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raman spectroscopic study on structure of human immunodeficiency virus (hiv) and hypericin-induced photosensitive damage of hiv.the first raman spectra of hiv1-hiv2 in human sera and hypericin-induced photosensitive damage of the virus have been obtained. the prominent raman lines in the spectra are assigned respectively to the carbohydrates of viral glycoprotein, rna, protein and lipid. the spectra are dominated by raman scattering of the carbohydrates. the lines of d-mannose and n-acetylglucosamine in carbohydrates are obvious and there is a beta-configuration in the anomeric c1 position in d-mannose. the viral rna dup ...200515986884
characterization of a long terminal repeat region from an infectious indian hiv type 2 isolate.an infectious indian human immunodeficiency virus type 2 isolate from mumbai, propagated in this laboratory, was found to bear an unusually short long terminal repeat (ltr) region. complete sequencing of the 601 bp ltr indicated a loss of around 250 nucleotide pairs from the unique 3' (u3) region as compared to other well-characterized hiv-2 isolates. phylogenetic analysis of this ltr shows closest relatedness to the guinea-bissau subtype a isolates hiv-2(cam2) and hiv-2(ali). the ltr from the b ...200515989467
performance of a rapid immunochromatographic screening test for detection of antibodies to human immunodeficiency virus type 1 (hiv-1) and hiv-2: experience at a tertiary care hospital in south india.the performance characteristics of a rapid immunochromatographic-screening test, sd bioline hiv-1/2 3.0 (standard diagnostics inc., kyonggi-do, south korea) on 23,754 sera and 30 plasma samples are reported. the sensitivity and specificity for the assay on serum samples are 100% and 99.4%, respectively. the assay detected antibodies in individuals infected with human immunodeficiency virus type 1 (hiv-1) genotypes a and c and hiv-2. this straightforward assay is a reliable diagnostic tool for sc ...200516081975
improved sensitivity of human immunodeficiency virus type 2 subtype b plasma viral load assay.we developed a new assay for human immunodeficiency virus type 2 plasma rna quantification based on a previous format. the new version performed significantly better than the original regarding the detection of subtype b, allowing the detection of 14 out of 36 plasma rnas in the subtype b-infected patients not detected with the original version.200516081987
increase in infectivity of targeted moloney murine leukemia virus-based gene-delivery vectors through lowering the threshold for fusion.many research groups have developed targeted vectors for gene therapy based on moloney murine leukemia virus (momlv). despite proper binding of the targeted vector to the target molecule, little or no infectivity of human cells expressing the target molecule has been achieved in most studies. one of the reasons for this lack of infectivity may be steric hindrance within the targeted envelope glycoprotein (env), impeding the conformational changes required for fusion and infection. here, attempts ...200516099905
human immunodeficiency virus nef induces rapid internalization of the t-cell coreceptor cd8alphabeta.human immunodeficiency virus (hiv) nef is a membrane-associated protein decreasing surface expression of cd4, cd28, and major histocompatibility complex class i on infected cells. we report that nef strongly down-modulates surface expression of the beta-chain of the cd8alphabeta receptor by accelerated endocytosis, while cd8 alpha-chain expression is less affected. by mutational analysis of the cytoplasmic tail of the cd8 beta-chain, an fmk amino acid motif was shown to be critical for nef-induc ...200516103193
predictive value of soluble haemoglobin scavenger receptor cd163 serum levels for survival in verified tuberculosis patients.pre-treatment serum levels of scd163 were measured in a cohort of 236 suspected tuberculosis (tb) cases from guinea-bissau, with a median follow-up period of 3.3 years (range 0-6.4 years). in 113 cases, the diagnosis of tb was verified by positive sputum microscopy and/or culture. among the verified tb cases, a decreased survival rate was found in 27 patients with scd163 levels above the upper reference limit (3.95 microg/ml). the difference in survival was significant during tb treatment (log r ...200516104988
evidence of hiv exposure and transient seroreactivity in archived hiv-negative severe hemophiliac sera.approximately 25% of hemophiliacs that were frequently exposed to blood clotting factor concentrates (cfcs) contaminated with human immunodeficiency virus (hiv) are presently hiv seronegative. in this study, we sought to determine if some of these individuals were at any time transiently hiv seropositive. in the early to mid-1980s the majority of severe hemophilia patients were exposed to cfcs contaminated with hiv. although many of these hemophiliacs became hiv-positive, a small percentage did ...200516107217
the chemokine sdf-1/cxcl12 binds to and signals through the orphan receptor rdc1 in t lymphocytes.combined phylogenetic and chromosomal location studies suggest that the orphan receptor rdc1 is related to cxc chemokine receptors. rdc1 provides a co-receptor function for a restricted number of human immunodeficiency virus (hiv) isolates, in particular for the cxcr4-using hiv-2 rod strain. here we show that cxcl12, the only known natural ligand for cxcr4, binds to and signals through rdc1. we demonstrate that rdc1 is expressed in t lymphocytes and that cxcl12-promoted chemotaxis is inhibited b ...200516107333
attenuation of hiv-1 infection by other microbial agents.although potentiation of human immunodeficiency virus (hiv) type 1 (hiv-1) infection has been known to occur in coinfection with a variety of pathogens and types of vaccination, there are emerging data on specific infectious agents that may attenuate hiv-1 infection. new literature suggests that certain pathogens are capable of inhibiting hiv-1 replication. these include gb virus c, measles virus, orientia tsutsugamushi, and human t lymphotropic virus types 1 and 2. in addition, there are confli ...200516107952
[diagnostic tests: human immunodeficiency virus type 1, type 2 (hiv-1, hiv 2)]. 200516111295
human african trypanosomiasis and human immunodeficiency virus co-infection in western kenya.to determine possible interaction between infections of trypanosoma brucei rhodesiense sleeping sickness and hiv/aids in western kenya.200516122107
infection with a molecularly cloned sivsm virus elicits high titer homologous neutralizing antibodies with heterologous neutralizing activity.we have evaluated the homologous and heterologous neutralizing antibody response in a cohort of six macaca nemestrina infected with the cloned virus sivsm62d that showed different levels of envelope diversification. two progressor macaques developed aids by 1.5 years post-inoculation and four non-progressors were asymptomatic for 3 years of follow-up. all macaques developed high titers of neutralizing antibodies against homologous sivsm viruses and intermediate titers against sivsmb670. heterolo ...200516128920
differential restriction of human immunodeficiency virus type 2 and simian immunodeficiency virus sivmac by trim5alpha alleles.primate lentiviruses have narrow host ranges, due in part to their sensitivities to mammalian intracellular antiviral factors such as apobec3g and trim5alpha. despite the protection provided by this innate immune system, retroviruses are able to transfer between species where they can cause disease. this is true for sooty mangabey simian immunodeficiency virus, which has transferred to humans as hiv-2 and to rhesus macaques as sivmac, where it causes aids. here we examine the sensitivities of th ...200516140735
