| 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. | 2006 | 16597889 |
| quality control assessment of human immunodeficiency virus type 2 (hiv-2) viral load quantification assays: results from an international collaboration on hiv-2 infection in 2006. | human immunodeficiency virus type 2 (hiv-2) rna quantification assays used in nine laboratories of the achi(e)v(2e) (a collaboration on hiv-2 infection) study group were evaluated. in a blinded experimental design, laboratories quantified three series of aliquots of an hiv-2 subtype a strain, each at a different theoretical viral load. quantification varied between laboratories, and international standardization of quantification assays is strongly needed. | 2008 | 18434556 |
| full-length genome characterization of an hiv type 2 isolate from india. | an infectious indian human immunodeficiency virus-2 (hiv-2) subtype a isolate was completely sequenced and analyzed and its phylogenetic relatedness was investigated. the unusual limited size of the long terminal repeat (ltr) from the isolate was caused due to a truncation within the nef open reading frame (orf) located at the u3 region of the ltr. the genetic relatedness and lineage of this hiv-2 strain were investigated. the close relatedness of this isolate to west african hiv-2 isolates conf ... | 2008 | 18821845 |
| molecular epidemiology of hiv type 2 infections in south india. | a small but significant number of hiv-2 cases have been reported from india. although all hiv-2 viruses identified belong to subtype a, there are no studies on the diversity of the hiv-2 envelope and other genomic regions from india. furthermore, hiv-2 envelope quasispecies in infected individuals has not been studied in detail. this study was designed to address these gaps existing in the epidemiology of hiv-2 in the country. amongst the 4685 hiv-positive samples, 27 (0.57%) were positive for a ... | 2009 | 19327056 |
| subtype & cytokine profiles of hiv infected individuals from south india. | the global surveillance of human immunodeficiency virus (hiv) subtypes (clades) helps understand the global distribution and incidence of different hiv subtypes. as knowledge about subtypes circulating in an area is needed for developing a candidate vaccine, prevalence of the subtypes hiv-1 and hiv-2 were studied in south india. the profile of cytokines interleukin 10 (il10) and interferon gamma (ifngamma) in both types of infection were also analysed as these are considered indicators of diseas ... | 2005 | 15817940 |
| nigerian hiv type 2 subtype a and b from heterotypic hiv type 1 and hiv type 2 or monotypic hiv type 2 infections. | the presence of hiv-2 in nigeria has been confirmed serologically, but not genetically. to determine the frequency of hiv-2 infections and the dynamics between hiv-1 and hiv-2 in 35 of 36 nigerian states, 420 blood samples were collected in 1999. antibodies to hiv-1 and hiv-2 were detected by eia and seroreactivity was confirmed with the inno-lia hiv line assay. the frequency of hiv-2 was 4.3% (18 of 420), with 3.8% (16 of 420) hiv-1 and hiv-2 (hiv-1/2) heterotypic and 0.5% (2 of 420) hiv-2 homo ... | 2005 | 15665641 |
| plasma rna viral load in human immunodeficiency virus type 2 subtype a and subtype b infections. | human immunodeficiency virus type 2 (hiv-2) is much less pathogenic than hiv-1, and hiv-2 infection is associated with plasma viral loads significantly lower than those found in hiv-1 infection. we have developed a real-time quantitative pcr method for measuring the hiv-2 rna load that covers the range of genetic diversity of hiv-2 isolates and that detects extremely low viral loads. samples from 49 patients were studied. proviral dna was first detected and quantified. the strains that were dete ... | 2002 | 12354861 |
| identification of hiv type 2 subtype b transmission in east asia. | we isolated an hiv-2 strain (01jp-imcj/kr020) from a korean patient who has lived in japan for the past 6 years. he was infected with hiv-2 through heterosexual contacts in either korea or japan. the phylogenetic analyses based on the near full-length nucleotide sequence revealed that 01jp-imcj/kr020 belongs to hiv-2 subtype b cluster with high bootstrap support. this isolate harbors a 13-nucleotide insertion upstream of the nf-kb site, which is one of the sequence signatures specific to hiv-2 s ... | 2003 | 14686325 |
