| induction of humoral and cellular immunity to simian immunodeficiency virus: what are the requirements for protection? | in an effort to produce a strong humoral and cellular immune response that might protect against simian immunodeficiency virus (siv) infection, groups of five rhesus macaques each were immunized intramuscularly at 0, 2 and 6 months with 100 micrograms of an inactivated preparation of siv/delta b670 in either an oil-in-water emulsion with ribi detox, containing mycobacterial cell wall skeleton and monophosphoryl lipid a (cws/mpl) (group a) or a water-in-oil emulsion with incomplete freund's adjuv ... | 1994 | 7998424 |
| suppression of simian immunodeficiency virus replication in primary peripheral mononuclear cells by antisense rna. | it has been demonstrated that human immunodeficiency virus (hiv) replication can be effectively blocked by an antisense sequence that was introduced into the lymphoid cell line through retroviral-mediated gene transfer. in this study, it is demonstrated that antisense rna can also inhibit simian immunodeficiency virus (siv) replication in the peripheral blood mononuclear cells (mncs) of healthy donors. mncs were transduced with amphotropic recombinant virus encoding either sense or antisense con ... | 1994 | 8006639 |
| quo vadis: perinatal aids issues--2004. | the hiv problem will inexorably increase over the next decade, with an increasing proportionate impact upon women and children over the next decade. hiv will become endemic, essentially worldwide. some regions in the developed world may be relatively spared if current trends continue. this may reduce the willingness to expend necessary resources, particularly if trends toward increasing isolationism continue. there are already signs of a world becoming "bored" with aids and the chronicity of a d ... | 1994 | 8013184 |
| prolonged clinical latency and survival of macaques given a whole inactivated simian immunodeficiency virus vaccine. | simian immunodeficiency virus (siv) infection of macaques is a useful and relevant model for evaluating candidate human immunodeficiency virus (hiv) vaccines. one important feature of this model is that siv vaccines can be evaluated for their ability to prevent infection as well as to prevent or delay the onset of aids. in the present study, a group of macaques was vaccinated with whole inactivated siv and challenged with peripheral blood mononuclear cells from an siv-infected macaque. this chal ... | 1994 | 8014520 |
| characterization of caprine microglial cells and in vitro infection with caprine arthritis-encephalitis lentivirus. | similar to human immunodeficiency virus-1 and simian immunodeficiency virus-1, microglial cells in brain tissue are a major cell target for infection with caprine arthritis-encephalitis lentivirus (caev) in vivo. these observations have raised interest in the role of microglial cells in the development of lentivirus-induced neurologic lesions. to initiate in vitro studies into the pathogenesis of encephalomyelitis caused by caev, we characterized primary cultures of caprine microglia, determined ... | 1994 | 8015297 |
| complex splicing of simian immunodeficiency virus (mac 251-32h) rev gene transcript from infected macaques. | sequences of the simian immunodeficiency virus (siv) rev mrna transcripts were characterized from peripheral blood lymphocytes (pbls) of two macaques experimentally infected with sivmac251 (32h reisolate). this analysis has demonstrated that the complex splicing patterns observed for the rev mrna transcripts originally identified in vitro is not an artifact of tissue culture, but is also found in vivo. | 1994 | 8018393 |
| insect iridescent virus type 6 encodes a polypeptide related to the largest subunit of eukaryotic rna polymerase ii. | cytoplasmic dna viruses encode a dna-dependent rna polymerase (ddrp) that is essential for transcription of viral genes. the amino acid sequences of known large subunits of ddrps contain highly conserved regions. oligonucleotide primers, deduced from two conserved domains [rqp(t/s)lh and nadfdgde] were used in pcr experiments for the detection of the corresponding gene of the genome of insect iridescent virus type 6, also known as chilo iridescent virus (civ). a specific dna product of about 150 ... | 1994 | 8021587 |
| mosaic genome structure of simian immunodeficiency virus from west african green monkeys. | elucidation of the phylogenetic origins of simian and human immunodeficiency viruses (siv and hiv) is fundamental to the understanding of hiv pathogenesis and the spread of aids worldwide. in this study, we molecularly characterized multiple sivagm isolates from four different african green monkey species (vervet, grivet, sabaeus and tantalus monkeys). phylogenetic analysis of partial (1 kb) env sequences indicated that all sivagm strains cluster together, and that they fall into four distinct s ... | 1994 | 8026477 |
| effects of cytoplasmic domain length on cell surface expression and syncytium-forming capacity of the simian immunodeficiency virus envelope glycoprotein. | we previously reported that truncation of the terminal 146 amino acids of the macaque simian immunodeficiency virus sivmac239 envelope glycoprotein enhanced envelope-specific syncytium formation in hela t4, cem x 174, and hut 78 cell lines and caused a change in the conformation of the transmembrane subunit of the envelope complex on the surface of these cells [ritter et al. (1993) virology 197, 255-264; spies et al. (1994) j. virol. 68, 585-591]. to investigate the effects of different lengths ... | 1994 | 8030287 |
| neuropathologic aspects of lentiviral infections. | studies of lentiviral infections of various animals and man have shown that all may invade the cns and induce pathological lesions. this is well established in infections with vv, caev, siv, hiv-1, and fiv. although vv and caev do not cause an overt immunodeficiency, they share several features pertinent for the establishment of neuropathologic lesions with those that induce immunodeficiency. this holds especially true for the initial steps and early cns lesions. 1) infection of the cns is from ... | 1994 | 8030977 |
| antiviral activity of a sulphated polysaccharide from the red seaweed nothogenia fastigiata. | the antiviral activity of polysaccharide fractions obtained from water extracts of the red seaweed nothogenia fastigiata was investigated. fraction f6, corresponding to a sulphated xylomannan, was found to inhibit efficiently the replication of herpes simplex virus type 1 (hsv-1). furthermore, f6 selectively inhibited the replication of several other enveloped viruses including herpes simplex virus type 2, human cytomegalovirus (hcmv), respiratory syncytial virus, influenza a and b virus, junin ... | 1994 | 8031312 |
| a new look at hiv transmission from seropositive mothers to their infants: the facts beyond serology. | once the curtain of maternal antibodies is removed (12-18 months) only a fraction of the infants are seropositive. some babies from whom virus has been isolated or detected in their cells subsequently become seronegative. what does the negative serology of these children really tell us about exposure to hiv? it is suggested that seroconverting is only one of the ways to respond to an hiv exposure from an infected mother; it is not the only or the best way. some form of tolerance to hiv, emerging ... | 1994 | 8034484 |
