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high level of susceptibility to human trim5α conferred by hiv-2 capsid sequences.hiv-2, which was transmitted to humans from a distant primate species (sooty mangabey), differs remarkably from hiv-1 in its infectivity, transmissibility and pathogenicity. we have tested the possibility that a greater susceptibility of hiv-2 capsid (ca) to the human restriction factor trim5α (htrim5α) could contribute to these differences.201323647667
the hiv-2 rev-response element: determining secondary structure and defining folding intermediates.interaction between the viral protein rev and the rna motifs known as rev response elements (rres) is required for transport of unspliced and partially spliced human immunodeficiency virus (hiv)-1 and hiv-2 rnas from the nucleus to the cytoplasm during the later stages of virus replication. a more detailed understanding of these nucleoprotein complexes and the host factors with which they interact should accelerate the development of new antiviral drugs targeting cis-acting rna regulatory signal ...201323640333
an hiv type 2 case series in italy: a phylogenetic analysis.in recent years, the increase of migration from countries where human immunodeficiency virus type 2 (hiv-2) is endemic to industrialized countries has facilitated the spread of the virus in individuals previously unexposed to this threat. in this report, we performed a phylogenetic analysis on pol and env sequences of hiv-2 strains identified in foreigners and native citizens to trace the origin of infection. all but one of the 17 pol gene sequences were classified as group a. hiv-2 strains were ...201323638670
platelet activation suppresses hiv-1 infection of t cells.platelets, anucleate cell fragments abundant in human blood, can capture hiv-1 and platelet counts have been associated with viral load and disease progression. however, the impact of platelets on hiv-1 infection of t cells is unclear.201323634812
a novel anti-hiv active integrase inhibitor with a favorable in vitro cytochrome p450 and uridine 5'-diphospho-glucuronosyltransferase metabolism profile.research efforts on the human immunodeficiency virus (hiv) integrase have resulted in two approved drugs. however, co-infection of hiv with mycobacterium tuberculosis and other microbial and viral agents has introduced added complications to this pandemic, requiring favorable drug-drug interaction profiles for antiviral therapeutics targeting hiv. cytochrome p450 (cyp) and uridine 5'-diphospho-glucuronosyltransferase (ugt) are pivotal determining factors in the occurrence of adverse drug-drug in ...201323602851
correlates of t-cell-mediated viral control and phenotype of cd8(+) t cells in hiv-2, a naturally contained human retroviral infection.while a significant proportion of hiv-2-infected individuals are asymptomatic and maintain undetectable viral loads (controllers), 15% to 20% progress to aids and are predicted by detectable viremia. identifying immune correlates that distinguish these 2 groups should provide insights into how a potentially pathogenic retrovirus can be naturally controlled. we performed a detailed study of hiv-2-specific cellular responses in a unique community cohort in guinea-bissau followed for over 2 decades ...201323558015
rapid detection of human immunodeficiency virus types 1 and 2 by use of an improved piezoelectric biosensor.disasters can create situations in which blood donations can save lives. however, in emergency situations and when resources are depleted, on-site blood donations require the rapid and accurate detection of blood-borne pathogens, including human immunodeficiency virus types 1 and 2 (hiv-1 and hiv-2). techniques such as pcr and antibody capture by an enzyme-linked immunosorbent assay (elisa) for hiv-1 and hiv-2 are precise but time-consuming and require sophisticated equipment that is not compati ...201323515541
the efficiency of vpx-mediated samhd1 antagonism does not correlate with the potency of viral control in hiv-2-infected individuals. 201323497283
restriction of diverse retroviruses by samhd1.samhd1 is a triphosphohydrolase that restricts the replication of hiv-1 and siv in myeloid cells. in macrophages and dendritic cells, samhd1 restricts virus replication by diminishing the deoxynucleotide triphosphate pool to a level below that which supports lentiviral reverse transcription. hiv-2 and related sivs encode the accessory protein vpx to induce the proteasomal degradation of samhd1 following virus entry. while samhd1 has been shown to restrict hiv-1 and siv, the breadth of its restri ...201323497255
hiv-2 and its role in conglutinated approach towards acquired immunodeficiency syndrome (aids) vaccine development.acquired immunodeficiency syndrome (aids) is one of the most critically acclaimed endemic diseases, caused by two lentiviruses hiv-1 and 2. hiv-2 displays intimate serological and antigenic resemblance to simian immunodeficiency virus (siv) along with less pathogenicity, lower infectivity and appreciable cross reactivity with hiv-1 antigens. the present era is confronted with the challenge to fabricate a vaccine effective against all clades of both the species of hiv. but vaccine development aga ...201323483108
monocyte and myeloid dendritic cell activation occurs throughout hiv type 2 infection, an attenuated form of hiv disease.monocytes and myeloid dendritic cells (mdcs) are important orchestrators of innate and human immunodeficiency virus (hiv)-specific immune responses and of the generalized inflammation that characterizes aids progression. to our knowledge, we are the first to investigate monocyte and mdc imbalances in hiv type 2 (hiv-2)-positive patients, who typically feature reduced viremia and slow disease progression despite the recognized ability of hiv-2 to establish viral reservoirs and overcome host restr ...201323460749
when phylogenetic analysis complements the epidemiological investigation: a case of hiv-2 infection, italy.human immunodeficiency virus type 2 (hiv-2) infection is geographically restricted, affecting west african countries such as guinea- bissau and cape verde. we describe a recent case of hiv-2 infection in an italian patient. phylogenetic analysis of the v3 region of hiv-2 indicated that the italian patient was infected by hiv-2 subtype a2. the sequence obtained from the italian patient clustered significantly with a sequence isolated from senegal. a phylogenetic doubt may arise from a guinea biss ...201323435822
hiv-2eu: supporting standardized hiv-2 drug resistance interpretation in europe.considering human immunodeficiency virus type 2 (hiv-2) phenotypic data and experience from hiv type 1 and from the follow-up of hiv-2-infected patients, a panel of european experts voted on a rule set for interpretation of mutations in hiv-2 protease, reverse transcriptase, and integrase and an automated tool for hiv-2 drug resistance analyses freely available on the internet (http://www.hiv-grade.de).201323429380
tetramerization of samhd1 is required for biological activity and inhibition of hiv infection.samhd1 is a dgtp-activated dntpase that has been implicated as a modulator of the innate immune response. in monocytes and their differentiated derivatives, as well as in quiescent cells, samhd1 strongly inhibits hiv-1 infection and, to a lesser extent, hiv-2 and simian immunodeficiency virus (siv) because of their virion-associated virulence factor vpx, which directs samhd1 for proteasomal degradation. here, we used a combination of biochemical and virologic approaches to gain insights into the ...201323426366
