| spermatogenesis and hormone levels in rhesus macaques inoculated with simian immunodeficiency virus. | the presence of sperm in testicular tissue of rhesus macaques that died as a result of infection with simian immunodeficiency virus (siv) was related to age and body weight. depressed testosterone levels were not associated with elevated lh levels. the data suggest that azoospermia in the siv-infected macaques was due to cachexia and not a direct effect of virus on the testis, supporting a similar hypothesis regarding azoospermia in men infected with human immunodeficiency virus. | 1993 | 8289223 |
| correlation between fusogenicity of synthetic modified peptides corresponding to the nh2-terminal extremity of simian immunodeficiency virus gp32 and their mode of insertion into the lipid bilayer: an infrared spectroscopy study. | the amino-terminal extremity of the simian immunodeficiency virus (siv) transmembrane protein (gp32) has been shown to play a pivotal role in cell-virus fusion and syncytium formation. we provide here evidence of a correlation between the structure and orientation of the modified siv fusion peptide after insertion into the lipid membrane and its fusogenic activity. the sequence of the wild-type siv peptide has been modified in such a way that the calculated angles of insertion correspond to an o ... | 1994 | 8289343 |
| truncation of the cytoplasmic domain of the simian immunodeficiency virus envelope glycoprotein alters the conformation of the external domain. | we previously reported that truncation of the cytoplasmic domain of the macaque simian immunodeficiency virus sivmac239 envelope glycoprotein enhanced its ability to induce cell fusion in a variety of cell lines. in the present study, we examined the expression of the full-length and truncated sivmac239 envelope glycoprotein complex on cell surfaces. using a membrane-impermeable reagent to biotinylate proteins on cell surfaces followed by immunoprecipitation, we found that under conditions in wh ... | 1994 | 8289362 |
| characterization of human immunodeficiency virus type 1-specific cytotoxic t lymphocyte clones isolated during acute seroconversion: recognition of autologous virus sequences within a conserved immunodominant epitope. | virus-specific cytotoxic t lymphocytes (ctl) are involved in protective immunity to many virus infections. it has recently been shown that ctl are detectable early during primary infection with the primate lentiviruses, human immunodeficiency virus type 1 (hiv-1) and simian immunodeficiency virus. to better characterize the ctl response during acute hiv-1 infection, hiv-1-specific ctl clones were generated from two patients during symptomatic hiv-1 seroconversion. these ctl clones demonstrated s ... | 1994 | 8294860 |
| severe pulmonary pneumocystosis in simian acquired immunodeficiency syndrome induced by simian immunodeficiency virus: its characterization by the polymerase-chain-reaction method and failure of experimental transmission to immunodeficient animals. | pneumocystis carinii (pc) infection was observed in three of five rhesus monkeys infected with simian immunodeficiency virus (sivmac251). they showed severe symptoms similar to those associated with human acquired immunodeficiency syndrome (aids). histopathology revealed severe pulmonary pneumocystosis in one of three pc-positive monkeys, and anti-pc antibodies were detected in sera from two of the three monkeys. localization of pc organisms in various organs of the monkeys was examined by the p ... | 1993 | 8295897 |
| new advances in vaccine delivery systems. | successful application of the next generation of vaccines will require that protection be induced with a minimal number of administrations, and that a practical approach to inducing immunity at mucosal surfaces be developed. for these reasons, vaccine-containing microspheres were formulated from the biodegradable and biocompatible copolymer poly(dl-lactide-co-glycolide) [dl-plg]. subcutaneous immunization of mice with 1- to 10-microns microspheres containing a toxoid vaccine of staphylococcal en ... | 1993 | 8303306 |
| association of interleukin-6 in the pathogenesis of acutely fatal sivsmm/pbj-14 in pigtailed macaques. | infection with a variant of simian immunodeficiency virus (sivsmm/pbj-14) causes death in juvenile pigtailed macaques within 8 days of infection. the primary pathology is localized to the lymphoid tissues of the gut and spleen. although the virus is present, the lesions are most consistent with acute reactive inflammation. we studied the serum and tissues for evidence of acute cytokine production often associated with acute inflammation. one factor, il-6, was found to be significantly increased ... | 1993 | 8312054 |
| in vitro spontaneous production of anti-siv antibodies is a reliable tool in the follow-up of protection of siv-vaccinated monkeys. | to assess the reliability of the spontaneous in vitro synthesis of simian immunodeficiency virus (siv)-specific antibodies as a marker in the monitoring of protection in siv-vaccinated animals, macaca fascicularis monkeys were immunized with formalin-inactivated sivmac251 or sivmac251/32h, and challenged with human-derived (sivmac251/32h) or monkey-derived live siv. as judged by virus isolation and polymerase chain reaction (pcr) techniques, immunized animals were protected against human-derived ... | 1993 | 8312055 |
| association of host cell surface adhesion receptors and other membrane proteins with hiv and siv. | we have developed a mab-based capture assay to study the association of host cell membrane proteins with hiv and siv. class i and ii mhc proteins were found to be associated with hiv as previously described. in addition to these molecules a number of other host molecules were found to be acquired by hiv, including cd71, cd63, cd43, and cd8. we have demonstrated that the major leukocyte adhesion receptors lfa-1 (cd11a/cd18) and cd44 are also associated with hiv. the level of surface expression of ... | 1993 | 8312057 |
| recombinant-expressed virus-like particle pseudotypes as an approach to vaccine development. | coinfection of a cell with two different types of enveloped virus can result in the generation of infectious virus particle pseudotypes having the internal proteins of one virus and the envelope proteins of the other virus. vaccinia virus recombinants expressing either non-infectious virus-like particles of simian immunodeficiency virus (siv) or the gd2 glycoprotein of herpes simplex virus were used to coinfect cells to determine if virus-like particle pseudotypes would be formed. sucrose gradie ... | 1993 | 8322492 |
| a pcr-derived library of random point mutations within the v3 region of simian immunodeficiency virus. | oligonucleotide primers corresponding to variable region 3 (v3) of simian immunodeficiency virus (siv) were randomly mutagenized during synthesis by doping each of the four nucleoside phosphoramidites with a small amount of the other three. pcr was then used to incorporate the altered sequences into larger, clonable dna fragments by spliced overlap extension (soe). with the composition of the phosphoramidites used, 53 of the 100 clones analyzed were unique, having one or more point mutation with ... | 1993 | 8324503 |
| inhibition of the replication of native and 3'-azido-2',3'-dideoxythymidine (azt)-resistant simian immunodeficiency virus (siv) by 3-nitrosobenzamide. | the 3-nitrosobenzamide (noba) drug abolishes siv replication sharply at 20 microm concentration when cem x 174 cells are preincubated for 1 h with the drug prior to viral infection. treatment of cem x 174 cells with 20 microm noba resulted in the inhibition of the synthesis of the dna sequence coding for the gag gene, as determined by the pcr technique. cell viability was directly proportional to the antiviral action of noba. replication of azt-resistant siv 23740 in mmu 23740 cells in vitro was ... | 1993 | 8325360 |