| male circumcision: a role in hiv prevention? | speculation has existed for decades on the association between the lack of male circumcision and the sexual transmission of disease. it has been suggested that the surface epithelium of the glans develops a protective keratin layer following circumcision which functions like a natural condom against contracting disease. circumcised males may therefore be less susceptible to contracting sexually transmitted diseases (std), including hiv. the identification of simian immunodeficiency virus-infe ... | 1994 | 8043224 |
| major histocompatibility complex class i-associated vaccine protection from simian immunodeficiency virus-infected peripheral blood cells. | to evaluate the effectiveness of vaccine protection from infected cells from another individual of the same species, vaccinated rhesus macaques (macaca mulatta) were challenged with peripheral blood mononuclear cells from another animal diagnosed with acquired immune deficiency syndrome (aids). half of the simian immunodeficiency virus (siv)-vaccinated animals challenged were protected, whereas unprotected vaccinates progressed as rapidly to aids. protection was unrelated to either total antibod ... | 1994 | 8046353 |
| early events in tissues during infection with pathogenic (sivmac239) and nonpathogenic (sivmac1a11) molecular clones of simian immunodeficiency virus. | the extent of virus replication, tissue distribution, localization of virus within tissues, and the presence of pathological lesions was examined early after experimental infection of rhesus monkeys with simian immunodeficiency virus (siv). three strains of siv were used: molecularly cloned pathogenic sivmac239; molecularly cloned nonpathogenic sivmac1a11; and uncloned pathogenic sivmac. the major targets of infection in all animals at 2 weeks postinoculation were the thymus and spleen. the dist ... | 1994 | 8053500 |
| a morphological and immunolabelling study of freeze-substituted human and simian immunodeficiency viruses. | rapid freezing, freeze substitution and low temperature embedding were used to obtain resin-embedded specimens of hiv and siv for morphological and immunolabelling studies, with particular emphasis on the 'lateral bodies' and p6 protein. hiv- or siv-infected cells were fixed in 3% paraformaldehyde and cryoprotected with 0.5 m sucrose. cells were applied to pieces of whatman no 1 filter paper and impact-frozen onto a liquid nitrogen cooled copper block. specimens were freeze-substituted at -90 de ... | 1994 | 8055244 |
| biological, molecular, and structural analysis of a cytopathic variant from a molecularly cloned simian immunodeficiency virus. | some isolates of simian immunodeficiency virus (siv) have been shown to infect sup-t1 cells with slow kinetics and in the absence of cytopathic effects, including cell fusion or cd4 down-modulation (j. a. hoxie, b. s. haggarty, s. bonser, j. rackowski, h. shan, and p. kanki, j. virol. 62:2557-2568, 1988). in the present study, we describe the isolation and characterization of a sivmac variant, derived from the bk28 infectious molecular clone, that became highly cytopathic for sup-t1 cells. this ... | 1994 | 8057433 |
| immune activation and viral burden in acute disease induced by simian immunodeficiency virus sivsmmpbj14: correlation between in vitro and in vivo events. | the simian immunodeficiency virus sivsmmpbj14 (siv-pbj14) is an atypical lentivirus that causes acute disease and death in pig-tailed macaques and in vitro replicates efficiently in resting macaque lymphocytes and activates and induces proliferation of lymphocytes. the present study was conducted to test the hypothesis that production of large quantities of siv-pbj14 induces widespread immune activation and elaboration of cytokines which lead directly to the death of infected pig-tailed macaques ... | 1994 | 8057436 |
| a lion lentivirus related to feline immunodeficiency virus: epidemiologic and phylogenetic aspects. | feline immunodeficiency virus (fiv) is a novel lentivirus that is genetically homologous and functionally analogous to the human aids viruses, human immunodeficiency virus types 1 and 2. fiv causes immunosuppression in domestic cats by destroying the cd4 t-lymphocyte subsets in infected hosts. a serological survey of over 400 free-ranging african and asian lions (panthera leo) for antibodies to fiv revealed endemic lentivirus prevalence with an incidence of seropositivity as high as 90%. a lion ... | 1994 | 8057472 |
| [the isolation and characteristics of the green monkey lentivirus]. | we characterized the simian immunodeficiency virus isolated from cercopithecus aethiops (subspecies c. a. pygerythrus) originating from kenya. siv was isolated and continuously produced with the molt4 clone 8 cell line and was designated as siv-su1. siv-su1 isolate replicated with high efficiency in molt4 clone 8, mt-2 with moderate efficiency in cem x 174 and with poor efficiency in hut-78, u937, c8166. the infection of mt-2, c8166 and hut-78 resulted in extensive cell killing. western blotting ... | 1993 | 8059527 |
| delta opioid receptor gene expression in lymphocytes. | previous studies have shown that morphine stimulates simian immunodeficiency virus (siv) replication in siv-infected human cem x174 cells as well as in monkey lymphocytes through a mechanism of delaying the lysis of infected cells (biochem. biophys. res. commun. 195:1165-1173, 1993). the present study describes the identification of brain-like opioid receptor sequences in rna transcripts of both cem x174 cells and monkey lymphocytes. study of the gene sequence of a lymphocyte opioid receptor enc ... | 1994 | 8060306 |
| [the immunological manifestations and cytological characteristics of infection caused by the simian immunodeficiency virus (siv) in rhesus monkeys]. | the results of immunological and morphological studies of asian macaques (macaca mulatta) infected by simian immunodeficiency virus (siv) are summarized in this review of literature. this virus causes development of the immunodeficiency disease that closely resembles human aids. immunological parameters (cd count, antibody response etc.) are described promoting prediction of progression of immunodeficiency in monkeys. the morphological features of injury of internal organs indicate that siv-indu ... | 1993 | 8066812 |
| pathogenic diversity of simian immunodeficiency viruses. | the siv family is a diverse group of viruses that vary considerably in pathogenesis and virulence in their natural host species or macaques. although the disease induced by the sivsm subtype in particular is remarkably similar to human aids, it must be remembered that this is an experimental animal model. therefore, although the pathogenesis of sivsm (and other viruses) in macaques offers an relevant animal model for pathogenesis and vaccine trials, the interactions of these viruses in their nat ... | 1994 | 8067053 |
| unique lentivirus--host interactions: sivsmmpbj14 infection of macaques. | the most virulent primate lentivirus identified to date, the simian virus sivsmmpbj14 (siv-pbj14), is unique not only because it causes acute disease and death within days instead of months or years, but also because of its replicative and cellular activation properties. the acute disease syndrome has many features in common with primary hiv-1 disease, but differences in the respective outcomes of these two acute lentiviral infections appear to be linked to the rapidity with which siv-pbj14 repl ... | 1994 | 8067054 |
| virus-specific helper t cell response of macaques immunized with inactivated whole siv is not correlated with reactivity against cellular components of vaccine preparation. | | 1994 | 8068411 |
