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aptamer displacement identifies alternative small-molecule target sites that escape viral resistance.aptamers targeting reverse transcriptase (rt) from hiv-1 inhibit viral replication in vitro, presumably by competing with binding of the primer/template complex. this site is not targeted by the currently available small-molecule anti-hiv-1 rt inhibitors. we have identified sy-3e4, a small-molecule inhibitor of hiv-1 rt, by applying a screening assay that utilizes a reporter-ribozyme regulated by the anti-hiv-1 rt aptamer. sy-3e4 displaces the aptamer from the protein, selectively inhibits dna-d ...200717656317
the hiv1 protein vpr acts to promote g2 cell cycle arrest by engaging a ddb1 and cullin4a-containing ubiquitin ligase complex using vprbp/dcaf1 as an adaptor.the roles of the hiv1 protein vpr in virus replication and pathogenesis remain unclear. expression of vpr in dividing cells causes cell cycle arrest in g(2). vpr also facilitates low titer infection of terminally differentiated macrophages, enhances transcription, promotes apoptosis, and targets cellular uracil n-glycosylase for degradation. using co-immunoprecipitation and tandem mass spectroscopy, we found that hiv1 vpr engages a ddb1- and cullin4a-containing ubiquitin-ligase complex through v ...200717620334
the origins of hiv and implications for the global epidemic.hiv type 1 (hiv-1) and type 2 (hiv-2) are the result of several cross-species transmissions from primates to humans. recently, the ancestral strains of hiv-1 groups m and n were shown to still persist in today's wild chimpanzee populations (pan troglodytes troglodytes) in south cameroon. lately, hiv-1 group o-related viruses have been identified in western gorillas (gorilla gorilla), called sivgor, but chimpanzees are most likely the original reservoir of this simian immunodeficiency virus (siv) ...200717618555
replication-competent variants of human immunodeficiency virus type 2 lacking the v3 loop exhibit resistance to chemokine receptor antagonists.entry of human immunodeficiency virus type 1 (hiv-1) and hiv-2 requires interactions between the envelope glycoprotein (env) on the virus and cd4 and a chemokine receptor, either ccr5 or cxcr4, on the cell surface. the v3 loop of the hiv gp120 glycoprotein plays a critical role in this process, determining tropism for ccr5- or cxcr4-expressing cells, but details of how v3 interacts with these receptors have not been defined. using an iterative process of deletion mutagenesis and in vitro adaptat ...200717609282
defect of human immunodeficiency virus type 2 gag assembly in saccharomyces cerevisiae.we have previously shown that the expression of human immunodeficiency virus type 1 (hiv-1) gag protein in saccharomyces cerevisiae spheroplasts produces gag virus-like particles (vlps) at the plasma membrane, indicating that yeast has all the host factors necessary for hiv-1 gag assembly. here we expand the study by using diverse primate lentiviral gags and show that yeast does not support the production of hiv-2 or simian immunodeficiency virus sivmac gag vlps but allows the production of siva ...200717609278
monitoring the dynamics of the hiv epidemic using assays for recent infection and serotyping among new hiv diagnoses: experience after 2 years in france.new tools to better monitor dynamics of human immunodeficiency virus (hiv) transmission are needed.200717597452
synthesis of some novel thiourea derivatives obtained from 5-[(4-aminophenoxy)methyl]-4-alkyl/aryl-2,4-dihydro-3h-1,2,4-triazole-3-thiones and evaluation as antiviral/anti-hiv and anti-tuberculosis agents.as a continuation of our previous efforts on n-alkyl/aryl-n'-[4-(4-alkyl/aryl-2,4-dihydro-3h-1,2,4-triazole-3-thione-5-yl)phenyl]thioureas 1-19 and n-alkyl/aryl-n'-[4-(3-aralkylthio-4-alkyl/aryl-4h-1,2,4-triazole-5-yl)phenyl]thioureas 20-22, a series of novel 5-[(4-aminophenoxy)methyl]-4-alkyl/aryl-2,4-dihydro-3h-1,2,4-triazole-3-thiones 23-26 and several related thioureas, n-alkyl/aryl-n'-{4-[(4-alkyl/aryl-5-thioxo-4,5-dihydro-1h-1,2,4-triazol-3-yl)methoxy]phenyl}thioureas 27-42 were synthesize ...200817583388
role of human immunodeficiency virus (hiv)-specific t-cell immunity in control of dual hiv-1 and hiv-2 infection.progressive immune dysfunction and aids develop in most cases of human immunodeficiency virus type 1 (hiv-1) infection but in only 25 to 30% of persons with hiv-2 infection. however, the natural history and immunologic responses of individuals with dual hiv-1 and hiv-2 infection are largely undefined. based on our previous findings, we hypothesized that among patients with dual infection the control of hiv-1 is associated with the ability to respond to hiv-2 gag epitopes and to maintain hiv-spec ...200717582003
in vitro selection and characterization of human immunodeficiency virus type 2 with decreased susceptibility to lopinavir.lopinavir (lpv)-ritonavir has demonstrated durable antiviral activity in human immunodeficiency virus type 1 (hiv-1)-infected antiretroviral-naïve and protease inhibitor (pi)-experienced patients. however, information on lpv activity against hiv-2 and the patterns of mutations in hiv-2 in response to selection by lpv is limited. the activity of lpv against three strains of hiv-2 was assessed and compared to activity against a reference hiv-1 strain. lpv demonstrated activity similar to that obse ...200717576848
[hiv-2 infection and human lymphotropic type 1 and type 2 virus in spain]. 200717570181
study on the blood-borne virus co-infection and t lymphocyte subset among intravenous drug users.to investigate the features of various blood-borne virus infections and co-infection in intravenous drug users (idus), and to examine the correlation of t lymphocyte subsets with virus co-infection.200717511038
hydrophilicity dependent budding and secretion of chimeric hiv gag-v3 virus-like particles.virus-like particles (vlps) of numerous viruses have been considered as possible candidates for vaccine development. we have constructed hiv chimeric genes by coupling the gag gene of hiv-2 with the v3 domain of the gp120 gene of either hiv-1 or hiv-2 and expressed the chimeric genes in sf21 cells using the recombinant baculovirus expression system. although the level of expression of the chimeric hiv-2 gag gene with the v3 domain of either hiv-1 gp120 (gagc-1v3) or hiv-2 gp120 (gagc-2v3) was hi ...200717510784
