Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| tenofovir treatment at 30 mg/kg/day can inhibit cortical bone mineralization in growing rhesus monkeys (macaca mulatta). | the acyclic nucleoside phosphonate analog, 9-[2-(r)-(phosphonomethoxy)propyl]adenine (pmpa; tenofovir: gilead sciences, inc., foster city, ca), has been shown to effectively inhibit simian immunodeficiency virus (siv) replication in rhesus macaques by blocking reverse transcription. however, chronic long-term tenofovir treatment at 30 mg/kg/day, intended to reduce viral replication and illness, has been shown to result in bone deformities and spontaneous fractures in rhesus monkeys. based on the ... | 2002 | 12472227 |
| rhesus monkey simian immunodeficiency virus infection as a model for assessing the role of selenium in aids. | the objective of this study was to determine whether simian immunodeficiency virus (siv) infection of macaques could be used as a model system to assess the role of selenium in aids. plasma and serum selenium levels were determined by standard assays in monkeys before and after inoculation of siv. siv-infected cells or cells expressing the hiv tat protein were labeled with 75se, and protein extracts were prepared and electrophoresed to analyze selenoprotein expression. total trna was isolated fr ... | 2002 | 12473832 |
| enhanced in vitro stimulation of rhesus macaque dendritic cells for activation of siv-specific t cell responses. | the macaque-simian immunodeficiency virus (siv) system is one of the best animal models available to study the role of dendritic cells (dcs) in transmission and pathogenesis of hiv, as well as to test dc-based vaccine and therapeutic strategies. to better define and optimize this system, the responsiveness of macaque monocyte-derived dcs to a variety of maturation stimuli was examined. characteristic immunophenotypic and functional dc maturation induced by standard monocyte conditioned medium (m ... | 2002 | 11792391 |
| replication-incompetent adenoviral vaccine vector elicits effective anti-immunodeficiency-virus immunity. | recent studies of human immunodeficiency virus type 1 (hiv-1) infection in humans and of simian immunodeficiency virus (siv) in rhesus monkeys have shown that resolution of the acute viral infection and control of the subsequent persistent infection are mediated by the antiviral cellular immune response. we comparatively assessed several vaccine vector delivery systems-three formulations of a plasmid dna vector, the modified vaccinia ankara (mva) virus, and a replication incompetent adenovirus t ... | 2002 | 11797011 |
| eventual aids vaccine failure in a rhesus monkey by viral escape from cytotoxic t lymphocytes. | potent virus-specific cytotoxic t lymphocyte (ctl) responses elicited by candidate aids vaccines have recently been shown to control viral replication and prevent clinical disease progression after pathogenic viral challenges in rhesus monkeys. here we show that viral escape from ctl recognition can result in the eventual failure of this partial immune protection. viral mutations that escape from ctl recognition have been previously described in humans infected with human immunodeficiency virus ... | 2002 | 11797012 |
| administration of recombinant rhesus interleukin-12 during acute simian immunodeficiency virus (siv) infection leads to decreased viral loads associated with prolonged survival in sivmac251-infected rhesus macaques. | the ability of recombinant rhesus interleukin-12 (rmamu-il-12) administration during acute simian immunodeficiency virus sivmac251 infection to influence the quality of the antiviral immune responses was assessed in rhesus macaques. group i (n = 4) was the virus-only control group. group ii and iii received a conditioning regimen of rmamu-il-12 (10 and 20 microg/kg, respectively, subcutaneously [s.c.]) on days -2 and 0. thereafter, group ii received 2 microg of il-12 per kg and group iii receive ... | 2002 | 11799168 |
| expression of dc-sign by dendritic cells of intestinal and genital mucosae in humans and rhesus macaques. | to better understand the role of dendritic cells (dcs) in human immunodeficiency virus (hiv) transmission at mucosal surfaces, we examined the expressions of the hiv adhesion molecule, dendritic-cell-specific icam-3 grabbing nonintegrin (dc-sign), its closely related homologue dc-signr, and hiv coreceptors by distinct dc populations in the intestinal and genital tracts of humans and rhesus macaques. we also developed monoclonal antibodies (mabs) specific for dc-sign or dc-signr. in the peyer's p ... | 2002 | 11799181 |
| recombinant canarypox vaccine-elicited ctl specific for dominant and subdominant simian immunodeficiency virus epitopes in rhesus monkeys. | since virus-specific ctl play a central role in containing hiv replication, a candidate aids vaccine should generate virus-specific ctl responses. in this study, the ability of a recombinant canarypox virus expressing siv gag-pol-env (alvac/siv gag-pol-env) was assessed for its ability to elicit both dominant and subdominant epitope-specific ctl responses in rhesus monkeys. following a series of five immunizations, memory ctl responses specific for a dominant gag epitope could be demonstrated in ... | 2002 | 11823518 |
| contribution of peaks of virus load to simian immunodeficiency virus pathogenesis. | the mechanisms causing aids and subsequently death in human immunodeficiency virus type 1 infection are not yet fully understood. nonetheless, correlates of accelerated progression to disease based on immunological and virological markers have been identified. the best correlate identified to date is the baseline virus load or the so-called viral set point. by focusing on a virus load measurement from a restricted time range, however, we ignore valuable information contained in the long-term pro ... | 2002 | 11836438 |
| fetal and maternal outcome after administration of tenofovir to gravid rhesus monkeys (macaca mulatta). | tenofovir has been shown to cross the placenta in quantities sufficient to sustain reductions in viral load in simian immunodeficiency virus (siv)-infected fetal monkeys. with chronic exposure (30 mg/kg), however, significant bone-related toxicity has been shown in approximately 25% of infants studied. further investigations were conducted to determine whether the bone-related toxicity observed was initiated during fetal life. gravid rhesus monkeys (n = 4) were administered tenofovir subcutaneou ... | 2002 | 11873070 |
| induction of mucosal protection against primary, heterologous simian immunodeficiency virus by a dna vaccine. | an effective vaccine against human immunodeficiency virus (hiv) should protect against mucosal transmission of genetically divergent isolates. as a safe alternative to live attenuated vaccines, the immunogenicity and protective efficacy of a dna vaccine containing simian immunodeficiency virus (siv) strain 17e-fr (siv/17e-fr) gag-pol-env was analyzed in rhesus macaques. significant levels of cytotoxic t lymphocytes (ctl), but low to undetectable serum antibody responses, were observed following ... | 2002 | 11884556 |
| generation of a life-expanded rhesus monkey fibroblast cell line for the growth of rhesus rhadinovirus (rrv). | rrv, the rhesus macaque equivalent to hhv-8 or kaposi's sarcoma-associated herpesvirus (kshv) was recently isolated from a simian immunodeficiency virus (siv) infected macaque with a lymphoproliferative disorder. the growth of rrv in tissue culture requires propagation of primary rhesus monkey fibroblasts (rfs). in an effort to extend the life of these primary cells in tissue culture, the catalytic subunit of telomerase (htert) was introduced into rf cells using a recombinant retrovirus. this ne ... | 2002 | 11890526 |
| development of anti-cd4 mab hu5a8 for treatment of hiv-1 infection: preclinical assessment in non-human primates. | the anti-cd4 mab 5a8 is a potent inhibitor of cd4-mediated infection of hiv-1. cd4 is obligatory for infection with primary hiv-1 isolates. humanized 5a8 (hu5a8) was constructed to reduce the potential immunogenicity and enhance the in vivo half-life when used in humans. hu5a8 is a molecularly engineered human igg4 antibody retaining the binding and functional properties of the murine version of 5a8 (mu5a8). this humanized mab has been shown to be very effective in inhibiting hiv-1 infection of ... | 2002 | 11893418 |