| quantification of proviral load of human immunodeficiency virus type 2 subtypes a and b using real-time pcr. | we have developed and evaluated a new method to quantify human immunodeficiency virus type 2 (hiv-2) proviral dna based on lightcycler real-time pcr. the assay has a detection limit of 5 copies/10(5) peripheral blood mononuclear cells (pbmc) and is insensitive to hiv-2 strain variability: hiv-2 subtypes a and b are both recognized and quantified. the intra- and interassay coefficients of variation range from 16 to 40% for high provirus concentrations (5 x 10(5) copies) and from 41 to 39% for low ... | 2001 | 11724830 |
| tracing the origin and history of the hiv-2 epidemic. | in this study we date the introduction of hiv-2 into the human population and estimate the epidemic history of hiv-2 subtype a in guinea-bissau, the putative geographic origin of hiv-2. the evolutionary history of the simian immunodeficiency virussooty mangabey/hiv-2 lineage was reconstructed by using available database sequences with known sampling dates, and a timescale for this history was calculated by using maximum likelihood methods. the date of the most recent common ancestor of hiv-2 sub ... | 2003 | 12743376 |
| hiv-2 subtype circulating in india (south). | the genetic types and subtypes of hiv vary from region to region. this study looked at the relative prevalence of hiv-2 subtypes in south india. nucleotide sequencing of the hiv-2 envelope v3 region of strains from 11 individuals infected with hiv-2 and one individual who had dual infection with hiv-1 and hiv-2 was performed. phylogenetic analysis showed that all individuals were infected with hiv-2 subtype a. these strains were from individuals who live in different regions of south india. in a ... | 2003 | 12794558 |
| molecular characterization of human immunodeficiency virus (hiv)-1 and -2 in individuals from guinea-bissau with single or dual infections: predominance of a distinct hiv-1 subtype a/g recombinant in west africa. | guinea-bissau in west africa has the highest prevalence of human immunodeficiency virus (hiv)-2 infection in the world, but recently the hiv-1 prevalence increased rapidly with the subsequent appearance of hiv-1 and hiv-2 dual infections. information about the genetic subtypes of hiv in the region is limited. therefore, we characterized the env v3 region of hiv-1 and hiv-2 variants through direct dna sequencing of peripheral blood mononuclear cell samples from 18 individuals with hiv-1 only and ... | 1999 | 10502510 |
| introduction of human immunodeficiency virus 2 infection into south korea. | although human immunodeficiency viruses 1 and 2 (hiv-1 and hiv-2) share mode of transmission, their epidemiologic characteristics differ and international spread of hiv-2 has been limited. to investigate the extent of hiv-2 infection in south korea and to clarify the characteristic of hiv-2 isolates, we describe epidemiological, serological and genetic analyses of five hiv-2 isolates from south korea. five of 964 hiv antibody-positive serum specimens showed positive reactivity by hiv1/2 enzyme i ... | 2000 | 10989687 |
| sequence specificity of the human immunodeficiency virus type 2 (hiv-2) long terminal repeat u3 region in vivo allows subtyping of the principal hiv-2 viral subtypes a and b. | sequences from the nef/ltr overlap region of the human immunodeficiency virus type 2 (hiv-2) genome were amplified from uncultured peripheral blood mononuclear cells (pbmcs) from 40 hiv-2-infected individuals in the gambia, west africa. additional sequences from the plasma of three blood donors were also derived. analysis of hiv-2 u3 ltr transcription factor elements (pub-1, p-ets, pub-2, peri-kappa b, and nf-kappa b sites) indicated a relatively high level of conservation in vivo. the region im ... | 2001 | 11177410 |