selective inhibition of hiv-1 reverse transcriptase-associated ribonuclease h activity by hydroxylated tropolones.high-throughput screening of a national cancer institute library of pure natural products identified the hydroxylated tropolone derivatives beta-thujaplicinol (2,7-dihydroxy-4-1(methylethyl)-2,4,6-cycloheptatrien-1-one) and manicol (1,2,3,4-tetrahydro-5-7-dihydroxy-9-methyl-2-(1-methylethenyl)-6h-benzocyclohepten-6-one) as potent and selective inhibitors of the ribonuclease h (rnase h) activity of human immunodeficiency virus-type 1 reverse transcriptase (hiv-1 rt). beta-thujaplicinol inhibited ...200515741178
the interaction of ledgf/p75 with integrase is lentivirus-specific and promotes dna binding.we have previously shown that the p75 isoform of the transcriptional co-activator lens epithelium-derived growth factor (ledgf) interacts tightly with human immunodeficiency virus (hiv)-1 integrase (in) and is essential for nuclear targeting of this protein in human cells (cherepanov, p., maertens, g., proost, p., devreese, b., van beeumen, j., engelborghs, y., de clercq, e., and debyser, z. (2003) j. biol. chem. 278, 372-381; maertens, g., cherepanov, p., pluymers, w., busschots, k., de clercq, ...200515749713
amino acid preferences for a critical substrate binding subsite of retroviral proteases in type 1 cleavage sites.the specificities of the proteases of 11 retroviruses representing each of the seven genera of the family retroviridae were studied using a series of oligopeptides with amino acid substitutions in the p2 position of a naturally occurring type 1 cleavage site (val-ser-gln-asn-tyr pro-ile-val-gln; the arrow indicates the site of cleavage) in human immunodeficiency virus type 1 (hiv-1). this position was previously found to be one of the most critical in determining the substrate specificity differ ...200515767422
newborn liver gene transfer by an hiv-2-based lentiviral vector.newborn gene therapy, because it can prevent the damage caused by the onset of a disease, deserves specific attention. to evaluate gene transfer in tissues of newborn mice, we used a human immunodeficiency virus (hiv)-2 based lentiviral vector pseudotyped with vesicular stomatitis virus g glycoprotein expressing the green fluorescent protein reporter gene under the control of the cytomegalovirus promoter. we found that very low doses of hiv-2 could infect and be expressed in newborn mice. under ...200515772691
[evaluation of a panel of commercial kits for the detection of serum hiv-specific antibodies, and choice of alternative strategies for the serological diagnosis in libreville (gabon)].nine commercially available kits for the screening of serum antibodies to the human immunodeficiency virus (hiv) were evaluated with a panel of 170 serum samples from adults in gabon. the reference procedures showed that 96 samples had no antibodies, while 74 produced antibodies to hiv-1 (n=72) or hiv-2 (n=2). the sensitivity for 2 kits was less than 99% and the specificity of 3 less than 95%. based on the panel of gabonese serum samples, 4 of the 9 kits met the world health organization (who) a ...200515919629
cloning, expression, and purification of hiv-2 gp125: a target for hiv vaccination.the envelope of the human immunodeficiency virus (hiv) is the main target for neutralizing antibodies. we report the cloning, purification, and characterization of two recombinant forms of the envelope glycoprotein gp125 from a primary hiv-2sbl-6669 isolate. both constructs were truncated at the n- and c-termini, and in the gp125deltav1v2 construct the variable v1 and v2 loops were deleted. the recombinant glycoproteins were stably expressed in chinese hamster ovarian cells, producing soluble gp ...200515920286
rapid assessment of injection practices in cambodia, 2002.injection overuse and unsafe injection practices facilitate transmission of bloodborne pathogens such as hepatitis b virus (hbv), hepatitis c virus (hcv), and human immunodeficiency virus (hiv). anecdotal reports of unsafe and unnecessary therapeutic injections and the high prevalence of hbv (8.0%), hcv (6.5%), and hiv (2.6%) infection in cambodia have raised concern over injection safety. to estimate the magnitude and patterns of such practices, a rapid assessment of injection practices was con ...200515929800
the replicative fitness of primary human immunodeficiency virus type 1 (hiv-1) group m, hiv-1 group o, and hiv-2 isolates.the main (m) group of human immunodeficiency virus type 1 (hiv-1) is responsible for the global aids epidemic while hiv-1 group o (outlier) and hiv type 2 are endemic only in west and central africa. the failure of hiv-2 and especially hiv-1 group o to spread following the initial zoonotic jumps is not well understood. this study was designed to examine the relative replicative capacities between these human lentiviruses. a pairwise competition experiment was performed with peripheral blood mono ...200515994792
an envelope-determined, ph-independent endocytic route of viral entry determines the susceptibility of human immunodeficiency virus type 1 (hiv-1) and hiv-2 to lv2 restriction.we identified a postentry restriction, termed lv2, which determines the cellular tropism of two related human immunodeficiency virus type 2 (hiv-2) isolates and is dependent on the sequence of the capsid (ca) and envelope (env) proteins. to explain the reliance on both ca and env, we proposed that restrictive envs deliver susceptible capsids to a compartment where lv2 is active whereas nonrestrictive envs deliver capsids into a compartment where lv2 is either absent or less active. to test this ...200516014904
the promiscuous cc chemokine receptor d6 is a functional coreceptor for primary isolates of human immunodeficiency virus type 1 (hiv-1) and hiv-2 on astrocytes.the role of coreceptors other than ccr5 and cxcr4 in the pathogenesis of human immunodeficiency virus (hiv) disease is controversial. here we show that a promiscuous cc chemokine receptor, d6, can function as a coreceptor for various primary dual-tropic isolates of hiv type 1 (hiv-1) and hiv-2. furthermore, d6 usage is common among chimeric hiv-1 constructs bearing the gp120 proteins of isolates from early seroconverting patients. d6 mrna and immunoreactivity were demonstrated to be expressed in ...200516014924
primary sooty mangabey simian immunodeficiency virus and human immunodeficiency virus type 2 nef alleles modulate cell surface expression of various human receptors and enhance viral infectivity and replication.the nef gene of the pathogenic simian immunodeficiency virus (siv) mac239 clone has been well characterized. little is known, however, about the function of nef alleles derived from naturally sivsm-infected sooty mangabeys (cercocebus atys) and from human immunodeficiency virus type 2 (hiv-2)-infected individuals. addressing this, we demonstrate that, similarly to the sivmac239 nef, primary sivsm and hiv-2 nef alleles down-modulate cell surface expression of human cd4, cd28, cd3, and class i or ...200516051847