| immunization of macaques with live simian human immunodeficiency virus (shiv) vaccines conferred protection against aids induced by homologous and heterologous shivs and simian immunodeficiency virus. | to evaluate the vaccine potential of shivs attenuated by deletion of viral accessory genes, seven rhesus macaques were sequentially immunized with delta vpu delta nefshiv-4 (vaccine-i) followed by delta vpushiv(ppc) (vaccine-ii). despite the absence of virological evidence of productive infection with the vaccine strains, based on analysis of infectivity among peripheral blood mononuclear cells (pbmc) of the vaccinated animals, all seven animals developed binding as well as neutralizing antibodi ... | 2002 | 12359422 |
| a simian immunodeficiency virus nef peptide is a dominant cytotoxic t lymphocyte epitope in indian-origin rhesus monkeys expressing the common mhc class i allele mamu-a*02. | the precise measurement of epitope-specific cytotoxic t lymphocyte (ctl) responses in simian immunodeficiency virus (siv)- and simian-human immunodeficiency virus (shiv)-infected or vaccinated rhesus monkeys has been important in the evaluation of potential hiv vaccine strategies. this quantitation of ctl has been limited to date by the identification of only one dominant siv/shiv epitope in these monkeys. we have recently defined a nef ctl epitope p199ry (ytsgpgiry) that is recognized by cd8(+) ... | 2002 | 12359438 |
| a dominant block to hiv-1 replication at reverse transcription in simian cells. | although nonhuman primates are genetically close to humans, their t cells do not support productive replication of hiv-1. in contrast, hiv-1 replicates in activated human cd4(+) t cells, monocytes, and metabolically active human cells of a variety of cell types become permissive for hiv-1 replication when transduced to express cd4 and ccr5 or cxcr4. the molecular basis of this species restriction to hiv-1 replication was investigated by using african green monkey and rhesus macaque cell lines th ... | 2002 | 12368468 |
| amino acid deletions are introduced into the v2 region of gp120 during independent pathogenic simian immunodeficiency virus/hiv chimeric virus (shiv) infections of rhesus monkeys generating variants that are macrophage tropic. | highly pathogenic simian immunodeficiency virus/hiv chimeric viruses (shivs) cause extremely rapid, irreversible, and systemic depletions of cd4(+) t lymphocytes in inoculated rhesus monkeys. in the absence of this t cell subset, virus production can be sustained for several months by tissue macrophage. during independent infections of seven animals with uncloned virus stocks, shiv variants emerged bearing amino acid deletions that affected specific residues of the gp120 v2 loop. some of these m ... | 2002 | 12370415 |
| elispot and elisa analysis of spontaneous, mitogen-induced and antigen-specific cytokine production in cynomolgus and rhesus macaques. | evaluation of cytokine production in macaques has been hampered by a lack of availability of optimized and standardized immunoassays such as elisa and enzyme-linked immune spot assay (elispot); only a limited number of macaque cytokines have been assessed by elispot. using monoclonal antibodies (mab) to human cytokines that cross-react with cynomolgus and rhesus macaque interferon-gamma (ifn-gamma), interleukin (il)-2, il-4, il-5, il-6, il-12, il-13 and granulocyte monocyte colony-stimulating fa ... | 2002 | 12379341 |
| live, attenuated simian immunodeficiency virus sivmac-m4, with point mutations in the env transmembrane protein intracytoplasmic domain, provides partial protection from mucosal challenge with pathogenic sivmac251. | attenuated molecular clones of simian immunodeficiency virus (sivmac) are important tools for studying the correlates of protective immunity to lentivirus infection in nonhuman primates. the most highly attenuated sivmac mutants fail to induce disease but also fail to induce immune responses capable of protecting macaques from challenge with pathogenic virus. we recently described a novel attenuated virus, sivmac-m4, containing multiple mutations in the transmembrane protein (tm) intracytoplasmi ... | 2002 | 12388697 |
| elicitation of simian immunodeficiency virus-specific cytotoxic t lymphocytes in mucosal compartments of rhesus monkeys by systemic vaccination. | since most human immunodeficiency virus (hiv) infections are initiated following mucosal exposure to the virus, the anatomic containment or abortion of an hiv infection is likely to require vaccine-elicited cellular immune responses in those mucosal sites. studying vaccine-elicited mucosal immune responses has been problematic because of the difficulties associated with sampling t lymphocytes from those anatomic compartments. in the present study, we demonstrate that mucosal cytotoxic t lymphocy ... | 2002 | 12388710 |
| escape in one of two cytotoxic t-lymphocyte epitopes bound by a high-frequency major histocompatibility complex class i molecule, mamu-a*02: a paradigm for virus evolution and persistence? | it is now accepted that an effective vaccine against aids must include effective cytotoxic-t-lymphocyte (ctl) responses. the simian immunodeficiency virus (siv)-infected rhesus macaque is the best available animal model for aids, but analysis of macaque ctl responses has hitherto focused mainly on epitopes bound by a single major histocompatibility complex (mhc) class i molecule, mamu-a*01. the availability of mamu-a*01-positive macaques for vaccine studies is therefore severely limited. further ... | 2002 | 12388723 |
| changes in dendritic cell migration and activation during siv infection suggest a role in initial viral spread and eventual immunosuppression. | dendritic cells (dc) serve an essential function in linking the innate and acquired immune responses to antigen. peripheral dc acquire antigen and migrate to draining lymph nodes, where they localize to the t cell-rich paracortex and function as potent antigen presenting cells. we examined the effects of human immunodeficiency virus (hiv) infection on dc function in vivo using the rhesus macaque/simian immunodeficiency virus (siv) model. our data show that during acute siv infection, langerhans ... | 2002 | 12390541 |
| whole inactivated siv virion vaccines with functional envelope glycoproteins: safety, immunogenicity, and activity against intrarectal challenge. | a novel type of whole inactivated simian immunodeficiency virus (siv) virion vaccine immunogen with functional envelope glycoproteins was evaluated, without adjuvant, in rhesus macaques. immunogens included purified inactivated virions of sivmac239, a designed mutant of sivmac239 with gp120 carbohydrate attachment sites deleted (sivmac239 g4,5), and sivmnee11s. the vaccines were noninfectious, safe, and immunogenic, inducing antibody responses and cellular responses, including responses by cd8+ ... | 2002 | 12390543 |
| protection by siv vlp dna prime/protein boost following mucosal siv challenge is markedly enhanced by il-12/gm-csf co-administration. | the ever increasing number of people infected by human immunodeficiency virus (hiv) throughout the world renders the development of effective vaccines an urgent priority. herein, we report on an attempt to induce and enhance antiviral responses using a deoxyribonucleic acid (dna) prime/virus-like particles (vlp) protein boost strategy adjuvanted with interleukin (il)-12/gm-csf in rhesus macaques challenged with simian immunodeficiency virus (siv). thus, groups of monkeys were administered three ... | 2002 | 12390544 |
| improved detection of simian immunodeficiency virus rna by in situ hybridization in fixed tissue sections: combined effects of temperatures for tissue fixation and probe hybridization. | in situ hybridization detection of viral rnas in formaldehyde-fixed tissue specimens is used frequently to characterize the extent of viral replication within host tissues. the ability to determine the level of expression of viral rnas in situ is dependent upon many factors including the extent of cross-linking during fixation, the pretreatment regimen utilized to relieve the effects of cross-linking, and the hybridization and wash protocols. in efforts to improve our ability to detect cells inf ... | 2002 | 11684300 |