[molecular epidemiological analysis of hiv-1 pol gene sequences isolated in istanbul, turkey].human immunodeficiency virus (hiv) characterized by a high genetic variability includes two genotypes namely hiv-1 and hiv-2. a major proportion of the infections worldwide is caused by hiv-1 which includes four groups (m, n, o and p). group m being responsible for the hiv pandemic is further divided into nine genetically distinct subtypes (a, b, c, d, f, g, h, j, and k). additionally, more than 49 circulating recombinant forms (crfs) have been recognized up to now. the aim of this study was to ...201323390906
host iron redistribution as a risk factor for incident tuberculosis in hiv infection: an 11-year retrospective cohort study.identifying people at higher risk of developing tuberculosis with human immunodeficiency virus (hiv) infection may improve clinical management of co-infections. iron influences tuberculosis (tb) pathogenesis, but understanding the exact mechanisms of how and timing of when iron is involved remains challenging since biological samples are rarely available from the disease susceptibility period due to the difficulty in predicting in who and when, if ever, tb will develop. the objective of this res ...201323360117
novel factors interfering with human immunodeficiency virus-type 1 replication in vivo and in vitro.the strategy of all retroviral infections is based on establishing an equilibrium between virus replication and proviral latency in the infected host. the human immunodeficiency virus-type 1 (hiv-1), belonging to the subfamily of lentiviridae, adds an additional level of sophistication to this general rule by encoding two regulatory genes (tat and rev) and four accessory genes (nef, vif, vpr and vpu); hiv-2, structurally similar to hiv-1 but characterized by lower pathogenicity in vivo, encodes ...201323330719
adaptation to the interferon-induced antiviral state by human and simian immunodeficiency viruses.the production of type i interferon (ifn) is an early host response to different infectious agents leading to the induction of hundreds of ifn-stimulated genes (isgs). the roles of many isgs in host defense are unknown, but their expression results in the induction of an "antiviral state" that inhibits the replication of many viruses. here we show that prototype primate lentiviruses human immunodeficiency virus type 1 (hiv-1) and simian immunodeficiency virus of macaques (siv(mac) and siv(mne)) ...201323325684
an ancestral hiv-2/simian immunodeficiency virus peptide with potent hiv-1 and hiv-2 fusion inhibitor activity.to produce new fusion inhibitor peptides for hiv-1 and hiv-2 based on ancestral envelope sequences.201323324659
evidence for a different susceptibility of primate lentiviruses to type i interferons.type i interferons induce a complex transcriptional program that leads to a generalized antiviral response against a large panel of viruses, including human immunodeficiency virus type 1 (hiv-1). however, despite the fact that interferons negatively regulate hiv-1 ex vivo, a chronic interferon state is linked to the progression of aids and to robust viral replication, rather than protection, in vivo. to explain this apparent contradiction, we hypothesized that hiv-1 may have evolved a partial re ...201323255800
hiv-2 antiviral potency and selection of drug resistance mutations by the integrase strand transfer inhibitor elvitegravir and nrtis emtricitabine and tenofovir in vitro.hiv-2 is susceptible to only a subset of approved antiretroviral drugs. a single tablet regimen containing the integrase strand transfer inhibitor elvitegravir (evg) boosted by cobicistat plus the nucleoside reverse transcriptase (rt) inhibitors emtricitabine (ftc) and tenofovir disoproxil fumarate (evg/cobi/ftc/tdf) has potent activity against hiv-1 and may have utility against hiv-2.201323187937
a rationally engineered anti-hiv peptide fusion inhibitor with greatly reduced immunogenicity.peptides derived from the c-terminal heptad repeat 2 (hr2) region of the hiv-1 gp41 envelope glycoprotein, so-called c peptides, are very efficient hiv-1 fusion inhibitors. we previously developed innovative gene therapeutic approaches aiming at the direct in vivo production of c peptides from genetically modified host cells and found that t cells expressing membrane-anchored or secreted c peptides are protected from hiv-1 infection. however, an unwanted immune response against such antiviral pe ...201323147734
performance evaluation of a new fourth-generation hiv combination antigen-antibody assay.education and diagnostic tests capable of early detection represent our most effective means of preventing transmission of human immunodeficiency virus (hiv). the importance of early detection is underlined by studies demonstrating increased life expectancy following early initiation of antiviral treatment. the elecsys(®) hiv combi pt assay is a fourth-generation antigen-antibody combination assay developed to allow earlier detection of seroconversion, and to have increased sensitivity and impro ...201322706797
antagonism of samhd1 is actively maintained in natural infections of simian immunodeficiency virus.restriction factors are effectors of the innate immune response to viral pathogens that inhibit viral replication by operating as molecular barriers to steps of the viral life cycle. the restriction factor samhd1 blocks lentiviral reverse transcription in myeloid cells and resting cd4+ t cells. many lineages of lentiviruses, including hiv-2 and other simian immunodeficiency viruses, encode accessory genes that serve to counteract host samhd1 restriction by causing degradation of the antiviral fa ...201324324150
[mechanisms of viral emergence and interspecies transmission: the exemple of simian foamy viruses in central africa].a large proportion of viral pathogens that have emerged during the last decades in humans are considered to have originated from various animal species. this is well exemplified by several recent epidemics such as those of nipah, severe acute respiratory syndrome, avian flu, ebola, monkeypox, and hantaviruses. after the initial interspecies transmission per se, the viruses can disseminate into the human population through various and distinct mechanisms. some of them are well characterized and u ...201326137812
the capsids of hiv-1 and hiv-2 determine immune detection of the viral cdna by the innate sensor cgas in dendritic cells.hiv-2 is less pathogenic for humans than hiv-1 and might provide partial cross-protection from hiv-1-induced pathology. although both viruses replicate in the t cells of infected patients, only hiv-2 replicates efficiently in dendritic cells (dcs) and activates innate immune pathways. how hiv is sensed in dc is unknown. capsid-mutated hiv-2 revealed that sensing by the host requires viral cdna synthesis, but not nuclear entry or genome integration. the hiv-1 capsid prevented viral cdna sensing u ...201324269171
