515808 |
| evolution of two types of rhesus lymphocryptovirus similar to type 1 and type 2 epstein-barr virus. | rhesus monkeys and other nonhuman old world primates are naturally infected with lymphocryptoviruses (lcv) that are closely related to epstein-barr virus (ebv). a rhesus lcv isolate (208-95) was derived from a b-cell lymphoma in a simian immunodeficiency virus-infected rhesus macaque. the ebna-2 homologues from 208-95 and a previous rhesus lcv isolate (lcl8664) were polymorphic on immunoblotting, so the ebna-2 genes from these two rhesus lcv were cloned, sequenced, and compared. the ebna-2 genes ... | 1999 | 10516028 |
| the effect of one injection of depo-provera on the human vaginal epithelium and cervical ectopy. | two studies in rhesus monkeys have shown that progesterone implants, depo-provera and norplant, were associated with vaginal thinning. progesterone implants have also been associated with an increased risk of simian immunodeficiency virus (siv) acquisition. this study in 16 women was done to assess vaginal epithelial thickness and number of cell layers from biopsies taken in the untreated follicular and luteal phases, and at 1 month and 3 months after administration of depo-provera. there was no ... | 1999 | 10549448 |
| transforming growth factor beta is a growth-inhibitory cytokine of b cell lymphoma in siv-infected macaques. | cytokine dysregulation is accepted as one of the pivotal factors in the pathogenesis of b cell lymphomas in hiv-positive patients. so far no data exist on inhibitory cytokines in the regulatory network of hiv-associated b-nhl. simian immunodeficiency virus (siv)-infected macaques are a well-established in vivo model of hiv infection in humans. we used this model for the identification of tgf-beta as a growth-inhibitory cytokine of siv-associated b cell lymphomas. fifty-seven rhesus macaques were ... | 1999 | 10555111 |
| performance norms for a rhesus monkey neuropsychological testing battery: acquisition and long-term performance. | a computerized behavioral battery based upon human neuropsychological tests (cantab, cenes, cambridge, uk) has been developed to assess cognitive behaviors of rhesus monkeys. monkeys reliably performed multiple tasks, providing long-term assessment of changes in a number of behaviors for a given animal. the overall goal of the test battery is to characterize changes in cognitive behaviors following central nervous system (cns) manipulations. the battery addresses memory (delayed non-matching to ... | 1999 | 10556598 |
| experimental infection of rhesus and pig-tailed macaques with macaque rhadinoviruses. | the recognition of naturally occurring rhadinoviruses in macaque monkeys has spurred interest in their use as models for human infection with kaposi sarcoma-associated herpesvirus (human herpesvirus 8). rhesus macaques (macaca mulatta) and pig-tailed macaques (macaca nemestrina) were inoculated intravenously with rhadinovirus isolates derived from these species (rhesus rhadinovirus [rrv] and pig-tailed rhadinovirus [prv]). nine rhadinovirus antibody-negative and two rhadinovirus antibody-positiv ... | 1999 | 10559350 |
| cytotoxic t lymphocytes specific for the simian immunodeficiency virus. | a non-human primate model for acquired immunodeficiency syndrome (aids), the simian immunodeficiency virus (siv)-infected rhesus monkey, was used to explore the role of the aids virus-specific cytotoxic t-lymphocyte (ctl) response in disease pathogenesis. this ctl response was measured using the major histocompatibility complex (mhc) class i/peptide tetramer technology. large numbers of tetramer-binding cd8+ t lymphocytes were demonstrable not only in the peripheral blood, but in lymph nodes and ... | 1999 | 10566147 |
| specific passage of simian immunodeficiency virus from end-stage disease results in accelerated progression to aids in rhesus macaques. | to determine whether passage of late-stage variants of simian immunodeficiency virus (siv) would lead to a more virulent infection and rapid disease progression, a study was designed to examine the effects of selective transmission of siv from late-stage cases of aids in macaca mulatta. in a uniform group of 10 age-matched animals from the same genetic breeding stock infected with siv(b670), it took 7 months before one of the ten animals developed aids. passage of virus taken from this animal im ... | 1999 | 10567639 |
| vaccination of macaques against pathogenic simian immunodeficiency virus with venezuelan equine encephalitis virus replicon particles. | vaccine vectors derived from venezuelan equine encephalitis virus (vee) that expressed simian immunodeficiency virus (siv) immunogens were tested in rhesus macaques as part of the effort to design a safe and effective vaccine for human immunodeficiency virus. immunization with vee replicon particles induced both humoral and cellular immune responses. four of four vaccinated animals were protected against disease for at least 16 months following intravenous challenge with a pathogenic siv swarm, ... | 2000 | 10590126 |
| recombinant human cd40 ligand inhibits simian immunodeficiency virus replication: a role for interleukin- 16. | cd40 ligand (cd40l), expressed on activated t cells, binds its receptor, cd40, on dendritic cells, b cells, and monocytes/ macrophages. human immunodeficiency virus (hiv)-infected individuals exhibit normal b-cell cd40 expression but diminished expression of cd40l on cd4 + t cells. thus, we studied recombinant human cd40l (hucd40l) in an in vitro rhesus macaque model of acquired immunodeficiency syndrome (aids). hucd40l induced peripheral blood mononuclear cell (pbmc) proliferation independent o ... | 1999 | 10593485 |
| an anti-hiv strategy combining chemotherapy and therapeutic vaccination. | combination chemotherapy using potent anti-retroviral agents has led to significant advances in the clinical management of human immunodeficiency virus (hiv) disease. however, the emergence of multiple drug-resistant mutants, the high need for compliance to adhere to demanding drug-dosing schemes, and the remaining toxic side-effects of drugs make the perspective of life-long treatment unattractive and possibly unrealistic. therefore, means must be sought to shorten the time span during which tr ... | 1999 | 10593486 |