false-positive result of a confirmatory human immunodeficiency virus line immuno assay in an apparently healthy individual--a case report.a case of a false-positive result of human immunodeficiency virus (hiv) confirmatory immunoblot-based assay is described. repeatedly borderline reactive anti-hiv screening enzyme immunoassay result obtained in a local hospital resulted in directing the sample to the slovenian hiv/aids reference laboratory. in the reference laboratory, both anti-hiv screening assays and confirmatory western blot were negative, while a confirmatory test inno-lia hiv i/ii score (innogenetics, ghent, belgium) was an ...200617508473
virus subtype-specific features of natural simian immunodeficiency virus sivsmm infection in sooty mangabeys.simian immunodeficiency virus (siv) siv(smm) naturally infects sooty mangabeys (sms) and is the source virus of pathogenic infections with human immunodeficiency virus type 2 (hiv-2) and siv(mac) of humans and macaques, respectively. in previous studies we characterized siv(smm) diversity in naturally siv-infected sms and identified nine different phylogenetic subtypes whose genetic distances are similar to those reported for the different hiv-1 group m subtypes. here we report that, within the ...200717507488
a single amino acid of the human immunodeficiency virus type 2 capsid affects its replication in the presence of cynomolgus monkey and human trim5alphas.human immunodeficiency virus type 2 (hiv-2) strains vary widely in their abilities to grow in old world monkey (owm) cells such as those of cynomolgus monkeys (cm). we evaluated eight hiv-2 isolates for their sensitivities to cm trim5alpha, an anti-hiv factor in owm cells. we found that different hiv-2 isolates showed differences in their sensitivities to cm trim5alpha. sequence analysis showed that trim5alpha-sensitive viruses had proline at the 120th position of the capsid protein (ca), wherea ...200717475650
inhibition of human immunodeficiency virus type 1 transcription by n-aminoimidazole derivatives.this study describes the mechanism of antiviral action of the n-aminoimidazole derivatives which exclusively inhibit retroviruses such as hiv-1, hiv-2, siv and msv. these antiretroviral compounds, with lead prototype nr-818, were found to inhibit hiv-1 replication at the transcriptional level. analysis of each individual step of viral transcription, including transcriptional activation mediated by nf-kappab, the chromatin remodeling process at the viral promoter and viral mrna transcription medi ...200717459445
transmission electron microscopy on simian immunodeficiency virus-infected cocultures of vervet monkeys.healthy african green monkeys are the natural reservoirs for certain hiv-related sivs. more research is now focused on these nonhuman primates that are asymptomatic, so as to answer questions of origins, pathogenesis and therapy with respect to hiv in man. the present study involves the isolation and subsequent co-cultivation of siv variants from two healthy vervet monkeys (cercopithecus aethiops pygerythrus). western blots (new lav blot 1 and new lav blot 2, pasteur) revealed sero cross-reactiv ...199617451298
dissecting the neutralizing antibody specificities of broadly neutralizing sera from human immunodeficiency virus type 1-infected donors.attempts to elicit broadly neutralizing antibody responses by human immunodeficiency virus type 1 (hiv-1) vaccine antigens have been met with limited success. to better understand the requirements for cross-neutralization of hiv-1, we have characterized the neutralizing antibody specificities present in the sera of three asymptomatic individuals exhibiting broad neutralization. two individuals were infected with clade b viruses and the third with a clade a virus. the broadly neutralizing activit ...200717409160
out of africa: what can we learn from hiv-2 about protective immunity to hiv-1?most people infected with human immunodeficiency virus 2 (hiv-2) do not progress to disease, even though the minority who do cannot be distinguished clinically from hiv-1-infected patients. here we review what is known about the basis of viral control in hiv-2 infection.200717375091
a novel bis-tetrahydrofuranylurethane-containing nonpeptidic protease inhibitor (pi), grl-98065, is potent against multiple-pi-resistant human immunodeficiency virus in vitro.we designed, synthesized, and identified grl-98065, a novel nonpeptidic human immunodeficiency virus type 1 (hiv-1) protease inhibitor (pi) containing the structure-based designed privileged cyclic ether-derived nonpeptide p2 ligand, 3(r),3a(s),6a(r)-bis-tetrahydrofuranylurethane (bis-thf), and a sulfonamide isostere, which is highly potent against laboratory hiv-1 strains and primary clinical isolates (50% effective concentration [ec(50)], 0.0002 to 0.0005 microm) with minimal cytotoxicity (50% ...200717371811
mechanism and history of evolution of symbiotic hiv strains into lethal pandemic strains: the key event may have been a 1927 trial of pamaquine in leopoldville (kinshasa), congo.in previous papers, i have rejected both the zoonosis and the serial transfer hypotheses of the origin and evolution of the current lethal pandemic strains of hiv. the hypothesis that fits the critical observations is that all the human and nonhuman primate species in central africa (an area of hyper-endemic malaria) have shared (through inter-species transfers) a "primate t-cell retrovirus" (ptrv), which has adapted to each host species. this retrovirus is believed to assist primate t-cells att ...200717368749
mechanisms of cd4 downregulation by the nef and vpu proteins of primate immunodeficiency viruses.human immunodeficiency virus type 1 (hiv-1), human immunodeficiency virus type 2 (hiv-2), and simian immunodeficiency virus (siv) are the etiological agents of acquired immunodeficiency syndrome (aids) in humans and a related disease in non-human primates. these viruses infect t cells and macrophages that express the surface glycoprotein, cd4, because this glycoprotein acts as a co-receptor for incoming virus particles. once infection has occurred, however, the presence of cd4 poses problems for ...200717346169