malaria and hiv co-infection and their effect on haemoglobin levels from three health-care institutions in lagos, southwest nigeria.malaria and human immunodeficiency virus (hiv) are two major infections with enormous public health consequence. together, they are endemic in many developing countries with anaemia being the most frequent haematological consequence of the infections.201324235927
influence of hiv-1 and/or hiv-2 infection and cd4 count on cervical hpv dna detection in women from senegal, west africa.hiv infection is associated with greater risk of precancerous lesions and cervical cancer in women. however, several factors remain unclarified regarding the association between hiv infection and hpv detection, especially among those with hiv type 2 versus type 1 infection and severely immunocompromised persons.201324210330
samhd1 host restriction factor: a link with innate immune sensing of retrovirus infection.samhd1 [sterile alpha motif and histidine-aspartic domain (hd) containing protein 1] is the most recent addition to a unique group of host restriction factors that limit retroviral replication at distinct stages of the viral life cycle. samhd1 is a deoxynucleoside triphosphate triphosphohydrolase that degrades the intracellular pool of deoxynucleoside triphosphates available during early reverse transcription. samhd1 activity is blocked by the vpx accessory function present in human immunodefici ...201324161438
[consensus statement by gesida/national aids plan secretariat on antiretroviral treatment in adults infected by the human immunodeficiency virus (updated january 2013)].this consensus document is an update of combined antiretroviral therapy (cart) guidelines for hiv-1 infected adult patients.201324161378
evolution of the human immunodeficiency virus type 2 envelope in the first years of infection is associated with the dynamics of the neutralizing antibody response.differently from hiv-1, hiv-2 disease progression usually takes decades without antiretroviral therapy and the majority of hiv-2 infected individuals survive as elite controllers with normal cd4⁺ t cell counts and low or undetectable plasma viral load. neutralizing antibodies (nabs) are thought to play a central role in hiv-2 evolution and pathogenesis. however, the dynamic of the nab response and resulting hiv-2 escape during acute infection and their impact in hiv-2 evolution and disease progr ...201324156513
discovery and full genome characterization of two highly divergent simian immunodeficiency viruses infecting black-and-white colobus monkeys (colobus guereza) in kibale national park, uganda.african non-human primates (nhps) are natural hosts for simian immunodeficiency viruses (siv), the zoonotic transmission of which led to the emergence of hiv-1 and hiv-2. however, our understanding of siv diversity and evolution is limited by incomplete taxonomic and geographic sampling of nhps, particularly in east africa. in this study, we screened blood specimens from nine black-and-white colobus monkeys (colobus guereza occidentalis) from kibale national park, uganda, for novel sivs using a ...201324139306
comparative evaluation of the bio-rad geenius hiv-1/2 confirmatory assay and the bio-rad multispot hiv-1/2 rapid test as an alternative differentiation assay for clsi m53 algorithm-i.the clsi-m53-a, criteria for laboratory testing and diagnosis of human immunodeficiency virus (hiv) infection; approved guideline includes an algorithm in which samples that are reactive on a 4th generation eia screen proceed to a supplemental assay that is able to confirm and differentiate between antibodies to hiv-1 and hiv-2. the recently ce-marked bio-rad geenius hiv-1/2 confirmatory assay was evaluated as an alternative to the fda-approved bio-rad multispot hiv-1/hiv-2 rapid test which has ...201324342484
field evaluation of the abbott architect hiv ag/ab combo immunoassay.fourth generation assays for hiv diagnosis are progressively being introduced into routine services, due to their improvement of diagnosis. in spite of this, hiv diagnosis remains a challenge in sub-saharan africa, due to false positive reactivity. there is a continuous need for field evaluations and routine validations of fourth generation hiv tests in african populations.201324342480
validation and clinical use of a sensitive hiv-2 viral load assay that uses a whole virus internal control.human immunodeficiency virus type 2 (hiv-2) is distantly related to the more widespread hiv-1. although hiv-2 infection is rare in the u.s., cases are concentrated in the northeast. no fda-approved hiv-2 viral load assays exist. a clinically validated laboratory-developed assay is currently available in the u.s., however it is not currently approved for use on new york state patients.201324342472
further characterisation of rotavirus cores: ss(+)rnas can be packaged in vitro but packaging lacks sequence specificity.rotavirus (rv) cores were released from double-layered particles (dlps) by high concentrations of cacl2, purified and 'opened' by treatment with edta or egta. under appropriate in vitro conditions dlps have been shown to have transcriptase and 'open cores' replicase activity. furthermore, it has been demonstrated that transcriptase activity and infectivity of native cores can be restored by transcapsidation with vp6, vp7 and vp4. the missing link for particle reconstitution in vitro has been the ...201324091366
[study of molecular function of proteins in human immunodeficiency virus].human immunodeficiency virus (hiv) has no more than nine genes expressing approximately twenty proteins. when t lymphocytes and macrophages in a body are infected with hiv, these proteins work in turn at specific time and location, causing acquired immunodeficiency syndrome (aids), a disease yet to be overcome. since the elucidation of molecular mechanism of hiv proteins should lead to remedy of aids, the author has been engaged in the study of hiv protein in the past decade. described herein ar ...201324088354
selection and characterization of viruses resistant to the dual acting pyrimidinedione entry and non-nucleoside reverse transcriptase inhibitor iqp-0410.the 1-(2-hydroxyethoxymethyl)-6-(phenylthio)thymine (hept)-like compounds with homocyclic moieties at the n-1 of the pyrimidinedione, including the highly potent lead compound iqp-0410, inhibit hiv-1 at sub-nanomolar concentrations primarily through a typical non-nucleoside mechanism involving allosteric inhibition at the hydrophobic binding pocket of the hiv-1 rt. like all nnrtis, the pyrimidinediones have no activity against hiv-2 rt. the pyrimidinediones, however, also possess a second mode o ...201324055450
ccr6 functions as a new coreceptor for limited primary human and simian immunodeficiency viruses.more than 12 chemokine receptors (ckrs) have been identified as coreceptors for the entry of human immunodeficiency virus type 1 (hiv-1), type 2 (hiv-2), and simian immunodeficiency viruses (sivs) into target cells. the expression of cc chemokine receptor 6 (ccr6) on th17 cells and regulatory t cells make the host cells vulnerable to hiv/siv infection preferentially. however, only limited information is available concerning the specific role of ccr6 in hiv/siv infection. we examined ccr6 as a co ...201324009735