| siv/hiv nef recombinant virus (shivnef) produces simian aids in rhesus macaques. | the simian immunodeficiency virus (siv) nef gene is an important determinant of viral load and acquired immunodeficiency syndrome (aids) in macaques. a role(s) for the hiv-1 nef gene in infection and pathogenesis was investigated by constructing recombinant viruses in which the nef gene of the pathogenic molecular clone sivmac239 nef was replaced with either hiv-1sf2nef or hiv-1sf33nef. these chimeras, designated shiv-2nef and shiv-33nef, expressed hiv-1 nef protein and replicated efficiently in ... | 1999 | 10600596 |
| simian immunodeficiency virus-specific cytotoxic t lymphocytes and protection against challenge in rhesus macaques immunized with a live attenuated simian immunodeficiency virus vaccine. | in this study, we examined the role of simian immunodeficiency virus (siv)-specific cytotoxic t lymphocytes (ctls) in macaques immunized with an attenuated strain of simian immunodeficiency virus (sivmac239deltanef) in protection against pathogenic challenge with sivmac251. our results indicate that attenuated sivmac239deltanef can elicit specific ctl precursor cells (ctlp), but no correlation was observed between breadth or strength of ctlp response to structural proteins siv-env, -gamg or -pol ... | 2000 | 10612675 |
| accumulation of mac387+ macrophages in paracortical areas of lymph nodes in rhesus monkeys acutely infected with simian immunodeficiency virus. | we investigated the histological features of lymph nodes, focusing on monocytes/macrophages, in rhesus monkeys (macaca mulatta) acutely infected with simian immunodeficiency virus (siv). in monkeys infected with a pathogenic siv, sivmac239, mac387(+) newly blood-derived macrophages markedly increased in number at paracortical areas at 11 to 14 days postinoculation, concomitant with the peak of the primary siv antigenemia. the mac387(+) macrophages densely gathered around high endothelial venules ... | 1999 | 10617929 |
| in vitro ethanol suppresses alveolar macrophage tnf-alpha during simian immunodeficiency virus infection. | pulmonary infections are a significant cause of morbidity and mortality in patients with alcohol abuse and human immunodeficiency virus (hiv) infection, two immunocompromising conditions that frequently coexist. this study examined the separate and combined effects of in vivo lentiviral infection and in vitro alcohol exposure on alveolar macrophage (am) production of tumor necrosis factor- alpha (tnf-alpha), a proinflammatory cytokine that is critical to normal pulmonary host defense. ams, recov ... | 2000 | 10619810 |
| normal t-cell turnover in sooty mangabeys harboring active simian immunodeficiency virus infection. | sooty mangabeys naturally infected with simian immunodeficiency virus (siv) remain healthy though they harbor viral loads comparable to those in rhesus macaques that progress to aids. to assess the immunologic basis of disease resistance in mangabeys, we compared the effect of siv infection on t-cell regeneration in both monkey species. measurement of the proliferation marker ki-67 by flow cytometry showed that mangabeys harbored proliferating t cells at a level of 3 to 4% in peripheral blood ir ... | 2000 | 10627531 |
| dilated cardiomyopathy associated with simian aids in nonhuman primates. | cardiomyopathy is being recognized with increasing frequency in patients with aids, yet the relationship between hiv infection and cardiac contractile dysfunction remains obscure. the purpose of the present study was to determine if infection with simian immunodeficiency virus (siv) in nonhuman primates is associated with cardiac dysfunction and myocardial injury. | 2000 | 10637207 |
| a strategy for cloning infectious molecular clones of retroviruses from serum or plasma. | to enable biological characterisation of lentiviral variants which emerge during infection and development of aids, a method was developed to construct molecular clones from circulating simian immunodeficiency virus (siv) particles present in as little as 20 microl of serum from infected rhesus monkeys. this technique uses a long distance rt-pcr method optimised for the amplification of partly overlapping 5-kb siv (half genome) amplimers. ligation of the genome halves resulted in the constructio ... | 2000 | 10644085 |
| cytokine expression, natural killer cell activation, and phenotypic changes in lymphoid cells from rhesus macaques during acute infection with pathogenic simian immunodeficiency virus. | we studied the innate and adaptive immune system of rhesus macaques infected with the virulent simian immunodeficiency virus isolate sivmac251 by evaluating natural killer (nk) cell activity, cytokine levels in plasma, humoral and virological parameters, and changes in the activation markers cd25 (interleukin 2r ¿il-2r alpha chain), cd69 (early activation marker), and cd154 (cd40 ligand) in lymphoid cells. we found that infection with sivmac251 induced the sequential production of interferon-alp ... | 2000 | 10644334 |
| antiretroviral therapy during primary immunodeficiency virus infection can induce persistent suppression of virus load and protection from heterologous challenge in rhesus macaques. | a limited period of chemotherapy during primary immunodeficiency virus infection might provide a long-term clinical benefit even if treatment is initiated at a time point when virus is already detectable in plasma. to evaluate this strategy, we infected rhesus macaques with the pathogenic simian/human immunodeficiency virus rt-shiv and treated them with the antiretroviral drug (r)-9-(2-phosphonylmethoxypropyl)adenine (pmpa) for 8 weeks starting 7 or 14 days postinfection. pmpa treatment suppress ... | 2000 | 10644340 |