development and evaluation of an oligonucleotide ligation assay for detection of drug resistance-associated mutations in the human immunodeficiency virus type 2 pol gene.human immunodeficiency virus type 2 (hiv-2) is naturally resistant to several antiretroviral drugs, including all of the non-nucleoside reverse transcriptase inhibitors and the entry inhibitor t-20, and may have reduced susceptibility to some protease inhibitors. these resistance properties make treatment of hiv-2 patients difficult, with very limited treatment options. therefore, early detection of resistance mutations is important for understanding treatment failures and guiding subsequent the ...200717329450
direct evidence of lower viral replication rates in vivo in human immunodeficiency virus type 2 (hiv-2) infection than in hiv-1 infection.studies have shown that human immunodeficiency virus type 2 (hiv-2) is less pathogenic than hiv-1, with a lower rate of disease progression. similarly, plasma viral loads are lower in hiv-2 infection, suggesting that hiv-2 replication is restricted in vivo in comparison to that of hiv-1. however, to date, in vivo studies characterizing replication intermediates in the viral life cycle of hiv-2 have been limited. in order to test the hypothesis that hiv-2 has a lower replication rate in vivo than ...200717329334
cross-clade inhibition of recombinant human immunodeficiency virus type 1 (hiv-1), hiv-2, and simian immunodeficiency virus sivcpz reverse transcriptases by rna pseudoknot aptamers.reverse transcriptase (rt) remains a primary target in therapies directed at human immunodeficiency virus type 1 (hiv-1). rna aptamers that bind rt from hiv-1 subtype b have been shown to protect human cells from infection and to reduce viral infectivity, but little is known about the sensitivity of the inhibition to amino sequence variations of the rt target. therefore, we assembled a panel of 10 recombinant rts from phylogenetically diverse lentiviral isolates (including strains of hiv-1, simi ...200717329328
molecular mechanisms of simian immunodeficiency virus siv(agm) rna encapsidation.primate lentiviruses are composed of several distinct lineages, including human immunodeficiency virus type 1 (hiv-1), hiv-2, and simian immunodeficiency virus sivagm. hiv-1 and hiv-2 have significant differences in the mechanisms of viral rna encapsidation. therefore, the rna packaging mechanisms of sivagm cannot be predicted from the studies of hiv-1 and hiv-2. we examined the roles of the nucleocapsid (nc) zinc finger motifs on rna packaging by mutating the conserved zinc finger (cchc) motifs ...200717321560
comparison of heterologous neutralizing antibody responses of human immunodeficiency virus type 1 (hiv-1)- and hiv-2-infected senegalese patients: distinct patterns of breadth and magnitude distinguish hiv-1 and hiv-2 infections.neutralizing antibody responses against heterologous isolates in human immunodeficiency virus type 1 (hiv-1) and hiv-2 infections were compared, and their relationships with established clinical markers of progression were examined. neutralizing responses against 7 heterologous primary isolates and 1 laboratory strain were compared between 32 untreated hiv-1-infected subjects and 35 untreated hiv-2-infected subjects using a pseudotyped reporter virus assay. the breadth of the neutralizing respon ...200717301136
efficient transduction of simian cells by hiv-1-based lentiviral vectors that contain mutations in the capsid protein.recently, the cyclophilin a (cypa)-binding region of the hiv-1 capsid protein was identified as a viral determinant involved in the post-entry restriction in old world monkey cells. here, we constructed a panel of hiv-1-based lentiviral vectors (lvs) that contain either mutations in the cypa-binding region or the cypa-binding region of the related viruses hiv-1 group o and hiv-2. we demonstrated that amino-acid changes in the cypa-binding region of the capsid can alter the phenotype of the virus ...200717299408
long-term intrapatient viral evolution during hiv-2 infection.background. disease progression and transmission of human immunodeficiency virus (hiv) type 2 are attenuated, compared with hiv-1, which is consistent with the lower plasma viral loads observed in hiv-2 infection. although numerous studies have characterized the intrapatient evolution of viral sequences during hiv-1 infection, prospective studies examining intrapatient evolution during hiv-2 infection have been limited.methods. we examined viral sequence evolution in the c2v3c3 region of the vir ...200717262716
modest human immunodeficiency virus coreceptor function of cxcr3 is strongly enhanced by mimicking the cxcr4 ligand binding pocket in the cxcr3 receptor.the chemokine receptor cxcr3 can exhibit weak coreceptor function for several human immunodeficiency virus type 1 (hiv-1) and hiv-2 strains and clinical isolates. these viruses produced microscopically visible cytopathicity in u87.cd4.cxcr3 cell cultures, whereas untransfected (cxcr3-negative) u87.cd4 cells remained uninfected. depending on the particular virus, the coreceptor efficiency of cxcr3 was 100- to >10,000-fold lower compared to that of cxcr4. a cxcr3 variant carrying the cxcr4 binding ...200717251291
an extended stem-loop 1 is necessary for human immunodeficiency virus type 2 replication and affects genomic rna encapsidation.genomic rna encapsidation in lentiviruses is a highly selective and regulated process. the unspliced rna molecules are selected for encapsidation from a pool of many different viral and cellular rna species. moreover, two molecules are encapsidated per viral particle, where they are found associated as a dimer. in this study, we demonstrate that a 10-nucleotide palindromic sequence (pal) located at the 3' end of the psi encapsidation signal is critical for human immunodeficiency virus type 2 (hi ...200717229705
rna recognition mechanism of the minimal active domain of the human immunodeficiency virus type-2 nucleocapsid protein.ncp8 of hiv-2 contains two cchc-type zinc fingers connected by a linker, and is involved in many critical steps of the virus life cycle. it was previously shown that the first zinc finger flanked by the linker is the minimal active domain for specific binding to viral rna. in our previous study, we determined the three-dimensional structure of ncp8-f1, including the minimal active domain, and found that a hydrogen bond between asn(11) n(delta)h and arg(27) o stabilized the conformation of the li ...200717202191