nef proteins from diverse groups of primate lentiviruses downmodulate cxcr4 to inhibit migration to the chemokine stromal derived factor 1.nef proteins of primate lentiviruses promote viral replication, virion infectivity, and evasion of antiviral immune responses by modulating signal transduction pathways and downregulating expression of receptors at the cell surface that are important for efficient antigen-specific responses, such as cd4, cd28, t-cell antigen receptor, and class i and class ii major histocompatibility complex. here we show that nef proteins from diverse groups of primate lentiviruses which do not require the chem ...200516051857
short communication: hiv type 2 dynamics.to gain a better understanding of why hiv-2 is less virulent than hiv-1 the viral dynamics of hiv-2 were studied in two swedish hiv-2-infected patients after starting antiretroviral therapy. linear regression analysis of log virus levels in plasma showed that virus decline during the first 2 weeks of therapy followed an exponential decay with half-lives of 2.2 and 2.0 days, respectively. these half-life measurements reflect the decline in the number of cells actively producing the virus, but may ...200516060831
isolation of human immunodeficiency virus type 2 biological clones from peripheral blood lymphocytes.infectious variants of human immunodeficiency virus (hiv) can be isolated from peripheral blood mononuclear cells (pbmc) of infected individuals by propagating the virus in co-cultures with healthy donor pbmc. standardized culture protocols have been designed specifically for the isolation of hiv type 1 (hiv-1) and proven effective for the isolation of virus from virtually all hiv-1-infected individuals. for the isolation of hiv-2, however, standard hiv-1 culture protocols have been only partial ...200516061969
detection of hiv-2 by pcr.genomes of human immunodeficiency virus type 2 (hiv-2), like those of hiv-1 or other retroviruses, are highly variable. these genetic variants have been classified into seven genetic subtypes. the average genetic divergence between different subtypes is about 20% in the gag gene, which is higher than those among hiv-1 group m subtypes. the current serological tests cannot distinguish the different subtypes from one another. to understand genetic variation, evolution, and subtype distribution of ...200516061976
quantification of proviral dna load of human immunodeficiency virus type 2 subtypes a and b using real-time pcr.hiv-2 infection is confined mostly to west africa. seven hiv-2 subtypes have so far been described; only hiv-2 subtypes a and b are prevalent, the others being considered self-limiting infections at the epidemiological level. the main limitation for the hiv-2 dna proviral quantification is the lack of hiv-2 dna standard. we designed and tested a new hiv-2 primer couple that amplifies both the hiv-2 rod strain and hiv-1 lav/bru strain. these hiv-2 primers were used to quantified an hiv-2 standard ...200516061978
amplification and cloning of near full-length hiv-2 genomes.the genomes of human immunodeficiency virus type 2 (hiv-2), like those of hiv-1, are not only extremely variable but are also highly recombinogenic. determination of subtypes based on partial genomes cannot predict the subtype classification of other regions of the genome owing to the frequent occurrence of recombinant genomes among subtypes. to fully understand the genetic variation and evolution of hiv-2s, full-length viral genomes need to be obtained for genetic analysis. full-length hiv-2 ge ...200516061992
polymorphism of the human immunodeficiency virus type 2 (hiv-2) protease gene and selection of drug resistance mutations in hiv-2-infected patients treated with protease inhibitors.we described the baseline polymorphism of the human immunodeficiency virus type 2 (hiv-2) protease gene from 94 treatment-naive patients and the longitudinal follow-up of 17 protease inhibitor-treated patients. compared to the hiv-2 consensus sequences, baseline polymorphism involved 47 positions. substitutions selected under treatment were observed at positions corresponding to hiv-1 resistance mutations as well as at positions of currently unknown impact on hiv-1.200515635022
hiv-2 infection and chemokine receptors usage - clues to reduced virulence of hiv-2.human immunodeficiency virus type 1 (hiv-1) and type 2 (hiv-2) are the causative agents of acquired immunodeficiency syndrome (aids). without therapeutic intervention, hiv-1 or hiv-2 infections in humans are characterized by a gradual and irreversible immunologic failure that ultimately leads to the onset of a severe immunodeficiency that constitutes the hallmark of aids. in the last two decades aids has evolved into a global epidemic affecting millions of persons worldwide. although sharing sev ...200515638719
antigen-specific beta-chemokine production and cd8 t-cell noncytotoxic antiviral activity in hiv-2-infected individuals.human immunodeficiency virus-2 (hiv-2) is less pathogenic than hiv-1, and the disease progression in hiv-2-infected individuals seems to be similar to that seen in hiv-1-infected long-term nonprogressors. cell-mediated immune responses and the production of noncytotoxic cd8+ t-cell antiviral factors (caf) and beta-chemokines have been correlated to protection against hiv-1 and associated with asymptomatic infection and slower disease progression. we investigated the antigen-induced beta-chemokin ...200515644124
polymorphism and drug-selected mutations in the reverse transcriptase gene of hiv-2 from patients living in southeastern france.few data are available about the susceptibility and the genotypic resistance pattern of human immunodeficiency virus type 2 (hiv-2) to nucleoside reverse transcriptase inhibitors (nrtis). the hiv-2 reverse transcriptase (rt) gene from 25 hiv-2-infected patients followed-up in marseilles and the surrounding area was analyzed. the aims of this study were to characterize the polymorphism of hiv-2 rt in the absence of drug, to determine whether it naturally harbors codons associated with drug-resist ...200515648062
ccr5, gpr15, and cxcr6 are major coreceptors of human immunodeficiency virus type 2 variants isolated from individuals with and without plasma viremia.human immunodeficiency virus type 2 (hiv-2) is generally considered capable of using a broad range of coreceptors. since hiv-2 variants from individuals with nonprogressive infection were not studied previously, the possibility that broad coreceptor usage is a property of variants associated with progressive infection could not be excluded. to test this, we determined the coreceptor usage of 43 hiv-2 variants isolated from six long-term-infected individuals with undetectable plasma viremia. usin ...200515650194
functional analysis of vif protein shows less restriction of human immunodeficiency virus type 2 by apobec3g.viral infectivity factor (vif) is one of the human immunodeficiency virus (hiv) accessory proteins and is conserved in the primate lentivirus group. this protein is essential for viral replication in vivo and for productive infection of nonpermissive cells, such as peripheral blood mononuclear cells (pbmc). vif counteracts an antiretroviral cellular factor in nonpermissive cells named cem15/apobec3g. although hiv type 1 (hiv-1) vif protein (vif1) can be functionally replaced by hiv-2 vif protein ...200515613310
detection and partial characterization of simian immunodeficiency virus sivsm strains from bush meat samples from rural sierra leone.human immunodeficiency virus type 2 (hiv-2) originated from simian immunodeficiency viruses (sivs) that naturally infect sooty mangabeys (sms; cercocebus atys). in order to further investigate the relationship between hiv-2 and sivsm, the siv specific to the sm, we characterized seven new sivsm strains from sms sold in sierra leone markets as bush meat. the gag, pol, and env sequences showed that, while the viruses of all seven sms belonged to the sivsm-hiv-2 lineage, they were highly divergent ...200515681464