| nef from primary isolates of human immunodeficiency virus type 1 suppresses surface cd4 expression in human and mouse t cells. | the human immunodeficiency virus type 1 (hiv-1) nef gene was originally described as a negative regulator of transcription from the viral long terminal repeat promoter. this observation has been disputed, and the function of nef remains unclear. in vivo experiments have indicated that an intact nef gene is required for disease progression in macaques infected with simian immunodeficiency virus, suggesting a role for nef in the pathogenesis of aids. we and others have previously shown that expres ... | 1993 | 8331733 |
| anti-cellular antibodies in sera from vaccinated macaques can induce complement-mediated virolysis of human immunodeficiency virus and simian immunodeficiency virus. | previous studies show that immunization of macaques with preparations of either human immunodeficiency virus (hiv) or simian immunodeficiency virus (siv) that has been produced in human cells can induce antibodies against both viral antigens and human cellular antigens. this is due to the fact that certain host cell antigens are carried along with the virus during the purification process. the current series of experiments were performed to determine whether these anti-cellular antibodies can ac ... | 1993 | 8337824 |
| in vitro and in vivo infection of rhesus monkey microglial cells by simian immunodeficiency virus. | the observation that microglial cells in brain tissue are probably a major target for human immunodeficiency virus (hiv) infection has raised interest in the pathogenic role of this cell population for the development of neuro-aids. since it is very difficult to obtain microglia from normal or diseased human brain we studied microglial cells isolated from fresh brain tissue of uninfected and simian immunodeficiency virus (siv) infected rhesus monkeys (macacca mulatta) in comparison to peripheral ... | 1993 | 8337831 |
| [screening of anti-simian immunodeficiency virus (siv) drugs from chinese medicinal herbs]. | the inhibitory activities of more than 40 species of chinese medicinal herbs or their single chemical components against simian immunodeficiency virus (siv) have been studied. the study revealed that four species of the medicinal herbs and a single chemical component had more than 50% inhibition of siv antigen expression and five other herbs' inhibitory rate of siv antigen expression was between 30-50%. the results showed that chinese medicinal herbs could inhibit the siv activity. | 1993 | 8339037 |
| serum inhibitors precede the development of saids. | rhesus macaque monkeys infected with the simian immunodeficiency virus develop a syndrome mimicking aids in humans. we have demonstrated previously that sera from individuals infected with human immunodeficiency virus type 1 inhibit the proliferation of lymphocytes from healthy noninfected subjects and that this phenomenon is associated with the development of clinical aids. we have also shown that sera from monkeys infected with siv also have such inhibitors. in this body of work, we attempted ... | 1993 | 8340901 |
| transcomplementation of simian immunodeficiency virus rev with human t-cell leukemia virus type i rex. | a molecular clone of the simian immunodeficiency virus sivsmm isolate pbj14, lacking the atg initiation codon for rev protein (pbj-1.5), did not produce virus or large unspliced or singly spliced viral rna upon transfection of hela cells. low but significant levels of virus and large viral rna production were observed upon transfection of pbj-1.5 into hela rev cells expressing the rev gene of human immunodeficiency virus type 1. furthermore, abundant virus and large viral rna production occurred ... | 1993 | 8350422 |
| prevention of transmission of simian immunodeficiency virus from vaccinated macaques that developed transient virus infection following challenge. | macaque immunization with a mixture of four siv peptides from conserved hydrophilic envelope regions has been shown to prevent virus persistence following challenge with sivmne/e11s. data shown here demonstrate that lymph node cells from all vaccinated monkeys and peripheral blood lymphocytes from one of the vaccinees were positive in a siv-pol 'nested' polymerase chain reaction (pcr) amplification analysis. however, by 37 months after infection, all immunized monkeys were healthy while two of t ... | 1993 | 8356845 |
| alterations of thymus cortical epithelium and interdigitating dendritic cells but no increase of thymocyte cell death in the early course of simian immunodeficiency virus infection. | the role of the thymus in the pathogenesis of simian acquired immunodeficiency syndrome was investigated in 18 juvenile rhesus monkeys (macaca mulatta). the thymus was infected from the first week post-sivmac inoculation, but the amount of virus-positive cells was very low (< 1 in 10(4) t cells) as demonstrated by polymerase chain reaction and in situ hybridization. first morphological alteration was a narrowing of the cortex at 12 and 24 wpi. morphometry revealed no increase of pyknotic t cells ... | 1993 | 8362972 |
| protection of monkeys by a split vaccine against sivmac depends upon biological properties of the challenge virus. | to investigate the role of the anti-cellular immune response in the protection of rhesus macaques against infection with the simian immunodeficiency virus sivmac. to determine the biological differences between siv challenge stocks grown either on human t-cell lines or on monkey peripheral blood mononuclear cells (mpbmc). | 1993 | 8363756 |
| inhibition of human immunodeficiency virus type 1 replication by regulated expression of a polymeric tat activation response rna decoy as a strategy for gene therapy in aids. | we are investigating a strategy for somatic gene therapy to treat human immunodeficiency virus type 1 (hiv-1) infection by intracellular expression of an rna decoy and a ribozyme. the rna decoy, consisting of polymeric tat activation response elements (tars), is designed to compete for tat binding in an equilibrium with viral tar rna, thereby inhibiting viral replication. the expression of polymeric tar is regulated by the hiv long terminal repeat (ltr) and transcriptional activation is dependen ... | 1993 | 8367455 |
| viral determinants of simian immunodeficiency virus (siv) virulence in rhesus macaques assessed by using attenuated and pathogenic molecular clones of sivmac. | to identify viral determinants of simian immunodeficiency virus (siv) virulence, two pairs of reciprocal recombinants constructed from a pathogenic (sivmac239) and a nonpathogenic (sivmac1a11) molecular clone of siv were tested in rhesus macaques. a large 6.2-kb fragment containing gag, pol, env, and the regulatory genes from each of the cloned (parental) viruses was exchanged to produce one pair of recombinant viruses (designated sivmac1a11/239gag-env/1a11 and sivmac239/1a11gag-env/239 to indic ... | 1993 | 8371353 |
| evidence of horizontal transmission of pneumocystis carinii pneumonia in simian immunodeficiency virus-infected rhesus macaques. | this retrospective study used sensitive immunohistochemical methods to detect pneumocystis carinii infections in fixed lung tissues collected from 107 simian immunodeficiency virus (siv)-infected and 10 noninfected rhesus macaques during a 4-year period. p. carinii were detected in 51% of 85 terminally ill siv-infected macaques but in only 2 of 22 macaques killed at earlier stages of siv infection. p. carinii were not detected in any siv-infected macaques held in isolators or in uninfected contr ... | 1993 | 8376830 |