| pathogenic conversion of live attenuated simian immunodeficiency virus vaccines is associated with expression of truncated nef. | rhesus macaques infected with simian immunodeficiency virus (siv) containing either a large nef deletion (sivmac239delta(152)nef) or interleukin-2 in place of nef developed high virus loads and progressed to simian aids. viruses recovered from both juvenile and neonatal macaques with disease produced a novel truncated nef protein, tnef. viruses recovered from juvenile macaques infected with serially passaged virus expressing tnef exhibited a pathogenic phenotype. these findings demonstrated stro ... | 2000 | 10644378 |
| rhesus lymphocryptovirus infection during the progression of saids and saids-associated lymphoma in the rhesus macaque. | saids-associated lymphoma (sal) represents a monoclonal expansion of b-cell origin in which simian immunodeficiency virus (siv) infection is not detected. however, tumor cells are frequently infected with rhesus lymphocryptovirus (rhlcv), a rhesus homologue of epstein-barr virus (ebv). in previous studies, the incidence of rhlcv infection in sal was determined to be 89% as measured by polymerase chain reaction (pcr) and/or in situ hybridization. the main objective of the present study was to asc ... | 2000 | 10659055 |
| effect of weekly adefovir (pmea) infusions on hiv-1 virus load: results of a phase i/ii study. | the compound 9-(2-phosphonylmethoxyethyl)adenine (adefovir; pmea) is a potent inhibitor of a number of viruses in vitro, such as human immunodeficiency virus (hiv) type 1 and 2, herpes simplex virus (hsv) type 1 and 2, human papillomavirus virus (hbv) and epstein-barr virus (ebv). adefovir also proved to be effective in vivo against feline immunodeficiency virus (fiv) in cats and simian immunodeficiency virus (siv) in rhesus monkeys. in an open, non-placebo-controlled trial the antiviral activit ... | 1999 | 10682155 |
| the kinetics of specific immune responses in rhesus monkeys inoculated with live recombinant bcg expressing siv gag, pol, env, and nef proteins. | development of an effective preventive or therapeutic vaccine against hiv-1 is an important goal in the fight against aids. effective virus clearance and inhibition of spread to target organs depends principally on the cellular immune response. therefore, a vaccine against hiv-1 should elicit virus-specific cytotoxic lymphocyte (ctl) responses to eliminate the virus during the cell-associated stages of its life cycle. the vaccine should also be capable of inducing immunity at the mucosal surface ... | 2000 | 10683331 |
| immunization with a modified vaccinia virus expressing simian immunodeficiency virus (siv) gag-pol primes for an anamnestic gag-specific cytotoxic t-lymphocyte response and is associated with reduction of viremia after siv challenge. | the immunogenicity and protective efficacy of a modified vaccinia virus ankara (mva) recombinant expressing the simian immunodeficiency virus (siv) gag-pol proteins (mva-gag-pol) was explored in rhesus monkeys expressing the major histocompatibility complex (mhc) class i allele, mamua*01. macaques received four sequential intramuscular immunizations with the mva-gag-pol recombinant virus or nonrecombinant mva as a control. gag-specific cytotoxic t-lymphocyte (ctl) responses were detected in all ... | 2000 | 10684264 |
| containment of simian immunodeficiency virus infection: cellular immune responses and protection from rechallenge following transient postinoculation antiretroviral treatment. | to better understand the viral and host factors involved in the establishment of persistent productive infection by primate lentiviruses, we varied the time of initiation and duration of postinoculation antiretroviral treatment with tenofovir (9-[2-(r)-(phosphonomethoxy)propyl]adenine) while performing intensive virologic and immunologic monitoring in rhesus macaques, inoculated intravenously with simian immunodeficiency virus sivsme660. postinoculation treatment did not block the initial infect ... | 2000 | 10684272 |
| recombinant modified vaccinia virus ankara expressing the surface gp120 of simian immunodeficiency virus (siv) primes for a rapid neutralizing antibody response to siv infection in macaques. | neutralizing antibodies were assessed before and after intravenous challenge with pathogenic sivsme660 in rhesus macaques that had been immunized with recombinant modified vaccinia virus ankara expressing one or more simian immunodeficiency virus gene products (mva-siv). animals received either mva-gag-pol, mva-env, mva-gag-pol-env, or nonrecombinant mva. although no animals were completely protected from infection with siv, animals immunized with recombinant mva-siv vaccines had lower virus loa ... | 2000 | 10684319 |
| the t-cell receptor zeta chain contains two homologous domains with which simian immunodeficiency virus nef interacts and mediates down-modulation. | we have recently demonstrated that simian immunodeficiency virus (siv) nef binds to the zeta chain of the t-cell receptor (tcr), leading to its down-modulation from t-cell surfaces (i. bell, c. ashman, j. maughan, e. hooker, f. cook, and t. a. reinhart, j. gen. virol. 79:2717-2727, 1998). using a panel of human as well as rhesus macaque tcr zeta cytoplasmic domain mutants, we have identified in this report two linear peptides in the cytoplasmic domain of tcr zeta which independently interact wit ... | 2000 | 10708444 |
| modulation of antigen-specific humoral responses in rhesus macaques by using cytokine cdnas as dna vaccine adjuvants. | an important limitation of dna immunization in nonhuman primates is the difficulty in generating high levels of antigen-specific antibody responses; strategies to enhance the level of immune responses to dna immunization may be important in the further development of this vaccine strategy for humans. we approached this issue by testing the ability of molecular adjuvants to enhance the levels of immune responses generated by multicomponent dna vaccines in rhesus macaques. rhesus macaques were coi ... | 2000 | 10708463 |
| opioids suppress chemokine-mediated migration of monkey neutrophils and monocytes - an instant response. | opioid users having acquired human immunodeficiency syndrome (aids) are at a greater risk than non-users of contracting opportunistic infections. opioid-administered and simian immunodeficiency virus (siv)-infected rhesus monkeys have been an excellent model for studying aids and drug abuse in humans. in this study, chemotaxis of monkey leukocytes was evaluated using the chemokines interleukin-8 (il-8) and regulated upon activation, normal t cell expressed (rantes) as the chemoattractants, and t ... | 2000 | 10708810 |