| alvac-siv-gag-pol-env-based vaccination and macaque major histocompatibility complex class i (a*01) delay simian immunodeficiency virus sivmac-induced immunodeficiency. | t-cell-mediated immune effector mechanisms play an important role in the containment of human immunodeficiency virus/simian immunodeficiency virus (hiv/siv) replication after infection. both vaccination- and infection-induced t-cell responses are dependent on the host major histocompatibility complex classes i and ii (mhc-i and mhc-ii) antigens. here we report that both inherent, host-dependent immune responses to sivmac251 infection and vaccination-induced immune responses to viral antigens wer ... | 2002 | 11739694 |
| decreased frequency of cytomegalovirus (cmv)-specific cd4+ t lymphocytes in simian immunodeficiency virus-infected rhesus macaques: inverse relationship with cmv viremia. | the frequency of cytomegalovirus (cmv)-specific cd4+ t lymphocytes was determined in cmv-seropositive rhesus macaques with or without simian immunodeficiency virus (siv) infection by using the sensitive assays of intracellular cytokine staining and gamma interferon elispot. both techniques yielded 3- to 1,000-fold-higher frequencies of cmv-specific cd4+ t lymphocytes than traditional proliferative limiting dilution assays. the median frequency of cmv-specific cd4+ t lymphocytes in 23 cmv-seropos ... | 2002 | 11907204 |
| il-4 increases simian immunodeficiency virus replication despite enhanced siv immune responses in infected rhesus macaques. | it is widely believed that a th1 type cd4 response is critical for enhancement of cd8 immunity and for controlling hiv-1 infection. th2 type responses, such as what might be seen in a chronic parasitic infection, would sacrifice cellular immunity and thus benefit the virus at the expense of the host. however, there has been little direct examination of the hypothesis in a primate model system. accordingly, the simian immunodeficiency virus (siv) infected rhesus macaque model was used to investig ... | 2002 | 11943227 |
| lack of simian immunodeficiency virus (siv) specific iga response in the intestine of siv infected rhesus macaques. | little is known about secretory immunity-the major defence mechanism at mucosal surfaces-in human immunodeficiency virus (hiv) infected patients, especially in the early stages of the disease. | 2002 | 11950804 |
| increased expression of the inflammatory chemokine cxc chemokine ligand 9/monokine induced by interferon-gamma in lymphoid tissues of rhesus macaques during simian immunodeficiency virus infection and acquired immunodeficiency syndrome. | chemokines are important mediators of cell trafficking during immune inductive and effector activities, and dysregulation of their expression might contribute to the pathogenesis of human immunodeficiency virus type 1 and the related simian immunodeficiency virus (siv). to understand better the effects of siv infection on lymphoid tissues in rhesus macaques, we examined chemokine messenger rna (mrna) expression patterns by using dna filter array hybridization. of the 34 chemokines examined, the ... | 2002 | 11964273 |
| the liver is a major organ for clearing simian immunodeficiency virus in rhesus monkeys. | infection with human or simian immunodeficiency virus (siv) is characterized by the rapid turnover of both viral particles and productively infected cells. it has recently been reported that the clearance of siv in vivo is exceedingly fast, with half-lives on the order of minutes. the underlying mechanism or site responsible for this rapid clearance, however, remains unknown. to investigate this issue, we chose to infuse infectious sivmac239 grown from autologous peripheral blood mononuclear cel ... | 2002 | 11967341 |
| effects of in vitro ethanol on tumor necrosis factor-alpha production by blood obtained from simian immunodeficiency virus-infected rhesus macaques. | tumor necrosis factor-alpha (tnf-alpha), a product of monocytes and macrophages, functions as an important proinflammatory cytokine in the host's response to invading pathogens. | 2002 | 11981130 |
| analysis of the immune response and viral evolution during the acute phase of siv infection. | development of an effective vaccine against human immunodeficiency virus (hiv) will require knowledge of the immune responses that correlate with protection. during the acute phase of hiv infection the host immune responses appear to control viral replication. it is thought that virus-specific cellular immunity is intimately involved in this viral control. we have developed a model system to measure the entire t cell response and viral evolution in the face of this onslaught in rhesus macaques d ... | 2002 | 11983247 |
| acute phase cytotoxic t lymphocyte escape is a hallmark of simian immunodeficiency virus infection. | cytotoxic t-lymphocyte (ctl) responses peak coincident with the decline in acute hiv viremia. despite two reports of ctl-resistant hiv variants emerging during acute infection, the contribution of acute ctl escape to hiv pathogenesis remains unclear. difficulties inherent in studying acute hiv infection can be overcome by modeling virus-host interactions in siv-infected rhesus macaques. we sequenced 21 complete simian immunodeficiency virus (siv)mac239 genomes at four weeks post-infection to det ... | 2002 | 11984594 |
| rhesus macaque resistance to mucosal simian immunodeficiency virus infection is associated with a postentry block in viral replication. | elucidation of the host factors which influence susceptibility to human immunodeficiency virus or simian immunodeficiency virus (siv) infection and disease progression has important theoretical and practical implications. rhesus macaque 359, a vaccine control animal, resisted two successive intravaginal challenges with siv(mac251) and failed to seroconvert. here, after an additional intrarectal sivmac32h challenge, macaque 359 remained highly resistant to infection. viral rna (10(6) copies/ml) w ... | 2002 | 12021334 |
| prior vaccination increases the epitopic breadth of the cytotoxic t-lymphocyte response that evolves in rhesus monkeys following a simian-human immunodeficiency virus infection. | although recent evidence has confirmed the importance of cytotoxic t-lymphocyte (ctl) responses in controlling human immunodeficiency virus type 1 and simian immunodeficiency virus replication, the relevance of the epitopic breadth of those ctl responses remains unexplored. in the present study, we sought to determine whether vaccination can expand ctl populations which recognize a repertoire of viral epitopes that is greater than is typically generated in the course of a viral infection. we dem ... | 2002 | 12021371 |
| innate differences between simian-human immunodeficiency virus (shiv)(ku-2)-infected rhesus and pig-tailed macaques in development of neurological disease. | neurological disease associated with hiv infection results from either primary replication of the virus or a combination of virus infection and replication of opportunistic pathogens in the cns. recent studies indicate that the primary infection is mediated mainly by viruses that utilize ccr5 as the coreceptor; it is not known whether the syndrome can be mediated by viruses that use the cxcr4 coreceptor. the macaque model of the disease using simian immunodeficiency virus (siv) has confirmed tha ... | 2002 | 12033765 |
| immunization of rhesus macaques with a dna prime/modified vaccinia virus ankara boost regimen induces broad simian immunodeficiency virus (siv)-specific t-cell responses and reduces initial viral replication but does not prevent disease progression following challenge with pathogenic sivmac239. | producing a prophylactic vaccine for human immunodeficiency virus (hiv) has proven to be a challenge. most biological isolates of hiv are difficult to neutralize, so that conventional subunit-based antibody-inducing vaccines are unlikely to be very effective. in the rhesus macaque model, some protection was afforded by dna/recombinant viral vector vaccines. however, these studies used as the challenge virus shiv-89.6p, which is neutralizable, making it difficult to determine whether the observed ... | 2002 | 12072518 |