| differences in the b and t cell immune response to the envelope glycoprotein 130 (gp130) of the macaque strain of simian immunodeficiency virus (sivmac), induced by immunization of rhesus macaques with virus-derived or vaccinia virus-expressed gp130. | rhesus macaques were immunized with purified virus-derived simian immunodeficiency virus of macaques (sivmac) 251/32h glycoprotein 130 (gp130) or primed with recombinant vaccinia virus (vv) expressing the env gene of the sivmac bk28 clone and boosted subsequently with virus-derived gp130. high antibody titres of at least 10(4) against recombinant gp140 were induced with both vaccines. analysis of the antibody specificity with a peptide elisa revealed that different linear epitopes were recognize ... | 1993 | 8376957 |
| lymphoid follicles in cynomolgus monkeys after infection with simian immunodeficiency virus. | | 1993 | 8379403 |
| simian immunodeficiency virus (siv) induced alterations of thymus idcs. | | 1993 | 8379421 |
| infection with the human immunodeficiency virus type 2. | to review the clinical, epidemiologic, and biological features of infection with the human immunodeficiency virus type 2 (hiv-2). | 1993 | 8380244 |
| importance of vpr for infection of rhesus monkeys with simian immunodeficiency virus. | the importance of the vpr gene for simian immunodeficiency virus (siv) replication, persistence, and disease progression was examined by using the infectious pathogenic molecular clone called sivmac239. the atg start codon of the vpr gene was converted to ttg by site-specific mutagenesis. the constructed vpr- mutant virus is identical with the parental sivmac239/nef-stop virus with the exception of this one nucleotide. these viruses replicated with similar kinetics and to similar extents in rhes ... | 1993 | 8380472 |
| antiretroviral activities of protease inhibitors against murine leukemia virus and simian immunodeficiency virus in tissue culture. | rationally designed synthetic inhibitors of retroviral proteases inhibit the processing of viral polyproteins in cultures of human immunodeficiency virus type 1 (hiv-1)-infected t lymphocytes and, as a result, inhibit the infectivity of hiv-1 for such cultures. the ability of hiv-1 protease inhibitors to suppress replication of the c-type retrovirus rauscher murine leukemia virus (r-mulv) and the hiv-related lentivirus simian immunodeficiency virus (siv) was examined in plaque reduction assays a ... | 1993 | 8381640 |
| a distinct african lentivirus from sykes' monkeys. | asymptomatic infection with simian immunodeficiency virus (siv) has been demonstrated in african sykes' monkeys (cercopithecus mitis albogularis), and virus isolation confirmed infection with a novel siv from sykes' monkeys (sivsyk). macaques inoculated with sivsyk became persistently infected but remained clinically healthy. we utilized polymerase chain reaction amplification to generate a full-length, infectious molecular clone of sivsyk. the genome organization of sivsyk is similar to that of ... | 1993 | 8382307 |
| lentivirus envelope sequences and proviral genomes are stabilized in escherichia coli when cloned in low-copy-number plasmid vectors. | a promoter-selection vector (pkk232-8) was used to identify sequences with strong escherichia coli promoter activity positioned near the start of the envelope-encoding genes (env) of two lentiviruses, simian immunodeficiency virus (siv) and equine infectious anemia virus (eiav). for eiav, cloning the cryptic promoter sequences together with downstream sequences encoding the envelope glycoprotein (gp90) in moderate- to high-copy-number (hcn) plasmid vectors, such as pbr322 or puc, resulted in rea ... | 1993 | 8382658 |
| inhibition of cellular activation of retroviral replication by cd8+ t cells derived from non-human primates. | to test the hypothesis that cd8+ t cells inhibit viral replication at the level of cellular activation, an epstein-barr virus (ebv)-transformed cell line (fec1) from a simian immunodeficiency virus (siv)-seropositive sooty mangabey monkey was transfected with a human cd4 gene and shown to be replication-competent for hiv-1, hiv-2 and siv. utilizing a dual-chamber culture system, it was found that inhibition of viral replication can be mediated by a soluble factor. the fec1 cell line was transien ... | 1993 | 8383022 |
| immunization with lentivirus-like particles elicits a potent siv-specific recall cytotoxic t-lymphocyte response in rhesus monkeys. | an effective acquired immunodeficiency syndrome (aids) vaccine should be capable of eliciting human immunodeficiency virus (hiv)-specific cytotoxic t-lymphocyte (ctl) responses. we have explored the use of lentivirus-like particles produced in mammalian cells infected with a recombinant vaccinia virus to immunize for the induction of ctl in the simian immunodeficiency virus (siv)/rhesus monkey model for aids. siv-like particles in a threonyl-mdp-based adjuvant did not elicit a high frequency of ... | 1993 | 8384466 |
| analysis of the rhesus cytomegalovirus immediate-early gene promoter. | a cytomegalovirus (cmv) isolate has been recovered from a rhesus macaque (macaca mulatta) experimentally infected with simian immunodeficiency virus. the full-length immediate-early gene (ie) was cloned from a genomic library of this primary rhesus cmv isolate (rhcmv) using the african green monkey (agm) cmv ie gene as probe. the promoter region and the first non-coding exon of the rhcmv ie gene have been sequenced. nucleotide sequence comparisons from positions -733 to +625 (relative to the sta ... | 1993 | 8389084 |
| conserved t-cell receptor repertoire in simian immunodeficiency virus-infected rhesus monkeys. | studies to assess the possibility that the hiv may encode a superantigen that plays a role in the depletion of functional cd4+ lymphocytes in the infected individual have yielded discrepant results. the problem in performing conclusive examinations of this issue may be attributed, at least in part, to the difficulty of prospectively studying individuals from before their infection until the time of profound cd4+ lymphocyte loss. to determine whether the aids virus deletes particular subpopulatio ... | 1993 | 8393899 |
| simian immunodeficiency virus-specific cytotoxic t lymphocytes in rhesus monkeys: characterization and vaccine induction. | an effective hiv vaccine should be capable of eliciting virus-specific cytotoxic t lymphocytes (ctl). we have characterized the cellular and molecular features of a simian immunodeficiency virus of macaques (sivmac) gag-specific ctl response in rhesus monkeys. we have shown that sivmac-infected rhesus monkeys expressing the major histocompatibility complex (mhc) class i molecule mamu-a*01 develop a sivmac gag-specific ctl response which recognizes a 9 amino acid fragment of the gag protein in as ... | 1993 | 8394161 |
| rates of amino acid change in the envelope protein correlate with pathogenicity of primate lentiviruses. | a spectrum of pathogenicity has been observed for primate lentiviruses in their natural hosts. for example, human immunodeficiency virus type 1 (hiv-1) is a potent etiologic agent for aids in man, whereas there is no evidence to date which indicates that simian immunodeficiency virus from african green monkeys (sivagm) causes immunodeficiency in agm. we measured the relative rates of amino acid change, as the ratio of the number of nonsynonymous to synonymous (silent) nucleotide substitutions, f ... | 1993 | 8395604 |
| a simple method to distinguish between simian immunodeficiency virus isolates by restriction analysis of pcr products. | a simple method to distinguish between simian immunodeficiency virus (siv) isolates of experimentally infected rhesus macaques is reported. peripheral blood mononuclear cells (pbmc) were prepared from a rhesus macaque infected with sivstm isolated originally from a stump-tailed macaque, or from a rhesus monkey infected with sivsm from a sooty mangabey monkey. pbmc were cocultivated with cem x 174 cells and a region of the siv envelope (env) gene was amplified by the polymerase chain reaction (pc ... | 1993 | 8397819 |
