| 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. | 2005 | 15635022 |
| 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 ... | 2005 | 15638719 |
| 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 ... | 2005 | 15644124 |
| 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 ... | 2004 | 15644217 |
| 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 ... | 2005 | 15648062 |
| 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 ... | 2005 | 15650194 |
| 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 ... | 2004 | 15650427 |
| 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 ... | 2004 | 15650432 |
| 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 ... | 2005 | 15681464 |
| 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 ... | 2004 | 15682876 |
| 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 ... | 2005 | 15705467 |
| 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 ... | 2005 | 15709044 |
| 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, ... | 2005 | 15725353 |
| 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 ... | 2005 | 15730394 |
| 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 ... | 2005 | 15731257 |
| 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. | 2005 | 15736023 |
| 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 ... | 2004 | 15737915 |
| 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 ... | 2005 | 15741178 |
| 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, ... | 2005 | 15749713 |
| 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 ... | 2005 | 15767422 |
| 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 ... | 2005 | 15772691 |
| status of infectious disease markers among blood donors in a teaching hospital, bhairahawa, western nepal. | a cross-sectional group of 1548 blood donors (voluntary--554 and replacement--994 blood donors) during the period february 2001 to april 2003 at blood bank centre (being run by nepal red cross society) in our teaching hospital in bhairahawa, were studied and screened for antibodies to human immunodeficiency virus type 1 and type 2 (hiv- 1 & 2), hepatitis c virus (hcv) and hepatitis b surface antigen (hbsag) by enzyme immunoassays and for reagin antibody for syphils by (rapid plasma reagin, rpr) ... | 2003 | 15796411 |
| 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 ... | 2005 | 15804957 |
| 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. | 2005 | 15809904 |
| 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 ... | 2005 | 15812488 |
| 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 ... | 2005 | 15817940 |
| 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 ... | 2005 | 15817946 |
| 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. | 2005 | 15819680 |
| 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 ... | 2005 | 15828842 |
| 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 ... | 2005 | 15832290 |
| 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 ... | 2005 | 15847926 |
| 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 ... | 2005 | 15848298 |
| 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 ... | 2005 | 15892966 |
| 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 ... | 2005 | 15893666 |
| 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 ... | 2004 | 15912198 |
| [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 ... | 2005 | 15919629 |
| 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 ... | 2005 | 15920286 |
| 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 ... | 2005 | 15929800 |
| [seroepidemiological survey of the human immunodeficiency virus, type 2]. | to perform a seroepidemiological study and identify associated factors in a population infected by human immunodeficiency virus, type 2 (hiv-2). a total of 2202 individuals were tested to determine the seroprevalence of this virus. | 2004 | 15941553 |
| modification of a viral envelope glycoprotein cell-cell fusion assay by utilizing plasmid encoded bacteriophage rna polymerase. | many viruses enter cells via an interaction of the viral envelope glycoprotein (env) with receptor inducing fusion of viral and cellular membranes. these interactions are often evaluated in cell-cell fusion, gene-reporting systems with effector cells expressing env and target cells expressing receptors. a common system utilizes vaccinia virus encoding t7 rna polymerase (rnap) in effector cells and a t7 promoted reporter plasmid in target cells. fusion is quantified with expression of the reporte ... | 2005 | 15941597 |