prevalence of hiv infection among tuberculosis patients in eastern india.india has a high tuberculosis (tb) burden. a significant percentage of tb patients are human immunodeficiency virus (hiv) positive. as the hiv epidemic is fueling the global tb epidemic, the prevalence of the virus in tb patients is a sensitive indicator of the spread of hiv into the general population in many regions. the aim of this study was to determine the prevalence of hiv-tb co-infection among a less studied population of eastern india.201323999356
evaluation of five simple rapid hiv assays for potential use in the brazilian national hiv testing algorithm.since 2005, the department of sexually transmitted diseases (stds), acquired immunodeficiency syndrome (aids) and viral hepatitis under the health surveillance secretariat in brazil's ministry of health has approved a testing algorithm for using rapid human immunodeficiency virus (hiv) tests in the country. given the constant emergence of new rapid hiv tests in the market, it is necessary to maintain an evaluation program for them. conscious of this need, this multicenter study was conducted to ...201323994148
vif proteins from diverse primate lentiviral lineages use the same binding site in apobec3g.apobec3g (a3g) is a cytidine deaminase that restricts human immunodeficiency virus type 1 (hiv-1) and other lentiviruses. most of these viruses encode a vif protein that directly binds a3g and leads to its proteasomal degradation. both vif proteins of hiv-1 and african green monkey simian immunodeficiency virus (sivagm) bind residue 128 of a3g. however, this position does not control the a3g degradation by vif variants derived from hiv-2 and sivmac, which both originated from siv of sooty mangab ...201323986590
inhibition of cul4a neddylation causes a reversible block to samhd1-mediated restriction of hiv-1.the deoxynucleoside triphosphohydrolase samhd1 restricts retroviral replication in myeloid cells. human immunodeficiency virus type 2 (hiv-2) and a simian immunodeficiency virus from rhesus macaques (sivmac) encode vpx, a virion-packaged accessory protein that counteracts samhd1 by inducing its degradation. samhd1 is thought to work by depleting the pool of intracellular deoxynucleoside triphosphates but has also been reported to have exonuclease activity that could allow it to degrade the viral ...201323986575
[role of line immunoassay in the diagnosis of early hiv infection: a diagnostic case].combined p24 antigen-hiv antibody fourth-generation assays that identify most of the early hiv infections have been used extensively worldwide for several years. this poses challenges for the traditional algorithm of line immunoassay (lia) confirmation. lia tests are useful methods with their high specificity and their ability to differentiate hiv-1 from hiv-2, but they are reactive days after the fourth generation enzyme immunoassays. with acute hiv infection, high levels of infectious virus ar ...201323971936
restriction of virus infection but not catalytic dntpase activity is regulated by phosphorylation of samhd1.samhd1 is a host protein responsible, at least in part, for the inefficient infection of dendritic, myeloid, and resting t cells by hiv-1. interestingly, hiv-2 and sivsm viruses are able to counteract samhd1 by targeting it for proteasomal degradation using their vpx proteins. it has been proposed that samhd1 is a dgtp-dependent deoxynucleoside triphosphohydrolase (dntpase) that restricts hiv-1 by reducing cellular dntp levels to below that required for reverse transcription. however, nothing is ...201323966382
hiv vaccine to induce cytotoxic t cells recognizing conserved hiv-1/2-epitopes derived from the most frequent hla types of the human population.evaluation of: pleguezuelos o, stoloff ga, caparros-wanderley w. synthetic immunotherapy induces hiv virus specific th1 cytotoxic response and death of an hiv-1 infected human cell line through classic complement activation. virol. j. 10(1), 107 (2013). aids vaccine development represents an unprecedented challenge in both immunogen design and delivery to induce potent and long-lasting hiv-specific immune responses, including neutralizing antibodies and cytotoxic t lymphocytes (ctl). pleguezuelo ...201323902551
would clsi m53-a have helped in the diagnosis of hiv in canada? results of the performance of canadian laboratories participating in a recent nlhrs proficiency testing panel containing hiv-1 antigen positive (antibody negative) and hiv-2 samples.the clinical and laboratory standards institute recently published m53-a, criteria for laboratory testing and diagnosis of human immunodeficiency virus (hiv) infection; approved guideline (2011), which includes a state of the art algorithm for identifying hiv-1 acute and hiv-2 infections. to assess the ability of canadian laboratories to detect these sample types and the impact of m53-a, the national laboratory for hiv reference services distributed a special proficiency testing panel.201323890809
evolutionary toggling of vpx/vpr specificity results in divergent recognition of the restriction factor samhd1.samhd1 is a host restriction factor that blocks the ability of lentiviruses such as hiv-1 to undergo reverse transcription in myeloid cells and resting t-cells. this restriction is alleviated by expression of the lentiviral accessory proteins vpx and vpr (vpx/vpr), which target samhd1 for proteasome-mediated degradation. however, the precise determinants within samhd1 for recognition by vpx/vpr remain unclear. here we show that evolution of vpx/vpr in primate lentiviruses has caused the interfac ...201323874202
low expression of dendritic cell-specific intercellular adhesion molecule-grabbing nonintegrin-related protein in non-hodgkin lymphoma and significant correlations with lactic acid dehydrogenase and β2-microglobulin.dendritic cell-specific intercellular adhesion molecule-grabbing nonintegrin-related protein (dc-signr), a type ii integral membrane protein and a member of the c-type lectins, has been reported to bind various strains of hiv-1, hiv-2, and simian immunodeficiency virus. serum dc-signr is not currently available for the detection of non-hodgkin lymphoma (nhl). using an enzyme-linked immunosorbent assay (elisa), we assessed the serum levels of dc-signr in 70 cancer patients and 100 healthy control ...201323859015
tetherin/bst-2 antagonism by nef depends on a direct physical interaction between nef and tetherin, and on clathrin-mediated endocytosis.nef is the viral gene product employed by the majority of primate lentiviruses to overcome restriction by tetherin (bst-2 or cd317), an interferon-inducible transmembrane protein that inhibits the detachment of enveloped viruses from infected cells. although the mechanisms of tetherin antagonism by hiv-1 vpu and hiv-2 env have been investigated in detail, comparatively little is known about tetherin antagonism by siv nef. here we demonstrate a direct physical interaction between siv nef and rhes ...201323853598
activity of and effect of subcutaneous treatment with the broad-spectrum antiviral lectin griffithsin in two laboratory rodent models.griffithsin (grft) is a red-alga-derived lectin that binds the terminal mannose residues of n-linked glycans found on the surface of human immunodeficiency virus type 1 (hiv-1), hiv-2, and other enveloped viruses, including hepatitis c virus (hcv), severe acute respiratory syndrome coronavirus (sars-cov), and ebola virus. grft displays no human t-cell mitogenic activity and does not induce production of proinflammatory cytokines in treated human cell lines. however, despite the growing evidence ...201324145548