nitroimidazoles, part 2: synthesis, antiviral and antitumor activity of new 4-nitroimidazoles.a series of 5-alkylamino and 5-alkylsulfanyl derivatives of 1-aryl-2-alkyl-4-nitro-1h-imidazoles 12-21, 31, and 34 were synthesized by a simple method with the aim to develop novel hiv non-nucleoside reverse transcriptase inhibitors (nnrtis). all the new compounds were tested against hiv-1 and hiv-2 in mt-4 cells. compound 21, with an arylsulfanyl group at c(5) of the 4-nitro-1h-imidazole backbone showed an ec(50) value of 0.22 microg/ml against hiv-1 with a therapeutic index of 13. this means t ...200617193287
chimeric hiv-1 and hiv-2 lentiviral vectors with added safety insurance.lentiviruses are unique in their ability to infect both dividing and non-dividing cells. this makes the vectors derived from them particularly useful for gene transfer into non-dividing cells, including stem cells. lentiviral vectors are becoming the vectors of choice for si/shrna delivery. the utility of the lentiviral vectors will be enhanced if additional elements of safety are built into their design. one safety concern is the generation of replication competent virus by recombination. we re ...200717177309
nfat5 regulates hiv-1 in primary monocytes via a highly conserved long terminal repeat site.to replicate, hiv-1 capitalizes on endogenous cellular activation pathways resulting in recruitment of key host transcription factors to its viral enhancer. rna interference has been a powerful tool for blocking key checkpoints in hiv-1 entry into cells. here we apply rna interference to hiv-1 transcription in primary macrophages, a major reservoir of the virus, and specifically target the transcription factor nfat5 (nuclear factor of activated t cells 5), which is the most evolutionarily diverg ...200617173480
antiviral activity obtained from aqueous extracts of the chilean soapbark tree (quillaja saponaria molina).natural, aqueous extracts of quillaja saponaria, the chilean soapbark tree, contain several physiologically active triterpenoid saponins that display strong adjuvant activity when used in either human or animal vaccines. in this paper, we describe studies that demonstrate a novel antiviral activity of quillaja extracts against six viruses: vaccinia virus, herpes simplex virus type 1, varicella zoster virus, human immunodeficiency viruses 1 and 2 (hiv-1, hiv-2) and reovirus. we demonstrate that m ...200717170461
adaptation of a diverse simian immunodeficiency virus population to a new host is revealed through a systematic approach to identify amino acid sites under selection.simian immunodeficiency viruses (siv) have had considerable success at crossing species barriers; both human immunodeficiency virus (hiv)-1 and hiv-2 have been transmitted on multiple occasions from siv-infected natural host species. however, the precise evolutionary and ecological mechanisms characterizing a successful cross-species transmission event remain to be elucidated. here, in addition to expanding and clarifying our previous description of the adaptation of a diverse, naturally occurri ...200717159231
natural polymorphisms of hiv type 2 pol sequences from drug-naive individuals.until today, the susceptibility of human immunodeficiency virus type 2 (hiv-2) to protease and nucleosidic reverse-transcriptase inhibitors (pi and nrti, respectively) has not been clearly documented. in this report we studied hiv-2 proviral sequences (n = 30) from drug-naive patients. our results revealed that several amino acid positions in the protease and reverse transcriptase coding sequence harbored residues that have been associated with drug resistance in hiv-1-infected patients. in part ...200617147507
natural polymorphisms in the human immunodeficiency virus type 2 protease can accelerate time to development of resistance to protease inhibitors.human immunodeficiency virus type 2 (hiv-2) contains numerous natural polymorphisms in its protease (pr) gene that are implicated in drug resistance in the case of hiv-1. this study evaluated emergent pr resistance in hiv-2. three hiv-2 isolates were selected for resistance to amprenavir (apv), nelfinavir (nfv), indinavir (idv), and tipranavir (tpv) in cell culture. genotypic analysis determined the time to the appearance of protease inhibitor (pi)-associated mutations compared to hiv-1. phenoty ...200717116674
characterization of hiv-1 integrase n-terminal mutant viruses.during infection, human immunodeficiency virus type 1 integrase engages a number of molecules and mechanisms, both of viral and cellular origin. in one of such instances, integrase is thought to be degraded by the n-end rule proteasome pathway a process that targets the n-terminal residue of its substrates. here we describe the properties of hiv-1 viruses in which the first amino acid residue of integrase has been substituted to render it resistant to the n-end rule pathway. as result of this ex ...200717109911
an adaptation of recombinant vaccinia-based elispot and intracellular cytokine staining for a comparative measurement of cellular immune responses in hiv-1 and hiv-2 infections in west africa.an efficient and quantitative tool for rapid assessment of human immunodeficiency virus (hiv)-induced cellular immune responses is important for resource-limited settings, such as in sub-saharan africa. modifications are required to previously reported methods for evaluating ex-vivo antigen-specific cellular responses based on direct recombinant vaccinia virus (rvv) stimulation of peripheral blood mononuclear cells (pbmcs) by enzyme linked immunosorbent assay (elispot) and by flow cytometry intr ...200617100767
[primary human immunodeficiency virus infection revealed by psychiatric symptoms].any atypical psychiatric disorder, especially if associated with somatic manifestations and when any psychiatric antecedents are missing, should lead to search for an organic pathology, and notably a human immunodeficiency virus (hiv) infection. in the case of primary human immunodeficiency virus infection (phi), which is often symptomatic, the diagnosis is seldom made, probably because of atypical or non specific manifestations. therefore, it is essential to consider such a diagnosis, because i ...200617099559