| mucosal infection of neonatal rhesus monkeys with cell-free siv. | although the mechanisms for maternal transmission are unknown, approximately half of the infants congenitally infected with the human immunodeficiency virus type 1 (hiv-1) seem to become infected late in gestation or during delivery. previously, we have developed a rhesus monkey model for congenital infection by injecting cell-free simian immunodeficiency virus (siv) directly into amniotic fluid. our results suggested that fetal infection may have occurred via skin or mucous membrane exposure. m ... | 1994 | 8068415 |
| crystallization and preliminary x-ray investigation of recombinant simian immunodeficiency virus matrix protein. | simian immunodeficiency virus matrix protein has been crystallized from tris-hcl buffer with polyethylene glycol and isopropanol as precipitants. the crystals belong to space group c2 with unit cell dimensions a = 69.9 a, b = 115.2 a, c = 32.5 a, beta = 108.1 degrees and diffract x rays to a minimum bragg spacing of 2 a. these crystals appear suitable for a high resolution structure analysis. | 1994 | 8071998 |
| chilo iridescent virus encodes a putative helicase belonging to a distinct family within the "dead/h" superfamily: implications for the evolution of large dna viruses. | the complete nucleotide sequence of the ecori dna fragment m (7099 bp; 0.310-0.345 map units) of the genome of insect iridescent virus type 6--chilo iridescent virus (civ)--was determined. a 606 codon open reading frame located in this region encoded a protein (p69) related to a distinct family of putative dna and/or rna helicases belonging to the "dead/h" superfamily. unique sequence signatures were derived that allowed selective retrieval of the putative helicases of the new family from amino ... | 1994 | 8073636 |
| expression and purification of nonglycosylated siv proteins, and their use in induction and detection of siv-specific immune responses. | two commercially available expression vectors were modified to generate plasmids pgexcpk and pq9cpk. proteins expressed from pgexcpk and pq9cpk had a short oligopeptide tag termed pk at their carboxy termini and either glutathione s-transferase (gst) or a small histidine (his) tag, respectively, at their n termini. gst fusion proteins can be purified on immobilized glutathione and proteins coupled to the his tag selectively bind to ni(2+)-nta columns. the pk tag is recognized by monoclonal antib ... | 1994 | 8074930 |
| an electron-lucent region within the virion distinguishes hiv-1 from hiv-2 and simian immunodeficiency virus. | ultrastructural comparisons of immature or budding particles of human immunodeficiency virus (hiv) types 1 and 2 and simian immunodeficiency virus of macaques (sivmac) revealed no significant difference between these genetically distinct, but related, viruses. however, a region encompassing the core of mature hiv-1 virions was found to be more electron lucent than that observed in hiv-2 and sivmac. this ultrastructural distinction cannot be attributed to hiv-1-specific vpu, hiv-2/siv-specific vp ... | 1994 | 8074937 |
| purification of simian immunodeficiency virus, sivmac251, and of its external envelope glycoprotein, gp148. | two-phase extraction in a system composed of dextran and polyethylene glycol was used to purify simian immunodeficiency virus, sivmac251 (32h isolate) from 25 l of culture supernatant. the virus partitioned to the interphase with 80% recovery of gag peptide p27 and reverse transcriptase and an about 25% recovery of the external env glycoprotein, gp148. the virus was treated with octylglycoside and its subcomponents separated. two gag-p27 containing fractions were obtained; gag-1, which also cont ... | 1994 | 8081461 |
| intracerebral infusion of tnf-alpha and il-6 failed to activate latent siv infection in the brains of macaques inoculated with macrophage-tropic neuroadapted sivmac. | lymphocyte-tropic (l-tropic) sivmac predictably causes immunosuppression and aids in rhesus macaques. siv encephalitis, on the other hand, is caused mainly by macrophage-tropic (m-tropic) sivmac. we have previously described the derivation of m-tropic, neuroadapted sivmac from molecularly cloned, l-tropic sivmac239. in this report we show that inoculation of four macaques with neuroadapted virus resulted in l-tropic sivmac-related diseases in all four but neurological disease in only two of the ... | 1994 | 8083607 |
| localization of the vpx packaging signal within the c terminus of the human immunodeficiency virus type 2 gag precursor protein. | viral protein x (vpx) is a human immunodeficiency virus type 2 (hiv-2) and simian immunodeficiency virus accessory protein that is packaged into virions in molar amounts equivalent to gag proteins. to delineate the processes of virus assembly that mediate vpx packaging, we used a recombinant vaccinia virus-t7 rna polymerase system to facilitate gag protein expression, particle assembly, and extracellular release. hiv genes were placed under control of the bacteriophage t7 promoter and transfecte ... | 1994 | 8083957 |
| intravaginal inoculation of rhesus macaques with cell-free simian immunodeficiency virus results in persistent or transient viremia. | the simian immunodeficiency virus (siv)-rhesus macaque model of heterosexual human immunodeficiency virus transmission consists of atraumatic application of cell-free sivmac onto the intact vaginal mucosa of mature female rhesus macaques. this procedure results in systemic infection, and eventually infected animals develop the clinical signs and pathologic changes of simian aids. to achieve 100% transmission with the virus stocks used to date, multiple intravaginal inoculations are required. the ... | 1994 | 8083977 |
| synergistic activation of simian immunodeficiency virus and human immunodeficiency virus type 1 transcription by retinoic acid and phorbol ester through an nf-kappa b-independent mechanism. | the activation of human immunodeficiency virus type 1 (hiv-1) expression in latently infected cells by exogenous agents is believed to be important in the progression of aids. most factors that are known to activate hiv-1 gene expression increase the binding of nf-kappa b or nf-kappa b-like transcription factors to the hiv-1 core enhancer region. in this report, we demonstrate that retinoic acid (ra) treatment of promonocytic u937 cells stimulates expression from the simian immunodeficiency viru ... | 1994 | 8083995 |
| [demonstration of cell death process by apoptosis in cat lymphocytes infected by fiv (feline immunodeficiency virus)]. | feline immunodeficiency virus (fiv), the causative agent of feline aids, induces a disease syndrome in cats characterized by a decreased lymphocyte-proliferative response to mitogens at all stages of infection and selective depletion of cd4 lymphocyte subsets. in this work, we report that peripheral blood lymphocytes isolated from fiv-infected cats undergo a spontaneous death, in vitro, according to a programmed cell death (pcd) or apoptosis. this phenomenon has also been seen in peripheral bloo ... | 1993 | 8087611 |
| downregulation of cell-surface cd4 expression by simian immunodeficiency virus nef prevents viral super infection. | the nef gene product encoded by the mac239 proviral clone of simian immunodeficiency virus (siv) markedly enhances viral replication and pathogenesis in vivo. we have used this biologically active nef isolate to examine the phenotype of nef in retrovirally transduced human t cells in culture. siv nef is shown to dramatically inhibit cell-surface expression of the cd4 glycoprotein without significantly affecting the total steady-state level of cellular cd4. this downregulation of the cell-surface ... | 1993 | 8098729 |