| characterization of the peptide-binding specificity of mamu-b*17 and identification of mamu-b*17-restricted epitopes derived from simian immunodeficiency virus proteins. | the siv-infected rhesus macaque is an excellent model to examine candidate aids virus vaccines. these vaccines should elicit strong cd8(+) responses. previous definition of the peptide-binding motif and optimal peptides for mamu-a*01 has created a demand for mamu-a*01-positive animals. we have now studied a second mhc class i molecule, mamu-b*17, that is present in 12% of captive-bred indian rhesus macaques. the peptide-binding specificity of the mamu-b*17 molecule was characterized using single ... | 2002 | 12077247 |
| morphine promotes simian acquired immunodeficiency syndrome virus replication in monkey peripheral mononuclear cells: induction of cc chemokine receptor 5 expression for virus entry. | rhesus monkeys (macaca mulatta) chronically administered opioids were more susceptible to simian immunodeficiency virus (siv) strain mac239 (sivmac239) infection than those without prior exposure to opioids. increased plasma viremia in morphine-dependent monkeys allowed siv to be detected in the animals' peripheral blood mononuclear cells (pbmc) without cocultivation with a tissue culture cell line. in contrast, virus titers from the pbmc of morphine-naive sivmac239-infected animals were undetec ... | 2002 | 12085334 |
| experimental coinfection of rhesus macaques with rhesus cytomegalovirus and simian immunodeficiency virus: pathogenesis. | human cytomegalovirus (hcmv) possesses low pathogenic potential in an immunocompetent host. in the immunosuppressed host, however, a wide spectrum of infection outcomes, ranging from asymptomatic to life threatening, can follow either primary or nonprimary infection. the variability in the manifestations of hcmv infection in immunosuppressed individuals implies that there is a threshold of host antiviral immunity that can effectively limit disease potential. we used a nonhuman primate model of c ... | 2002 | 12097580 |
| rapid progression to simian aids can be accompanied by selection of cd4-independent gp120 variants with impaired ability to bind cd4. | aspartate 368 on human immunodeficiency virus type 1 (hiv-1) gp120 forms multiple contacts with cd4; in mutagenesis studies, its replacement by asparagine and corresponding changes in simian immunodeficiency virus sivmac (d385n) reduced binding with cd4. nevertheless, simian immunodeficiency virus envelopes with d385n were prevalent in several studies. extending these observations, we also found d385n to be dominant among env clones from two rhesus macaques that progressed rapidly to simian aids ... | 2002 | 12097605 |
| siv-associated lymphomas in rhesus monkeys (macaca mulatta) in comparison with hiv-associated lymphomas. | a retrospective study was performed to characterize malignant lymphomas of 16 simian immunodeficiency virus (siv)-infected rhesus monkeys (macaca mulatta), 2-9 years of age, on the basis of clinical data, histologic and immunophenotypic results, and cell death indices compiled with the tdt-mediated x-dutp nick end labeling method. we particularly focused on providing immunohistochemical evidence of expression products of ebna2, bc12, c-myc, p21, p53, and bc16. results were compared with data fro ... | 2002 | 12102218 |
| the relationship between simian immunodeficiency virus rna levels and the mrna levels of alpha/beta interferons (ifn-alpha/beta) and ifn-alpha/beta-inducible mx in lymphoid tissues of rhesus macaques during acute and chronic infection. | to define the role of alpha/beta interferons (ifn-alpha/beta) in simian immunodeficiency virus (siv) infection, ifn-alpha and ifn-beta mrna levels and mrna levels of mx, an antiviral effector molecule, were determined in lymphoid tissues of rhesus macaques infected with pathogenic siv. ifn-alpha/beta responses were induced during the acute phase and persisted in various lymphoid tissues throughout the chronic phase of infection. ifn-alpha/beta responses were most consistent in tissues with high ... | 2002 | 12134046 |
| a novel chimeric rev, tat, and nef (retanef) antigen as a component of an siv/hiv vaccine. | the human immunodeficiency virus type 1 (hiv-1) regulatory proteins rev, tat, and nef are expressed at early time post-infection and represent attractive targets to be included in a vaccine candidate for aids. however, the putative immunosuppressive activities of some of these proteins may limit their immunogenicity. to circumvent these issues, a novel chimeric polyprotein vaccine candidate (retanef), comprising genetically modified and re-assorted rev, tat, and nef open reading frames of simian ... | 2002 | 12163269 |
| proliferating cellular nuclear antigen expression as a marker of perivascular macrophages in simian immunodeficiency virus encephalitis. | brain perivascular macrophages are a major target of simian immunodeficiency virus (siv) infection in rhesus macaques and hiv infection in humans. perivascular macrophages are distinct from parenchymal microglia in their location, morphology, expression of myeloid markers, and turnover in the cns. in contrast to parenchymal microglia, perivascular macrophages are continuously repopulated by blood monocytes, which undergo maturation to macrophages on entering the central nervous system (cns). we ... | 2002 | 12163382 |
| a humanized, nondepleting anti-cd4 antibody that blocks virus entry inhibits virus replication in rhesus monkeys chronically infected with simian immunodeficiency virus. | therapeutic approaches that interfere with viral entry hold promise in preventing or treating hiv infection. hu5a8, a humanized monoclonal antibody against cd4, was previously shown to inhibit hiv and siv replication in vitro and was safely administered to rhesus monkeys without depleting cd4(+) t cells. this antibody completely suppressed replication of six different sivmac 251 primary isolates in vitro. twice weekly administration of 3-mg/kg doses of hu5a8 for 2 to 4 weeks to siv-infected rhes ... | 2002 | 12167266 |
| increased macrophage infection upon subcutaneous inoculation of rhesus macaques with simian immunodeficiency virus-loaded dendritic cells or t cells but not with cell-free virus. | information on the establishment of immunodeficiency virus infection through transmission of infected cells is sparse. dendritic cells (dcs) and t cells may be central to the onset and subsequent spread of infection following mucosal exposure. to directly investigate the consequences of virus being introduced by dcs or t cells, we reinjected ex vivo simian immunodeficiency virus (siv)-loaded autologous immature dcs and t cells subcutaneously (s.c.) into healthy macaques. s.c. injection of cell-b ... | 2002 | 12208957 |
| restricted siv replication in rhesus macaque lung tissues during the acute phase of infection. | the extent to which simian immunodeficiency virus (siv) replication in lung tissues contributes to the pool of viruses replicating during acute infection is incompletely understood. to address this issue, in situ hybridization was used to examine siv replication in multiple lobes of lung from rhesus macaques infected with pathogenic siv. despite widespread viral replication in lymphoid and intestinal tissues, the lungs during acute infection harbored rare productively infected cells. simultaneou ... | 2002 | 12213725 |
| mhc class i alleles influence set-point viral load and survival time in simian immunodeficiency virus-infected rhesus monkeys. | in hiv-infected humans and siv-infected rhesus macaques, host genes influence viral containment and hence the duration of the disease-free latency period. our knowledge of the rhesus monkey immunogenetics, however, is limited. in this study, we describe partial cdna sequences of five newly discovered rhesus macaque (mamu) class i alleles and pcr-based typing techniques for the novel and previously published mhc class i alleles. using 15 primer pairs for pcr-based typing and dna sequence analysis ... | 2002 | 12218167 |