mitochondrial dna and retroviral rna analyses of archival oral polio vaccine (opv chat) materials: evidence of macaque nuclear sequences confirms substrate identity.inoculation of live experimental oral poliovirus vaccines (opv chat) during the 1950s in central africa has been proposed to account for the introduction of hiv into human populations. for this to have occurred, it would have been necessary for chimpanzee rather than macaque kidney epithelial cells to have been included in the preparation of early opv materials. theoretically, this could have led to contamination with a progenitor of hiv-1 derived from a related simian immunodeficiency virus of ...200515705467
chimeric human immunodeficiency virus type 1 virions that contain the simian immunodeficiency virus nef gene are cyclosporin a resistant.we have previously shown that human immunodeficiency virus type 1 (hiv-1) virions which have their own nef gene deleted and are trans complemented to contain hiv-2 or simian immunodeficiency virus (siv) nef become resistant to treatment with cyclosporin a. to expand and confirm these studies, we have tested an hiv-1 isolate in which the hiv-1 nef gene has been replaced by the nef gene from siv in a multiround infectivity assay using more physiologically relevant cell types. our results confirm t ...200515709044
the vpr protein from hiv-1: distinct roles along the viral life cycle.the genomes of human and simian immunodeficiency viruses (hiv and siv) encode the gag, pol and env genes and contain at least six supplementary open reading frames termed tat, rev, nef, vif, vpr, vpx and vpu. while the tat and rev genes encode regulatory proteins absolutely required for virus replication, nef, vif, vpr, vpx and vpu encode for small proteins referred to "auxiliary" (or "accessory"), since their expression is usually dispensable for virus growth in many in vitro systems. however, ...200515725353
human immunodeficiency virus (hiv)-2-specific t lymphocyte proliferative responses in hiv-2-infected and in hiv-2-exposed but uninfected individuals in guinea-bissau.human immunodeficiency virus (hiv)-2-specific t lymphocyte proliferative responses were determined in cultures of peripheral blood mononuclear cells from hiv-2-exposed uninfected individuals, hiv-2-infected individuals and hiv-negative controls in guinea-bissau. increased hiv-2-specific t lymphocyte proliferative responses were detected in both groups compared to hiv-negative controls (healthy hiv-uninfected individuals without known exposure to an hiv-infected person); five out of 29 of the hiv ...200515730394
functional domains within the human immunodeficiency virus type 2 envelope protein required to enhance virus production.primate lentiviruses code for a protein that stimulates virus production. in human immunodeficiency virus type 1 (hiv-1), the activity is provided by the accessory protein, vpu, while in hiv-2 and simian immunodeficiency virus it is a property of the envelope (env) glycoprotein. using a group of diverse retroviruses and cell types, we have confirmed the functional equivalence of the two proteins. however, despite these similarities, the two proteins have markedly different functional domains. wh ...200515731257
no observed effect of gb virus c coinfection on disease progression in a cohort of african woman infected with hiv-1 or hiv-2.we studied mortality among subjects with human immunodeficiency virus (hiv)-1 and hiv-2 infection in relation to gb virus (gbv)-c coinfection. no significant differences in mortality were seen between subjects with and subjects without gbv-c coinfection who also had either hiv-1 or hiv-2 infection. no association between gbv-c and hiv plasma virus loads or cd4 cell count was observed.200515736023
cognitive and motor deficits associated with hiv-2(287) infection in infant pigtailed macaques: a nonhuman primate model of pediatric neuro-aids.lentivirus-infected nonhuman primates exhibit behavioral and neurological pathology similar to human immunodeficiency virus (hiv)-infected humans and offer a means to examine the effects of lentivirus infection while controlling for confounding factors inherent in human populations. the purpose of this study was to examine cognitive and motor development in infant macaques vertically infected with hiv-2287. subjects were 20 infant pigtail macaques (macaca nemestrina); 8 controls born to uninfect ...200515804957
viral dynamics of primary hiv-1 infection in senegal, west africa.few studies have addressed primary human immunodeficiency virus (hiv) type 1 infection in sub-saharan africa, where the epidemic is of a predominantly heterosexual character and is caused by different subtypes. the present study examines the dynamics of viral replication in subjects infected with various hiv-1 subtypes.200515809904
annulling a dangerous liaison: vaccination strategies against aids and tuberculosis.human immunodeficiency virus (hiv) and mycobacterium tuberculosis annually cause 3 million and 2 million deaths, respectively. last year, 600,000 individuals, doubly infected with hiv and m. tuberculosis, died. since world war i, approximately 150 million people have succumbed to these two infections--more total deaths than in all wars in the last 2,000 years. although the perceived threats of new infections such as sars, new variant creutzfeldt-jakob disease and anthrax are real, these outbreak ...200515812488
subtype & cytokine profiles of hiv infected individuals from south india.the global surveillance of human immunodeficiency virus (hiv) subtypes (clades) helps understand the global distribution and incidence of different hiv subtypes. as knowledge about subtypes circulating in an area is needed for developing a candidate vaccine, prevalence of the subtypes hiv-1 and hiv-2 were studied in south india. the profile of cytokines interleukin 10 (il10) and interferon gamma (ifngamma) in both types of infection were also analysed as these are considered indicators of diseas ...200515817940
biology of the hiv nef protein.the accessory nef protein is expressed by all primate lentiviruses--hiv-1,hiv-2 and simian immune deficiency virus (siv). its expression in the early stages of the viral life cycle ensures two basic attributes of hiv infection. these are t-cell activation and the establishment of a persistent state of infection. nef has a positive effect on viral infection and replication by promoting the survival of infected cells. its role in hiv persistence is based largely on the ability of nef to downmodula ...200515817946
inactivation of viruses in platelet concentrates by photochemical treatment with amotosalen and long-wavelength ultraviolet light.viral contamination of platelet (plt) concentrates can result in transfusion-transmitted diseases. a photochemical treatment (pct) process with amotosalen-hcl and long-wavelength ultraviolet light (uva), which cross-links nucleic acids, was developed to inactivate viruses and other pathogens in plt concentrates.200515819680