| acute infection of macaca nemestrina by human immunodeficiency virus type 1. | the pigtail macaque (macaca nemestrina) has a marked sensitivity to infection by simian immunodeficiency virus and human immunodeficiency virus type 2 (hiv-2). on this basis, we previously studied this species' susceptibility to hiv-1 and demonstrated infection in six macaques inoculated with either cell-associated hiv-1 or cell-free virus alone. this report expands upon our initial in vitro and in vivo findings. five laboratory-adapted and one primary clinical strain of hiv-1 replicated in vitr ... | 1993 | 8101673 |
| programmed cell death in aids-related hiv and siv infections. | one of the difficulties in understanding the complex pathology of human immunodeficiency virus (hiv) infection is to explain the progressive depletion of the cd4 helper t cell population and consequently the destruction of the immune system. although cytopathic effects of hiv are observed in vitro, they cannot in vivo account for cd4 t cell depletion because relatively few cells are productively infected. thus immunological mechanisms must be envisaged. we have found that peripheral blood lympho ... | 1993 | 8102239 |
| decline in the cd4+ lymphocyte population in the blood of siv-infected macaques is not reflected in lymph nodes. | although loss of cd4+ lymphocytes in peripheral blood is a standard criterion for evaluating the course of hiv disease, little is known about changes within lymphoid organs, which contain the bulk (> 50%) of the body's lymphocytes. because such studies are feasible only by using non-human primates, we have examined lymph nodes (lns), spleen, and blood from monkeys infected with two isolates of simian immunodeficiency virus (siv). during both the acute and chronic phases of these infections, char ... | 1993 | 8103665 |
| western equine encephalomyelitis: virulence markers and their epidemiologic significance. | comparative studies are described on the virulence of the western equine encephalomyelitis (wee) complex viruses for mice. three epizootic wee virus strains (mcmillan, cba 87, and cba civ 180) and five enzootic wee complex viruses (highlands j [hj], y62-33, aura, fort morgan [fm], and wee ag80-646) were examined. the neurovirulence and the neuroinvasiveness of these viruses for adult mice were established and correlated with viremia and virus replication in brain tissue. adult mice inoculated in ... | 1993 | 8103970 |
| preexposure prophylaxis with 9-(2-phosphonylmethoxyethyl)adenine against simian immunodeficiency virus infection in macaques. | a reverse transcriptase inhibitor, 9-(2-phosphonylmethoxyethyl)adenine (pmea), was evaluated for efficacy against acute simian immunodeficiency virus (siv) infection in juvenile macaques (macaca fascicularis). macaques were pretreated subcutaneously with pmea for 48 h before siv inoculation. drug treatment continued for an additional 28 days. efficacy of pmea was determined by detection of siv in blood, siv dna in peripheral blood mononuclear cells, and siv antibodies. protection from acute siv ... | 1994 | 8106760 |
| a new subtype of human immunodeficiency virus type 1 (mvp-5180) from cameroon. | a new subtype (mvp-5180) of human immunodeficiency virus type 1 (hiv-1) was isolated from a cameroonian aids patient. mvp-5180 was grown in several human t-cell lines and the monocytic u937 line. mvp-5180 dna could not be amplified by nested primer pcr with conventional env primers and could be only very faintly amplified with gag and pol primers. most german, ivoirian, and malawian anti-hiv-1 sera reacted faintly or moderately with env proteins in an mvp-5180 immunoblot, whereas some cameroonia ... | 1994 | 8107219 |
| mucosal model of genital immunization in male rhesus macaques with a recombinant simian immunodeficiency virus p27 antigen. | human immunodeficiency virus (hiv) can be transmitted through infected seminal fluid or vaginal or rectal secretions during heterosexual or homosexual intercourse. to prevent mucosal transmission and spread to the regional lymph nodes, an effective vaccine may need to stimulate immune responses at the genitourinary mucosa. in this study, we have developed a mucosal model of genital immunization in male rhesus macaques, by topical urethral immunization with recombinant simian immunodeficiency vir ... | 1994 | 8107223 |
| incomplete protection, but suppression of virus burden, elicited by subunit simian immunodeficiency virus vaccines. | we compared the efficacy of immunization with either simian immunodeficiency virus (siv) env glycoprotein (env), env plus gag proteins (gag-env), or whole inactivated virus (wiv), with or without recombinant live vaccinia vector (vv) priming, in protecting 23 rhesus macaques (six vaccine and two control groups) from challenge with sivmac251 clone bk28. vaccination elicited high titers of syncytium-inhibiting and anti-env (gp120/gp160) antibodies in all vaccinated macaques and anti-gag (p27) anti ... | 1994 | 8107246 |
| upstream u3 sequences in simian immunodeficiency virus are selectively deleted in vivo in the absence of an intact nef gene. | major transcriptional control elements are located within the u3 region of the long terminal repeats (ltrs) of lentivirus and other retroviral genomes. the nef auxiliary gene of simian immunodeficiency virus (siv) and human immunodeficiency virus overlaps about 70% of the 450- to 560-bp-long u3 region present in these primate lentiviruses. we analyzed viral dna sequences present in rhesus monkeys infected with a mutant of sivmac containing a 182-bp deletion in the region of nef that does not ove ... | 1994 | 8107267 |
| expression, characterization and purification of simian immunodeficiency virus soluble, oligomerized gp160 from mammalian cells. | the envelope glycoprotein, gp160, of human (hiv) and simian (siv) immunodeficiency viruses mediates virus-host cell binding followed by fusion of the viral and plasma membranes. the envelope proteins are known to exist as non-covalently associated oligomers on the virus surface. the production of permanent mammalian cell lines that constitutively secrete relatively high levels of soluble forms of siv gp160 is described and we show that these proteins are secreted predominantly as tetramers with ... | 1994 | 8113729 |
| serological survey for type d retroviruses and simian immunodeficiency virus in monkeys living in hungary. | acquired immunodeficiency in non-human primates has been associated with two types of retroviruses: (i) simian retrovirus (srv), a type d virus and (ii) a lentivirus, simian immunodeficiency virus (siv). both types represent a serious health threat to animals living in different primate research centres, zoos, medical institutions and in private homes. the sera of 175 monkeys belonging to different species were tested for the presence of antibodies against type d retroviruses and siv. the mason- ... | 1993 | 8116496 |
| hiv-1 nef inhibits a common activation pathway in nih-3t3 cells. | the human immunodeficiency virus type 1 (hiv-1) nef is a myristylated 27-kda, cytoplasmic protein. it is attributed to have suppressive effects on ltr-based expression and t cell activation. additionally, siv nef has been shown to possess an essential in vivo function in the development of immunodeficiency. to define the biochemical activity of hiv-1 nef in a signal transduction pathway, we have transduced murine nih-3t3 cells with a retroviral nef expression system. in nef-expressing cells, but ... | 1994 | 8120020 |