| endometrial hyperplasia, polyps, and adenomyosis associated with unopposed estrogen in rhesus monkeys (macaca mulatta). | the purpose of this study was to evaluate the effects of estrogen and progesterone on the vaginal mucosa and their role in vaginal transmission of simian immunodeficiency virus. incidentally, endometrial hyperplasia was observed in estrogen-treated monkeys at necropsy. six adult female rhesus monkeys (macaca mulatta) were ovariectomized and 120 days later received two subcutaneous implants, each containing 200 mg estradiol. the animals were sacrificed 17-27 months later and the uterus examined a ... | 2002 | 12243467 |
| emergence of cytotoxic t lymphocyte escape mutations in nonpathogenic simian immunodeficiency virus infection. | although ctl escape has been well documented in pathogenic simian immunodeficiency virus (siv) infection, there is no information on ctl escape in nonpathogenic siv infection in nonhuman primate hosts like the sooty mangabeys. ctl responses and sequence variation in the siv nef gene were evaluated in one sooty mangabey and one rhesus macaque inoculated together with the same stock of cloned sivmac239. each animal developed an immunodominant response to a distinct ctl epitope in nef, aa 157-167 i ... | 2001 | 11745337 |
| identification of protein kinases dysregulated in cd4(+) t cells in pathogenic versus apathogenic simian immunodeficiency virus infection. | human immunodeficiency virus infection in humans and simian immunodeficiency virus (siv) infection in rhesus macaques (rm) leads to a generalized loss of immune responses involving perturbations in t-cell receptor (tcr) signaling. in contrast, naturally siv-infected sooty mangabeys (sm) remain asymptomatic and retain immune responses despite relatively high viral loads. however, siv infection in both rm and sm led to similar decreases in tcr-induced lck phosphorylation. in this study, a protein ... | 2001 | 11689610 |
| conserved, n-linked carbohydrates of human immunodeficiency virus type 1 gp41 are largely dispensable for viral replication. | the transmembrane subunit (tm) of human immunodeficiency virus type 1 (hiv-1) envelope protein contains four well-conserved sites for the attachment of n-linked carbohydrates. to study the contribution of these n-glycans to the function of tm, we systematically mutated the sites individually and in all combinations and measured the effects of each on viral replication in culture. the mutants were derived from shiv-kb9, a simian immunodeficiency virus/hiv chimera with an envelope sequence that or ... | 2001 | 11689624 |
| impairment of gag-specific cd8(+) t-cell function in mucosal and systemic compartments of simian immunodeficiency virus mac251- and simian-human immunodeficiency virus ku2-infected macaques. | the identification of several simian immunodeficiency virus mac251 (siv(mac251)) cytotoxic t-lymphocyte epitopes recognized by cd8(+) t cells of infected rhesus macaques carrying the mamu-a*01 molecule and the use of peptide-major histocompatibility complex tetrameric complexes enable the study of the frequency, breadth, functionality, and distribution of virus-specific cd8(+) t cells in the body. to begin to address these issues, we have performed a pilot study to measure the virus-specific cd8 ... | 2001 | 11689630 |
| mucosal aids vaccine reduces disease and viral load in gut reservoir and blood after mucosal infection of macaques. | given the mucosal transmission of hiv-1, we compared whether a mucosal vaccine could induce mucosal cytotoxic t lymphocytes (ctls) and protect rhesus macaques against mucosal infection with simian/human immunodeficiency virus (shiv) more effectively than the same vaccine given subcutaneously. here we show that mucosal ctls specific for simian immunodeficiency virus can be induced by intrarectal immunization of macaques with a synthetic-peptide vaccine incorporating the lt(r192g) adjuvant. this r ... | 2001 | 11726972 |
| enhanced activation of rhesus t cells by vectors encoding a triad of costimulatory molecules (b7-1, icam-1, lfa-3). | since the rhesus is often used as a "gatekeeper" model for the evaluation of malaria and simian immunodeficiency virus (siv)/hiv vaccines, the identification of strategies to enhance the activation of rhesus t cells would potentially aid in the generation of more potent vaccines directed against these infectious agents. several molecules normally found on the surface of professional human apcs are capable of providing the second signals critical for t cell activation: b7-1 (cd80), icam-1 (cd54), ... | 2001 | 11738738 |
| simian immunodeficiency virus (siv)-specific cytotoxic t lymphocytes in gastrointestinal tissues of chronically siv-infected rhesus monkeys. | although systemic virus-specific cytotoxic t lymphocyte (ctl) responses are of critical importance in controlling virus replication in individuals infected with human immunodeficiency virus 1 (hiv-1), little is known about this immune response in the gastrointestinal (gi) tract. this study investigated the gi tract ctl response in a nonhuman primate model for hiv-1 infection, simian immunodeficiency virus (siv)-infected rhesus monkeys. lymphocytes from duodenal pinch biopsy specimens were obtain ... | 2001 | 11739183 |
| identification of enteropathogenic escherichia coli in simian immunodeficiency virus-infected infant and adult rhesus macaques. | enteropathogenic escherichia coli (epec) was recognized as a common opportunistic pathogen of simian immunodeficiency virus-infected rhesus macaques (macaca mulatta) with aids. retrospective analysis revealed that 27 of 96 (28.1%) animals with aids had features of epec infection, and epec was the most frequent pathogen of the gastrointestinal tract identified morphologically. in 7.3% of animals dying with aids, epec represented the sole opportunistic agent of the gastrointestinal tract at death. ... | 2001 | 11230413 |
| detection of viral rna in cd4(-)cd8(-) and cd4(-)cd8(+) lymphocytes in vivo in rhesus monkeys infected with simian immunodeficiency virus of macaques. | a definition of the specific cell types that support hiv replication early in the course of infection will be important for understanding aids pathogenesis and designing strategies for preventing infection. observations have indicated that the population of lymphocytes susceptible to productive infection extends beyond activated cd4(+) t cells. to explore this issue, we have employed laser scanning cytometry technology and the techniques of lymphocyte surface immunophenotyping followed by fluore ... | 2001 | 11242521 |
| immunohistochemical detection of simian immunodeficiency virus (siv) in rectal mucosa of experimentally infected rhesus macaques (macaca mulatta). | experimental simian immunodeficiency virus (siv) infection is the most appropriate animal model for human hiv infection. eight male rhesus monkeys (macaca mulatta) were intravenously or intrarectally infected with sivmac251/mpbmc to comparatively investigate the distribution and spread of the virus within the rectum during the course of the disease. siv-positive cells were immunohistochemically detected in rectal biopsies obtained at days 3 and 7 and week 2, 4 and 12 postinfection. siv-expressin ... | 2001 | 11252630 |
| the tcr repertoire of an immunodominant cd8+ t lymphocyte population. | the tcr repertoire of an epitope-specific cd8(+) t cell population remains poorly characterized. to determine the breadth of the tcr repertoire of a cd8(+) t cell population that recognizes a dominant epitope of the aids virus, the cd8(+) t cells recognizing the tetrameric mamu-a*01/p11c(,cm) complex were isolated from simian immunodeficiency virus (siv)-infected mamu-a*01(+) rhesus monkeys. this cd8(+) t cell population exhibited selected usage of tcr v beta families and complementarity-determi ... | 2001 | 11254709 |