| quantitative image analysis of simian immunodeficiency virus replication in macrophages coinfected with mycobacterium avium complex. | mycobacterium avium is the most frequent cause of disseminated bacterial infection in patients with human immunodeficiency virus type 1 infection and in rhesus macaques with simian immunodeficiency virus (siv) infection. this animal model of aids was used to test the hypothesis that this frequent association is the result of reciprocal enhancement of replication of both microorganisms. the replication of m. avium and siv was analyzed in lymphatic tissues obtained from rhesus macaques experimenta ... | 2000 | 10720506 |
| morphologic and immunophenotypic characteristics of malignant lymphomas in siv-infected rhesus macaques. | eight cases of extranodal non-hodgkin's lymphoma in simian immunodeficiency virus (siv)-infected rhesus macaques, aged 4-9 years, were phenotypically and immunologically characterized, using the updated kiel classification, in order to determine both the differences and the similarities between these types of lymphoma in immunodeficient rhesus macaques (macaca mulatta) and man. the high-grade malignant tumors were of b-cell origin, with a predilection for extranodal growth in viscera and periorb ... | 1999 | 10733204 |
| simian immunodeficiency virus containing mutations in n-terminal tyrosine residues and in the pxxp motif in nef replicates efficiently in rhesus macaques. | sivmac nef contains two n-terminal tyrosines that were proposed to be part of an sh2-ligand domain and/or a tyrosine-based endocytosis signal and a putative sh3-ligand domain (p(104)xxp(107)). in the present study, we investigated the effects of combined mutations in these tyrosine and proline residues on simian immunodeficiency virus (siv) nef interactions with the cellular signal transduction and endocytic machinery. we found that mutation of y(28)f, y(39)f, p(104)a, and p(107)a (ffaa-nef) had ... | 2000 | 10756028 |
| augmentation of immune responses to hiv-1 and simian immunodeficiency virus dna vaccines by il-2/ig plasmid administration in rhesus monkeys. | the potential utility of plasmid dna as an hiv-1 vaccination modality currently is an area of active investigation. however, recent studies have raised doubts as to whether plasmid dna alone will elicit immune responses of sufficient magnitude to protect against pathogenic aids virus challenges. we therefore investigated whether dna vaccine-elicited immune responses in rhesus monkeys could be augmented by using either an il-2/ig fusion protein or a plasmid expressing il-2/ig. sixteen monkeys, di ... | 2000 | 10759543 |
| passive infusion of immune serum into simian immunodeficiency virus-infected rhesus macaques undergoing a rapid disease course has minimal effect on plasma viremia. | antibody responses are often considered to play only a limited role in controlling viremia during chronic infections with human or simian immunodeficiency virus (siv). we investigated this by determining the effect of passively infused antibody on plasma viremia in infected rhesus macaques. the emphasis of the study was to understand the mechanism(s) underlying any observed effects. we infused serum immunoglobulins (sivig) purified from siv(mac)251-infected macaques into other siv(mac)251-infect ... | 2000 | 10772996 |
| early activation and proliferation of t cells in simian immunodeficiency virus-infected rhesus monkeys. | to longitudinally determine t cell activation and turnover in early simian immunodeficiency virus (siv) infection of macaques, immunological and virological parameters were monitored in 10 siv-infected animals starting before infection until 40 weeks postinfection (wpi). lymphocyte subsets in blood and lymph nodes (lns) were characterized by three-color flow cytometry for expression of markers of activation, proliferation, and differentiation. as early as 1 wpi, cd69 expression was upregulated b ... | 2000 | 10791879 |
| up-regulation of beta-chemokines and down-modulation of ccr5 co-receptors inhibit simian immunodeficiency virus transmission in non-human primates. | a non-cognate mechanism of protection against human immunodeficiency virus-1 (hiv-1) infection involves up-regulation of beta-chemokines, which bind and may down-modulate the ccr5 co-receptors, thereby preventing transmission of m-tropic hiv-1. the objective of this investigation was to evaluate this mechanism in vivo in non-human primates. rhesus macaques were immunized by a modified targeted lymph nodes (tln) route with recombinant simian immunodeficiency virus (siv) glycoprotein 120 (gp120) a ... | 2000 | 10792505 |
| immunological memory and acquired immunodeficiency syndrome pathogenesis. | infection with the human immunodeficiency virus results in profound perturbations in immunological memory, ultimately resulting in increased susceptibility to opportunistic infections and acquired immunodeficiency syndrome (aids). we have used rhesus macaques infected with the simian immunodeficiency virus (siv) as a model to understand better the effects of aids virus infection on immunological memory. acute infection with siv resulted in significant deficits in cd4+ helper responses to cytomeg ... | 2000 | 10794059 |
| simian immunodeficiency virus utilizes human and sooty mangabey but not rhesus macaque strl33 for efficient entry. | it has been established that many simian immunodeficiency virus (siv) isolates utilize the orphan receptors gpr15 and strl33 about as efficiently as the chemokine receptor ccr5 for entry into target cells. most studies were performed, however, with coreceptors of human origin. we found that siv from captive rhesus macaques (sivmac) can utilize both human and simian ccr5 and gpr15 with comparable efficiencies. strikingly, however, only human strl33 (hustrl33), not rhesus macaque strl33 (rhstrl33) ... | 2000 | 10799581 |