| cytopathologic and neurochemical correlates of progression to motor/cognitive impairment in siv-infected rhesus monkeys. | neurochemical, pathologic, virologic, and histochemical correlates of simian immunodeficiency virus (siv)-associated central nervous system (cns) dysfunction were assessed serially or at necropsy in rhesus monkeys that exhibited motor and cognitive deficits after siv infection. some infected monkeys presented with signs of acquired immunodeficiency disease (aids) at the time of sacrifice. seven of eight animals exhibited motor skill impairment which was associated with elevated quinolinic acid i ... | 1994 | 8120538 |
| identification of genes encoding zinc finger proteins, non-histone chromosomal hmg protein homologue, and a putative gtp phosphohydrolase in the genome of chilo iridescent virus. | five rna transcripts of about 1.2 to 1.7 kilobases were mapped to a part of the genome of insect iridescent virus type 6 (chilo iridescent virus; civ) between genome coordinates 0.832 and 0.856 within the ecori dna fragment f. the nucleotide sequence of this particular region (5702 base pairs) of the civ genome was determined. the dna sequence contains a number of perfect direct, inverted, and palindromic repeats including three clusters of tandemly organized repetitive dna elements located betw ... | 1994 | 8121799 |
| hiv-2 viral protein x association with the gag p27 capsid protein. | vpx is a 16 kda accessory protein expressed in cells infected with hiv-2 and most siv strains and is packaged into virus particles. in order to define the requirements for incorporation of vpx into virions, vpx and hiv-2 gag-pol were expressed independently from a vaccinia virus-based transient expression system. under these conditions, vpx was exported from transfected cells only when coexpressed with the hiv-2 gag-pol plasmid. a 27 kda protein coprecipitating with vpx was found to have an iden ... | 1994 | 8122374 |
| molecular and biological characterization of simian immunodeficiency virus macaque strain 32h proviral clones containing nef size variants. | the proviral genome of the 32h reisolate of simian immunodeficiency of macaques (sivmac32h) has been cloned and sequenced. including both long terminal repeats, it is 10277 base pairs in length and contains open reading frames for all known siv genes (gag, pol, vif, vpx, vpr, tat, rev, env and nef). this is the first report of an infectious sivmac molecular clone which contains no premature termination codons. three molecular clones of sivmac32h have been constructed differing in sequence only w ... | 1994 | 8126450 |
| simian immunodeficiency virus as a model for vaccination against hiv. induction in rhesus macaques of gag- or nef-specific cytotoxic t lymphocytes by lipopeptides. | the protection against infection by hiv probably requires the induction of both neutralizing abs and ctl responses. vaccination by attenuated hiv is hardly acceptable and the use of viral genes inserted in recombinant living vectors needs further development, especially with respect to safety. the peptidic vaccination is a promising approach but free peptides are usually poorly immunogenic. because potent immune responses have been obtained in mice with modified peptides such as lipopeptides, we ... | 1994 | 8133061 |
| immunopathogenic events in acute infection of rhesus monkeys with simian immunodeficiency virus of macaques. | infection of the rhesus monkey with simian immunodeficiency virus of macaques (sivmax) was employed to explore the early immune events associated with the initial containment of an acute aids virus infection. in nine rhesus monkeys infected intravenously with uncloned sivmac strain 251, high-level p27 plasma antigenemia was usually detected transiently from approximately day 7 through day 21 following virus inoculation. sivmac replication in lymph nodes measured by in situ rna hybridization clos ... | 1994 | 8139022 |
| spontaneous substitutions in the vicinity of the v3 analog affect cell tropism and pathogenicity of simian immunodeficiency virus. | simian immunodeficiency virus (siv) exists within tissues of infected macaques as a mixture of diverse genotypes. the goal of this study was to investigate the biologic significance of this variation in terms of cellular tropism and pathogenicity. pcr was used to amplify and clone 3'-half genomes from the spleen of an immunodeficiency siv-infected pig-tailed macaque (macaca nemestrina). eight infectious clones were generated by ligation of respective 3' clones into a related sivsm 5' clone, and ... | 1994 | 8139042 |
| variability of the env gene in cynomolgus macaques persistently infected with human immunodeficiency virus type 2 strain ben. | the sequence variability of distinct regions of the proviral env gene of human immunodeficiency virus type 2 strain ben (hiv-2ben) isolated sequentially over 3 to 4 years from six experimentally infected macaques was studied. the regions investigated were homologous to the v1, v2, v3, v4, v5, and v7 hypervariable regions identified in the env genes of hiv-1 and simian immunodeficiency virus sivmac, respectively. in contrast to findings with hiv-1 and sivmac, the v1- and v2-homologous regions wer ... | 1994 | 8139054 |
| pathology and localization of simian immunodeficiency virus in the reproductive tract of chronically infected male rhesus macaques. | despite the fact that human immunodeficiency virus (hiv) is transmitted by sexual contact, the biology of this mode of transmission remains largely undefined. hiv is present in semen in both cell-free and cell-associated forms and can be isolated from asymptomatic individuals and aids patients. the source of hiv in semen and the target cells for hiv transmission to men are unknown. epidemiologic studies have shown that in men, the presence of an intact foreskin is associated with increased risk ... | 1994 | 8139266 |
| extensive envelope heterogeneity of simian immunodeficiency virus in tissues from infected macaques. | the extent of virus genetic variation within tissues and peripheral blood mononuclear cells (pbmc) from two simian immunodeficiency virus (siv)-infected macaques was analyzed. the products of pcr amplification of two regions, region 1 (siv v1 region) and region 2 (region corresponding to the human immunodeficiency virus v3 cysteine loop and part of the c3 region immediately downstream), of the siv envelope were examined for single-stranded conformation polymorphism followed by sequence analysis ... | 1994 | 8151778 |
| specificity of antipeptide antibodies produced against v2 and v3 regions of the external envelope of human immunodeficiency virus type 2. | the v2 region of simian immunodeficiency virus (siv) and v3 region of human immunodeficiency virus type 1 (hiv-1) have been reported to be neutralization epitopes. we analysed the corresponding regions in hiv-2. synthetic peptides modeling the v2 (aa 149-168) and v3 (cv3: aa 298-315 and nv3: aa 306-324) regions of the hiv-2 external envelope glycoprotein were coupled to klh and used as immunogens in rabbits. we characterized the resulting antiv2 and antiv3 antibodies for their ability to recogni ... | 1994 | 8152439 |
| biphasic in vitro regulation of retroviral replication by cd8+ cells from nonhuman primates. | cd8+ t cells from naturally infected disease-resistant sooty mangabeys (cercocebus atys) secrete a soluble factor which inhibits the in vitro replication of the simian immunodeficiency virus (siv). to gain further insight on the mechanism(s) involved, cd8+ effector t cells and target cells from sooty mangabeys were immortalized and cloned. the target cells were then stably transfected with an siv-ltr-cat construct or with the parental cat plasmid as a control. a quantitative rt-pcr method, provi ... | 1994 | 8158536 |