| route of simian immunodeficiency virus inoculation determines the complexity but not the identity of viral variant populations that infect rhesus macaques. | a better understanding of the host and viral factors associated with human immunodeficiency virus (hiv) transmission is essential to developing effective strategies to curb the global hiv epidemic. here we used the rhesus macaque-simian immunodeficiency virus (siv) animal model of hiv infection to study the range of viral genotypes that are transmitted by different routes of inoculation and by different types of viral inocula. analysis of transmitted variants was undertaken in outbred rhesus mac ... | 2001 | 11264364 |
| ability of the v3 loop of simian immunodeficiency virus to serve as a target for antibody-mediated neutralization: correlation of neutralization sensitivity, growth in macrophages, and decreased dependence on cd4. | to better define the effects of sequence variation and tropism on the ability of the simian immunodeficiency virus sivmac v3 loop to act as a target of antibody-mediated neutralization, a series of experiments were performed. three siv strains, sivmac239, sivmac316, and sivmac155/t3, each with defined differences in env sequence and tropism, were used to construct a panel of viruses chimeric for a portion of envelope that includes the v2 and v3 regions. peptides with sequences corresponding to t ... | 2001 | 11264379 |
| enhancement of central nervous system pathology in early simian immunodeficiency virus infection by dopaminergic drugs. | human immunodeficiency virus infection (hiv) at late stages of the disease is accompanied by neurological complications, including motor, behavioral and cognitive impairment. using simian immunodeficiency virus (siv)-infected rhesus monkeys, an animal model of hiv infection, we found that during the asymptomatic siv infection dopamine (da) deficits are early components of central nervous system (cns) dysfunction. to investigate the role of the da system in siv infection and to restore the da def ... | 2001 | 11271377 |
| quintuple deglycosylation mutant of simian immunodeficiency virus sivmac239 in rhesus macaques: robust primary replication, tightly contained chronic infection, and elicitation of potent immunity against the parental wild-type strain. | we previously generated a mutant of simian immunodeficiency virus (siv) lacking 5 of a total of 22 n-glycans in its external envelope protein gp120 with no impairment in viral replication capability and infectivity in tissue culture cells. here, we infected rhesus macaques with this mutant and found that it also replicated robustly in the acute phase but was tightly, though not completely, contained in the chronic phase. thus, a critical requirement for the n-glycans for the full extent of chron ... | 2001 | 11287551 |
| construction and in vitro properties of a series of attenuated simian immunodeficiency viruses with all accessory genes deleted. | we have generated simplified simian immunodeficiency virus (siv) constructs lacking the nef, vpr, vpx, vif, tat, and rev genes (delta6 viruses). to accomplish this, we began with an infectious molecular clone of siv, i.e. sivmac239, and replaced the deleted segments with three alternate elements: (i) a constitutive transport element (cte) derived from simian retrovirus type 1 to replace the rev/rev-responsive element (rre) posttranscriptional regulation system, (ii) a chimeric siv long terminal ... | 2001 | 11287555 |
| in vivo t-lymphocyte activation and transient reduction of viral replication in macaques infected with simian immunodeficiency virus. | while it is well established that cellular activation can increase human immunodeficiency virus (hiv) replication in t lymphocytes, it is also clear that both activated cd8+ and cd4+ t lymphocytes mediate anti-hiv activity. to assess the relative importance of these contrary effects on hiv replication in vivo, we evaluated the consequences of mycobacterium bovis bcg and staphylococcal enterotoxin b (seb) inoculation in vivo in rhesus monkeys chronically infected with simian immunodeficiency viru ... | 2001 | 11312343 |
| expression of the interleukin-18 gene from rhesus macaque by the simian immunodeficiency virus does not result in increased viral replication. | interleukin-18 (il-18), previously known as interferon-gamma (ifn-gamma)-inducing factor (igif), is a proinflammatory cytokine expressed by activated macrophages that acts in synergy with il-12 as an important amplifying factor for ifn-gamma production and th1 development. to study the effect of il-18 on a lentiviral infection, we cloned the il-18 gene from a rhesus macaque and constructed replication-competent simian immunodeficiency virus (siv) that expressed either the precursor pro-il-18 (si ... | 2001 | 11331040 |
| in vivo attenuation of simian immunodeficiency virus by disruption of a tyrosine-dependent sorting signal in the envelope glycoprotein cytoplasmic tail. | attenuated simian immunodeficiency viruses (sivs) have been described that produce low levels of plasma virion rna and exhibit a reduced capacity to cause disease. these viruses are particularly useful in identifying viral determinants of pathogenesis. in the present study, we show that mutation of a highly conserved tyrosine (tyr)-containing motif (yxxphi) in the envelope glycoprotein (env) cytoplasmic tail (amino acids yrpv at positions 721 to 724) can profoundly reduce the in vivo pathogenici ... | 2001 | 11119598 |
| relative resistance in the development of t cell anergy in cd4+ t cells from simian immunodeficiency virus disease-resistant sooty mangabeys. | despite high viral loads, t cells from sooty mangabey (sm) monkeys that are naturally infected with siv but remain clinically asymptomatic, proliferate and demonstrate normal ag-specific memory recall cd4(+) t cell responses. in contrast, cd4(+) t cells from rhesus macaques (rm) experimentally infected with siv lose ag-specific memory recall responses and develop immunological anergy. to elucidate the mechanisms for these distinct outcomes of lentiviral infection, highly enriched alloreactive cd ... | 2001 | 11123330 |
| cd8(+) lymphocytes from simian immunodeficiency virus-infected rhesus macaques recognize 14 different epitopes bound by the major histocompatibility complex class i molecule mamu-a*01: implications for vaccine design and testing. | it is becoming increasingly clear that any human immunodeficiency virus (hiv) vaccine should induce a strong cd8(+) response. additional desirable elements are multispecificity and a focus on conserved epitopes. the use of multiple conserved epitopes arranged in an artificial gene (or epigene) is a potential means to achieve these goals. to test this concept in a relevant disease model we sought to identify multiple simian immunodeficiency virus (siv)-derived cd8(+) epitopes bound by a single no ... | 2001 | 11134287 |
| macrophage are the principal reservoir and sustain high virus loads in rhesus macaques after the depletion of cd4+ t cells by a highly pathogenic simian immunodeficiency virus/hiv type 1 chimera (shiv): implications for hiv-1 infections of humans. | the highly pathogenic simian immunodeficiency virus/hiv type 1 (shiv) chimeric virus shiv(dh12r) induces a systemic depletion of cd4(+) t lymphocytes in rhesus monkeys during the initial 3-4 weeks of infection. nonetheless, high levels of viral rna production continue unabated for an additional 2-5 months. in situ hybridization and immunohistochemical analyses revealed that tissue macrophage in the lymph nodes, spleen, gastrointestinal tract, liver, and kidney sustain high plasma virus loads in ... | 2001 | 11136236 |
| dna vaccination of macaques with several different nef sequences induces multispecific t cell responses. | cd8(+) t lymphocytes play a key role in controlling viremia during primary human immunodeficiency virus-1 and in maintaining disease-free infection. it has recently been shown that dna immunization of rhesus monkeys can elicit strong, long-lived antigen-specific cytotoxic t lymphocyte (ctl) responses. in previous work, it was shown that macaque ctl responses to lipopeptide vaccination were directed against a limited number of epitopes. in the present study, we used the dna immunization approach ... | 2001 | 11145897 |