quantitative detection of plasma human immunodeficiency virus type 2 subtype a rna by the nuclisens easyq assay (version 1.1).no commercial viral load assay has yet been approved for use for measurement of human immunodeficiency virus type 2 (hiv-2) rna levels in plasma. we assessed the performance of the nuclisens easyq (version 1.1) assay (easyq; biomérieux, boxtel, the netherlands) to quantify hiv-2 viremia. a viral stock was prepared from an hiv-2 (subtype a)-infected patient. culture supernatant was subjected to viral particle counting by electron microscopy. serial dilutions of the viral stock were made in hiv-ne ...200717093034
the sivmac239 pr55gag isoform, siv p43, suppresses proteolytic cleavage of pr55gag.in human immunodeficiency virus type 1 (hiv-1) and simian immunodeficiency virus (siv) the gag gene encodes the precursor polyprotein pr55gag, which is cleaved by the viral protease to produce the major structural proteins. recently, it has been shown that hiv and siv gag rnas contain internal ribosome entry sites (iress) that mediate translation of pr55gag [pr57gag in hiv type 2 (hiv-2)] isoforms. previously, we demonstrated that sivmac239 p43(-), a mutant that does not express the pr55gag isof ...200717092530
human trim5alpha mediated restriction of different hiv-1 subtypes and lv2 sensitive and insensitive hiv-2 variants.in order to characterize the antiviral activity of human trim5alpha in more detail human derived indicator cell lines over expressing wild type human trim5alpha were generated and challenged with hiv-1 and hiv-2 viruses pseudotyped with hiv envelope proteins in comparison to vsv-g pseudotyped particles. hiv envelope protein pseudotyped particles (hiv-1[nl4.3], hiv-1[bal]) showed a similar restriction to infection (12 fold inhibition) compared to vsv-g pseudotyped viruses after challenging tzm-hu ...200617087820
multicenter evaluation of a new 4th generation hiv screening assay elecsys hiv combi.fourth-generation screening assays which permit a simultaneous detection of human immunodeficiency virus (hiv) antigen and antibody reduce the diagnostic window on average by four days in comparison to third-generation antibody assays. recently, the new automated elecsys hiv combi was compared in a multicenter study to alternative fourth- and third-generation assays, p24 antigen test and hiv-1 rna rt-pcr. a total of 104 serocon-version panels, samples of the acute phase of infection after seroco ...200617078473
increased frequency of circulating ccr5+ cd4+ t cells in human immunodeficiency virus type 2 infection.ccr5 expression determines susceptibility to infection, cell tropism, and the rate of human immunodeficiency virus type 1 (hiv-1) disease progression. ccr5 is also considered the major hiv-2 coreceptor in vivo, in spite of broad coreceptor use in vitro. here we report a significantly increased proportion of memory-effector cd4 t cells expressing ccr5 in hiv-2-infected patients correlating with cd4 depletion. moreover, hiv-2 proviral dna was essentially restricted to memory-effector cd4, suggesti ...200617035326
proviral progeny of heterodimeric virions reveal a high crossover rate for human immunodeficiency virus type 2.human immunodeficiency virus type 1 (hiv-1), the causative agent of aids in humans, exhibits a very high rate of recombination. bearing in mind the significant epidemiological and clinical contrast between hiv-2 and hiv-1 as well as the critical role that recombination plays in viral evolution, we examined the nature of hiv-2 recombination. towards this end, a strategy was devised to measure the rate of crossover of hiv-2 by evaluating recombinant progeny produced exclusively by heterodimeric vi ...200617020945
nuclear export of simian immunodeficiency virus vpx protein.lentiviruses, human immunodeficiency viruses (hivs), and simian immunodeficiency viruses (sivs) are distinguished from oncoretroviruses by their ability to infect nondividing cells such as macrophages. retroviruses must gain access to the host cell nucleus for replication and propagation. hiv and siv preintegration complexes (pic) enter nuclei after traversing the central aqueous channel of the limiting nuclear pore complex without membrane breakdown. among the nucleophilic proteins, namely, mat ...200616987982
a hiv-2-based self-inactivating vector for enhanced gene transduction.the employment of hiv-1-based vectors in clinical trials is controversial mainly due to the lethal nature of the virus. hiv-2 is less pathogenic in nature and therefore is likely to be safer for vector design and production. we developed hiv-2-based self-inactivating vectors in which 520 bp out of 554 bp of the viral u3 was deleted. interestingly, high titers were obtained only when an exogenous promoter was used to drive expression of viral rna. it was found that the vectors could target a wide ...200716979253
high frequency of genetic recombination is a common feature of primate lentivirus replication.recent studies indicate that human immunodeficiency virus type 1 (hiv-1) recombines at exceedingly high rates, approximately 1 order of magnitude more frequently than simple gammaretroviruses such as murine leukemia virus and spleen necrosis virus. we hypothesize that this high frequency of genetic recombination is a common feature of primate lentiviruses. alternatively, it is possible that hiv-1 is unique among primate lentiviruses in possessing high recombination rates. among other primate len ...200616973569
morphological study on biologically distinct vpx/vpr mutants of hiv-2.we have previously shown that human immunodeficiency virus type 2 (hiv-2) without functional vpx and vpr genes is severely defective for viral growth in lymphocytic cells, and suggested that the virions produced in the absence of vpx and vpr are critically damaged. to examine the nature of replication-defect for the vpx/vpr double mutant, we quantitatively and morphologically studied the virions produced in cells transfected or infected with wild type clone, single (vpx and vpr mutants) or the d ...200616953064