| purification and characterization of simian immunodeficiency virus (sivmac) envelope glycoprotein gp130 from virus-infected cells. | a non-denaturing method has been developed for the purification of the envelope glycoprotein gp130 of the simian immunodeficiency virus (siv) using infected cells as starting material. the procedure involves solubilization of cells infected with siv (sivmac251), enrichment of glycoproteins by lectin affinity chromatography, fractionation by reverse phase chromatography and purification by immunoaffinity chromatography. this procedure results in a greater than 95% purification of gp130 as assesse ... | 1994 | 8165858 |
| purification of crystallizable recombinant sivmac251-32h proteinase. | we have cloned a simian immunodeficiency virus (siv) proteinase gene directly from proviral dna of the infectious viral stock sivmac251-32h (11/88 pool). the deduced amino acid sequence from this proteinase gene is similar to that for the published sivmac239 molecular clone. sivmac251-32h proteinase (siv pr) and its flanking pol sequences were expressed in escherichia coli as a fusion protein with most of the t7 bacteriophage gene 10 protein. the expressed protein formed cytoplasmic inclusion bo ... | 1994 | 8167477 |
| primary acute simian immunodeficiency virus infection of intestinal lymphoid tissue is associated with gastrointestinal dysfunction. | human immunodeficiency virus (hiv)-associated intestinal abnormalities can occur before immunodeficiency or infection with opportunistic enteropathogens. rhesus macaques infected with simian immunodeficiency virus (siv) develop an aids-like illness that frequently includes enteropathy. the development of enteropathy and its association with siv infection in the intestinal tract was examined. by 1 week after infection, siv-infected macrophages and t lymphocytes were detected in gut-associated lym ... | 1994 | 8169404 |
| a rev-inducible mutant gag gene stably transferred into t lymphocytes: an approach to gene therapy against human immunodeficiency virus type 1 infection. | one strategy for somatic gene therapy for human immunodeficiency virus type 1 (hiv-1) infection is based on the regulated expression of dominant negative mutants of the hiv-1 gag gene. to limit expression of the mutant gag polypeptide to hiv-1-infected cells, we have constructed a replication-defective retroviral vector that contains a rev-responsive element. by using this construct we have obviated problems that can be associated with constitutive expression of an exogenous gene, an important s ... | 1994 | 8170964 |
| hiv-1 nef activity in murine t cells. cd4 modulation and positive enhancement. | immediately after infection of the targeted cell by hiv-1, proviral gene expression is limited to the three regulatory proteins, tat, rev, and nef, with the nef transcript representing nearly 80% of total expression. additionally, simian immunodeficiency virus nef has been shown to be essential for high in vivo titer and the development of immunodeficiency. recent findings demonstrate that the negative effects of nef expression, as first defined in transformed t cell lines, are not present when ... | 1994 | 8176229 |
| evidence for simian immunodeficiency virus-specific igm and igg response in peripheral blood mononuclear cells of serum enzyme-linked immunosorbent assay-negative nonhuman primates. | in vitro polyclonal activation of peripheral blood mononuclear cells (pbmcs) from 70% of the simian immunodeficiency virus (siv) serum enzyme-linked, immunosorbent assay (elisa)-negative sooty mangabeys leads to synthesis and release of low but significant and reproducible levels of siv-reactive antibodies, as determined by elisa and western blot analysis. the predominant isotype of siv-reactive antibodies in the pokeweed mitogen (pwm) supernatant fluids from serum elisa-negative mangabeys is ig ... | 1994 | 8176639 |
| pathogenesis of sivmac infection in chinese and indian rhesus macaques: effects of splenectomy on virus burden. | the spleen and lymph nodes are the predominant sites of viral replication in siv and hiv infections. we studied splenectomized and control unsplenectomized rhesus macaques of both the indian and the chinese subspecies of macaca mulatta. all animals were inoculated with sivmac239, a molecularly cloned strain of siv. our data showed: (1) splenectomized animals, particularly among the indian subspecies, had a lower virus burden and longer survival than unsplenectomized controls, (2) the chinese mac ... | 1994 | 8178433 |
| purification of antibody-antigen complexes containing recombinant siv proteins: comparison of antigen and antibody-antigen complexes for immune priming. | this paper describes a general procedure for the two-step purification of recombinant proteins as antibody-antigen complexes in which there is no uncomplexed antibody or antigen. in this way, immune complexes containing the p17, p27, vpr and vpx proteins of simian immunodeficiency virus (siv) have been purified. antibody-antigen complexes are more immunogenic than antigen when administered either alone or with alum. the significance of the work is that this general method could be modified for t ... | 1994 | 8178558 |
| immune responses induced by prototype vaccines for aids in rhesus monkeys. | a battery of assay systems was used to profile both humoral and cell-mediated immune responses induced by immunization with candidate vaccines consisting of recombinant simian immunodeficiency virus (siv) glycoproteins rgp110 (nondenatured) with saf-m adjuvant (gp110 + saf-m) or rgp140 (denatured) with freund's adjuvant (gp140 + fa). all of the monkeys became infected after intravenous challenge. however, 16 days following infection, viral antigenemia was reduced in both groups of vaccinates com ... | 1994 | 8179961 |
| simian immunodeficiency virus sivsmmpbj 1.9 induces multinucleated giant cell formation in human peripheral blood monocytes. | sivsmmpbj 1.9 is an extremely virulent clone of the simian immunodeficiency virus sivsmmpbj 14 that causes an acute lethal disease in pigtail macaques, with death occurring 6 to 8 days after infection. the disease is characterized by bloody mucoid diarrhea, lymphoid hyperplasia, and giant cell pneumonia. we have developed an in vitro model for the production of multinucleated giant cells (mgcs) in which peripheral blood monocytes rapidly fuse to form mgcs when cultured in lymphocyte-conditioned ... | 1994 | 8179965 |
| intrathecal synthesis of igg in simian immunodeficiency virus (siv)-infected rhesus macaques (macaca mulatta). | we examined cerebrospinal fluid (csf) and serum from 25 simian immunodeficiency (siv)-infected rhesus macaques for the presence of siv-specific immunoglobulin g (igg) and for intrathecal synthesis of igg. siv-specific igg was present in csf from almost 50% of the macaques. in approximately half of these animals the siv-specific igg appeared to be derived from serum by leakage across a disrupted blood-brain barrier, whereas in the remaining animals there was evidence of intrathecal igg synthesis. ... | 1994 | 8179966 |