| a novel simian immunodeficiency virus from black mangabey (lophocebus aterrimus) in the democratic republic of congo. | in order to understand primate lentivirus evolution, characterization of additional simian immunodeficiency virus (siv) strains is essential. here, an siv from a black mangabey (lophocebus aterrimus) originating from the democratic republic of congo was analysed phylogenetically. the monkey had cross-reactive antibodies against human immunodeficiency virus type 1 (hiv-1) and hiv-2. the viral pol region sequence was amplified by nested pcr and sequence analysis confirmed that it was related to kn ... | 2005 | 15958675 |
| pharmacology and pharmacokinetics of the antiviral agent beta-d-2',3'-dideoxy-3'-oxa-5-fluorocytidine in cells and rhesus monkeys. | beta-d-2',3'-dideoxy-3'-oxa-5-fluorocytidine (d-fdoc) is an effective inhibitor of human immunodeficiency virus 1 (hiv-1) and hiv-2, simian immunodeficiency virus, and hepatitis b virus (hbv) in vitro. the purpose of this study was to evaluate the intracellular metabolism of d-fdoc in human hepatoma (hepg2), human t-cell lymphoma (cem), and primary human peripheral blood mononuclear (pbm) cells by using tritiated compound. by 24 h, the levels of d-fdoc-triphosphate (d-fdoc-tp) were 2.8 +/- 0.4, ... | 2005 | 15980324 |
| viral response to antiretroviral therapy in a patient coinfected with hiv type 1 and type 2. | clinical experience with the treatment of human immunodeficiency virus (hiv) type 2 (hiv-2) infection is limited, and even more scarce is information on therapy for patients coinfected with hiv type 1 (hiv-1) and hiv-2. here, we describe the outcome for a coinfected patient in whom infection with both viruses was successfully controlled at the start of antiretroviral therapy, but for whom hiv-2 infection escaped control after a treatment simplification change while hiv-1 remained undetectable. | 2005 | 15983906 |
| 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 ... | 2005 | 15986884 |
| 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 ... | 2005 | 15989467 |
| stavudine:pharmacology,clinical use and future role. | stavudine is a nucleoside analogue reverse transcriptase inhibitor of hiv-1 and hiv-2 and demonstrates in vitro activity with an acceptable therapeutic index in a range of t-lymphocyte and haematopoietic precursor cell lines. it is additive or synergistic in vitro with a range of other antiretrovirals, including the proteinase inhibitor saquinavir, in two- and three-way combinations and is active against zidovudine (zdv)-resistant virus. it exhibits excellent oral bioavailability, with cerebrosp ... | 1997 | 15989602 |
| 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 ... | 2005 | 15994792 |
| 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 ... | 2005 | 16014904 |
| 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 ... | 2005 | 16014924 |
| 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 ... | 2005 | 16051847 |
| 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 ... | 2005 | 16051857 |
| 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 ... | 2005 | 16060831 |
| 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 ... | 2005 | 16061969 |
| 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 ... | 2005 | 16061976 |
| 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 ... | 2005 | 16061978 |
| 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 ... | 2005 | 16061992 |
| amd-3100 (anormed). | anormed is developing amd-3100, a cxcr4 chemokine receptor antagonist discovered by a collaboration between anormed and the rega institute, as a potential treatment for hiv infection [337657]. amd-3100 is a bis-tetraazamacrocycle, which is a potent inhibitor of hiv-1 and hiv-2 viruses. it interacts with the virus-associated uncoating process [172189]. it is currently being evaluated in phase ii clinical trials at the john's hopkins university school of medicine and two other us sites. the phase ... | 2000 | 16080056 |
| 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 ... | 2005 | 16081975 |
| 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. | 2005 | 16081987 |
| 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 ... | 2005 | 16099905 |
| 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 ... | 2005 | 16103193 |
| 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 ... | 2005 | 16104988 |
| 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 ... | 2005 | 16107217 |
| 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 ... | 2005 | 16107333 |
| 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 ... | 2005 | 16107952 |
| [diagnostic tests: human immunodeficiency virus type 1, type 2 (hiv-1, hiv 2)]. | | 2005 | 16111295 |
| 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. | 2005 | 16122107 |
| 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 ... | 2005 | 16128920 |
| 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 ... | 2005 | 16140735 |