non-nucleoside hiv-1 reverse transcriptase inhibitors, part 7. synthesis, antiviral activity, and 3d-qsar investigations of novel 6-(1-naphthoyl) hept analogues.a series of novel 1-[(2-hydroxyethoxy)methyl]-6-(phenylthio)thymine (hept) analogues bearing a 6-(1-naphthoyl) group of non-nucleoside human immunodeficiency virus (hiv) reverse transcriptase inhibitors were synthesized and evaluated for their activity against hiv-1 and hiv-2. it was found that most of these compounds showed good activity against hiv-1. among them, compound 5-isopropyl-6-(1-naphthoyl)-1-[(2e)-3-phenylallyl]-2,4-pyrimidinedione (23) displayed the greatest inhibitory potency (ic(5 ...200616946529
the absence of anti-tat antibodies is associated with risk of disease progression in hiv-2 infection.the tat protein of human immunodeficiency virus (hiv) is essential for viral replication and has extracellular pathogenic activity. we sought to determine whether the anti-tat antibody response was predictive of disease progression in 144 hiv type 2 (hiv-2)-infected subjects observed longitudinally between 1985 and 2003. sixty-eight percent of the subjects tested positive for anti-tat antibodies, with reactivity notably established early after seroconversion and stably maintained over the course ...200616941341
carrageenan/miv-150 (pc-815), a combination microbicide.the objective of this article is to study the effect of pc-815, a novel combination microbicide containing carrageenan and the nonnucleoside reverse transcriptase inhibitor (nnrti) miv-150, in blocking hiv-1 and hiv-2 infections in vitro as compared with carraguard alone.200716924181
characterization of the human chemerin receptor--chemr23/cmklr1--as co-receptor for human and simian immunodeficiency virus infection, and identification of virus-binding receptor domains.studies were conducted to elucidate co-receptor spectrum and function of the inflammatory receptor, cmklr1/chemr23, which was recently identified as the receptor for the cystatin-like chemoattractant, tig2, also named chemerin. an infection model was applied based on stably transfected np-2.cd4 host cells expressing various co-receptor constructs and exposed to panels of hiv-1, hiv-2 and siv primary isolates. in a panel of 27 hiv-1 isolates tested, 12 isolates could use cmklr1/chemr23. as expect ...200616904155
indeterminate human immunodeficiency virus western blot results in iranian patients with discordant screening assay results.the western blot (wb) assay is the most widely accepted confirmatory assay for the detection and confirmation of antibodies to human immunodeficiency virus type 1 (hiv-1) and 2 (hiv-2). however, indeterminate wb reactivity to hiv-1 and hiv-2 proteins may occur in individuals who do not appear to be infected with hiv.200616883439
contribution of vpu, env, and nef to cd4 down-modulation and resistance of human immunodeficiency virus type 1-infected t cells to superinfection.human immunodeficiency virus type 1 (hiv-1) utilizes vpu, env, and nef to down-modulate its primary cd4 receptor from the cell surface, and this function seems to be critical for the pathogenesis of aids. the physiological relevance of cd4 down-modulation, however, is currently not well understood. in the present study, we analyzed the kinetics of cd4 down-modulation and the susceptibility of hiv-1-infected t cells to superinfection using proviral hiv-1 constructs containing individual and combi ...200616873261
coassembly and complementation of gag proteins from hiv-1 and hiv-2, two distinct human pathogens.approximately one million people in the world are dually infected with both hiv-1 and hiv-2. to identify potential interactions between these two human pathogens, we examined whether hiv-1 and hiv-2 gag proteins can coassemble and functionally complement each other. we generated hiv-1- and hiv-2-based vectors with mutations in gag; compared with wild-type vectors, these mutants had drastically decreased viral titers. coexpression of the mutant hiv-1 and hiv-2 gag could generate infectious viruse ...200616857594
tar-rna recognition by a novel cyclic aminoglycoside analogue.the formation of the tat-protein/tar-rna complex is a crucial step in the regulation of human immunodeficiency virus (hiv)-gene expression. to obtain full-length viral transcripts the tat/tar complex has to recruit the positive transcription elongation factor complex (p-eftb), which interacts with tar through its cyclin t1 (cyct1) component. mutational studies identified the tar hexanucleotide loop as a crucial region for contacting cyct1. interfering with the interaction between the tat/cyct1 c ...200616855296
peptides derived from hiv-1, hiv-2, ebola virus, sars coronavirus and coronavirus 229e exhibit high affinity binding to the formyl peptide receptor.peptides derived from the membrane proximal region of fusion proteins of human immunodeficiency viruses 1 and 2, coronavirus 229 e, severe acute respiratory syndrome coronavirus and ebola virus were all potent antagonists of the formyl peptide receptor expressed in chinese hamster ovary cells. binding of viral peptides was affected by the naturally occurring polymorphisms at residues 190 and 192, which are located at second extracellular loop-transmembrane helix 5 interface. substitution of r190 ...200616842982
isolation of an active lv1 gene from cattle indicates that tripartite motif protein-mediated innate immunity to retroviral infection is widespread among mammals.lv1/trim5alpha (tripartite motif 5alpha) has recently emerged as an important factor influencing species-specific permissivity to retroviral infection in a range of primates, including humans. old world monkey trim5alpha blocks human immunodeficiency virus type 1 (hiv-1) infectivity, and the human and new world monkey trim5alpha proteins are inactive against hiv-1 but active against divergent murine (n-tropic murine leukemia virus [mlv-n]) and simian (simian immunodeficiency virus from rhesus ma ...200616840314
genomic sites of human immunodeficiency virus type 2 (hiv-2) integration: similarities to hiv-1 in vitro and possible differences in vivo.retroviruses have distinct preferences in integration site selection in the host cell genome during in vitro infection, with human immunodeficiency virus type 1 (hiv-1) integration strongly favoring transcriptional units. additionally, studies with hiv-1 have shown that the genomic site of proviral integration may impact viral replication, with integration in heterochromatin associated with a block in viral transcription. hiv-2 is less pathogenic than hiv-1 and is believed to have a lower replic ...200616840312