| specific suppression of human cd4 surface expression by nef from the pathogenic simian immunodeficiency virus sivmac239open. | hiv-1 nef down-modulates expression of human cd4, the human immunodeficiency virus (hiv) receptor, at the cell surface. down-modulation of retrovirus receptors has been shown to be important in the survival of infected cells. to relate this observation to aids pathogenesis, we compared the ability of nef from the sivmac239open and hiv-1 sf2 isolates to suppress cd4 surface levels. we first obtained the simian immunodeficiency virus (siv)nef gene by pcr and cloned it into the retroviral vector pl ... | 1994 | 8184546 |
| the "v3" domain is a determinant of simian immunodeficiency virus cell tropism. | thirty-one different mutant forms of simian immunodeficiency virus (sivmac) were created with changes in the region of env corresponding to the v3 domain of hiv-1. sixteen of these mutants had one amino acid change, 12 had two changes, two had three changes, and one had four changes in the sivmac "v3" loop. the ability of the mutant viruses to replicate in cemx174 cells, rhesus monkey peripheral blood mononuclear cells, and rhesus monkey alveolar macrophages was investigated. ten of the mutant v ... | 1994 | 8189506 |
| persistence of simian immunodeficiency virus mne variants upon transmission. | in macaques infected with a clone of simian immunodeficiency virus (siv) mne, viral variants consistently evolve multiple new potential glycosylation sites in the first variable region (v1) prior to the development of aids. in the present study, we asked whether viruses with these glycosylation sites persist when they are transmitted to a naive macaque. variants that evolved after transmission to a recipient macaque were compared with virus that evolved in the donor, which had been infected by c ... | 1994 | 8189548 |
| in vitro susceptibility of macaca nemestrina to human herpesvirus 6: a potential animal model of coinfection with primate immunodeficiency viruses. | human herpesvirus 6 (hhv-6), a lymphotropic herpesvirus, has been suggested as a potential cofactor in the acquired immunodeficiency syndrome (aids). previous studies indicate that hhv-6 has a restricted range of susceptible species. in this study, we tested the in vitro susceptibility to hhv-6 of macaca nemestrina (pig-tailed macaque), a species that has been found to be infectable by human immunodeficiency virus type i in vivo and that develops an aids-like syndrome following simian immunodefi ... | 1994 | 8198870 |
| reduced virus load in rhesus macaques immunized with recombinant gp160 and challenged with simian immunodeficiency virus. | as a safe alternative to inactivated and live-attenuated whole-virus siv vaccines, we have evaluated the potential of sivmac239 gp160 expressed by recombinant vaccinia virus (vsivgp160) and baculovirus (bsivgp160) to protectively immunize rhesus macaques against intravenous (i.v.) infection with pathogenic sivmac isolates. macaques were immunized with live vsivgp160 and/or bsivgp160 protein partially purified from insect cells. the challenge viruses, propagated in rhesus peripheral blood mononuc ... | 1994 | 8198872 |
| titration and characterization of two rhesus-derived sivmac challenge stocks. | simian immunodeficiency virus infection of macaques is a model for human immunodeficiency virus infection of humans. in vivo-titrated stocks of siv are essential for the utilization of this model for vaccine development. the elicitation of anti-human cell antibodies by some vaccines prepared in human cells and the related protective effects of the vaccine produced in human cells suggest a need for new macaque-derived siv stocks. here we describe the titration and characterization of two stocks o ... | 1994 | 8198874 |
| early stages of simian immunodeficiency virus infection in lymph nodes. evidence for high viral load and successive populations of target cells. | lymph nodes obtained from 14 macaques sacrificed at early time points following experimental inoculation with simian immunodeficiency virus were analyzed by in situ hybridization for virus load and virus cellular tropism. the lymph nodes presented a remarkably high viral load during the early phase of infection, as viral rna was detected in as many as 2% of lymph node cells 1 week after inoculation. at this stage, macrophages and t4 lymphocytes were identified by combined immunohistochemistry an ... | 1994 | 8203463 |
| crystallization and biochemical characterisation of simian immunodeficiency virus proteinase mutant. | | 1994 | 8206284 |
| cell fusion activity of the simian immunodeficiency virus envelope protein is modulated by the intracytoplasmic domain. | the processing and biological activity of envelope glycoproteins of pathogenic and nonpathogenic simian immunodeficiency viruses (sivs) was compared using recombinant vaccinia viruses (rvvs). the env glycoprotein of the nonpathogenic sivmac1a11 virus caused much larger and more numerous syncytia than the glycoprotein of the pathogenic sivmac239 virus in several cd4+ human cell lines. the env gene of sivmac239 codes for a full-length transmembrane (tm) protein, while the sivmac1a11 virus has a tm ... | 1993 | 8212561 |
| increased replication of simian immunodeficiency virus in cem x174 cells by morphine sulfate. | infection with simian immunodeficiency virus induces cytopathic effects on cem x174 cells in vitro. syncytium formation of siv-infected cem x174 cells was significantly enhanced in the presence of morphine sulfate, with a concomitant increase in the activity of cellular reverse transcriptase and in the expression of siv p27 core antigen. parallel establishment of the viability of the morphine-treated cells indicates that the short-acting opioid protects against cell lysis induced by siv so that ... | 1993 | 8216245 |
| virus isolation and quinolinic acid in primary and chronic simian immunodeficiency virus infection. | in this 2.5-year study of simian immunodeficiency virus (sivsm) infection in rhesus monkeys, quinolinic acid (quin) levels and virus isolation determinations were made in serial cerebrospinal fluid (csf) and blood samples to evaluate the relationship between these parameters over the course of infection. | 1993 | 8216973 |
| rapid screening for simian immunodeficiency virus variants using single-strand conformation polymorphism of pcr-amplified dna fragments. | | 1993 | 8217349 |
| cytosolic domain of the human immunodeficiency virus envelope glycoproteins binds to calmodulin and inhibits calmodulin-regulated proteins. | calmodulin (cam), the major intracellular receptor for calcium, is involved in regulation of diverse cellular functions. positively charged amphipathic helical segments have been identified as an important structural motif in the recognition of cam by different cam-activated enzymes and peptides. the carboxyl-terminal domain of the envelope glycoproteins of human and simian immunodeficiency viruses (hiv-1, hiv-2, and siv) contain regions that can fold into amphipathic helical segments, which clo ... | 1993 | 8226798 |
| t-cell activation influences initial dna synthesis of simian immunodeficiency virus in resting t lymphocytes from macaques. | the relationship between t-cell activation and early events in the replication cycle of simian immunodeficiency virus (siv) was analyzed in resting t lymphocytes from macaques. we used the polymerase chain reaction to detect an early product of reverse transcription (r/u5) and almost complete viral dna (long terminal repeat/gag). we found that siv can enter resting t lymphocytes and initiate replication but that the reverse transcription process is not efficient and proceeds slowly in resting ce ... | 1993 | 8230425 |