| genetic variation of the sivagm transmembrane glycoprotein in naturally and experimentally infected primates. | an in-frame stop codon prematurely truncating the transmembrane glycoprotein (tmp) is a common feature of many simian immunodeficiency virus, african green monkey strain (sivagm) molecular clones. the purpose of this study was to investigate the native form of the sivagm tmp in a naturally infected african green monkey (agm) and to study the fate of the stop codon following the passage of sivagm in primates. | 1993 | 8397939 |
| nonhuman primate models for aids. | historically, animal model systems have been important components of biomedical research, and the same is proving true for research directed at the human immunodeficiency virus (hiv) pandemic. the most relevant and valuable models for studying infection by hiv-1 and hiv-2 and progression to aids involve infection of nonhuman primates with hiv-1, hiv-2, or some of the closely related simian immunodeficiency viruses (sivs). the siv macaque model has proven valuable in all aspects of aids-related r ... | 1993 | 8399921 |
| expression of epstein-barr-virus-related nuclear antigens and b-cell markers in lymphomas of siv-immunosuppressed monkeys. | simian-immunodeficiency-virus(siv)-infected cynomolgus monkeys develop b-cell lymphomas in approximately one third of the cases. we have now studied the expression of cynomolgus-epstein-barr-virus(cyno-ebv) nuclear antigens in 13 cyno-ebv-carrying sivsm-associated monkey lymphomas and established cell lines from 3 of these tumors. immunoblots of cell lysates were probed with polyspecific and monospecific reagents directed against human eb-virus ebnai-6, and against the membrane protein lmpi. an ... | 1993 | 8406989 |
| identification of the gene encoding the major capsid protein of fish lymphocystis disease virus. | the gene encoding the major capsid protein (mcp) of fish lymphocystis disease virus (flounder isolate; flcdv-f) has been identified by pcr using oligonucleotide primers corresponding to different regions of the mcp of tipula iridescent virus (tiv), iridescent virus 22 (iv22) and chilo iridescent virus (civ). dna fragments of 0.4 kbp, 0.5 kbp and 0.27 kbp in size were amplified using oligonucleotide primers corresponding to amino acids (aa) 146 to 153 (primer 1) and 274 to 268 (primer 6), or aa 1 ... | 1993 | 8409939 |
| effect of dosing frequency on zdv prophylaxis in macaques infected with simian immunodeficiency virus. | the effect of dosing frequency on zidovudine (zdv) prophylaxis against simian immunodeficiency virus (siv) infection was examined in long-tailed macaque monkeys (macaca fascicularis). the results indicate that dosing frequency is extremely important for drug efficacy. the monkeys were divided into three groups based on dosing frequencies of 6-, 8-, or 12-h intervals. all were given a total daily dose of 100 mg/kg of zdv. the drug was administered subcutaneously starting 24 h before siv inoculati ... | 1993 | 8410666 |
| whole inactivated siv vaccine grown on human cells fails to protect against homologous siv grown on simian cells. | several groups have reported protection against experimental siv infection in macaques immunized with a whole inactivated virus vaccine. the aim of the current study was to investigate whether five macaques vaccinated with whole inactivated siv and previously shown to be protected against challenge with two divergent strains of siv grown on human cells could resist challenge with a subsequent homologous siv grown on macaque cells. we show here that this same vaccine did not protect when the chal ... | 1993 | 8411101 |
| immunisation of macaques with siv env recombinants: specificity of t cell and antibody responses and evaluation of protective efficacy. | macaques were immunised with lentil lectin purified recombinant sivmac (bk28) derived gp160 (rgp160) with or without live vaccinia (vac)-env (bk28) priming, followed by a final boost with solid matrix antibody antigen (smaa)-gp160 (j5) complexes and challenged with the sivmac molecularly cloned virus j5m. rgp160 and vac-env plus gp160 induced strong ab responses against the homologous virus. live vac-env did not enhance or prolong the antibody response, however, t cell responses were stronger. a ... | 1993 | 8411102 |
| immunization of macaca fascicularis with inactivated siv preparations: challenge with human- or monkey-derived siv and the effects of a longer immunization schedule. | in cynomolgus monkeys, we compared two human-derived sivmac251 whole virus vaccines, a long vs short immunization schedule, and two different challenge viruses. both vaccines induced protection after challenge with human-derived sivmac251/32h. there was no difference between the two schedules of immunization. seven monkeys, five of which were protected following the first challenge, were reboosted and rechallenged with monkey-derived sivmac251, but no protection was observed. the titers of anti- ... | 1993 | 8411103 |
| pathogenesis of sivmac251 after atraumatic inoculation of the rectal mucosa in rhesus monkeys. | intrarectal inoculation of rhesus monkeys with low doses of sivmac led to a prolonged clinical and virological latency that was not observed for high intrarectal doses or for intravenous inoculation. animals infected intrarectally with low virus doses remained negative for serum antibody responses to siv for at least one year even though they readily transferred siv to naive recipients via transfusion of whole blood. | 1993 | 8411107 |
| intra-amniotic inoculation of pigtailed macaque (macaca nemestrina) fetuses with siv and hiv-1. | six pregnant pigtailed macaques (macaca nemestrina) were inoculated intra-amniotically (i.a.) with sivmne. all became viremic and seroconverted; three viable offspring were siv-positive and at autopsy showed disseminated viral infection; one of three abortuses had siv-infected thymic macrophages. three of five pregnant macaques inoculated i.v. and/or i.a. with hiv-1lai became virus-positive, and four seroconverted, suggesting fetal-maternal transmission. one abortus had hiv-1-antigen in lymph no ... | 1993 | 8411108 |
| protection of vaccinia-primed macaques against sivmne infection by combination immunization with recombinant vaccinia virus and sivmne gp160. | two macaca fascicularis with preexisting immunity to vaccinia virus were immunized twice with recombinant vaccinia virus expressing sivmne gp160. their siv-specific antibody responses were lower than that of vaccinia-naive animals immunized similarly. upon repeated boosting with gp160, the siv-specific antibody titers in vaccinia-primed animals reached similar levels as vaccinia-naive animals and with comparable neutralizing titers. both animals were protected against repeated intravenous challe ... | 1993 | 8411113 |
| analysis of simian immunodeficiency virus sequence variation in tissues of rhesus macaques with simian aids. | one rhesus macaque displayed severe encephalomyelitis and another displayed severe enterocolitis following infection with molecularly cloned simian immunodeficiency virus (siv) strain sivmac239. little or no free anti-siv antibody developed in these two macaques, and they died relatively quickly (4 to 6 months) after infection. manifestation of the tissue-specific disease in these macaques was associated with the emergence of variants with high replicative capacity for macrophages and primary in ... | 1993 | 8411355 |