| persistence of pathogenic challenge virus in macaques protected by simian immunodeficiency virus sivmacdeltanef. | live attenuated simian immunodeficiency virus (siv) is the most efficient vaccine yet developed in monkey models of human immunodeficiency virus infection. in all successful vaccine trials, attenuation was achieved by inactivating at least the nef gene. we investigated some virological and immunological characteristics of five rhesus macaques immunized with a nef-inactivated sivmac251 molecular clone (sivmac251deltanef) and challenged 15 months later with the pathogenic sivmac251 isolate. three ... | 2001 | 11152522 |
| elicitation of high-frequency cytotoxic t-lymphocyte responses against both dominant and subdominant simian-human immunodeficiency virus epitopes by dna vaccination of rhesus monkeys. | increasing evidence suggests that the generation of cytotoxic t-lymphocyte (ctl) responses specific for a diversity of viral epitopes will be needed for an effective human immunodeficiency virus type 1 (hiv-1) vaccine. here, we determine the frequencies of ctl responses specific for the simian immunodeficiency virus gag p11c and hiv-1 env p41a epitopes in simian-human immunodeficiency virus (shiv)-infected and vaccinated rhesus monkeys. the p11c-specific ctl response was high frequency and domin ... | 2001 | 11160750 |
| mucosal exposure to subinfectious doses of siv primes gut-associated antibody-secreting cells and t cells: lack of enhancement by nonneutralizing antibody. | it has been suggested that the presence of immunoglobulin and complement receptors on rectal epithelium may facilitate the entry of hiv complexed to nonneutralizing antibody. we tested this hypothesis using simian immunodeficiency virus (siv) infection of rhesus macaques. first, in a pilot study, a nonneutralizing igg fraction of macaque anti-siv gp120 was shown to enhance the immunogenicity of siv envelope following rectal immunization. the same antibody was then mixed with a subinfectious dose ... | 2001 | 11162808 |
| novel, live attenuated simian immunodeficiency virus constructs containing major deletions in leader rna sequences. | we have constructed a series of simian immunodeficiency virus (siv) mutants containing deletions within a 97-nucleotide (nt) region of the leader sequence. deletions in this region markedly decreased the replication capacity in tissue culture, i.e., in both the c8166 and cemx174 cell lines, as well as in rhesus macaque peripheral blood mononuclear cells. in addition, these deletions adversely affected the packaging of viral genomic rna into virions, the processing of gag precursor proteins, and ... | 2001 | 11222701 |
| simian immunodeficiency virus (siv) infection of a rhesus macaque induces siv-specific cd8(+) t cells with a defect in effector function that is reversible on extended interleukin-2 incubation. | a vigorous expansion of antigen-specific cd8(+) t cells lacking apparent effector function was observed in a rhesus macaque acutely infected with the simian immunodeficiency virus (siv) strain sivmac239. antigen-specific cd8(+) t cells were identified using antigenic-peptide class i major histocompatibility complex tetramers. as many as 8.3% of cd8(+) cells recognized the mamu-a*01-associated siv epitope gag(181-189) (ctpydinqm); however, these cells demonstrated no effector function when presen ... | 2001 | 11222730 |
| immunogenicity of the extracellular domains of c-c chemokine receptor 5 and the in vitro effects on simian immunodeficiency virus or hiv infectivity. | the c-c chemokine receptor ccr5 serves an important function in chemotaxis of lymphocytes, monocytes, and dendritic cells. ccr5 is also the major coreceptor in most macrophage-tropic hiv-1 infections. immunization of rhesus macaques with a baculovirus-generated ccr5 construct or peptides derived from the sequences of the four extracellular domains of ccr5 elicited igg and iga abs, inhibition of siv replication, and cd4+ t cell proliferative responses to three of the extracellular domains of ccr5 ... | 2001 | 11390497 |
| simian immunodeficiency virus in kidney cell cultures from highly infected rhesus macaques (macaca mulatta). | trace amounts of simian immunodeficiency virus (siv) proviral dna were detected in monolayers of primary kidney cells from two rhesus macaques (macaca mulatta) heavily infected with the highly pathogenic strain sivmac251. there was no detectable infectious siv in the supernatant from the kidney cell cultures obtained from either monkey. however, infectious siv was rescued by co-culture of kidney cells with a permissive lymphoid cell line. macrophages, present in these cultures, may be the reserv ... | 2001 | 11405931 |
| perspectives on inducing efficient immune control of hiv-1 replication--a new goal for hiv therapeutics? | a goal for long-term therapy of hiv infection is immune control of virus replication rather than the somewhat unrealistic aim of complete viral elimination. this paper will review the evidence that the control of viral infection can be achieved by an active cd8+ t-cell-mediated response. | 2001 | 11424975 |
| simian immunodeficiency virus from mandrill (mandrillus sphinx) sivmnd experimentally infects human and nonhuman primate cells. | this study set out to characterize the features of experimental infection by simian immunodeficiency virus in mandrill (sivmnd) (mandrillus sphinx), cynomolgus macaque (macaca fascicularis), rhesus macaque (macaca mulatta), chimpanzee (pan troglodytes), african green monkey (cercopithecus pygerythrus), baboon (papio cynocephalus) and human cells. purified cells were exposed to a primary isolate of sivmnd grown in the infected mandrill peripheral blood mononuclear cells, and viral p27 gag antigen ... | 2001 | 11445446 |
| chronic myelocytic leukemia in a juvenile rhesus macaque (macaca mulatta). | myeloid neoplasia has been studied extensively in human beings but has not been reported in macaques. a 2-year-old female rhesus macaque that was experimentally exposed to lead as a neonate, was noted to have immature circulating myelocytic cells, including 1% blasts, and normocytic normochromic anemia on a blood sample obtained for monthly health monitoring. the animal was treated with hydroxyurea, blood transfusion, and recombinant human erythropoietin to reduce the leukocytosis and correct th ... | 2001 | 11451396 |
| an il-2/ig fusion protein influences cd4+ t lymphocytes in naive and simian immunodeficiency virus-infected rhesus monkeys. | the t cell-stimulatory cytokine interleukin 2 (il-2) is being evaluated as a therapeutic in the clinical settings of hiv infection and cancer. however, the clinical utility of il-2 may be mitigated by its short in vivo half-life, toxic effects, and high production costs. we show here that an il-2/ig fusion protein possesses il-2 immunostimulatory activity in vitro and a long in vivo half-life. il-2/ig treatment of healthy rhesus monkeys induced significant increases in cd4(+) t lymphocyte counts ... | 2001 | 11461674 |
| simian immunodeficiency virus in which nef and u3 sequences do not overlap replicates efficiently in vitro and in vivo in rhesus macaques. | the nef genes of human immunodeficiency virus and simian immunodeficiency virus (siv) overlap about 80% of the u3 region of the 3' long terminal repeat (ltr) and contain several essential cis-acting elements (here referred to as the tpi region): a t-rich region, the polypurine tract, and attachment (att) sequences required for integration. we inactivated the tpi region in the nef reading frame of the pathogenic sivmac239 clone (239wt) by 13 silent point mutations. to restore viral infectivity, i ... | 2001 | 11483759 |
| induction of disseminated mycobacterium avium in simian aids is dependent upon simian immunodeficiency virus strain and defective granuloma formation. | mycobacterium avium complex (mac) is the most common disseminated bacterial disease in patients infected by the human immunodeficiency virus. although murine models of disseminated mac exist, they are primarily based on underlying genetic susceptibilities and cannot adequately address the complex interactions that occur between host, mycobacteria, and immunosuppressive lentivirus. to address this problem we have developed an experimental system to co-inoculate rhesus macaques with the simian imm ... | 2001 | 11485927 |