in vitro replication capacity of hiv-2 variants from long-term aviremic individuals.to establish whether efficient suppression of virus replication in hiv-2-infected individuals is associated with low replicative capacity of hiv-2, replication kinetics of hiv-2 variants from long-term aviremic individuals was analyzed and compared with that of the relatively slow-replicating hiv-1 variants from asymptomatics and long-term nonprogressors (as/ltnp). on average, hiv-2 from aviremic individuals had lower replication rates than hiv-1 variants from as/ltnp in cells of 8 donors (0.45 ...200616814357
role of invariant thr80 in human immunodeficiency virus type 1 protease structure, function, and viral infectivity.sequence variability associated with human immunodeficiency virus type 1 (hiv-1) is useful for inferring structural and/or functional constraints at specific residues within the viral protease. positions that are invariant even in the presence of drug selection define critically important residues for protease function. while the importance of conserved active-site residues is easily understood, the role of other invariant residues is not. this work focuses on invariant thr80 at the apex of the ...200616809296
multicenter evaluation of the bayer advia centaur hiv 1/o/2 enhanced (ehiv) assay.it is important that serological assays detect antibodies to human immunodeficiency virus (hiv) in all infected individuals, including those infected with less prevalent, more diverse subtypes.200616769045
no association between seropositivity for hepatitis c virus and lichen planus: a case control study.the epidemiological association of lichen planus (lp) with hepatitis c virus (hcv) infection has been recorded from some countries and hcv rna3 has been isolated from lesional skin in patients with lp and chronic hcv infection. the observed geographical differences regarding hcv infection and lp could be immuno-genetically related.200616766832
evolution of hiv/aids prevention programs--united states, 1981-2006.when the first cases of what would become known as acquired immunodeficiency syndrome (aids) were reported in 1981, the magnitude of the epidemic and the numbers of deaths were unimaginable. during the next 25 years, an unprecedented mobilization of individual, community, and government resources was directed at stopping the epidemic. cdc currently supports a wide range of human immunodeficiency virus (hiv) prevention activities in the united states, including 1) collection of behavioral and hiv ...200616741496
prevalence of human immunodeficiency virus infection among tuberculosis suspect patients in accra, ghana.acquired immunodeficiency syndrome is a major public health concern worldwide, particularly in ghana, where recent reports indicate an increase of the disease. a close association between infection with human immunodeficiency virus (hiv) and tuberculosis (tb) is well known. a previous study showed a 16.8% seroprevalence of hiv in tb patients on admission at the chest clinic of the korle-bu teaching hospital. however this was in severely ill patients on admission and there was a likely selection ...200616722357
cleavage, a real turn-off? hiv-mediated proteolysis of pabp1.in this issue of the biochemical journal, alvarez and colleagues have identified pabp1 [poly(a)-binding protein 1] as a target of protease cleavage during hiv infection. the study shows that hiv-1, hiv-2 and mouse mammary tumour virus, but not other retroviruses, target pabp1 for cleavage and identifies cleavage sites within the rna-recognition motifs and c-terminal region of the protein. this suggests that pabp1 cleavage may be important in the shut-off of host translation during hiv infection. ...200616703665
(a3) hiv phenotypes, oral lesions, and management of hiv-related disease.workshop participants discussed: the role of hiv subtypes in disease; the treatment of oral candidiasis; the relationship between and among viral load, cd4+ counts, oral candidiasis and oral hairy leukoplakia, pigmentation; and the development of a reliable oral index to predict disease progression. regarding hiv, the literature revealed that type i (hiv-i), in particular group m, is involved in the majority (90%) of documented infections, and groups n and o to a lesser extent. viral envelope di ...200616672562
use of an acute seroconversion panel to evaluate a third-generation enzyme-linked immunoassay for detection of human immunodeficiency virus-specific antibodies relative to multiple other assays.a human immunodeficiency virus type 1 (hiv-1)/hiv-2 antibody screening assay, the genetic systems hiv-1/hiv-2 plus o eia, was compared to several established screening or confirmatory tests using an acute hiv seroconversion panel. the hiv-1/hiv-2 plus o eia showed an improved sensitivity over all tested antibody screening methods, and detected antibody in 7 of 19 specimens found to be negative by a first-generation eia but positive for the presence of hiv rna.200616672422
sensitivity of the multispot hiv-1/hiv-2 rapid test using samples from human immunodeficiency virus type 1-positive individuals with various levels of exposure to highly active antiretroviral therapy.the multispot hiv-1/hiv-2 rapid test detects human immunodeficiency virus type 1 (hiv-1) gp41 antibodies, which can wane over time in some hiv-1-infected populations, resulting in false-negative screening results. multispot sensitivity was 100% using 248 sera from one such population, and it correctly identified serostatus in individuals who previously tested false negative with rapid testing.200616672414
hiv type 2 demyelinating encephalomyelitis.a human immunodeficiency virus (hiv) type 2 (hiv-2)-infected african patient developed inflammatory demyelinating lesions of the optic nerves, spinal cord, and brain, which coincided with a decreasing cd4 cell count and with active hiv-2 replication. this case provides evidence that hiv-2 is neurotropic, extends the range of known hiv-2-associated neurological complications, and confirms the overlap between the neurological complications of hiv type 1 and hiv-2 infection.200616652302