| alternate pathways of secretion of simian immunodeficiency virus envelope glycoproteins. | a biotinylation assay was used to detect the envelope glycoprotein of the simian immunodeficiency virus (siv) envelope glycoprotein expressed by a recombinant vaccinia virus on the surface of hela t4 cells. the relationship between the detection of the envelope glycoprotein on the cell surface and its secretion from the cell was examined. it was found that much more gp120 was released into the culture medium than could be accounted for by shedding of the biotinylated siv envelope protein from th ... | 1993 | 8411356 |
| generation of deletion mutants of simian immunodeficiency virus incapable of proviral integration. | | 1993 | 8411398 |
| immune response of rhesus macaques to recombinant simian immunodeficiency virus gp130 does not protect from challenge infection. | simian immunodeficiency virus (siv) infection of rhesus macaques is a model for human immunodeficiency virus (hiv) infection in humans. inactivated and modified live whole-virus vaccines have provided limited protective immunity against siv in rhesus macaques. because of safety concerns in the use of inactivated and live whole-virus vaccines, we evaluated the protective immunity of vaccinia virus recombinants expressing the surface glycoprotein (gp130) of sivmac and subunit preparations of gp130 ... | 1993 | 8416384 |
| distinguishing features of an infectious molecular clone of the highly divergent and noncytopathic human immunodeficiency virus type 2 uc1 strain. | a full-length infectious molecular clone was derived from the noncytopathic human immunodeficiency virus type 2 uc1 strain (hiv-2uc1) that was originally recoverd from an individual from the ivory coast. like the parental isolate, the molecularly cloned virus (hiv-2uc1mc or uc1 mc) demonstrates a reduced ability to induce syncytium formation, to kill cells, and to down-modulate the cell surface cd4 receptor in infected cells. phylogenetic analysis of the dna sequence of uc1mc revealed that it is ... | 1993 | 8419635 |
| human immunodeficiency viruses containing heterologous enhancer/promoters are replication competent and exhibit different lymphocyte tropisms. | the human immunodeficiency virus (hiv) type 1 long terminal repeat (ltr) contains binding sites for nuclear factor kappa b (nf-kappa b) and the constitutively expressed transcription factor sp1, both of which are highly conserved in hiv and simian immunodeficiency virus isolates. to delineate the effects of these motifs on the replicative capacity of hiv and to explore the possibility of extending the virus host range, known heterologous enhancer/promoters were inserted into the hiv-1 ltr in pla ... | 1993 | 8419644 |
| analysis of multiple mrnas from pathogenic equine infectious anemia virus (eiav) in an acutely infected horse reveals a novel protein, ttm, derived from the carboxy terminus of the eiav transmembrane protein. | transcription of pathogenic equine infectious anemia virus (eiav) in an acutely infected horse was examined by using the polymerase chain reaction and nucleotide sequencing. four spliced transcripts were identified in liver tissue, in contrast to the multiplicity of alternatively spliced messages reported for in vitro-propagated human immunodeficiency virus, simian immunodeficiency virus, and, to a lesser extent, eiav. nucleotide sequence analysis demonstrated that three of these mrnas encode kn ... | 1993 | 8419648 |
| n-linked oligosaccharides of simian immunodeficiency virus envelope glycoproteins are dispensable for the interaction with the cd4 receptor. | in contrast to others groups, we have previously shown that n-linked glycans of hiv-1 and hiv-2 envelope glycoproteins do not play a major role in the gp-cd4 interaction. in order to clarify these inconsistencies, we investigated the role of n-glycans in the interaction of siv with the cd4 receptor. the inhibition of binding of radiolabeled siv envelope glycoprotein (gp140) to cd4+ cells by increasing concentrations of soluble cd4 shows that the interaction occurred with high affinity (k0.5 = 1. ... | 1993 | 8427576 |
| studies on the specificity of the vaccine effect elicited by inactivated simian immunodeficiency virus. | inactivated, partially purified simian immunodeficiency virus (sivmac) protected macaques from intravenous challenge with homologous and heterologous strains of siv that had been grown on human cells but no protection against challenge with monkey peripheral blood mononuclear cell-grown sivmac was afforded. human immunodeficiency virus type 1 prepared in an analogous way to the sivmac vaccine on the c8166 human t cell line protected macaques against challenge with human cell-grown sivmac. these ... | 1993 | 8427714 |
| simian immunodeficiency virus infection via amniotic fluid: a model to study fetal immunopathogenesis and prophylaxis. | the rising prevalence of infection with the human immunodeficiency virus type 1 (hiv-1) in young women will increase the number of infected children worldwide. because hiv-1 seems to be transmitted mostly intrapartum, fetal infection probably occurs mainly via skin or mucous membrane exposure. a model for this route of fetal infection has been established in primates. after injecting the simian immunodeficiency virus (siv) into amniotic fluid during late gestation, six of seven rhesus monkeys we ... | 1993 | 8433276 |
| electrostatic interactions modulate the rna-binding and transactivation specificities of the human immunodeficiency virus and simian immunodeficiency virus tat proteins. | the transcriptional activating (tat) proteins from human immunodeficiency virus and simian immunodeficiency virus are sequence-specific rna-binding proteins. in human immunodeficiency virus tat, a single arginine residue, flanked on each side by three to four basic amino acids, mediates specific binding to a bulge region in trans-acting responsive element (tar) rna. we have systematically mutated the flanking charged residues and found that, in addition to the position of the sequence-specific a ... | 1993 | 8434019 |
| simian immunodeficiency viruses from central and western africa: evidence for a new species-specific lentivirus in tantalus monkeys. | although up to 50% of african green monkeys (agms) are infected by simian immunodeficiency viruses (siv) in their natural habitat, they remain asymptomatic carriers of these lentiviruses. they provide an attractive model to study not only the origin but also the link among genetic variation, host-virus adaptation, and pathogenicity of primate lentiviruses. sivagm have been isolated from three species of agm: the vervet (cercopithecus pygerythrus), the grivet (cercopithecus aethiops), and the sab ... | 1993 | 8437214 |
| simian immunodeficiency virus-specific cd8+ lymphocyte response in acutely infected rhesus monkeys. | to assess the possible role of cytotoxic t lymphocytes (ctls) in containing the spread of human immunodeficiency virus in acutely infected individuals, the temporal evolution of the virus-specific cd8+ lymphocyte response was defined in simian immunodeficiency virus of macaques (sivmac)-infected rhesus monkeys. a brief period of sivmac plasma antigenemia was seen 9 to 16 days following intravenous infection with sivmac, ending as the absolute number of cd8+ peripheral blood lymphocytes (pbls) in ... | 1993 | 8437240 |
| replication and persistence of simian immunodeficiency virus variants after passage in macaque lymphocytes and established human cell lines. | in lentivirus infections, there are typically few cells in the host that harbor the provirus. for this reason, molecular clones of human and simian immunodeficiency viruses (hiv and siv) are generally derived after passage and amplification of the virus in cell culture. to determine whether siv variants that persist in culture are similar to the variants that predominate in the host, we examined the proviral sequence of the siv envelope (env) gene before and after cocultivation of lymphocytes fr ... | 1993 | 8437241 |