| simian immunodeficiency virus (siv)-specific ctl are present in large numbers in livers of siv-infected rhesus monkeys. | the immunopathogenesis of aids-associated hepatitis was explored in the siv/rhesus monkey model. the livers of siv-infected monkeys showed a mild hepatitis, with a predominantly cd8+ t lymphocyte infiltration in the periportal fields and sinusoids. these liver-associated cd8+ t cells were comprised of a high percentage of siv-specific ctl as defined by mhc class i/gag peptide tetramer binding and gag peptide epitope-specific lytic activity. there was insufficient viral replication in these liver ... | 2000 | 10820285 |
| detection of the human immunodeficiency virus regulatory protein tat in cns tissues. | neuropathologically, human immunodeficiency virus (hiv) is associated with a range of inflammatory disorders, extensive cortical neuronal loss, and dendritic and synaptic damage. although the mechanisms resulting in these abnormalities are still unclear, the neurotoxic effects are thought to be due in part to viral products including the tat gene product. we have previously shown that tat when presented to neurons extracellularly interacts with neuronal cell membranes to cause neuronal excitatio ... | 2000 | 10822328 |
| simian and human immunodeficiency virus nef proteins use different surfaces to downregulate class i major histocompatibility complex antigen expression. | simian immunodeficiency virus (siv) and human immunodeficiency virus type 1 (hiv-1) nef proteins are related regulatory proteins that share several functions, including the ability to downregulate class i major histocompatibility complex (mhc) and cd4 expression on the cell surface and to alter t-cell-receptor-initiated signal transduction in t cells. we compared the mechanisms used by siv mac239 nef and hiv-1 nef to downregulate class i mhc and found that the ability of siv nef to downregulate ... | 2000 | 10823877 |
| effect of pmpa and pmea on the kinetics of viral load in simian immunodeficiency virus-infected macaques. | in this study we compared the effect of postexposure treatment of the acyclic nucleoside analogs 9-(2-phosphonylmethoxyethyl)-adenine (pmea) and 9-(2-phosphonylmethoxypropyl)-adenine (pmpa) on the kinetics of viral load in the blood and lymph nodes of rhesus macaques chronically infected with sivmac251 for 18 weeks. two of the four macaques treated with pmpa (20 mg/kg per day) for 28 consecutive days had demonstrable reductions in viral loads of 1.5 and 3 logs. three of four macaques given the s ... | 2000 | 10826485 |
| effects of in vivo cd8(+) t cell depletion on virus replication in rhesus macaques immunized with a live, attenuated simian immunodeficiency virus vaccine. | the role of cd8(+) t lymphocytes in controlling replication of live, attenuated simian immunodeficiency virus (siv) was investigated as part of a vaccine study to examine the correlates of protection in the siv/rhesus macaque model. rhesus macaques immunized for >2 yr with nef-deleted siv (sivmac239deltanef) and protected from challenge with pathogenic sivmac251 were treated with anti-cd8 antibody (okt8f) to deplete cd8(+) t cells in vivo. the effects of cd8 depletion on viral load were measured ... | 2000 | 10839807 |
| survival and failure to thrive in the siv-infected juvenile rhesus monkey. | in aids patients, wasting in adults and failure to thrive in children are common and devastating problems. weight loss in rhesus macaques infected with simian immunodeficiency virus (siv) has not been well characterized. the purpose of this study was to determine growth curves in siv-infected juvenile macaques to determine the effects of siv infection on body weight and growth. medical records of seven juvenile male siv-infected macaques were retrospectively reviewed to determine body weights, s ... | 1999 | 10843524 |
| simian immunodeficiency virus evades a dominant epitope-specific cytotoxic t lymphocyte response through a mutation resulting in the accelerated dissociation of viral peptide and mhc class i. | the ability of an aids virus to escape from immune containment by selective mutation away from recognition by ctl was explored in simian immunodeficiency virus of macaques (sivmac)-infected rhesus monkeys. ctl recognition of a previously defined common viral mutation in an immunodominant sivmac gag epitope was evaluated. ctl were assessed for their ability to recognize a sivmac gag protein with a single residue 2 (t --> a) replacement in the minimal epitope peptide bound by the mhc class i molec ... | 2000 | 10843704 |
| the intracytoplasmic domain of the env transmembrane protein is a locus for attenuation of simian immunodeficiency virus sivmac in rhesus macaques. | the human and simian immunodeficiency virus (hiv-1 and sivmac) transmembrane proteins contain unusually long intracytoplasmic domains (icd-tm). these domains are suggested to play a role in envelope fusogenicity, interaction with the viral matrix protein during assembly, viral infectivity, binding of intracellular calmodulin, disruption of membranes, and induction of apoptosis. here we describe a novel mutant virus, sivmac-m4, containing multiple mutations in the coding region for the icd-tm of ... | 2000 | 10846063 |
| simian immunodeficiency virus rapidly penetrates the cervicovaginal mucosa after intravaginal inoculation and infects intraepithelial dendritic cells. | despite recent insights into mucosal human immunodeficiency virus (hiv) transmission, the route used by primate lentiviruses to traverse the stratified squamous epithelium of mucosal surfaces remains undefined. to determine if dendritic cells (dc) are used by primate lentiviruses to traverse the epithelial barrier of the genital tract, rhesus macaques were intravaginally exposed to cell-free simian immunodeficiency virus sivmac251. we examined formalin-fixed tissues and hla-dr(+)-enriched cell s ... | 2000 | 10846092 |
| the rate of progression to aids is independent of virus dose in simian immunodeficiency virus-infected macaques. | of the viral factors that are proposed to influence the rate of progression to aids, the role of infectious dose remains unresolved. intravenous infection of outbred macaca mulatta with various doses of simian immunodeficiency virus isolate 8980 (siv(8980)) revealed an endpoint from which an infectious dose 50 (id(50)) was defined. in the six infected animals, the time to develop aids was variable with a spectrum of rapid, intermediate and slow progressors. high and sustained plasma viraemia wit ... | 2000 | 10859377 |