| comparative study on the structure and cytopathogenic activity of hiv vpr/vpx proteins. | the three-dimensional (3-d) structure of human immunodeficiency virus type 2 (hiv-2) vpr/vpx was predicted by homology modeling based on the nmr structure of human immunodeficiency virus type 1 (hiv-1) vpr. the three proteins similarly have three major amphipathic alpha-helices. in contrast to hiv-1 vpr, vpr/vpx of hiv-2 have a long n-terminal loop and clustered prolines in the second half of the c-terminal loop. hiv-2 vpx uniquely contains a long region between the second and third major helice ... | 2006 | 16153874 |
| inhibition of ccr5-mediated infection by diverse r5 and r5x4 hiv and siv isolates using novel small molecule inhibitors of ccr5: effects of viral diversity, target cell and receptor density. | highly active anti-retroviral therapy (haart) has been very effective in reducing viral loads in human immunodeficiency virus (hiv)-1 patients. however, current therapies carry detrimental side effects, require complex drug regimes and are threatened by the emergence of drug-resistant variants. there is an urgent need for new anti-hiv drugs that target different stages of the replication cycle. several synthetic small organic molecules that inhibit hiv infection by binding to the ccr5 coreceptor ... | 2005 | 16157392 |
| simian immunodeficiency virus infection in free-ranging sooty mangabeys (cercocebus atys atys) from the taï forest, côte d'ivoire: implications for the origin of epidemic human immunodeficiency virus type 2. | simian immunodeficiency virus of sooty mangabeys (sivsmm) is recognized as the progenitor of human immunodeficiency virus type 2 (hiv-2) and has been transmitted to humans on multiple occasions, yet the epidemiology and genetic diversity of sivsmm infection in wild-living populations remain largely unknown. here, we report the first molecular epidemiological survey of sivsmm in a community of approximately 120 free-ranging sooty mangabeys in the taï forest, côte d'ivoire. fecal samples (n = 39) ... | 2005 | 16160179 |
| potential clinical applications of the cxcr4 antagonist bicyclam amd3100. | the bicyclam amd3100 (originally called jm3100), in which the two cyclam rings are tethered by an aromatic bridge, emanated from jm2763, where the two cyclam moieties are tethered by an aliphatic linker - jm2763 in turn originated from jm1657, where the cyclam rings are directly linked to one another via a c-c bridge, and which was identified as an impurity, showing anti-hiv activity, in a commercial cyclam preparation. amd3100 proved very effective against hiv-1 and hiv-2, inhibiting virus repl ... | 2005 | 16178723 |
| structure of the zinc finger domain encompassing residues 13-51 of the nucleocapsid protein from simian immunodeficiency virus. | the ncps (nucleocapsid proteins) of hiv-1 (hiv type 1), hiv-2 and siv (simian immunodeficiency virus) are small highly basic proteins, characterized by the presence of two cchc zf (zinc finger) domains. ncps, closely associated with the dimeric rna genome in the core of the virus particle, were shown to promote the specific encapsidation of the viral rna and are implicated in reverse transcription. solution structure of the hiv-1 ncp7 and complexes of ncp7 with rna or dna showed the critical rel ... | 2006 | 16229684 |
| 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. | 2005 | 16229778 |
| 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 ... | 2005 | 16244661 |
| 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 ... | 2005 | 16247948 |
| 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 ... | 2005 | 16274627 |
| 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 ... | 2005 | 16298986 |
| performance evaluation of three automated human immunodeficiency virus antigen-antibody combination immunoassays. | three fourth-generation antigen/antibody combination assays (elecsys, axsym, architect hiv) and two third-generation (axsym, centaur) hiv antibody immunoassays were evaluated. the evaluation panel of 479 samples included: nine tissue culture derived hiv-1 strains at four different p24 antigen concentrations (n=36), a p24 antigen sensitivity panel (n=10), 149 hiv-1 or hiv-2 confirmed antibody positive samples, ten anti-hiv-1 positive low titer samples, three seroconversion panels (n=21), and 253 ... | 2006 | 16313975 |
| conserved amino acids of the human immunodeficiency virus type 2 vpx nuclear localization signal are critical for nuclear targeting of the viral preintegration complex in non-dividing cells. | the hiv-2 viral accessory protein vpx is related to, but distinct from the vpr protein of hiv-1. vpx is packaged into virions and as a component of the viral preintegration complex (pic) is required for efficient virus replication in non-dividing cells. we have previously reported that the minimal transferable region of vpx that contained karyophilic properties was aa 65 to 72. analysis of vpx sequences from various hiv-2/siv strains reveals that this region contains highly conserved amino acids ... | 2006 | 16325220 |