| self-limiting infection by int/nef-double mutants of simian immunodeficiency virus. | simian immunodeficiency virus (sivmac) infectious for rhesus monkeys was altered by site-directed mutagenesis of genes influencing in vivo replication and persistence with the long-term goal to develop attenuated lentiviruses with limited replication capacity in vivo. double mutants of sivmac (termed delta-int 1 to 3) were generated by introducing frameshift and deletion mutations into the nef gene and into the pol gene region coding for the integrase protein. delta-int/delta-nef viruses formed ... | 1993 | 8438561 |
| intracellular transport and virion incorporation of vpx requires interaction with other virus type-specific components. | viral protein x (vpx) is a virion-associated hiv-2/siv accessory protein that enhances viral infectivity and replication in natural target cells. to investigate whether other viral components affect its biosynthesis, subcellular localization, and virion incorporation, we expressed hiv-2 vpx in a mammalian cell system and examined its transport and packaging requirements using an in trans complementation assay. the complete vpx coding region of hiv-2st was placed under the control of a high-effic ... | 1993 | 8438567 |
| cysteine and glutathione deficiency in aids patients: a rationale for the treatment with n-acetyl-cysteine. | a series of clinical studies and laboratory investigations suggests that the acquired immunodeficiency syndrome (aids) may be the consequence of a virus-induced cysteine deficiency. hiv-infected persons at all stages of the disease were found to have decreased plasma cystine and cysteine concentrations and decreased intracellular glutathione levels. in rhesus macaques, cysteine levels decrease already within 1-2 weeks after infection with the closely related virus sivmac. hiv-infected persons an ... | 1993 | 8441757 |
| target cells during early siv encephalopathy. | early encephalopathy was studied in rhesus macaques in the first month following intravenous (i.v.) infection with siv-mac-251. histopathological analysis of brain tissues showed slight gliosis, associated with perivascular infiltrates and occasional glial nodules. immunophenotyping of brain tissue showed microgliosis with expression of mhc class ii molecule and macrophage infiltration associated with a few lymphocytes. at the early stage of infection, most infected cells were perivascular, sugg ... | 1993 | 8446776 |
| comparison of the effects of 3'-azidothymidine with those of neutralizing antibodies on simian immunodeficiency virus infection in macrophages. | we previously showed that simian immunodeficiency virus-infected macaque macrophages contacting uninfected cd4+ lymphocytes caused extensive cell fusion and synthesis of phlogistic cytokines. in this study, macaque macrophage cultures inoculated with sivmac251 and treated simultaneously with 10 microm 3'-azidothymidine (azt) became infected and produced small amounts of viral antigen (p27) but failed to fuse with cd4+ cem174 cells. when azt was added 1 to 3 days after virus inoculation, the infe ... | 1993 | 8452370 |
| antigenic and immunogenic sites of hiv-2 glycoproteins. | a new human retrovirus, hiv-2, serologically distinct from human immunodeficiency virus type 1 (hiv-1), was first reported in 1985 and isolated in 1986 from 2 aids patients from guinea-bissau and cape verde islands. findings related to the characterization of hiv-2 antigenic and immunogenic sites that stimulate strain and type-cross-reactive immunity are illustrated; data from preliminary studies of simian immunodeficiency virus (siv) are presented; and epidemiological and biological characteri ... | 1993 | 8452654 |
| immunization with recombinant bcg-siv elicits siv-specific cytotoxic t lymphocytes in rhesus monkeys. | because the transmission of hiv is likely to occur through cell-associated virus, an effective hiv vaccine should be capable of eliciting hiv-specific ctl. we have employed the simian immunodeficiency virus (siv)/rhesus monkey model to explore the use of the attenuated tuberculosis bacillus, calmette guérin bacillus (bcg), as a vaccine vehicle to elicit aids virus-specific ctl. bcg was engineered to express sivmac gag under the control of hsp70 regulatory sequences. immunization with this rbcg-s ... | 1993 | 8454878 |
| simian immunodeficiency virus (mac 251-32h) transmembrane protein sequence remains conserved throughout the course of infection in macaques. | two cynomolgus macaques were infected with a genetically complex challenge stock of simian immunodeficiency virus (sivmac251-32h). the polymerase chain reaction (pcr) was used to amplify the env gp41, rev, and nef overlapping coding sequences from provirus present in the blood of both animals at 1, 6, and 15 months post infection (p.i.). the predominant, env sequences found in both animals at the three time points were very similar to that found in the original 11/88 challenge stock. the functio ... | 1993 | 8457380 |
| effect of mutations in the v3 loop of hiv-1 gp120 on infectivity and susceptibility to proteolytic cleavage. | it has been suggested that the v3 domain of human immunodeficiency virus type 1 (hiv-1) isolates has to interact with a cell-surface-associated or endosomal proteinase during virus entry into susceptible cells. to investigate this hypothesis, we examined the effect of several mutations in the v3 loop on its susceptibility to proteolytic cleavage by thrombin and cathepsin e and compared it with the effect of these mutations on viral infectivity. the data obtained indicate that, if an interaction ... | 1993 | 8457383 |
| identification of a region in the pr55gag-polyprotein essential for hiv-1 particle formation. | the pr55gag polyprotein of hiv-1 plays a critical role in the formation of immature virus particles in the cell and during the budding process. we investigated the influence of amino acid substitutions in the p24ca- region of the gag polyprotein on the viral assembly process. deletion of the amino acids 341-352 in the carboxy terminal part of the p24ca resulted in a loss of the capacity of the gag polyprotein to form virus-like particles when expressed in eucaryotic cells by recombinant vaccinia ... | 1993 | 8460500 |
| isolation and characterization of simian immunodeficiency virus from african white-crowned mangabey monkeys (cercocebus torquatus lunulatus). | forty-eight of 236 sera from seven species of african non-human primates in kenya, including those of white-crowned mangabey monkeys (cercocebus torquatus lunulatus) had antibodies to simian immunodeficiency viruses (sivs). isolates of simian lentivirus were obtained from seropositive white-crowned mangabey monkeys which are indigenous in west africa. this virus, designated as sivwcm, appeared morphologically similar to hiv by electron microscopy, showed mg(2+)-dependent reverse transcriptase ac ... | 1993 | 8470959 |
| in vivo administration to rhesus monkeys of a cd4-specific monoclonal antibody capable of blocking aids virus replication. | monoclonal antibodies (mabs) specific for cd4 are potent inhibitors of hiv replication in vitro. these agents may be useful prophylactically or in chronic hiv infection if they can be administered without inducing immunosuppression. in the present study, we explored the safety of a cd4-specific murine mab in rhesus monkeys. the mab 5a8, which binds to domain 2 of the cd4 molecule, inhibits aids virus replication noncompetitively at a postvirus binding step. this antibody, which had a similar aff ... | 1993 | 8471310 |