differential inhibition of hiv-1 and siv envelope-mediated cell fusion by c34 peptides derived from the c-terminal heptad repeat of gp41 from diverse strains of hiv-1, hiv-2, and siv.the spectrum of inhibition of human (hiv) and simian (siv) immunodeficiency virus envelope (env)-mediated cell fusion by c34, a 34 residue peptide corresponding to the c-heptad repeat of gp41 (residues 628-661 of hiv-1 env), has been examined using a panel of five envelope glycoproteins, three from hiv-1 (lav, sf162 and 89.6) and two from siv (mac239 and mac316), and six c34 peptides derived from three strains of hiv-1 (lav, n cm, and o cm), two strains of hiv-2 (eho and ali), and one strain of ...200515828842
cd8+ t cell responses to human immunodeficiency viruses type 2 (hiv-2) and type 1 (hiv-1) gag proteins are distinguishable by magnitude and breadth but not cellular phenotype.the mechanisms underlying the relatively slow progression of human immunodeficiency virus type 2 (hiv-2) compared with hiv-1 infection are undefined and could be a result of more effective immune responses. we used hiv-2 and hiv-1 ifn-gamma enzyme-linked immunospot assays to evaluate cd8(+) t cell responses in antiretroviral-naive hiv-2- ('hiv-2(+)') and hiv-1-infected ('hiv-1(+)') individuals. gag-specific responses were detected in the majority of hiv-2(+) and hiv-1(+) subjects. overlapping ga ...200515832290
novel single-round pcr and cloning of full-length envelope genes of hiv-1 may yield new insight into biomolecular antibacterial drug development.nested or semi-nested polymerase chain reaction (pcr) with a 'hot start' is the preferred amplification method for full-length, in-frame envelope genes (gp160) of the human immunodeficiency virus type 1 (hiv-1). this generally follows an extensive screening process. this paper describes an effective single-round pcr method and cloning process for hiv-1 gp160 from clinical samples, and cell and tissue cultures developed during the early stages of construction of a molecular hiv-1 vaccine. the amp ...200515847926
spectrum of antiviral activity of o-(acetoxyphenyl)hept-2-ynyl sulphide (aphs).since some antiviral drugs have a broad spectrum of action, the aim of this study was to assess whether o-(acetoxyphenyl)hept-2-ynyl sulphide (aphs), a recently described inhibitor of human immunodeficiency virus type 1 (hiv-1) replication, has an effect on the replication of other retroviruses, (-) and (+) rna viruses and dna viruses. aphs did not affect the replication of feline immunodeficiency virus, hiv-2 and a hiv-1 strain resistant to non-nucleoside reverse transcriptase inhibitors (nnrti ...200515848298
natural resistance of human immunodeficiency virus type 2 to zidovudine.zidovudine (azt) is a reverse transcriptase (rt) inhibitor widely used to treat persons infected with hiv-1 and hiv-2. recent data on treated patients suggest differences in the antiviral activity of azt between hiv-1 and hiv-2. we evaluated the antiviral activity of azt on hiv-2 by using multiple approaches including in vitro selection experiments, analysis of growth kinetics with azt, and phenotypic testing. a total of 5 wild-type (wt) hiv-2 viruses were used in the analysis. for comparison, 4 ...200515892966
scorpion-toxin mimics of cd4 in complex with human immunodeficiency virus gp120 crystal structures, molecular mimicry, and neutralization breadth.the binding surface on cd4 for the hiv-1 gp120 envelope glycoprotein has been transplanted previously onto a scorpion-toxin scaffold. here, we use x-ray crystallography to characterize atomic-level details of gp120 with this transplant, cd4m33. despite known envelope flexibility, the conformation of gp120 induced by cd4m33 was so similar to that induced by cd4 that localized measures were required to distinguish ligand-induced differences from lattice variation. to investigate relationships betw ...200515893666
anti-hiv activity against immunodeficiency virus type 1 (hiv-i) and type ii (hiv-ii) of compounds isolated from the stem bark of combretum molle.in vitro anti-hiv activity of various extracts prepared from the stem bark of combretum molle (r. br. ex. g. don.) engl & diels (combretaceae), a plant widely used in ethiopian traditional medicine for the treatment of liver diseases, malaria and tuberculosis has been assessed against human imnmuunodeficiencvy virus type 1 (hiv-1) and type 2 (hiv-2). the total extract was prepared by percolation with 80% methanol whilst the petroleum ether, chloroform, acetone and 100% methanol fractions were ob ...200516370525
duplication of peri-kappab and nf-kappab sites of the first human immunodeficiency virus type 2 (hiv-2) transmission in brazil.after the identification of hiv-2 in 1986, most of the cases reported have been concentrated in west africa. we identified a case of hiv-2 infection in são paulo, brazil of a 45-year-old female who presented with pneumocystis carinii pneumonia, with a cd4 count of 22 cells/ml. dna samples from this patient were subjected to end-point pcr amplification of the ltr region. clones were sequenced and subjected to phylogenetic analyses. all clones were subtype a related, and four presented an insertio ...200516386115
characterization of human immunodeficiency virus (hiv)-2 vector mobilization by hiv-1.conditionally replicating human immunodeficiency virus type 2 (crhiv-2) vectors can compete with hiv-1 for packaging in hiv-1-infected cells, indicating that the mobilization of vectors could selectively target as well as protect reservoirs susceptible to hiv-1 infection. the incorporation of hiv-1-specific antiviral transgenes in crhiv-2 vectors, although increasing the direct antiviral effect, may decrease mobilization and transmission to surrounding cells. to investigate how hiv-1-specific ca ...200516390277
tipranavir.tipranavir is a newly approved protease inhibitor that belongs to the class of 4-hydroxy-5,6-dyhydro-2-pyrones. it exhibits potent in vitro activity against both human immunodeficiency virus (hiv)-1 and hiv-2, including clinical isolates with multiple protease inhibitor-resistant mutations. tipranavir requires coadministration with ritonavir to achieve clinically meaningful serum concentration. in randomized, phase iii, open-label trials, it was found to be superior to the currently available bo ...200516395412
divergent hiv and simian immunodeficiency virus surveillance, zaire.recent hiv infection or divergent hiv or simian immunodeficiency virus (siv) strains may be responsible for western blot-indeterminate results on 70 serum samples from zairian hospital employees that were reactive in an enzyme immunoassay. using universal polymerase chain reaction hiv-1, hiv-2, and siv primers, we detected 1 (1.4%) hiv-1 sequence. except for 1 sample, no molecular evidence for unusual hiv- or siv-like strains in this sampling was found.200516229778
hiv-2 genomic rna contains a novel type of ires located downstream of its initiation codon.eukaryotic translation initiation begins with assembly of a 48s ribosomal complex at the 5' cap structure or at an internal ribosomal entry segment (ires). in both cases, ribosomal positioning at the aug codon requires a 5' untranslated region upstream from the initiation site. here, we report that translation of the genomic rna of human immunodeficiency virus type 2 takes place by attachment of the 48s ribosomal preinitiation complex to the coding region, with no need for an upstream 5' untrans ...200516244661
antiviral potential of a new generation of acyclic nucleoside phosphonates, the 6-[2-(phosphonomethoxy)alkoxy]-2,4-diaminopyrimidines.three acyclic nucleoside phosphonates (anps) have been formally approved for clinical use in the treatment of 1) cytomegalovirus retinitis in aids patients (cidofovir, by the intravenous route), 2) chronic hepatitis b virus (hbv) infections (adefovir dipivoxil, by the oral route), and 3) human immunodeficiency virus (hiv) infections (tenofovir disoproxil fumarate, by the oral route). the activity spectrum of cidofovir {(s)- 1-[3-hydroxy-2-(phosphonomethoxy)propyl]cytosine [(s)-hpmpc)]}, like tha ...200516247948