| direct measurement of cd8+ t cell responses in macaques infected with simian immunodeficiency virus. | the simian immunodeficiency virus (siv) macaque model system has been used extensively to study aids pathogenesis and to test candidate vaccines for their ability to protect against homologous or heterologous challenge with pathogenic siv or shiv. recent studies suggest that stimulation of hiv-1-specific ctl responses is important for effective vaccination against hiv-1. while quantitative measurements of siv-specific cytotoxic t lymphocyte (ctl) responses have been facilitated by the use of tet ... | 2000 | 10873778 |
| antiviral treatment normalizes neurophysiological but not movement abnormalities in simian immunodeficiency virus-infected monkeys. | simian immunodeficiency virus (siv) infection of rhesus monkeys provides an excellent model of the central nervous system (cns) consequences of hiv infection. to discern the relationship between viral load and abnormalities induced in the cns by the virus, we infected animals with siv and later instituted antiviral treatment to lower peripheral viral load. measurement of sensory-evoked potentials, assessing cns neuronal circuitry, revealed delayed latencies after infection that could be reversed ... | 2000 | 10880046 |
| expression and coreceptor activity of strl33/bonzo on primary peripheral blood lymphocytes. | ccr5 and cxcr4 are the major coreceptors that mediate human immunodeficiency virus 1 (hiv-1) infection, while most simian immunodeficiency virus (siv) isolates use ccr5. a number of alternative coreceptors can also mediate infection of some virus strains in vitro, although little is known about their in vivo relevance. therefore, we characterized the expression pattern and coreceptor activity of one of these alternative coreceptors, strl33/bonzo, using a newly developed monoclonal antibody. in a ... | 2000 | 10891428 |
| definition of five new simian immunodeficiency virus cytotoxic t-lymphocyte epitopes and their restricting major histocompatibility complex class i molecules: evidence for an influence on disease progression. | simian immunodeficiency virus (siv) infection of the rhesus macaque is currently the best animal model for aids vaccine development. one limitation of this model, however, has been the small number of cytotoxic t-lymphocyte (ctl) epitopes and restricting major histocompatibility complex (mhc) class i molecules available for investigating virus-specific ctl responses. to identify new mhc class i-restricted ctl epitopes, we infected five members of a family of mhc-defined rhesus macaques intraveno ... | 2000 | 10906193 |
| simian immunodeficiency virus (siv) gag dna-vaccinated rhesus monkeys develop secondary cytotoxic t-lymphocyte responses and control viral replication after pathogenic siv infection. | the potential contribution of a plasmid dna construct to vaccine-elicited protective immunity was explored in the simian immunodeficiency virus (siv)/macaque model of aids. making use of soluble major histocompatibility class i/peptide tetramers and peptide-specific killing assays to monitor cd8(+) t-lymphocyte responses to a dominant siv gag epitope in genetically selected rhesus monkeys, a codon-optimized siv gag dna vaccine construct was shown to elicit a high-frequency siv-specific cytotoxic ... | 2000 | 10906202 |
| vaccine protection against simian immunodeficiency virus by recombinant strains of herpes simplex virus. | an effective vaccine for aids may require development of novel vectors capable of eliciting long-lasting immune responses. here we report the development and use of replication-competent and replication-defective strains of recombinant herpes simplex virus (hsv) that express envelope and nef antigens of simian immunodeficiency virus (siv). the hsv recombinants induced antienvelope antibody responses that persisted at relatively stable levels for months after the last administration. two of seven ... | 2000 | 10933680 |
| differential effects of simian immunodeficiency virus infection on immune inductive and effector sites in the rectal mucosa of rhesus macaques. | the rectal mucosa, a region involved in human immunodeficiency virus/simian immunodeficiency virus (siv) infection and transmission, contains immune inductive sites, rectal lymphoid nodules (rln), and effector sites, the lamina propria (lp). this study was designed to evaluate cell populations involved in rectal mucosal immune function in both rln and lp, by immunocytochemical analysis of rectal mucosa from 11 siv-infected (2 to 21 months postinfection) and five naive rhesus macaques. in the rec ... | 2000 | 10934152 |
| inverse correlation of telomerase activity/proliferation of cd4+ t lymphocytes and disease progression in simian immunodeficiency virus-infected nonhuman primates. | both increased lymphocyte renewal with subsequent exhaustion of the immune system and impaired t-cell renewal have been put forth to account for cd4+ t-cell depletion and development of aids in hiv-1-infected humans and siv-infected nonhuman primates. in the present study, telomeric terminal restriction fragment length and telomerase activity were used as measures of proliferative activity of t lymphocytes from three nonhuman primate species before and after being infected with siv. in periphera ... | 2000 | 10935683 |
| simian immunodeficiency virus-specific cytotoxic t lymphocytes and cell-associated viral rna levels in distinct lymphoid compartments of sivmac-infected rhesus monkeys. | major histocompatibility class i-peptide tetramer technology and simian immunodeficiency virus of macaques (sivmac)-infected rhesus monkeys were used to clarify the distribution of acquired immunodeficiency syndrome virus-specific cytotoxic t lymphocytes (ctl) in secondary lymphoid organs and to assess the relationship between these ctl and the extent of viral replication in the various anatomic compartments. sivmac gag epitope-specific cd8(+) t cells were evaluated in the spleen, bone marrow, t ... | 2000 | 10942394 |