| early pathogenesis of disease caused by sivsmmpbj14 molecular clone 1.9 in macaques. | we have studied the early pathogenesis of infection by molecular clone 1.9 of sivsmmpbj14 in pig-tailed and cynomolgus macaques. like the uncloned pbj14 parent, sivsmmpbj14-1.9 consistently induced an acute clinical syndrome characterized by behavioral depression, fever, profuse diarrhea, dehydration, lymphadenopathy, splenomegaly, and mucocutaneous exanthema that began at 7 days postinfection (dpi). the acute clinical disease coincided with a marked cell-associated and cell-free viremia, during ... | 1993 | 8471319 |
| multiple viral determinants contribute to pathogenicity of the acutely lethal simian immunodeficiency virus sivsmmpbj variant. | simian immunodeficiency virus (siv) induces an immunodeficiency syndrome similar to human aids. although the disease course of siv-induced immunodeficiency is generally measured in months to years, a disease syndrome that results in death in 5 to 14 days has been described in pig-tailed macaques infected with the sivsmmpbj (pbj) strain. the purpose of this study was to derive an acutely lethal pbj molecular clone in order to study viral genes involved in pathogenesis. six infectious molecular cl ... | 1993 | 8474153 |
| simian immunodeficiency virus rna is efficiently encapsidated by human immunodeficiency virus type 1 particles. | packaging of retroviral rna is attained through the specific recognition of a cis-acting encapsidation site (located near the 5' end of the viral rna) by components of the gag precursor protein. human immunodeficiency virus type 1 (hiv-1) and simian immunodeficiency virus (siv) are two lentiviruses that lack apparent sequence similarity in their putative encapsidation regions. we used siv vectors to determine whether hiv-1 particles can recognize the siv encapsidation site and functionally propa ... | 1993 | 8474168 |
| truncation of the cytoplasmic domain of the simian immunodeficiency virus envelope glycoprotein increases env incorporation into particles and fusogenicity and infectivity. | growth of macaque simian immunodeficiency virus (sivmac) in certain cloned human t-cell lines, such as hut.78, selects for isolates containing a premature stop codon within the cytoplasmic domain of the transmembrane envelope glycoprotein. in contrast, propagation of virus in macaques or in their cultured t cells favors replication of virus containing the full-length envelope glycoprotein. to elucidate the causes of this phenomenon, we used a human immunodeficiency virus pseudotyping system to a ... | 1993 | 8474176 |
| the nf-kappa b binding site is necessary for efficient replication of simian immunodeficiency virus of macaques in primary macrophages but not in t cells in vitro. | we demonstrate here that the nuclear factor-kappa b (nf-kappa b) binding site in the simian immunodeficiency virus (sivmac) long terminal repeat is essential for efficient virus replication in primary alveolar macrophages but dispensable for efficient replication in primary t cells. mutation of the nf-kappa b site does not seriously impair replication of a t-cell-tropic sivmac239 or a macrophagetropic sivmacem* in peripheral blood lymphocytes or established cd4+ cell lines; however, mutation of ... | 1993 | 8474179 |
| early central nervous system changes in human immunodeficiency virus (hiv)-infection. | early hiv infection of the cns, as demonstrated by cerebrospinal fluid studies, seems relatively common. however most hiv carriers remain neurologically unimpaired during the incubation period. a few psychometric, radiological, and electrophysiological studies suggest that neurological abnormalities are present at early stages of hiv infection; the findings of these studies are controversial and until recently, they have not been supported by neuropathological data. early brain changes, includin ... | 1993 | 8474597 |
| human immunodeficiency virus type 1 (hiv-1) fusion with model membranes: kinetic analysis and the role of lipid composition, ph and divalent cations. | the kinetics and extent of hiv-1 fusion with model membranes was studied. hiv-1 was labeled with octadecyl rhodamine b chloride, and fusion was monitored continuously as the dilution of the probe into target membranes. the results were analyzed by a mass action model which yielded good simulations and predictions for the kinetics and final extents of fluorescence increase. the model determined the percent of virions capable of fusing and rate constants of fusion, aggregation and dissociation. ul ... | 1993 | 8476916 |
| cortical astrocytosis in juvenile rhesus monkeys infected with simian immunodeficiency virus. | the pattern of expression of gfap immunoreactivity in astrocytes of the juvenile rhesus monkey cortex was examined following infection with simian immunodeficiency virus (siv). blocks of cerebral cortex plus subjacent white matter from saline- and formalin-perfused brain were examined by peroxidase-linked immunochemical and immunofluorescence staining of deparaffinized sections. strong gfap immunoreactivity was found in astrocytic cells in both uninfected and siv-infected juvenile macaque in the ... | 1993 | 8477048 |
| where are we now with vaccines against aids? | extensive studies in experimental animal models and phase i and ii clinical trials in humans provide some grounds for optimism about developing a vaccine for aids. over 200 monkeys have been protected by simple inactivated vaccines against infection with a lethal challenge dose of simian immunodeficiency virus (siv). passive transfer of the antibody to siv has been shown to prevent infection. recent vaccination with attenuated, live siv protected against a challenge with 1000 monkey infectiou ... | 1993 | 8490466 |
| sequence variation in the env gene of simian immunodeficiency virus recovered from immunized macaques is predominantly in the v1 region. | three cynomolgus macaques were immunized with recombinant envelope protein preparations derived from simian immunodeficiency virus (siv). although humoral and cellular responses were elicited by the immunization regime, all macaques became infected upon challenge with 10 mid50 of the 11/88 virus challenge stock of sivmac251-32h. the polymerase chain reaction was used to amplify proviral siv gp120 sequences present in the blood of both immunized and control macaques at 2 months post-infection. a ... | 1993 | 8492090 |
| identification of the gene encoding the major capsid protein of insect iridescent virus type 6 by polymerase chain reaction. | the gene encoding the major capsid protein of chilo iridescent virus (civ) has been identified by pcr using oligonucleotide primers corresponding to different regions of the major capsid proteins of tipula iridescent virus (tiv) and iridescent virus 22 (iv22). a dna fragment of 0.5 kbp was amplified using two oligonucleotide primers corresponding to the amino acid positions 146 to 153 and 304 to 313 of the major capsid protein of tiv, respectively. the radioactively labelled dna fragment derived ... | 1993 | 8492091 |
| protection against vaginal siv transmission with microencapsulated vaccine. | although protection in animal models against intravenous challenges with simian immunodeficiency virus (siv) has been reported, no previous vaccines have protected against a heterosexual route of infection. in this study, five of six macaques were protected against vaginal challenge when immunized with formalin-treated siv in biodegradable microspheres by the intramuscular plus oral or plus intratracheal route. oral immunization alone did not protect. after a second vaginal challenge, three of f ... | 1993 | 8493576 |