contribution of sam and hd domains to retroviral restriction mediated by human samhd1.the human samhd1 protein is a novel retroviral restriction factor expressed in myeloid cells. previous work has correlated the deoxynucleotide triphosphohydrolase activity of samhd1 with its ability to block hiv-1 and siv(mac) infection. samhd1 is comprised of the sterile alpha motif (sam) and histidine-aspartic (hd) domains; however the contribution of these domains to retroviral restriction is not understood. mutagenesis and deletion studies revealed that expression of the sole hd domain of sa ...201323158101
immunising with the transmembrane envelope proteins of different retroviruses including hiv-1: a comparative study.the induction of neutralizing antibodies is a promising way to prevent retrovirus infections. neutralizing antibodies are mainly directed against the envelope proteins, which consist of two molecules, the surface envelope (su) protein and the transmembrane envelope (tm) protein. antibodies broadly neutralizing the human immunodeficiencvy virus-1 (hiv-1) and binding to the tm protein gp41 of the virus have been isolated from infected individuals. their epitopes are located in the membrane proxima ...201323249763
small ruminant lentiviruses (srlvs) break the species barrier to acquire new host range.zoonotic events of simian immunodeficiency virus (siv) from non-human primates to humans have generated the acquired immunodeficiency syndrome (aids), one of the most devastating infectious disease of the last century with more than 30 million people dead and about 40.3 million people currently infected worldwide. human immunodeficiency virus (hiv-1 and hiv-2), the two major viruses that cause aids in humans are retroviruses of the lentivirus genus. the genus includes arthritis-encephalitis viru ...201323881276
men, primates, and germs: an ongoing affair.humans and nonhuman primates are phylogenetically (i.e., genetically) related and share pathogens that can jump from one species to another. the specific strategies of three groups of pathogens for crossing the species barrier among primates will be discussed. in africa, gorillas and chimpanzees have succumbed for years to simultaneous epizootics (i.e.. "multi-emergence") of ebola virus in places where they are in contact with chiropters, which could be animal reservoirs of these viruses. human ...201323239237
synthesis and broad spectrum antiviral evaluation of bis(pom) prodrugs of novel acyclic nucleosides.a series of seventeen hitherto unknown anp analogs bearing the (e)-but-2-enyl aliphatic side chain and modified heterocyclic base such as cytosine and 5-fluorocytosine, 2-pyrazinecarboxamide, 1,2,4-triazole-3-carboxamide or 4-substituted-1,2,3-triazoles were prepared in a straight approach through an olefin acyclic cross metathesis as key synthetic step. all novel compounds were evaluated for their antiviral activities against a large number of dna and rna viruses including herpes simplex virus ...201323911854
synthesis and antiviral activity of new substituted methyl [2-(arylmethylene-hydrazino)-4-oxo-thiazolidin-5-ylidene]acetates.a series of new methyl [2-(arylmethylene-hydrazono)-4-oxo-thiazolidin-5-ylidene]acetates (5a-o) were synthesized via cyclocondensation of thiosemicarbazones (3a-o) with dimethyl but-2-ynedioate (4) in good yields under solvent-free conditions. the environmentally friendly solvent-free protocol overcomes the limitations associated with the customary protracted solution phase synthesis and afforded the title compounds in a few minutes. compounds 5b-i and 5h-o were evaluated for their antiviral act ...201323828482
evaluation of two, commercial, multi-dye, nucleic acid amplification technology tests, for hbv/hcv/hiv-1/hiv-2 and b19v/hav, for screening blood and plasma for further manufacture.the cobas taqscreen mpx test, version 2.0, a multiplex, multi-dye nucleic acid amplification technology (nat) test from roche was evaluated by two european blood banks, the german red cross blood donor service, frankfurt, germany and centro de hemoterapia y hemodonación de castilla y león, valladolid, spain. in addition, the cobas taqscreen dpx test was evaluated for the simultaneous detection and quantitation of parvovirus b19 and the detection of hepatitis a virus (hav).201323252689
[evolution of residual risk for hiv, hcv and hbv, from 1999 to 2010, in blood donations of the centro hospitalar s. joão, epe, porto, portugal].monitoring the residual risk of transfusion-transmitted viral infections is important to evaluate the improvement achieved in the blood donation safety and to adopt policies to reduce risks. the present study calculates the incidence of the key infectious diseases, human immunodeficiency virus (hiv), hepatitis b virus (hbv) and hepatitis c virus (hcv) as well as the residual risk of transfusion-transmitted viral infections, during twelve years, 1999 through 2010. data were analyzed over 3 period ...201324016646
transfusion transmittable infections - seroprevalence among blood donors in a tertiary care hospital of delhi.transfusion transmittable infections (tti) continue to be a major threat to safe transfusion practices. blood is one of the major sources of transmission of infectious diseases viz. human immunodeficiency virus (hiv), hepatitis b virus (hbv), hepatitis c virus (hcv), syphilis, malaria, and many other infections in india. screening assays for the infectious diseases with excellent sensitivity and specificity helps to enhance the safety of the blood transfusions reducing the diagnostic window peri ...201324014940
prevalence of human immunodeficiency virus, hepatitis c virus, hepatitis b virus and syphilis among individuals attending anonymous testing for hiv in luanda, angola.human immunodeficiency virus (hiv), hepatitis b virus (hbv), hepatitis c virus (hcv) and syphilis remain major infections around the world. in angola there are about 166 000 individuals living with hiv, representing a prevalence of 1.98% in adults between 15 and 49 years of age. in a 2003 study in luanda, 4.5% of pregnant women had antibodies to hiv and 8.1% to hbv, and 5.4% were infected with treponema pallidum. objectives. the aim of this study was to determine the prevalence of hiv-1 and 2, h ...201323472697
seroprevalence of certain bacterial and viral infections among the irula tribal population of marakkanam, tamil nadu state, india.seroprevalence study in irula tribe of marakkanam, tamil nadu state was carried out for certain bacterial (typhoid, syphilis and leptospirosis) and viral infection (hanta, hepatitis b and human immunodeficiency virus (hiv)).201323174132
effect of sex steroid hormones on replication and transmission of major hiv subtypes.the hiv epidemic is expanding worldwide with an increasing number of distinct viral subtypes and circulating recombinant forms (crfs). out of 34 million adults living with hiv and aids, women account for one half of all hiv-1 infections worldwide. these gender differences in hiv pathogenesis may be attributed to sex hormones. little is known about the role of sex hormone effects on hiv subtypes pathogenesis. the aim of our study was to determine sex hormone effects on replication and transmissib ...201323542659