theta-defensins prevent hiv-1 env-mediated fusion by binding gp41 and blocking 6-helix bundle formation.retrocyclin-1, a -defensin, protects target cells from human immunodeficiency virus, type 1 (hiv-1) by preventing viral entry. to delineate its mechanism, we conducted fusion assays between susceptible target cells and effector cells that expressed hiv-1 env. retrocyclin-1 (4 microm) completely blocked fusion mediated by hiv-1 envs that used cxcr4 or ccr5 but had little effect on cell fusion mediated by hiv-2 and simian immunodeficiency virus envs. retrocyclin-1 inhibited hiv-1 env-mediated fusi ...200616648135
human immunodeficiency virus serotyping on dried serum spots as a screening tool for the surveillance of the aids epidemic.many studies have demonstrated the utility of the dried blood spot (dbs) or dried plasma/serum spot (dss) method for serological and molecular diagnosis of hiv infection. here, we report on the description of a serotyping assay performed on dss, and its application to a national surveillance program of hiv variants. we combined serotyping assays that we developed previously to discriminate between hiv-1 and hiv-2, between hiv-1 group o and hiv-1 group m, and between b and non-b subtypes of hiv-1 ...200616622871
tipranavir: pnu 140690, tipranivir.tipranavir [pnu 140690, tipranivir, aptivus] is a second-generation hiv dihydropyrone (a sulphonamide derivative), nonpeptidic protease inhibitor (nppi) discovered by pharmacia & upjohn (now pfizer) in the us. the compound is in development with boehringer ingelheim. tipranavir has potent in vitro activity against a variety of hiv-1 laboratory strains and clinical isolates, including those resistant to ritonavir, as well as hiv-2. tipranavir has been shown to act synergistically with other antir ...200616620137
using hidden markov models and observed evolution to annotate viral genomes.motivation: ssrna (single stranded) viral genomes are generally constrained in length and utilize overlapping reading frames to maximally exploit the coding potential within the genome length restrictions. this overlapping coding phenomenon leads to complex evolutionary constraints operating on the genome. in regions which code for more than one protein, silent mutations in one reading frame generally have a protein coding effect in another. to maximize coding flexibility in all reading frames, ...200616613911
no association between gb virus c infection and disease progression in hiv-2-infected patients from the french anrs hiv-2 cohort.out of 183 hiv-2-infected patients tested in the anrs co8 hiv-2 cohort, 69 were exposed to gb virus c (gbv-c), yielding a prevalence of 38% (95% ci 30.7, 45.2). there was no significant difference between the cd4 cell count and hiv-2-rna plasma viral load in patients exposed and not exposed to gbv-c. after adjusting for age and cd4 cell count, co-infection with gbv-c was not associated with clinical progression (hazard ratio 0.78; 95% ci 0.24-2.56, 16 clinical events).200616603866
molecular investigation of human immunodeficiency virus type 2 subtype a cases in south korea.we investigated the molecular characteristics of human immunodeficiency virus type 2 (hiv-2) subtype a isolates to clarify the transmission mode of hiv-2 within korea. these findings indicated that the viruses from the six patients infected within korea formed a distinct subcluster in the phylogenetic tree and might have been transmitted from one source.200616597889
hiv protease cleaves poly(a)-binding protein.the pabp [poly(a)-binding protein] is able to interact with the 3' poly(a) tail of eukaryotic mrna, promoting its translation. cleavage of pabp by viral proteases encoded by several picornaviruses and caliciviruses plays a role in the abrogation of cellular protein synthesis. we report that infection of mt-2 cells with hiv-1 leads to efficient proteolysis of pabp. analysis of pabp integrity was carried out in bhk-21 (baby-hamster kidney) and cos-7 cells upon individual expression of the protease ...200616594896
worldwide molecular epidemiology of hiv.human immunodeficiency virus (hiv) is the worldwide disseminated causative agent of acquired immunodeficiency syndrome (aids). hiv is a member of the lentivirus genus of retroviridae family and is grouped in two types named hiv-1 and hiv-2. these viruses have a notable ability to mutate and adapt to the new conditions of human environment. a large incidence of errors at the transcriptional level results in changes on the genetic bases during the reproductive cycle. the elevated genomic variabili ...200616583048
development and evaluation of a real-time rt-pcr assay for quantification of cell-free human immunodeficiency virus type 2 using a brome mosaic virus internal control.quantification of cell-free virus in plasma is important for monitoring disease progression and for assessing the response to antiretroviral therapy in both human immunodeficiency type 1 and type 2 (hiv-1, hiv-2) infections. although commercial assays suitable for hiv-1 quantification have been used for more than a decade, no commercial assays are yet available for the measurement of cell-free hiv-2. we have therefore developed a novel real-time rt-pcr assay which, unlike previously described 'i ...200616563526
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 ...200616542002
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 ...200616501101
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 ...200616494914
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 ...200616485036
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 ...200616474159
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 ...200616455923
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 ...200616454709
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.200616439866
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.200616432590
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 ...200616432029
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 ...200616420604
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.200616418512
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 ...200616396876
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
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
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
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
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