| truncations of the simian immunodeficiency virus transmembrane protein confer expanded virus host range by removing a block to virus entry into cells. | we have investigated how truncation of the cytoplasmic domain of the transmembrane (tm) glycoprotein of simian immunodeficiency virus (siv) modulates the host range of this virus. termination codons were introduced into the env gene of sivmac239 which resulted in the truncation of the transmembrane protein from a wild-type 354 amino acids (tm354) to 207 (tm207) and 193 (tm193) amino acids. expression of the wild-type and mutant env genes from a simian virus 40-based vector resulted in normal bio ... | 1993 | 8497044 |
| assembly of the matrix protein of simian immunodeficiency virus into virus-like particles. | to obtain a better understanding of the processes of assembly and morphogenesis of simian immunodeficiency virus (siv), recombinant vaccinia viruses containing regions of the gag-pol open reading frame were constructed and their intracellular expression as well as the ability of the gag polypeptides to be released into the culture medium as constituents of virus-like particles were studied. biochemical and electron microscopy analyses of cells infected with a recombinant expressing only the siv ... | 1993 | 8503172 |
| the majority of simian immunodeficiency virus/mne circle junctions result from ligation of unintegrated viral dna ends that are aberrant for integration. | siv/mne circle junctions were amplified by the polymerase chain reaction (pcr) and cloned in a bacterial plasmid. sequence analysis of clones isolated from 11 independent pcrs reveals that the start site for plus dna synthesis is 5' actg. . ., and thus an asymmetric cleavage must occur during viral integration. in addition, most of the sequences found resulted from the ligation of aberrant proviral dna ends that were apparently generated by priming errors, primer removal errors, or integrase pro ... | 1993 | 8503190 |
| antiviral effects of different cd4-immunoglobulin constructs against hiv-1 and siv: immunological characterization, pharmacokinetic data and in vivo experiments. | the cd4 cell surface antigen belongs to the immunoglobulin superfamily and is the primary receptor for the human immunodeficiency virus 1 (hiv-1). the high affinity interaction between hiv-1 and cd4 is mediated by the viral envelope glycoprotein gp120. recombinant soluble cd4 (rscd4) has been shown in vitro to be an effective inhibitor of hiv-1 and hiv-2 propagation in lymphoid cells. a variety of antibody-like molecules were constructed, consisting of different parts of the extracellular domain ... | 1993 | 8503781 |
| early phenotypic and functional alterations in lymphocytes from simian immunodeficiency virus infected macaques. | phenotypic and functional changes in lymphocytes from rhesus monkeys (macaca mulatta) were investigated during the first 6 months after infection with siv mac 32h. animals preimmunized with keyhole limpet hemocyanin (klh) were sacrificed 1, 3, 6, 12, and 24 weeks post infection. subset composition and function of lymphocytes from blood, spleen, lymph node and thymus were analysed. in addition to a rapid decline in cd4/cd8 ratios, a massive reduction in cd29+ cd4+ cells was seen in the periphery. ... | 1993 | 8506614 |
| simian immunodeficiency virus infection of the gastrointestinal tract of rhesus macaques. functional, pathological, and morphological changes. | gastrointestinal dysfunction and wasting are frequent complications of human immunodeficiency virus (hiv) infection. nutrient malabsorption, decreased digestive enzymes and hiv transcripts have been documented in jejunal mucosa of hiv-infected patients; however, the pathogenesis of this enteropathy is not understood. rhesus macaques infected with simian immunodeficiency virus (siv) also exhibit diarrhea and weight loss; therefore, we investigated the use of this animal model to study hiv-associa ... | 1993 | 8506946 |
| simian immunodeficiency virus (sivmac251) membrane lipid mixing with human cd4+ and cd4- cell lines in vitro does not necessarily result in internalization of the viral core proteins and productive infection. | the cell binding site of simian immunodeficiency virus (siv) is believed to be the cd4 molecule. several cd4+ cell lines are, however, resistant to infection by sivmac251 in vitro and additional cell membrane molecules have been implicated in sivmac251 entry. we investigated the binding, envelope fusion and entry of the viral core proteins (p27) of sivmac251 into two human cd4+ cell lines (h9 and sup-t1) which are infectible, and one cd4+ (a3.01) and two cd4- cell lines (k562 and raji) that are ... | 1993 | 8509758 |
| simian immunodeficiency virus mutants resistant to serum neutralization arise during persistent infection of rhesus monkeys. | we previously described the pattern of sequence variation in gp120 following persistent infection of rhesus monkeys with the pathogenic simian immunodeficiency virus sivmac239 molecular clone (d.p.w. burns and r.c. desrosiers, j. virol. 65:1843, 1991). sequence changes were confined largely to five variable regions (v1 to v5), four of which correspond to human immunodeficiency virus type 1 (hiv-1) gp120 variable regions. remarkably, 182 of 186 nucleotide substitutions that were documented in the ... | 1993 | 8510218 |
| vpx of simian immunodeficiency virus is localized primarily outside the virus core in mature virions. | human immunodeficiency virus type 2 and the related simian immunodeficiency virus (siv) contain a unique regulatory gene, vpx. the vpx protein is packaged in mature virions and is required for efficient viral replication in peripheral blood lymphocytes and macrophages. to study the localization of vpx in mature virions, conical and bar-shaped core structures of siv from macaques (sivmac) were purified. the sivmac core has a density of approximately 1.25 g/cm3, compared with 1.16 g/cm3 for an int ... | 1993 | 8510227 |
| biochemical and immunological characterization of micellar complexes of the envelope glycoprotein of a simian immunodeficiency virus isolated from an african green monkey. | the external envelope glycoprotein gp130 of a simian immunodeficiency virus isolated from an african green monkey (sivagmtyo-7) was purified as micellar complexes. the molecular weight of the gp130 micelles was about 700 k. on electron microscopy, the micelles appeared as spherical particles with a diameter of 15 to 20 nm. such aggregates consisted of about 4 to 5 gp130 monomers. hyperimmune sera raised in rabbits and rhesus monkeys against these gp130 micelles exhibited titers between 10(5) and ... | 1993 | 8514839 |
| crystallization and preliminary x-ray investigation of recombinant simian immunodeficiency virus proteinase. | simian immunodeficiency virus (siv) proteinase has been crystallized from sodium acetate buffer with sodium chloride as precipitant. the crystals are orthorhombic and the space group is c222(1) with unit cell dimensions a = 32.18 a, b = 62.52 a, c = 95.76 a, alpha = beta = gamma = 90 degrees, indicating a single monomer of 10 kda in the asymmetric unit. the crystals grow to dimensions of 0.2 mm x 0.2 mm x 0.07 mm within a week and are stable in the x-ray beam for at least 50 hours. a different c ... | 1993 | 8515473 |
| analysis of the cell fusion activities of chimeric simian immunodeficiency virus-murine leukemia virus envelope proteins: inhibitory effects of the r peptide. | it was previously reported that truncation or proteolytic removal of the c-terminal 16 amino acids (the r peptide) from the cytoplasmic tail of the murine leukemia virus (mulv) envelope protein greatly increases its fusion activity. in this study, to investigate the specificity of the effect of the r peptide on the fusion activity of viral envelope proteins, we expressed simian immunodeficiency virus (siv)-mulv chimeric proteins in which the entire cytoplasmic tail of the siv envelope protein wa ... | 1996 | 8523533 |