[evaluation of a new vesion of the human immunodeficiency virus antigen and antibody combination assay with improved sensitivity in hiv-1 p24 antigen detection].the performance of a new version of the hiv p24 antigen and antibody combination assays (genscreen ultra hiv ag-ab) was evaluated by comparing it with three other fourth-generation enzyme immunoassays (architect hiv ag/ab combo assay, vidas hiv duo quick and genscreen plus hiv ag-ab). the assays were examined with 200 hiv positive samples, 1,000 hiv negative samples, 30 samples (28 positives including 24 samples of subtype a, b, b', c, d, f, g, b/d, crf01_ae in hiv-1 group m, one sample of hiv-1 ...201323984590
non-m variants of human immunodeficiency virus type 1.the aids pandemic that started in the early 1980s is due to human immunodeficiency virus type 1 (hiv-1) group m (hiv-m), but apart from this major group, many divergent variants have been described (hiv-1 groups n, o, and p and hiv-2). the four hiv-1 groups arose from independent cross-species transmission of the simian immunodeficiency viruses (sivs) sivcpz, infecting chimpanzees, and sivgor, infecting gorillas. this, together with human adaptation, accounts for their genomic, phylogenetic, and ...201323824367
update on the human immunodeficiency virus.at the end of 2011, unaids estimated that 34 million (31.4 to 35.9) individuals were infected by hiv worldwide and that 2.5 million were newly infected during the year. since 2001, we have observed an increased number of hiv-infected patients in the world, due to an expanded access to antiretroviral drugs. more than 23,5 million (22.1 to 24.8) hiv-infected patients live in sub-saharan africa. the number of hiv-infected patients in france is estimated at 152,000. two types of hiv cause aids: hiv- ...201323628423
cell-cell transmission allows human t-lymphotropic virus 1 to circumvent tetherin restriction.tetherin is part of the cellular innate immunity and impedes cell-free transmission of viruses that bud from the plasma membrane by retaining them on the cell surface. some viruses have evolved activities in different proteins such as vpu (hiv-1), k-protein (kshv), nef (siv) or env (hiv-2) to downregulate tetherin and overcome its restriction. we found that chronically htlv-1 infected t-cell lines express eightfold more tetherin than uninfected transformed t-cell lines suggesting that tetherin e ...201323260108
variable clinical presentations of classic kaposi sarcoma in turkish patients.kaposi sarcoma (ks) is a vascular neoplasm with multicentric cutanenous and extracutaneous involvements, which was first described by moriz kaposi in 1872. since then, different epidemiological clinical and histopathological variants of this neoplasm have been identified. classic kaposi sarcoma (cks) is one of four main clinico-epidemiologiologic variants. characteristics of the disease.201222514583
synthesis and antiviral evaluation of bis(pom) prodrugs of (e)-[4'-phosphono-but-2'-en-1'-yl]purine nucleosides.seventeen hitherto unknown bis(pom) prodrugs of novel (e)-[4'-phosphono-but-2'-en-1'-yl]purine nucleosides were prepared in a straight approach and at good yields. those compounds were synthesized by the reaction of purine nucleobases directly with the phosphonate synthon 3 bearing pom biolabile groups under mitsunobu conditions. all obtained compounds were evaluated for their antiviral activities against a large number of dna and rna viruses including herpes simplex viruses 1 and 2, varicella z ...201223047229
viral hepatitis and hiv infection among injection drug users in a central iranian city.this study aimed to determine the prevalence of serological markers for hepatitis b virus (hbv), hepatitis c virus (hcv), human immunodeficiency virus (hiv), and occult hbv infection among injection drug users (idus) with isolated anti-hepatitis b core (anti-hbc).201222895463
clinical care versus ethical obligations: hiv-1 and -2 co-infection with hepatitis b in a pregnant jehovah's witness.co-infection with hiv-1 and -2 is rare, even in west africa. we present the case of a 38-year-old pregnant jehovah's witness presenting late in pregnancy with triple infection with hiv-1, hiv-2 and hepatitis b virus. there was a successful outcome in averting vertical transmission despite objections to management based on religious and cultural beliefs.201222844019
exploration of the in vitro antiviral activity of a series of new pyrimidine analogues on the replication of hiv and hcv.in continuation of our search for new anti-hiv and anti-hcv agents, the suggestion, synthesis and structure elucidation of a new series of 2,6-diamino-4-alkylthio- or (2-benzylhydrazinyl)-5-p-chlorophenylazopyrimidines), 2,6-diamino-4-(2-benzylhydrazinyl)-5-(aryl-[1,1'-biphenyl]-4-yl)pyrimidines, 2,6-diamino-4-(aryl)-5-(aryl[1,1'-biphenyl]-4-yl) pyrimidines), 6-(aryl)-1,3-dimethyl-5-nitro pyrimidine-2,4-dione and 6-amino-4-methoxy-n,n-dimethyl-6-arylpyrimidines were described.201223010622
inactivation effect of standard and fractionated electron beam irradiation on enveloped and non-enveloped viruses in a tendon transplant model.background: for increasing allograft tendon safety in reconstructive surgery, an effective sterilization method achieving sterility assurance including viruses without impairing the grafts properties is needed. fractionated electron beam (ebeam) has shown promising in vitro results. the proof of sufficient virus inactivation is a central part of the process validation. methods: the ebeam irradiation of the investigated viruses was performed in an optimized manner (oxygen content < 0.1%, -78 °c). ...201222896764
structure-activity relationship study of pyrimido[1,2-c][1,3]benzothiazin-6-imine derivatives for potent anti-hiv agents.3,4-dihydro-2h,6h-pyrimido[1,2-c][1,3]benzothiazin-6-imine (pd 404182) is an antiretroviral agent with submicromolar inhibitory activity against human immunodeficiency virus-1 (hiv-1) and hiv-2 infection. in the current study, the structure-activity relationships of accessory groups at the 3- and 9-positions of pyrimido[1,2-c][1,3]benzothiazin-6-imine were investigated for the development of more potent anti-hiv agents. several different derivatives containing a 9-aryl group were designed and sy ...201223022280
feline tetherin is characterized by a short n-terminal region and is counteracted by the feline immunodeficiency virus envelope glycoprotein.tetherin (bst2) is the host cell factor that blocks the particle release of some enveloped viruses. two putative feline tetherin proteins differing at the level of the n-terminal coding region have recently been described and tested for their antiviral activity. by cloning and comparing the two reported feline tetherins (called here cbst2(504) and cbst2*) and generating specific derivative mutants, this study provides evidence that feline tetherin has a shorter intracytoplasmic domain than those ...201222514338
development of real-time pcr array for simultaneous detection of eight human blood-borne viral pathogens.real-time pcr array for rapid detection of multiple viral pathogens should be highly useful in cases where the sample volume and the time of testing are limited, i.e. in the eligibility testing of tissue and organ donors.201222912836