| mutations in the u5 sequences adjacent to the primer binding site do not affect trna cleavage by rous sarcoma virus rnase h but do cause aberrant integrations in vivo. | in most retroviruses, the first nucleotide added to the trna primer becomes the right end of the u5 region in the right long terminal repeat (ltr); the removal of this trna primer by rnase h defines the right end of the linear double-stranded dna. most retroviruses have two nucleotides between the 5' end of the primer binding site (pbs) and the ca dinucleotide that will become the end of the integrated provirus. however, human immunodeficiency virus type 1 (hiv-1) has only one nucleotide at this ... | 2006 | 16352569 |
| simian immunodeficiency virus vpx is imported into the nucleus via importin alpha-dependent and -independent pathways. | vpx protein of human immunodeficiency virus type 2/simian immunodeficiency virus (siv) has been implicated in the transport of the viral genome into the nuclei of nondividing cells. the mechanism by which vpx enters the nucleus remains unknown. here we have identified two distinct noncanonical nuclear localization signals (nlss) in vpx of siv(smpbj1.9) and defined the pathways for its nuclear import. although nuclear targeting signals identified here are distinct from known nuclear import signal ... | 2006 | 16352576 |
| 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 ... | 2005 | 16370525 |
| 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 ... | 2005 | 16386115 |
| 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 ... | 2005 | 16390277 |
| 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 ... | 2005 | 16395412 |
| disease versus disease: how one disease may ameliorate another. | systemic disease, either genetic or acquired, may prevent or decrease the severity of another disease. these observations have led to important therapeutic advances. the best-known examples are edward jenner's use in 1798 of cowpox to prevent smallpox and j.b. haldane's 1942 observation that erythrocyte disorders such as thalassemia and sickle cell disease modify the severity of malaria. patients with and carriers of cystic fibrosis may have genetic resistance to tuberculosis and/or secretory di ... | 2006 | 16396876 |
| incident high-grade squamous intraepithelial lesions in senegalese women with and without human immunodeficiency virus type 1 (hiv-1) and hiv-2. | women infected with human immunodeficiency virus type 1 (hiv-1) and -2 may be at higher risk of developing cervical cancer than uninfected women. we assessed the relationships among human papillomavirus (hpv) types and persistence, hiv-1 and/or hiv-2 infection, and the development of high-grade cervical squamous intraepithelial lesions (hsils) in a prospective study. | 2006 | 16418512 |
| comparison by flow cytometry of immune changes induced in human monocyte-derived dendritic cells upon infection with dengue 2 live-attenuated vaccine or 16681 parental strain. | dengue is an important threat for world-wide public health. different vaccines are under development, which are currently assessed using a battery of in vitro and in vivo assays before moving on to humans. it is also important to assess vaccine characteristics on human primary cells; among them, dendritic cells, the most efficient antigen-presenting cells, are the first targets of dengue virus infection. in this study, we used flow cytometry to compare the consequences of such an infection by de ... | 2006 | 16420604 |
| human immunodeficiency virus types 1 and 2 have different replication kinetics in human primary macrophage culture. | this study compares the replication of primary isolates of human immunodeficiency virus type 2 (hiv-2) and type 1 (hiv-1) in monocyte-derived macrophages (mdms). eleven hiv-2 and five hiv-1 primary isolates that use ccr5, cxcr4 or both coreceptors to enter cells were included. regardless of coreceptor preference, 10 of 11 hiv-2 viruses could enter, reverse transcribe and produce fully infectious virus in mdms with efficiency equal to that in peripheral blood mononuclear cells. however, the kinet ... | 2006 | 16432029 |
| evaluation of a new dot blot assay for confirmation of human immunodeficiency virus type 1 and 2 infections using recombinant p24, gp41, gp120 and gp36 antigens. | a sensitive and accurate dot blot assay using recombinant p24 (gag), gp41 and gp120 (env) proteins of hiv-1 and also recombinant gp36, the specific hiv-2 antigen was developed to confirm the presence of antibodies in sera reactive in screening enzyme-linked immunosorbent assays. | 2006 | 16432590 |