| predominance of human immunodeficiency virus type 2 subtype b in abidjan, ivory coast. | we analyzed the genetic variability and phylogenetic relationships among 28 hiv-2 strains collected from patients enrolled in an hiv epidemiologic study in abidjan, ivory coast, during 1995-1996. although both subtype a (n = 8; 29%) and subtype b (n = 20; 71%) were present in this sampling, the majority of infections were caused by subtype b viruses. these findings contrasted with the reported predominance of hiv-2 subtype a in other african countries. the broad genetic diversity identified amon ... | 1999 | 10221538 |
| molecular characterization of a full-length genome of a hiv-2 isolate from india. | india accounts for 95% of hiv-2 infections in asia. molecular epidemiological studies have been performed on hiv-2 partial envelope gene and ltr sequences from isolates in india. although, a single full-length sequence of an isolate from india is available in the genbank, a comprehensive molecular analysis of a large number of hiv-2 isolates would be essential for understanding the genomic heterogeneity of hiv-2 isolates prevalent in the country. | 2009 | 19727000 |
| human immunodeficiency virus type 2 (hiv-2) seroprevalence and characterization of a distinct hiv-2 genetic subtype from the natural range of simian immunodeficiency virus-infected sooty mangabeys. | the extent of zoonotic infections in rural sierra leone, where both feral and pet sooty mangabeys harbor divergent members of the human immunodeficiency virus type 2 (hiv-2)-sooty mangabey simian immunodeficiency virus (sivsm) family, was tested in blood samples collected from 9,309 human subjects in 1993. using hiv-1- and hiv-2-specific enzyme immunoassays and confirmatory western blot analysis to test for antibodies to sivsm-related lentiviruses, we found only nine subjects (0.096%) who tested ... | 1997 | 9094672 |
| the epidemiology of hiv in india. | india is the first country outside africa where an hiv-2 epidemic is running in parallel to an hiv-1 epidemic, resulting in a significant proportion of double infections. hiv is spreading rapidly, mainly by heterosexual contact, but also among intravenous drug users. genetic analyses of the hiv variants circulating in india point towards hiv-1 and hiv-2 having been introduced into the country recently. | 1995 | 7719634 |
| 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 ... | 2007 | 17093034 |
| human immunodeficiency virus type 2 (hiv-2) in portugal: clinical spectrum, circulating subtypes, virus isolation, and plasma viral load. | the human immunodeficiency virus type 2 (hiv-2) is responsible for 4. 5% of aids cases in portugal. six hiv-2 subtypes have been described so far, subtype a being proposed as more pathogenic than the rest. the relationship between the clinical status and levels of both cellular and plasma hiv-2 viraemia is not well known, nor their modifications under antiretroviral therapy. thirty-two consecutive hiv-2 infected persons (17 men, 15 women) attending two different hospitals in lisbon in 1997 were ... | 2000 | 10745242 |
| genetic variability of human immunodeficiency virus type 2 c2v3 region within and between individuals from bissau, guinea-bissau, west africa. | the v3 loop of both hiv-1 and hiv-2 is characterized by a high degree of genetic variation. to investigate the spectrum of hiv-2 variability in nature we have focused on the c2v3 region of env and analyzed 108 viral sequences obtained from uncultured peripheral blood mononuclear cells obtained from 16 hiv-2-seropositive individuals from bissau (guinea-bissau). the estimated values of genetic divergence between individuals were higher than those calculated from sequence information collected in a ... | 2000 | 10957727 |
| nef proteins of distinct hiv-1 or -2 isolates differ in their binding properties for hck: isolation of a novel nef binding factor with characteristics of an adaptor protein. | the nef gene of the human and simian immunodeficiency viruses hiv and siv has been implicated in pathogenicity; however, the mechanism by which nef induces disease is still unknown. an impact on signal transduction in cells has been suggested by the interaction of nef from an hiv-1 strain and tyrosine kinases like hck and lck as well as serine/threonine kinases. we have confirmed the binding of hck to hiv-1 subtype b nef and demonstrated an equally strong interaction with a subtype e nef protein ... | 1998 | 9656992 |