gcn2 has inhibitory effect on human immunodeficiency virus-1 protein synthesis and is cleaved upon viral infection.the reversible phosphorylation of the alpha-subunit of eukaryotic translation initiation factor 2 (eif2alpha) is a well-characterized mechanism of translational control in response to a wide variety of cellular stresses, including viral infection. beside pkr, the eif2alpha kinase gcn2 participates in the cellular response against viral infection by rna viruses with central nervous system tropism. pkr has also been involved in the antiviral response against hiv-1, although this antiviral effect i ...201223110064
tailored hiv-1 vectors for genetic modification of primary human dendritic cells and monocytes.monocyte-derived dendritic cells (mddcs) play a key role in the regulation of the immune system and are the target of numerous gene therapy applications. the genetic modification of mddcs is possible with human immunodeficiency virus type 1 (hiv-1)-derived lentiviral vectors (lvs) but requires high viral doses to bypass their natural resistance to viral infection, and this in turn affects their physiological properties. to date, a single viral protein is able to counter this restrictive phenotyp ...201223077304
molecular determinants of hiv-2 r5-x4 tropism in the v3 loop: development of a new genotypic tool.objective. the use of ccr5 inhibitors requires a tool to predict human immunodeficiency virus type 2 (hiv-2) tropism, as established in hiv-1. the aim of our study was to identify genotypic determinants of hiv-2 tropism located in the gp105 v3 loop. methods. hiv-2 tropism phenotypic assays were performed on 53 hiv-2 clinical isolates using gfp expressing human osteosarcoma t4 [ghost(3)] cell lines expressing cd4 and ccr5 or cxcr4 coreceptors. the gp105 v3 loop was sequenced and analyzed. results ...201222140264
broad and potent neutralizing antibody responses elicited in natural hiv-2 infection.compared with human immunodeficiency virus type 1 (hiv-1), little is known about the susceptibility of hiv-2 to antibody neutralization. we characterized the potency and breadth of neutralizing antibody (nab) responses in 64 subjects chronically infected with hiv-2 against three primary hiv-2 strains: hiv-2(7312a), hiv-2(st), and hiv-2(uc1). surprisingly, we observed in a single-cycle jc53bl-13/tzm-bl virus entry assay median reciprocal 50% inhibitory concentration (ic(50)) nab titers of 1.7 × 1 ...201222031948
synthesis, antiviral and cytotoxicity studies of novel n-substituted indophenazine derivatives.a series of novel n-substituted indophenazine derivatives were synthesised and screened for antiviral activity against a panel of human pathogenic viruses. new compounds were synthesised through modifying the n-hydrogen of indophenazine moiety with different substitution and formaldehyde by mannich reaction. the structure of the synthetic compounds was characterised by means of infra red and nuclear magnetic resonance spectral data. the compound 10h-indolo-2-amino pyridine [3,2-b] quinoxalines i ...201223440065
integrating antiretroviral therapy into antenatal care and maternal and child health settings: a systematic review and meta-analysis.to determine whether integrating antiretroviral therapy (art) into antenatal care (anc) and maternal and child health (mch) clinics could improve programmatic and patient outcomes.201223397350
absence of routine molecular testing and prevalence of hiv-2 infection in regions hardest-hit by hiv infection.investigating the incidence and dynamics of hiv-2 and false-negative hiv test results in a highly sexually active population where frequent opportunities exist for acquiring and transmitting infections provides additional understanding of the epidemiology of the virus in africa.201223276739
samhd1 restricts hiv-1 cell-to-cell transmission and limits immune detection in monocyte-derived dendritic cells.samhd1 is a viral restriction factor expressed in dendritic cells and other cells, inhibiting infection by cell-free human immunodeficiency virus type 1 (hiv-1) particles. samhd1 depletes the intracellular pool of deoxynucleoside triphosphates, thus impairing hiv-1 reverse transcription and productive infection in noncycling cells. the vpx protein from hiv-2 or simian immunodeficiency virus (sivsm/sivmac) antagonizes the effect of samhd1 by triggering its degradation. a large part of hiv-1 sprea ...201223269793
electrostatic potential of human immunodeficiency virus type 2 and rhesus macaque simian immunodeficiency virus capsid proteins.human immunodeficiency virus type 2 (hiv-2) and simian immunodeficiency virus isolated from a macaque monkey (sivmac) are assumed to have originated from simian immunodeficiency virus isolated from sooty mangabey (sivsm). despite their close similarity in genome structure, hiv-2 and sivmac show different sensitivities to trim5α, a host restriction factor against retroviruses. the replication of hiv-2 strains is potently restricted by rhesus (rh) monkey trim5α, while that of sivmac strain 239 (si ...201222679444
interplay between hiv-1 and host genetic variation: a snapshot into its impact on aids and therapy response.as of february 2012, 50 circulating recombinant forms (crfs) have been reported for hiv-1 while one crf for hiv-2. also according to hiv sequence compendium 2011, the hiv sequence database is replete with 414,398 sequences. the fact that there are crfs, which are an amalgamation of sequences derived from six or more subtypes (crf27_cpx (cpx refers to complex) is a mosaic with sequences from 6 different subtypes besides an unclassified fragment), serves as a testimony to the continual divergent e ...201222666249
enhanced u.s. army hiv diagnostic algorithm used to diagnose acute hiv infection in a deployed soldier.antibody screening alone may fail to detect human immunodeficiency virus (hiv) in recently infected individuals. by u.s. army regulation, hiv-infected soldiers are not permitted to deploy to areas of conflict, including iraq and afghanistan. we report here the first case of acute hiv infection (ahi) in a soldier in a combat area of operation detected by an enhanced u.s. army hiv testing algorithm and discuss features of the tests which aided in clinical diagnosis. we tested the sample from the a ...201222645891
[consensus document of gesida and spanish secretariat for the national plan on aids (spns) regarding combined antiretroviral treatment in adults infected by the human immunodeficiency virus (january 2012)].this consensus document has been prepared by a panel consisting of members of the aids study group (gesida) and the spanish secretariat for the national plan on aids (spns) after reviewing the efficacy and safety results of clinical trials, cohort and pharmacokinetic studies published in medical journals, or presented in medical scientific meetings. gesida has prepared an objective and structured method to prioritise combined antiretroviral treatment (cart) in naïve patients. recommendations str ...201222633764