immune responses to six synthetic peptides of capsid protein with sera from hiv-1 infected individuals.many b cell epitopes within p24 of human immunodeficiency virus type 1 (hiv-1) were identified, while most of them were determined by using murine monoclonal antibodies reacting with overlapping peptides of p24. therefore these epitopes may not represent the actual epitopes recognized by the hiv-1 infected individuals. in the present study, immune responses of 67 hiv-1 positive sera from yunnan province, china to five peptides on p24 of hiv-1 and one of hiv-2 were analyzed. all of 67 sera did no ...200516274627
evolution of human immunodeficiency virus type 2 coreceptor usage, autologous neutralization, envelope sequence and glycosylation.to investigate why human immunodeficiency virus type 2 (hiv-2) is less virulent than hiv-1, the evolution of coreceptor usage, autologous neutralization, envelope sequence and glycosylation was studied in sequentially obtained virus isolates and sera from four hiv-2-infected individuals. neutralization of primary hiv-2 isolates was tested by a cell line-based assay and igg purified from patients' sera. significant autologous neutralization was observed for the majority (39 of 54) of the hiv-2 se ...200516298986
genomic diversity of human immunodeficiency viruses.globally circulating strains of human immunodeficiency virus type one (hiv-1) exhibit an extraordinary degree of genetic diversity. sequences derived from hiv-1 strains have historically been classified on the basis of their phylogenetic relationships. the viruses have been classified into groups, subtypes or clades and circulating recombinant forms (crfs). groups were originally named m for main, o for outlier and n for non-m-non-o. the identification of subtypes and crfs provides a means of tr ...200527407775
an accurate confirmation of human immunodeficiency virus type 1 (hiv-1) and 2 (hiv-2) infections with a dot blot assay using recombinant p24, gp41, gp120 and gp36 antigens.an immunoblot assay using four recombinant proteins corresponding to human immunodeficiency virus type 1 (hiv-1) and type 2 (hiv-2) gene products was developed to confirm the presence of antibodies to hiv-1 and 2 in sera reactive in screening elisas. serum samples for testing were obtained from healthy seronegative blood donors and from different categories of hiv-infected individuals (asymptomatic hiv-infected, and aids). a positive reaction was defined as reactivity against gag (p24) and at le ...200415912198
evidence for negative selective pressure in hiv-2 evolution in vivo.hiv-2 sequence divergence and evolution in vivo has not been well characterized so far. to investigate the extent of hiv-2 genetic diversity and better understand how hiv-2 evolves in vivo, env c2-c3 nucleotide sequences were obtained from the plasma and pbmcs virus populations of four hiv-2 patients with different infection periods. phylogenetic analysis showed that three patients were infected with subtype a hiv-2 and the remaining patient was infected with a divergent hiv-2 that could not be ...200415737915
human retroviruses in leukaemia and aids: reflections on their discovery, biology and epidemiology.the study of retroviruses has had a profound impact by unveiling an unusual form of viral replication: the multiplication of rna viruses via a proviral dna, for which jan svoboda provided the experimental model over forty years ago. in 1970 temin, mizutani and baltimore discovered that this group of viruses contains a unique enzyme catalysing the synthesis of a dna copy of the viral rna: reverse transcriptase (rt). the discovery of rt has itself had an enormous impact on molecular biology in gen ...200415682876
the rationale for pathogen-inactivation treatment of blood components.blood transfusion provides an ideal portal of entry for microorganisms. although current residual risks of microbial infection by transfusion are extremely low in the developed world, the requirements for even safer blood are paradoxically increasing. such requirements are partly a legacy of the tragic transmissions of human immunodeficiency virus (hiv) by blood early in the acquired immunodeficiency syndrome pandemic and are legally expressed in consumer protection laws imposing strict product ...200415615254
a link between sivsm in sooty mangabeys (sm) in wild-living monkeys in sierra leone and sivsm in an american-based sm colony.we have developed a noninvasive method for sivsm virion rna detection in feces of captive sooty mangabeys (sms) (cercocebus atys). employing this method to investigate the natural history of sivsm in endangered sms is useful for understanding the diversity and evolution of sivsm and hiv-2. the fecal samples of 61 wild-living sms and 14 chimpanzees (pan troglodytes verus) were studied. samples were collected in rural sierra leone in 1993. one sm sample tested positive by reverse transcriptase-pcr ...200415650427
phylogenetic demonstration of two cases of perinatal human immunodeficiency virus type 2 infection diagnosed in adulthood.hiv-2 infection was diagnosed in two patients 15 and 24 years of age and, thereafter, in their mothers. epidemiological data suggested that vertical transmission was the most probable mode of infection in both patients (mota-miranda a, et al.: aids 2001;15:2460-2461). phylogenetic analysis of env c2-c3 sequences from the patients and their mothers was used in an attempt to confirm or exclude the events of perinatal hiv-2 transmission. sequences from each putative transmission pair formed monophy ...200415650432
functional solubilization of aggregation-prone hiv envelope proteins by covalent fusion with chaperone modules.the envelope proteins of human immunodeficiency virus (hiv) and human t-cell lymphotrophic virus (htlv) mediate cell attachment and membrane fusion. for hiv-1, the precursor protein gp160 is cleaved proteolytically into two fragments, the surface-associated receptor binding subunit gp120 and the membrane spanning subunit gp41, which is involved in membrane fusion during virus entry. soluble and immunoreactive variants of gp41 are essential for the reliable diagnosis of hiv-1 infections. hitherto ...200415644217
a simple semi-rapid hiv-1&2 confirmatory immunoassay using magnetic particles.the bionor hiv-1&2 confirmatory test is a semi-rapid simple immunoassay based on magnetic particles for the confirmation of serological status to human immunodeficiency virus (hiv). the specificity and sensitivity of this assay was evaluated by comparison with the diagnostic biotechnology hiv-1 western blot (wb) 2.2 and the hiv-2/sbl-6669 wb. bionor's confirmatory test demonstrated 98% specificity when testing sero-negative blood donors and false positive sera in screening tests compared to 81.5 ...200414667535
the history of sivs and aids: epidemiology, phylogeny and biology of isolates from naturally siv infected non-human primates (nhp) in africa.simian immunodeficiency virus (siv) naturally infects non-human primates in africa. to date, 40 sivs have been described both in natural hosts and in heterologous species. these viruses are highly diverse and the majority cluster in 6 relatively equidistant phylogenetic lineages. at least 8 sivs are currently considered as recombinant viruses, based on different clustering patterns in different genomic regions. only three types of genomes are known, based on the number of accessory genes: vpr-co ...200414766362