| homozygosity for a conserved mhc class ii dq-drb haplotype is associated with rapid disease progression in simian immunodeficiency virus-infected macaques: results from a prospective study. | in human immunodeficiency virus type 1 (hiv-1)-infected individuals, disease progression varies considerably. this is also observed after experimental infection of macaques with simian immunodeficiency virus (siv). major histocompatibility complex (mhc) genes may influence disease progression in both species. homozygosity for mhc-mamu (macaca mulatta)-dqb1*0601 was previously identified to be associated with rapid disease progression in siv-infected macaques. to validate the association of this ... | 2000 | 10950764 |
| differential dynamics of cd4(+) and cd8(+) t-lymphocyte proliferation and activation in acute simian immunodeficiency virus infection. | although lymphocyte turnover in chronic human immunodeficiency virus and simian immunodeficiency virus (siv) infection has been extensively studied, there is little information on turnover in acute infection. we carried out a prospective kinetic analysis of lymphocyte proliferation in 13 rhesus macaques inoculated with pathogenic siv. a short-lived dramatic increase in circulating ki-67(+) lymphocytes observed at 1 to 4 weeks was temporally related to the onset of siv replication. a 5- to 10-fol ... | 2000 | 10954541 |
| induction of mucosal homing virus-specific cd8(+) t lymphocytes by attenuated simian immunodeficiency virus. | induction of virus-specific t-cell responses in mucosal as well as systemic compartments of the immune system is likely to be a critical feature of an effective aids vaccine. we investigated whether virus-specific cd8(+) lymphocytes induced in rhesus macaques by immunization with attenuated simian immunodeficiency virus (siv), an approach that is highly effective in eliciting protection against mucosal challenge, express the mucosa-homing receptor alpha4beta7 and traffic to the intestinal mucosa ... | 2000 | 10954580 |
| simian-human immunodeficiency virus-associated nephropathy in macaques. | a number of chimeric simian-human immunodeficiency virus (shiv) viruses containing tat, rev, vpu, and env from hiv-1 (strain hxbc2) in a genetic background of simian immunodeficiency virus (siv(mac)239) have been derived from the parental nonpathogenic shiv-4 virus. in this article we examine the renal pathology associated with the derivation of these pathogenic shiv strains. the first of the pathogenic shivs, shiv(ku-1), is associated with rapid cd4(+) t cell loss and opportunistic infections a ... | 2000 | 10957726 |
| progressive multifocal leukoencephalopathy and oligodendroglioma in a monkey co-infected by simian immunodeficiency virus and simian virus 40. | a rhesus monkey experimentally inoculated with simian immunodeficiency virus (siv) mac251 was killed 42 months later because of poor general condition. cd4 lymphocyte count which was 3,430/mm3 before inoculation, had decreased to 638/mm3 2 months before death. neuropathological examination revealed changes characteristic of progressive multifocal leukoencephalopathy (pml) in the white matter of the cerebral hemispheres and brain stem. in situ hybridization was negative for jc virus but markedly ... | 2000 | 10965804 |
| the chimpanzee and other non-human-primate models in hiv-1 vaccine research. | animal models are of great importance for the study of disease pathogenesis, particularly non-human-primate models of infectious diseases. the role of non-human primates in hiv-1 research is continually discussed and debated. here, we examine three primate models: chimpanzee-hiv-1, rhesus macaque-simian immunodeficiency virus and rhesus macaque-shiv, and discuss immunological similarities and differences, safety and monetary issues, and ethical concerns. | 2000 | 10989311 |
| the replicative capacity of rhesus macaque peripheral blood mononuclear cells for simian immunodeficiency virus in vitro is predictive of the rate of progression to aids in vivo. | survival of rhesus macaques (macaca mulatta) experimentally infected with simian immunodeficiency virus (siv) varies significantly from animal to animal. some animals die within 2 months while others survive for more than 5 years, even when identical inocula are used. this diversity in survival creates a significant problem in the design of therapeutic and vaccine trials using the siv-macaque model because the use of small numbers of animals may provide results that are misleading. identifying a ... | 2000 | 10993932 |
| intrinsic susceptibility of rhesus macaque peripheral cd4(+) t cells to simian immunodeficiency virus in vitro is predictive of in vivo viral replication. | previous studies with simian immunodeficiency virus (siv) infection of rhesus macaques suggested that the intrinsic susceptibility of peripheral blood mononuclear cells (pbmc) to infection with siv in vitro was predictive of relative viremia after siv challenge. the present study was conducted to evaluate this parameter in a well-characterized cohort of six rhesus macaques selected for marked differences in susceptibility to siv infection in vitro. rank order relative susceptibility of pbmc to s ... | 2000 | 11000207 |
| preparation and induction of immune responses by a dna aids vaccine. | in an effort to evaluate the feasibility of developing a safe dna vaccine for acquired immunodeficiency syndrome (aids), we have prepared a plasmid-based immunogen modeled after a naturally occurring noninfectious mutant of the simian immunodeficiency virus (siv). the mutant siv genome produces defective virus particles that are noninfectious in vitro and nonpathogenic in vivo in rhesus macaques. analysis of the mutant genome revealed a 1.6 kb deletion that is in frame and spans integrase, vif, ... | 2000 | 11016598 |