tight interplay among samhd1 protein level, cellular dntp levels, and hiv-1 proviral dna synthesis kinetics in human primary monocyte-derived macrophages.recently, samhd1 has come under intense focus as a host anti-hiv factor. samhd1 is a dntp triphosphohydrolase, which leads to the regulation of dna metabolism in host cells. hiv-2/siv (simian immunodeficiency virus) viral protein x (vpx) has been shown to promote the degradation of samhd1. in this study, we examine the kinetics of samhd1 degradation, the increase in the dntp pool level, and the efficiency of proviral dna synthesis in vpx+ virus-like particle (vlp)-treated monocyte-derived macrop ...201222589553
vpx is critical for sivmne infection of pigtail macaques.viral protein x (vpx) of siv has been reported to be important for establishing infection in vivo. vpx has several different activities in vitro, promoting preintegration complex import into the nucleus in quiescent lymphocytes and overcoming a block in reverse transcription in macrophages. vpx interacts with the ddb1-cul4-dcaf1 e3 ligase complex, which may or may not be required for the ascribed functions. the goal of the current study was to determine whether these activities of vpx are import ...201222531456
role of human trim5α in intrinsic immunity.human immunodeficiency virus (hiv) has a very narrow host range. hiv type 1 (hiv-1) does not infect old world monkeys, such as the rhesus monkey (rh). rh trim5α was identified as a factor that confers resistance, intrinsic immunity, to hiv-1 infection. unfortunately, human trim5α is almost powerless to restrict hiv-1. however, human trim5α potently restricts n-tropic murine leukemia viruses (mlv) but not b-tropic mlv, indicating that human trim5α represents the restriction factor previously desi ...201222435067
hiv-2 genome dimerization is required for the correct processing of gag: a second-site reversion in matrix can restore both processes in dimerization-impaired mutant viruses.a unique feature of retroviruses is the packaging of two copies of their genome, noncovalently linked at their 5' ends. in vitro, dimerization of human immunodeficiency virus type 2 (hiv-2) rna occurs by interaction of a self-complementary sequence exposed in the loop of stem-loop 1 (sl-1), also termed the dimer initiation site (dis). however, in virions, hiv-2 genome dimerization does not depend on the dis. instead, a palindrome located within the packaging signal (psi) is the essential motif f ...201222419802
hiv-1 and hiv-2 infections induce autophagy in jurkat and cd4+ t cells.autophagy plays important roles during innate and adaptive immune responses to pathogens, including virus infection. viruses develop ways to subvert the pathway for their own benefit in order to escape restriction by autophagy, leading to increased viral replication and/or control over apoptosis of their host cells. the effects of hiv infection on the autophagic pathway in host cells have been little documented. using the susceptible jurkat cell line and cd4(+) t cells, we studied the relationsh ...201222406083
switching virally suppressed, treatment-experienced patients to a raltegravir-containing regimen does not alter levels of hiv-1 dna.current hiv-1 antiretroviral therapy (art) greatly reduces virus replication but does not significantly affect the viral reservoir. raltegravir, a recently introduced integrase inhibitor, could, at least theoretically, reduce residual viremia in patients on art and affect the viral reservoir size. the aim of this study was to assess whether switching therapy in treatment-experienced patients that were virally suppressed to a raltegravir-containing regimen reduces the size of the viral reservoir, ...201222396745
overview of microbicides for the prevention of human immunodeficiency virus.human immunodeficiency virus (hiv) prevention tools that women can use and control are urgently needed. microbicides are chemical products applied to the vagina or rectum to prevent the sexual transmission of hiv. four classes of candidate microbicides have been tested to date: those that (1) enhance the natural defences in the vagina to inactivate hiv; (2) inactivate hiv in the vagina; (3) prevent hiv from attaching to, and fusing with, the host cells; and (4) prevent hiv from replicating in ge ...201222386823
hiv-2 viral protein x (vpx) ubiquitination is dispensable for ubiquitin ligase interaction and effects on macrophage infection.hiv-2 vpx, a virus-associated accessory protein, is critical for infection of non-dividing myeloid cells. to understand the function of vpx ubiquitination, interaction with an e3 ubiquitin ligase complex, and ability to overcome an inhibition of reverse transcription, we analyzed vpx lysine mutants for their function and replication capability in macrophages. both wt vpx and vpx ta (lysine-less vpx) localized to the cytoplasm and nucleus in hela cells. all hiv-2 vpx lysine mutants were functiona ...201222386056
hiv/simian immunodeficiency virus (siv) accessory virulence factor vpx loads the host cell restriction factor samhd1 onto the e3 ubiquitin ligase complex crl4dcaf1.the sterile alpha motif and hd domain-containing protein-1 (samhd1) inhibits infection of myeloid cells by human and related primate immunodeficiency viruses (hiv and siv). this potent inhibition is counteracted by the vpx accessory virulence factor of hiv-2/sivsm viruses, which targets samhd1 for proteasome-dependent degradation, by reprogramming cellular crl4(dcaf1) e3 ubiquitin ligase. however, the precise mechanism of vpx-dependent recruitment of human samhd1 onto the ligase, and the molecul ...201222362772
human immunodeficiency virus type-2-a milder, kinder virus: an update.human immunodeficiency virus type-2 (hiv-2) belongs to the family retroviridae which is phylogenetically clusters with siv sm from sooty mangabeys. this virus is morphologically similar to human immunodeficiency virus type-1 (hiv-1) but has got only a 40% homology at the nucleotide level. there is a distinct geographical distribution of hiv-2 unlike hiv-1. there are currently eight subtypes/groups identified with subtype/group a responsible for the majority of infections. hiv-2 shows a considera ...201222361754
efficient nef-mediated downmodulation of tcr-cd3 and cd28 is associated with high cd4+ t cell counts in viremic hiv-2 infection.the role of the multifunctional accessory nef protein in the immunopathogenesis of hiv-2 infection is currently poorly understood. here, we performed comprehensive functional analyses of 50 nef genes from 21 viremic (plasma viral load, >500 copies/ml) and 16 nonviremic (<500) hiv-2-infected individuals. on average, nef alleles from both groups were equally active in modulating cd4, tcr-cd3, cd28, mhc-i, and ii cell surface expression and in enhancing virion infectivity. thus, many hiv-2-infected ...201222345473
samhd1 restricts the replication of human immunodeficiency virus type 1 by depleting the intracellular pool of deoxynucleoside triphosphates.samhd1 restricts the infection of dendritic and other myeloid cells by human immunodeficiency virus type 1 (hiv-1), but in lentiviruses of the simian immunodeficiency virus of sooty mangabey (sivsm)-hiv-2 lineage, samhd1 is counteracted by the virion-packaged accessory protein vpx. here we found that samhd1 restricted infection by hydrolyzing intracellular deoxynucleoside triphosphates (dntps), lowering their concentrations to below those required for the synthesis of the viral dna by reverse tr ...201222327569
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