polymorphism and drug-selected mutations in the protease gene of human immunodeficiency virus type 2 from patients living in southern france.the susceptibility of human immunodeficiency virus type 2 (hiv-2) to protease inhibitors (pi) is largely unknown. we studied hiv-2 protease genes from 21 hiv-2-infected patients who were exposed or not exposed to pi. the aim of this study was (i). to characterize the polymorphism of hiv-2 protease in the absence of drug, (ii). to know whether the hiv-2 protease gene naturally harbors hiv-1 drug resistance codons, and (iii). to identify mutations emerging under pi-selective pressure. sixty-five h ...200414766818
phenotypic susceptibility to nonnucleoside inhibitors of virion-associated reverse transcriptase from different hiv types and groups.to evaluate a phenotype assay based on plasma reverse transcriptase (rt) to assess hiv susceptibility to nonnucleoside rt inhibitors (nnrtis). to compare rt-based phenotype with recombinant virus assay (rva) phenotype- and genotype-based analysis. to assess group o and hiv-2 susceptibility to nnrtis in correlation with genotype polymorphisms.200415577405
rapid discrimination between human immunodeficiency virus type 2 groups a and b by real-time pcr.we studied the feasibility of genotyping human immunodeficiency virus (hiv) type 2 groups a and b by real-time pcr. two group-specific pcrs were developed. real-time genotyping of 22 samples of genotype a, 10 samples of genotype b, and the isolate of new group h were compared to genotyping by sequencing and phylogeny. the group-specific pcrs specifically identified 84.3% of group a or b samples; isolate h was not detected. this method allowed rapid and specific discrimination between hiv-2 group ...200415583327
a single amino acid substitution in human apobec3g antiretroviral enzyme confers resistance to hiv-1 virion infectivity factor-induced depletion.hiv-1 and other retroviruses occasionally undergo hypermutation, characterized by a high rate of g-to-a substitution. recently, the human apolipoprotein b mrna-editing, enzyme-catalytic, polypeptide-like 3g (apobec3g), first identified as cem15, was shown to be packaged into retroviral virions and to deaminate deoxycytidine to deoxyuridine in newly synthesized viral minus-strand dna, thereby inducing g-to-a hypermutation. this innate mechanism of resistance to retroviral infection is counteracte ...200415054139
enigmas and paradoxes: the genetic diversity and prevalence of the primate lentiviruses.in a comparatively few years a previously unknown virus has spread from its animal host to infect more than 40 million people by the end of 2003, causing an estimated 3 million deaths in that year (world health organization figures). the size of this human immunodeficiency virus (hiv) epidemic and its associated health, social and economic problems make it imperative that we understand how its two types, hiv-1 and hiv-2, have evolved from their simian relatives, the primate lentiviruses (plvs). ...200415078176
anti-hiv-1 gene expressing lentiviral vectors as an adjunctive therapy for hiv-1 infection.lentiviral based gene therapy may provide a valuable addition to the current anti-hiv arsenal. many lentiviral vector systems have been described including those based on feline immunodeficiency virus (fiv), human immunodeficiency virus 1 (hiv) and 2 (hiv-2/siv) as well as replication incompetent, self-inactivating (sin) vs. conditionally replicating (mobilizable) vectors. lentiviral vectors offer promise in treating hiv-1 infection as they are capable of stably transducing both dividing and non ...200415078182
frequent dual initiation in human immunodeficiency virus-based vectors containing two primer-binding sites: a quantitative in vivo assay for function of initiation complexes.we previously demonstrated that murine leukemia virus (mlv)-based vectors containing two primer-binding sites (pbss) have the capacity to initiate reverse transcription more than once (y. a. voronin and v. k. pathak, virology 312:281-294, 2003). to determine whether human immunodeficiency virus (hiv)-based vectors also have the capacity to initiate reverse transcription twice, we constructed an hiv type 1 (hiv-1)-based vector containing the hiv-1 pbs, a green fluorescent protein reporter gene (g ...200415113919
prevalence of markers of transfusion transmissible diseases in voluntary and replacement blood donors.transfusion of safe blood requires a safe donor. the voluntary donor movement encompasses the concept of a donor who is free from transfusion transmissible infections. it is now mandatory to screen blood for hepatitis b surface antigen, antibodies to hiv-1 and hiv-2, antibodies to hepatitis c virus, syphilis and malarial parasites.200415115227
the crystal structure of the monomeric reverse transcriptase from moloney murine leukemia virus.reverse transcriptases (rts) are multidomain enzymes of variable architecture that couple both rna- and dna-directed dna polymerase activities with an rnase h activity specific for an rna:dna hybrid in order to replicate the single-stranded rna genome of the retrovirus. previous structural work has been reported for the heterodimeric hiv-1 and hiv-2 rts. we now report the first crystal structure of the full-length moloney murine leukemia virus (mmlv) rt at 3.0 a resolution. the structure reveals ...200415130474
current status of the non-nucleoside reverse transcriptase inhibitors of human immunodeficiency virus type 1.almost fifteen years ago, the first non-nucleoside reverse transcriptase (rt) inhibitor (nnrti) lead compounds have been discovered. nowadays, three nnrtis are approved for treatment of hiv-1-infected individuals and several others are subject of (advanced) clinical trials. although the nnrtis target hiv-1 rt, they are clearly different from the nucleoside rt inhibitors (nrtis). they are highly selective for hiv-1 and do not inhibit hiv-2 or any other (retro)virus. they target hiv-1 rt by a dire ...200415134549
human immunodeficiency virus type 2 dna vaccine provides partial protection from acute baboon infection.we determined if the genetic adjuvants, granulocyte-macrophage colony stimulating factor (gm-csf) and b7-2, could improve the immunogenicity and efficacy of an hiv-2 dna vaccine. the vaccine consisted of the hiv-2 tat, nef, gag, and env genes synthesized using optimized codons and formulated with cationic liposomes. baboons (papio cynocephalus hamadryas) were immunized by the intramuscular, intradermal, and intranasal routes with these expression constructs and challenged with hiv-2(uc2) by the ...200415149785
a second human antiretroviral factor, apobec3f, is suppressed by the hiv-1 and hiv-2 vif proteins.the hiv-1 vif protein suppresses the inhibition of viral replication caused by the human antiretroviral factor apobec3g. as a result, hiv-1 mutants that do not express the vif protein are replication incompetent in 'nonpermissive' cells, such as primary t cells and the t-cell line cem, that express apobec3g. in contrast, vif-defective hiv-1 replicates effectively in 'permissive' cell lines, such as a derivative of cem termed cem-ss, that do not express apobec3g. here, we show that a second human ...200415152192
chronic hiv-2 infection protects against total cd4+ cell depletion and rapid disease progression induced by shiv89.6p challenge.to better understand hiv-1 sexual transmission risk, we have studied the susceptibility of hiv-2-exposed, uninfected (eu) female pig-tailed macaques to intravaginal (ivag) re-challenge with the homologous hiv-2 strain, followed by heterologous shiv89.6p.200415166528