| viremia control following antiretroviral treatment and therapeutic immunization during primary siv251 infection of macaques. | prolonged antiretroviral therapy (art) is not likely to eradicate human immunodeficiency virus type i (hiv-i) infection. here we explore the effect of therapeutic immunization in the context of art during primary infection using the simian immunodeficiency virus (siv251) macaque model. vaccination of rhesus macaques with the highly attenuated poxvirus-based nyvac-siv vaccine expressing structural genes elicited vigorous virus-specific cd4 + and cd8+ t cell responses in macaques that responded ef ... | 2000 | 11017146 |
| disrupting surfaces of nef required for downregulation of cd4 and for enhancement of virion infectivity attenuates simian immunodeficiency virus replication in vivo. | the multifunctional simian and human immunodeficiency virus (siv and hiv) nef proteins are important for virulence. we studied the importance of selected nef functions using an siv nef with mutations in two regions that are required for cd4 downregulation. this nef mutant is defective for downregulating cd4 and, in addition, for enhancing siv infectivity and induction of siv replication from infected quiescent peripheral blood mononuclear cells, but not for other known functions, including downr ... | 2000 | 11024110 |
| enterocytozoon bieneusi as a cause of proliferative serositis in simian immunodeficiency virus-infected immunodeficient macaques (macaca mulatta). | enterocytozoon bieneusi is the most frequent microsporidian parasite of human patients with acquired immunodeficiency syndrome and is a significant cause of diarrhea and wasting. recently, this organism has also been recognized as a spontaneous infection of several species of captive macaques. as in humans, e bieneusi frequently causes enteropathy and cholangiohepatitis in immunodeficient simian immunodeficiency virus (siv)-infected macaques. | 2000 | 11035580 |
| effect of a cellulose acetate phthalate topical cream on vaginal transmission of simian immunodeficiency virus in rhesus monkeys. | human immunodeficiency virus type 1 (hiv-1) infection continues to spread in developing countries, mostly through heterosexual transmission. the development of a safe and cost-effective topical microbicide, effective against a range of stds including hiv-1, would greatly impact the ongoing epidemic. when formulated in a vehicle, a micronized form of cellulose acetate phthalate (cap), which is an inactive pharmaceutical excipient, has been shown to inactivate hiv-1, herpes simplex virus types 1 a ... | 2000 | 11036053 |
| b-cell leukemia in a rhesus macaque (macaca mulatta) infected with simian immunodeficiency virus. | conditions associated with abnormal b-cell proliferation have an increased incidence in the hiv-infected population. a longitudinal study conducted at the tulane regional primate research center has followed more than 1,000 rhesus macaques infected with simian-immunodeficiency virus (siv) since 1984. while spontaneous b-cell malignancy in siv-negative macaques has not been reported, 42 cases of siv-associated-lymphoma (sal) have been documented in this cohort. recently we identified a single cas ... | 2000 | 11042530 |
| mechanisms for adaptation of simian immunodeficiency virus to replication in alveolar macrophages. | in contrast to the simian immunodeficiency virus sivmac239, which replicates poorly in rhesus monkey alveolar macrophages, a variant with nine amino acid changes in envelope (sivmac239/316e) replicates efficiently and to high titer in these same cells. we examined levels of viral dna, rna, antigen, and infectious virus to identify the nature of the block to sivmac239 replication in these cells. low levels of viral antigen (0.1 to 1.0 ng of p27 per ml) and infectious virus (100 to 1,000 infectiou ... | 2000 | 11044136 |
| pulmonary cryptosporidiosis in simian immunodeficiency virus-infected rhesus macaques. | cryptosporidiosis is a common opportunistic infection in the gastrointestinal tract of human and nonhuman primates with aids. pulmonary infection associated with cryptosporidium spp. has not been previously reported in monkeys. two macaques experimentally infected with simian immunodeficiency virus (siv) had lesions containing cryptosporidial organisms involving the trachea, lungs, bile ducts, pancreas, and intestine. the pulmonary sections revealed moderate to severe bronchopneumonia associated ... | 2000 | 11055873 |
| the level of cd4 expression limits infection of primary rhesus monkey macrophages by a t-tropic simian immunodeficiency virus and macrophagetropic human immunodeficiency viruses. | the entry of primate immunodeficiency viruses into cells is dependent on the interaction of the viral envelope glycoproteins with receptors, cd4, and specific members of the chemokine receptor family. although in many cases the tropism of these viruses is explained by the qualitative pattern of coreceptor expression, several instances have been observed where the expression of a coreceptor on the cell surface is not sufficient to allow infection by a virus that successfully utilizes the corecept ... | 2000 | 11069993 |
| early changes in peripheral blood t cells during primary infection of rhesus macaques with a pathogenic siv. | primary infection of rhesus macaques with pathogenic strains of simian immunodeficiency virus (siv) leads to rapid and dynamic changes in both viral load and t cell counts in the peripheral blood. we have performed a sequential analysis of peripheral blood cd4 and cd8 t cells in five macaques during the 8 weeks following sivmac251 infection. we observed a transient lymphopenia of both cd4 and cd8 t cells during the first 2 weeks, followed by a rebound. the primary phase of infection was associat ... | 2000 | 11085574 |
| long-term follow-up study on siv intestinal proviral load in rhesus macaques. | after experimental infection with simian immunodeficiency virus (siv), intestinal endoscopy proved to be an easily tolerated, minimal invasive procedure to obtain biopsies from the gastrointestinal tract of rhesus macaques during all stages of disease. as the gi tract is affected by many opportunistic infections and immunological impairment after siv/human immunodeficiency virus (hiv) infection, knowledge on the proviral load is an important parameter for a better understanding of disease pathog ... | 2000 | 11085575 |