| a common rhesus macaque mhc class i molecule which binds a cytotoxic t-lymphocyte epitope in nef of simian immunodeficiency virus. | 2001 | 11486280 | |
| simian immunodeficiency virus infections in vervet monkeys (clorocebus aethiops) at an australian zoo. | a number of monkey species, including african green monkeys and african vervet monkeys (chlorocebus aethiops), are frequently infected in the wild and in captivity with a simian immunodeficiency virus strain, sivagm, a primate lentivirus. up to 50% of african green monkeys are estimated to be infected with sivagm. siv strains are very closely related to hiv-2 strains, which are a cause of aids in humans, predominantly in western africa, although cases in australia have also been reported. it is ... | 2001 | 11491218 |
| rhesus macaque brain microvessel endothelial cells behave in a manner phenotypically distinct from umbilical vein endothelial cells. | activation of endothelium is a critical step in leukocyte recruitment to the cns and in development of neurological diseases, such as hiv-associated dementia. due to limited availability of early disease course data, it is important to develop in vitro models of the blood-brain barrier (bbb) that can be used to address these early events. no such model of the bbb has been established for the macaque. here, we characterize rhesus microvascular brain endothelial cells (mbec), comparing them with r ... | 2001 | 11498257 |
| expression of the simian epstein-barr virus-encoded latent membrane protein-1 in malignant lymphomas of siv-infected rhesus macaques. | during the course of simian immunodeficiency virus (siv) infection, nearly 15% of rhesus macaques (macaca mulatta) and up to 40% of cynomolgus macaques (macaca fascicularis) developed siv-associated non-hodgkin's lymphomas. most of these malignant lymphomas harbored lymphocryptoviruses, which are closely related to the human epstein-barr virus (ebv; herpesvirus m. mulatta and herpesvirus m. fascicularis). to characterize the oncogenic role of simian ebv infection for lymphomagenesis during siv i ... | 2001 | 11505452 |
| induction of simian immunodeficiency virus (siv)-specific ctl in rhesus macaques by vaccination with modified vaccinia virus ankara expressing siv transgenes: influence of pre-existing anti-vector immunity. | a major aim in aids vaccine development is the definition of strategies to stimulate strong and durable cytotoxic t lymphocyte (ctl) responses. here we report that simian immunodeficiency virus (siv)-specific ctl developed in 4/4 macaques following a single intramuscular injection of modified vaccinia virus ankara (mva) constructs expressing both structural and regulatory/accessory genes of siv. in two animals nef-specific responses persisted, but other responses diminished and new responses wer ... | 2001 | 11514732 |
| natural infection of wild-born mandrills (mandrillus sphinx) with two different types of simian immunodeficiency virus. | we found a novel primate lentivirus in mandrill (mandrillus sphinx). to clarify the evolutionary relationships and transmission patterns of human/simian immunodeficiency virus (hiv/siv), we screened blood samples from 30 wild-born healthy cameroonian mandrills. five (16.7%) of them were seropositive for siv. three siv strains were isolated from the five seropositive mandrills by cocultivation of their peripheral blood mononuclear cells (pbmcs) with pbmcs of rhesus macaques, a human t cell line ( ... | 2001 | 11522184 |
| characteristics of a pathogenic molecular clone of an end-stage serum-derived variant of simian immunodeficiency virus (siv(f359)). | end-stage simian immunodeficiency virus (siv) isolates are suggested to be the most fit of the evolved virulent variants that precipitate the progression to aids. to determine if there were common characteristics of end-stage variants which emerge from accelerated cases of aids, a molecular clone was derived directly from serum following in vivo selection of a highly virulent siv isolate obtained by serial end-stage passage in rhesus monkeys (macaca mulatta). this dominant variant caused a marke ... | 2001 | 11533196 |
| comparison of early plasma rna loads in different macaque species and the impact of different routes of exposure on siv/shiv infection. | various simian immunodeficiency virus (siv)sm/mac and simian/human immunodeficiency virus (shiv) strains are used in different macaque species to study aids pathogenesis, as well as to evaluate candidate vaccine and anti-retroviral drugs efficacy. in this study we investigated the effect of route of infection, species of macaques and nature of virus stock on early plasma viral rna load. we monitored the plasma rna concentrations of 63 rhesus (macaca mulatta) and cynomolgus macaques (macaca fasci ... | 2001 | 11555139 |
| early immunologic events in mucosal and systemic lymphoid tissues after intrarectal inoculation with simian immunodeficiency virus. | the pathogenesis of human immunodeficiency virus transmission via the rectal route remains poorly understood. by use of the simian immunodeficiency virus (siv)-rhesus macaque model and intrarectal inoculation with pathogenic sivmac251, a significant increase was found in the percentage of cd11b(+) monocyte lineage cells expressing hla-dr and/or b7-2 in local and peripheral immune inductive sites, but not in mucosal effector sites, as early as 7 days after inoculation and up to 50 days after inoc ... | 2001 | 11574915 |
| a commonly recognized simian immunodeficiency virus nef epitope presented to cytotoxic t lymphocytes of indian-origin rhesus monkeys by the prevalent major histocompatibility complex class i allele mamu-a*02. | the ability to monitor vaccine-elicited cd8(+) cytotoxic t-lymphocyte (ctl) responses in simian immunodeficiency virus (siv)- and simian-human immunodeficiency virus (shiv)-infected rhesus monkeys has been limited by our knowledge of viral epitopes predictably presented to those lymphocytes by common rhesus monkey mhc class i alleles. we now define an siv and shiv nef ctl epitope (ytsgpgiry) that is presented to cd8(+) t lymphocytes by the common rhesus monkey mhc class i molecule mamu-a*02. all ... | 2001 | 11581386 |
| role of cd8(+) lymphocytes in control of simian immunodeficiency virus infection and resistance to rechallenge after transient early antiretroviral treatment. | transient antiretroviral treatment with tenofovir, (r)-9-(2-phosphonylmethoxypropyl)adenine, begun shortly after inoculation of rhesus macaques with the highly pathogenic simian immunodeficiency virus (siv) isolate sivsme660, facilitated the development of siv-specific lymphoproliferative responses and sustained effective control of the infection following drug discontinuation. animals that controlled plasma viremia following transient postinoculation treatment showed substantial resistance to s ... | 2001 | 11581387 |
| emergence and kinetics of simian immunodeficiency virus-specific cd8(+) t cells in the intestines of macaques during primary infection. | in this report, three mamu-a*01(+) rhesus macaques were examined to compare the emergence of simian immunodeficiency virus (siv)-specific cd8(+) t cells in the intestines and blood in early siv infection using a major histocompatibility complex class i tetramer complexed with the gag(181-189) peptide. fourteen days after intravenous inoculation with sivmac251, large numbers of siv gag(181-189)-specific cd8(+) t cells were detected in the intestinal mucosa (3.1 to 11.5% of cd3(+) cd8(+) lymphocyt ... | 2001 | 11581423 |
| efficient class i major histocompatibility complex down-regulation by simian immunodeficiency virus nef is associated with a strong selective advantage in infected rhesus macaques. | substitution of y223f disrupts the ability of simian immunodeficiency virus (siv) nef to down-modulate major histocompatibility complex (mhc) class i from the cell surface but has no effect on other nef functions, such as down-regulation of cd4, cd28, and cd3 cell surface expression or stimulation of viral replication and enhancement of virion infectivity. inoculation of three rhesus macaques with the sivmac239 y223f-nef variant revealed that this point mutation consistently reverts and that nef ... | 2001 | 11581427 |