| Frequency of human immunodeficiency virus type-2 in hiv infected patients in Maputo City, Mozambique. | The HIV/AIDS pandemic is primarily caused by HIV-1. Another virus type, HIV-2, is found mainly in West African countries. We hypothesized that population migration and mobility in Africa may have facilitated the introduction and spreading of HIV-2 in Mozambique. The presence of HIV-2 has important implications for diagnosis and choice of treatment of HIV infection. Hence, the aim of this study was to estimate the prevalence of HIV-2 infection and its genotype in Maputo, Mozambique.HIV-infected i ... | 2011 | 21849066 |
| genetic analysis of hiv type 2 in monotypic and dual hiv infections. | a significant level of genetic variation among hiv-1 and hiv-2 has been described. the interaction of specific hiv-2 subtypes with hiv-1 may serve to identify potential biological properties associated with dual infection. to genetically characterize the hiv-2 strains circulating in senegal and their relationship to coinfection with hiv-1, we sequenced the hiv-2 envelope c2-c3 region of 12 subjects coinfected with hiv-1 and hiv-2 and 9 subjects singly infected with hiv-2. the phylogenetic analys ... | 2000 | 10710218 |
| profile of the hiv epidemic in cape verde: molecular epidemiology and drug resistance mutations among hiv-1 and hiv-2 infected patients from distinct islands of the archipelago. | hiv-1 and hiv-2 have been detected in cape verde since 1987, but little is known regarding the genetic diversity of these viruses in this archipelago, located near the west african coast. in this study, we characterized the molecular epidemiology of hiv-1 and hiv-2 and described the occurrence of drug resistance mutations (drm) among antiretroviral therapy naïve (artn) patients and patients under treatment (artexp) from different cape verde islands. blood samples, socio-demographic and clinical- ... | 2014 | 24763617 |
| genetic analysis of hiv type 2 from ghana and guinea-bissau, west africa. | the phylogenetic variability of part of the long terminal repeat (ltr) region of hiv-2 strains isolated in 1995 from five individuals residing in bissau, the capital city of guinea-bissau, and collected from seven persons from kumasi, ghana in 1996-1997, was analyzed. all guinean samples and all but one ghanaian sample clustered with hiv-2 subtype a. one ghanaian sample (14%) was classified as hiv-2 subtype b. this study adds to previous reports on hiv-2 subtype distribution in west africa indic ... | 2001 | 11779354 |
| various types of hiv mixed infections in cameroon. | in order to assess the incidence of hiv mixed infection as well as to clarify the molecular epidemiology of hiv in central africa, we investigated 43 hivs obtained from 211 cameroonian ac, arc, and aids patients in 1994 and 1995. part of the pol region and part of the env region were phylogenetically analyzed. the genotypes observed were varied: of 43 specimens, 28 (65%) were subtype a, 1 (2%) was subtype b, 2 (5%) were subtype d, 3 (7%) were subtype f, and 2 (5%) were group o. of the remaining ... | 1998 | 9614862 |
| secondary structural elements as a basis for antibody recognition in the immunodominant region of human immunodeficiency viruses 1 and 2. | synthetic peptide antigens corresponding to the entire third variable region v3, the principal neutralizing determinant of the human immunodeficiency virus (hiv) envelope glycoprotein of hiv-1 subtype b (1), hiv-2 subtype a (5), and hiv-2 subtype b (7) were synthesized by solid-phase peptide synthesis (table 1). 1 and 5 were also prepared as their glcnac-glycosylated forms at the natural n-glycosylation site nxt (positions 6-8; peptides 4 and 6). additionally, the proposed beta-turn region of 1 ... | 1996 | 8620873 |