| a novel soluble mimic of the glycolipid, globotriaosyl ceramide inhibits hiv infection. | to determine the effect of a gp120 binding, non-cytotoxic soluble analogue of the glycosphingolipid (gsl), globotriaosyl ceramide (gb3) on hiv infection in vitro. | 2006 | 16439866 |
| uracils as a cellular weapon against viruses and mechanisms of viral escape. | uracil in dna is a deleterious event that may arise either by cytosine deamination or misincorporation of dutp. consequently, cells from all free-living organisms have developed strategies to protect their genome against the presence of uracils, by using uracil dna glycosylase (ung) and deoxyuridine triphosphatase (dutpase) enzymatic activities. in the viral kingdom, some (namely poxviruses and herpesviruses) but not all of the dna viruses encode their own ung and dutpase to control uracilation ... | 2006 | 16454709 |
| use of a new dual-antigen enzyme-linked immunosorbent assay to detect and characterize the human antibody response to the human immunodeficiency virus type 2 envelope gp125 and gp36 glycoproteins. | a dual-antigen enzyme-linked immunosorbent assay specific for human immunodeficiency virus type 2 (hiv-2) envelope proteins, elisa-hiv2, was developed with two new recombinant polypeptides, rpc2-c3 and rgp36, derived from the hiv-2 envelope. the diagnostic performance was determined with hiv-2, hiv-1, and hiv-1/2 samples. both polypeptides showed 100% specificity. clinical sensitivity was 100% for rgp36 and 93.4% for rpc2-c3. elisa-hiv2 may be used for the specific diagnosis and confirmation of ... | 2006 | 16455923 |
| natural killer cell function is well preserved in asymptomatic human immunodeficiency virus type 2 (hiv-2) infection but similar to that of hiv-1 infection when cd4 t-cell counts fall. | natural killer (nk) cells are potent effectors of natural immunity and their activity prevents human immunodeficiency virus type 1 (hiv-1) viral entry and viral replication. we sought to determine whether nk immune responses are associated with different clinical course of hiv-1 and hiv-2 infections. a cross-sectional analysis of nk cell responses was undertaken in 30 hiv-1 and 30 hiv-2 subjects in each of three categories of cd4(+)-t-cell counts (>500, 200 to 500, and <200 cells/microl) and in ... | 2006 | 16474159 |
| why do hiv-1 and hiv-2 use different pathways to develop azt resistance? | the human immunodeficiency virus type 1 (hiv-1) develops resistance to all available drugs, including the nucleoside analog reverse transcriptase inhibitors (nrtis) such as azt. atp-mediated excision underlies the most common form of hiv-1 resistance to azt. however, clinical data suggest that when hiv-2 is challenged with azt, it usually accumulates resistance mutations that cause azt resistance by reduced incorporation of azttp rather than selective excision of aztmp. we compared the propertie ... | 2006 | 16485036 |
| an internal ribosome entry site promotes translation of a novel siv pr55(gag) isoform. | in complex retroviruses including simian immunodeficiency virus (siv) and human immunodeficiency virus type 1 (hiv-1), the major structural proteins are encoded by the gag gene and translated as a precursor polyprotein, pr55(gag). an internal ribosome entry site (ires) within the coding region of hiv-1 and hiv type 2 (hiv-2) gag rna mediates expression of n-terminally truncated isoforms of the precursor polyprotein. in this study, we identify an n-terminally truncated siv pr55(gag) isoform expre ... | 2006 | 16494914 |
| recruitment of the adaptor protein 2 complex by the human immunodeficiency virus type 2 envelope protein is necessary for high levels of virus release. | the envelope (env) protein of human immunodeficiency virus type 2 (hiv-2) and the hiv-1 vpu protein stimulate the release of retroviral particles from human cells that restrict virus production, an activity that we call the enhancement of virus release (evr). we have previously shown that two separate domains in the hiv-2 envelope protein are required for this activity: a glycine-tyrosine-x-x-hydrophobic (gyxxtheta) motif in the cytoplasmic tail and an unmapped region in the ectodomain of the pr ... | 2006 | 16501101 |
| the effect of a methyl or 2-fluoroethyl substituent at the n-3 position of thymidine, 3'-fluoro-3'-deoxythymidine and 1-beta-d-arabinosylthymine on their antiviral and cytostatic activity in cell culture. | thymidine (thd), 1-beta-d-arabinosylthymine (ara-t) and 3'-fluoro-3'-deoxythymidine (flt) have been substituted at n-3 by a methyl or a 2-fluoroethyl group. flt and ara-t are markedly inhibitory against human immunodeficiency virus type 1 (hiv-1) and hiv-2, and herpes simplex virus type 1 (hsv-1) and hsv-2, respectively. modification at n-3 of these compounds markedly decreases both the antiviral and cytostatic activity of the parent compounds flt and ara-t except for n-3-(methyl)-thd that prove ... | 2006 | 16542002 |