| different patterns of neuropathological disease in rhesus monkeys infected by simian immunodeficiency virus, and their relation to the humoral immune response. | the brains of 21 rhesus monkeys inoculated with sivmac251 were examined after intervals ranging from 3 to 27 months and compared with five uninoculated controls. eighteen animals became infected and individually exhibited several distinct patterns of disease. nine (50%) had largely intramural leptomeningeal venous infiltrates (lmvi) without multinucleate giant cells (mgc) or foamy macrophages. three (17%) had only mgc lesions, involving the cerebral parenchyma. one had both patterns and five (33 ... | 1993 | 8232754 |
| molecular and biological characteristics of a novel hiv-2 isolate, hiv-2hom. | in 1991 a new hiv-2 isolate (hiv-2hom) was isolated first from a german individual most likely infected in west africa in the beginning of the 1970s. the virus was isolated from both, the plasma and the peripheral blood lymphocytes of the patient by using okt-3-stimulated cord blood lymphocytes. the recovered viruses could be further propagated on jurkat cells and exhibited a broad cell tropism. biochemical and antigenic properties of hiv-2hom were examined by radioimmunoprecipitations. for a mo ... | 1993 | 8237111 |
| structure of the protease from simian immunodeficiency virus: complex with an irreversible nonpeptide inhibitor. | a variant of the simian immunodeficiency virus protease (siv pr), covalently bound to the inhibitor 1,2-epoxy-3-(p-nitrophenoxy)propane (epnp), was crystallized. the structure of the inhibited complex was determined by x-ray crystallography to a resolution of 2.4 a and refined to an r factor of 19%. the variant, siv pr s4h, was shown to diminish the rate of autolysis by at least 4-fold without affecting enzymatic parameters. the overall root mean square (rms) deviation of the alpha-carbons from ... | 1993 | 8241141 |
| three-dimensional structure of a simian immunodeficiency virus protease/inhibitor complex. implications for the design of human immunodeficiency virus type 1 and 2 protease inhibitors. | simian immunodeficiency virus (siv) proteins have considerable amino acid sequence homology to those from human immunodeficiency virus (hiv); thus monkeys are considered useful models for the preclinical evaluation of acquired immune deficiency syndrome (aids) therapeutics. we have crystallized and determined the three-dimensional structure of siv protease bound to the hydroxyethylene isostere inhibitor skf107457. crystals of the complex were grown from 25-32% saturated sodium chloride, by the h ... | 1993 | 8241159 |
| brief report: infection of a laboratory worker with simian immunodeficiency virus. | | 1994 | 8264739 |
| simian immunodeficiency virus in people. | | 1994 | 8264747 |
| animal models for perinatal transmission of pathogenic viruses. | in earlier work, mouse models have been used to demonstrate the efficacy and lack of toxicity of transplacental and perinatal azt therapy. these practical small animal models can be useful for evaluating antiviral drugs aimed at common retroviral functions only, since type c mulvs are used. a primate model for fetal infection with an immunosuppressive lentivirus, siv, has been established using ultrasound-guided inoculation of the amniotic fluid. the infection rate was 86% overall and 100% if th ... | 1993 | 8267266 |
| the human immunodeficiency virus-1 nef gene product: a positive factor for viral infection and replication in primary lymphocytes and macrophages. | considerable controversy and uncertainty have surrounded the biological function of the human immunodeficiency virus (hiv)-1 nef gene product. initial studies suggested that this early, nonstructural viral protein functioned as a negative regulatory factor; thus, it was proposed to play a role in establishing or maintaining viral latency. in contrast, studies in simian immunodeficiency virus (siv)mac-infected rhesus monkeys have suggested that nef is not a negative factor but rather plays a cent ... | 1994 | 8270859 |
| human adenovirus type 5 recombinants expressing simian immunodeficiency virus macaque strain gag antigens. | the p55 gag gene of simian immunodeficiency virus macaque strain (sivmac) and the core p27 gag component linked to a synthetic aug codon have been cloned into adenovirus type 5 vectors to generate either viable e3-replacement or defective e1-replacement viruses. the viruses express the expected siv proteins in both human and, for the non-defective viruses, monkey cells. a considerable proportion of the p55 produced is exported from the infected cell. these viruses should prove useful both in stu ... | 1993 | 8277293 |
| infectivity and pathogenesis of titered dosages of simian immunodeficiency virus experimentally inoculated into longtailed macaques (macaca fascicularis). | the 50% macaque infectious dose (mid50) and pathogenesis of uncloned simian immunodeficiency virus (isolated from a pigtailed macaque, sivmne) was determined in longtailed macaques (macaca fascicularis). five pairs of macaques were inoculated with 10-fold dilutions of the virus stock, and one macaque was mock-infected. the virologic and clinical status of these macaques was monitored for up to 80 weeks. the mid50 of sivmne was determined to be 10(2) cell culture infectious dose of the original v ... | 1993 | 8277718 |
| specific ablation of human immunodeficiency virus tat-expressing cells by conditionally toxic retroviruses. | the identification of human immunodeficiency virus (hiv) as the etiologic agent of aids has led to the proposal of novel intervention strategies to block hiv infection and viral replication or eliminate hiv-infected cells. we have produced recombinant retroviruses for a molecular ablation system, whereby a toxin gene can be delivered to hematopoietic cells for the specific elimination of hiv tat-expressing cells. for this cell-specific ablation, we have coupled the conditional toxin herpes simpl ... | 1994 | 8278395 |
| inhibition of hiv infection by flavanoids. | of a variety of flavanoids, the flavans were generally more effective than flavones and flavanones in selective inhibition of hiv-1, hiv-2 or siv infection. studies of their effects on the binding of scd4 and antibody to gp120 indicated that the effective compounds interact irreversibly with gp120 to inactive virus infectivity and block infection. | 1993 | 8279812 |
| further evidence of icosahedral symmetry in human and simian immunodeficiency virus. | specimens of hiv and siv have been examined by electron microscopy, using the techniques of conventional thin sectioning, freeze-substitution, cryosectioning, and cryomicroscopy of frozen hydrated specimens. in addition freeze-drying and critical point drying were used for both shadowed replicas and scanning electron microscopy. thin sections revealed hexagonal, pentagonal, or near-spherical profiles. angular particles were seen in shadowed replicas and also by scanning electron microscopy. the ... | 1993 | 8280478 |
| langerhans cells in oral mucosa of rhesus monkeys before and after infection by simian retrovirus-1 and simian immunodeficiency virus. | to study the influence of experimental infection with simian retrovirus-1 and simian immunodeficiency virus on the number and distribution of langerhans cells in oral mucosa of rhesus monkeys, 10 monkeys were intravenously inoculated with simian retrovirus-1, 7 with simian immunodeficiency virus, and 2 were mock-inoculated. biopsies were taken from gingiva and cheek pouch before infection and at 1 (simian immunodeficiency virus group only), 4, and 7 months after infection. langerhans cells were ... | 1993 | 8284080 |