tracking global patterns of n-linked glycosylation site variation in highly variable viral glycoproteins: hiv, siv, and hcv envelopes and influenza hemagglutinin.human and simian immunodeficiency viruses (hiv and siv), influenza virus, and hepatitis c virus (hcv) have heavily glycosylated, highly variable surface proteins. here we explore n-linked glycosylation site (sequon) variation at the population level in these viruses, using a new web-based program developed to facilitate the sequon tracking and to define patterns (www.hiv.lanl.gov). this tool allowed rapid visualization of the two distinctive patterns of sequon variation found in hiv-1, hiv-2, an ...200415175256
expression and biochemical analysis of the entire hiv-2 gp41 ectodomain: determinants of stability map to n- and c-terminal sequences outside the 6-helix bundle core.the folding of hiv gp41 into a 6-helix bundle drives virus-cell membrane fusion. to examine the structural relationship between the 6-helix bundle core domain and other regions of gp41, we expressed in escherichia coli, the entire ectodomain of hiv-2(st) gp41 as a soluble, trimeric maltose-binding protein (mbp)/gp41 chimera. limiting proteolysis indicated that the cys-591-cys-597 disulfide-bonded region is outside a core domain comprising two peptides, thr-529-trp-589 and val-604-ser-666. a bioc ...200415178320
hiv type 2 primary isolates induce a lower degree of apoptosis "in vitro" compared with hiv type 1 primary isolates.to determine whether subtypes of hiv-1 and hiv-2 vary in their ability to induce t cell apoptosis in vitro, human peripheral blood mononuclear cells (pbmc) from healthy donors and cem.nkr-ccr5 cells were infected with a variety of hiv-1 and hiv-2 isolates in vitro. apoptotic cell levels and chemokine and cytokine production were analyzed. significant variations in cytopathic effects following in vitro infection with primary isolates of hiv-1 or hiv-2 subtypes were observed in pbmcs. the percent ...200415186525
current status and potential application of iscoms in veterinary medicine.the immune stimulating complex (iscom) is a 40 nm nanoparticle used as a delivery system for vaccine antigens, targeting the immune system both after parenteral and mucosal administration. the iscom is made up of saponin, lipids and antigen usually held together by hydrophobic interaction between these three components. the compulsory elements to form the iscom structure are cholesterol and saponin. when the antigen is omitted the iscom-matrix is formed. there are a number of saponins that can f ...200415191787
potent neutralizing serum immunoglobulin a (iga) in human immunodeficiency virus type 2-exposed igg-seronegative individuals.the mechanisms behind the resistance to human immunodeficiency virus type 2 (hiv-2) infection are still not fully understood. in the present study, we explored the hiv-2-specific humoral serum immunoglobulin a (iga) immune response in hiv-2-exposed igg-seronegative (egsn) individuals. serum samples from heterosexual egsn individuals and their known hiv-2-infected partners, as well as controls originating from guinea-bissau in africa, were studied. antibody reactivity to native and recombinant en ...200415194778
differential regulation of human immunodeficiency virus type 2 and simian immunodeficiency virus promoter activity.promoter activity of the hiv-1 long terminal repeat (ltr) is largely dependent on intact nf-kb and spi binding sites in the u3 region. in contrast, upstream ltr sequences allow efficient simian immunodeficiency virus (sivmac) transcription in the absence of the core enhancer promoter region. in the present study, we investigated whether the regulation of hiv-2 rod ltr activity is more reminiscent of hiv-1 having the same host or of sivmac239 belonging to the same phylogenetic group. viral promot ...200415207635
hiv-2-infected individuals with undetectable plasma viremia carry replication-competent virus in peripheral blood lymphocytes.using an optimized hiv co-culture protocol it was possible to isolate infectious hiv-2 variants from 6 hiv-2-infected individuals who had undetectable plasma viremia and maintained high cd4 t-cell numbers for prolonged periods. this shows for the first time that hiv-2-infected individuals with no demonstrable in vivo virus production carry replication-competent virus in peripheral blood mononuclear cells (pbmcs). the frequency of pbmcs with infectious virus was low, ranging from 0.01-0.9 infecti ...200415213560
elevated expression of gm3 in receptor-bearing targets confers resistance to human immunodeficiency virus type 1 fusion.gm3, a major ganglioside of t lymphocytes, promotes human immunodeficiency virus type 1 (hiv-1) entry via interactions with hiv-1 receptors and the viral envelope glycoprotein (env). increased gm3 levels in t lymphocytes and the appearance of anti-gm3 antibodies in aids patients have been reported earlier. in this study, we investigated the effect of gm3 regulation on hiv-1 entry by utilizing a mouse cell line (b16f10), which expresses exceptionally high levels of gm3. strikingly, b16 cells bear ...200415220409
the phenylmethylthiazolylthiourea nonnucleoside reverse transcriptase (rt) inhibitor msk-076 selects for a resistance mutation in the active site of human immunodeficiency virus type 2 rt.the phenylmethylthiazolylthiourea (pett) derivative msk-076 shows, besides high potency against human immunodeficiency virus type 1 (hiv-1), marked activity against hiv-2 (50% effective concentration, 0.63 microm) in cell culture. time-of-addition experiments pointed to hiv-2 reverse transcriptase (rt) as the target of action of msk-076. recombinant hiv-2 rt was inhibited by msk-076 at 23 microm. as was also found for hiv-1 rt, msk-076 inhibited hiv-2 rt in a noncompetitive manner with respect t ...200415220416
prevalence and incidence of hiv, hepatitis b virus, and hepatitis c virus infections among males in rhode island prisons.we evaluated prevalence and intraprison incidence of hiv, hepatitis b virus, and hepatitis c virus infections among male prison inmates.200415226146
highly active antiretroviral therapy and viral response in hiv type 2 infection.human immunodeficiency virus type 2 (hiv-2), the second human retrovirus known to cause aids, is endemic to west africa but is infrequently found outside this region. we present a case series of 10 hiv-2--infected individuals treated in the united states. physicians applied the principles of highly active antiretroviral therapy (haart), normally used in treating hiv type 1, with modifications considered appropriate for treating hiv-2. cd4+ cell count, hiv-2 virus load, and clinical status were f ...200415227626
identification of a highly divergent hiv type 2 and proposal for a change in hiv type 2 classification.we report the complete genome sequence of a highly divergent strain of human immunodeficiency virus type 2 (hiv-2), 96fr12034, identified in france from a patient of west african origin. this lineage, h, represents only the third definitive instance of a monkey-to-human transfer of sivsm that has given rise to pathogenic hiv-2. as the different "subtypes" of hiv-2 are analogous to the different groups of hiv-1 we propose that hiv-2 subtypes henceforth by renamed groups in agreement with the hiv ...200415242544
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