Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The occurrence of dominant linear antigenic sites in the envelope glycoproteins of human immunodeficiency virus type 2 (HIV-2) was evaluated. Twenty-five peptides representing different regions of HIV-2, strain SBL-6669, were synthesized. For comparison the corresponding peptides of HIV-1, strain BRU, were also prepared. The peptides were tested in enzyme-linked immunosorbent assay (ELISA) with human sera from individuals with proven HIV-1 or HIV-2 infection and simian sera from animals infected with HIV-2 or simian immunodeficiency virus of sooty mangabay monkey origin (SIVsm). Four major antigenic regions were identified. Peptides representing parts or the whole V3 (neutralizing loop) region and an additional stretch of amino acids located at the carboxy terminal of this region showed considerable reactivity. This reaction was predominantly type specific, but some heterotypic reactivity was also seen. Peptides representing the carboxy terminal 21 amino acids of the V3 region of the type-related viruses HIV-2 and SIVsm allowed selective identification of strain-specific antibodies. A second major antigenic region was found close to the carboxy terminal end of the large glycoproteins. This region was cross-reactive between the two types. The two additional dominating antigenic regions were located in the amino terminal region of the transmembrane glycoprotein. One region has previously been shown to be a uniquely antigenic type-specific site. The other region was also type-specific, but was identified only in HIV-2, amino acids Glu634-Lys649. Excellent facilities are available for the design of not only type-unique site-specific serological tests but potentially also type-cross-reactive and strain-specific assays.
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PMID:Comparison of linear antigenic sites in the envelope proteins of human immunodeficiency virus (HIV) type 2 and type 1. 171 15

Although the immunodeficiency diseases associated with human immunodeficiency virus (HIV) 1 and 2 are indistinguishable from each other, there is some evidence that HIV-2 isolates may have a longer incubation period. Thus, an investigation was conducted of the biological properties and molecular variability of the spectrum of HIV-2 isolates existing in The Gambia. Serum samples were obtained from 20 HIV-2-positive individuals attending a sexually transmitted diseases clinic in Fajara. Seven new HIV-2 isolates (CBL-20 to CBL-26) were identified. Each differed in terms of its growth rate, cytopathogenicity in vitro, and sensitivity to neutralizing antibodies in patient sera. In addition, there was a close association between the isolates' in vitro cytopathogenicity and the clinical cytopathogenic strains, were obtained from the two patients with acquired immunodeficiency syndrome (AIDS). In contrast, patients from whom CBL-25 and 26 were isolated have been asymptomatic for at least 3 years. CBL-22 was highly sensitive to neutralization by HIV-2 sera and was cross-neutralized by some HIV-1 sera. It is speculated that the observed differences in sensitivity to neutralization reflect differences in antigenic epitope expression or the number and presentation of envelope glycoprotein molecules on an infectious virion. Analysis of the molecular weight of the envelope precursor and the outer envelope protein of various HIV-2 isolates revealed that all the CBL isolated and SBL-6669 have smaller envelope proteins than the prototype strain, LAV-2 ROD. Also observed were differences in the amino acid sequences of these HIV-2 isolates.
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PMID:Biological and molecular variability of human immunodeficiency virus type 2 isolates from The Gambia. 197 44

Simian immunodeficiency virus (SIV) infection in cynomolgus macaques leads to severe immunodeficiency with a fatal outcome. In contrast, HIV-2 infects these primates without apparently causing any immunological abnormalities. In this study three cynomolgus monkeys were experimentally infected with HIV-2 strain SBL-K135 and 168 days later challenged with 10-100 animal infectious doses of the closely related SIV strain SM to study protective immunity. At the time of SIV challenge the HIV-2-infected monkeys had neutralizing antibodies against HIV-2, but virus could no longer be recovered from their peripheral blood mononuclear cells (PBMCs) and no clinical symptoms or decrease in CD4+ lymphocytes were observed. Follow-up for 9 months after challenge with SIV showed that the HIV-2-infected monkeys were protected against SIV-induced immunodeficiency (no decrease of CD4+ lymphocytes) and lymphadenopathy. However, they were not resistant to SIV infection since virus could be recovered from their PBMCs and they developed anamnestic antibody responses. Four naive control monkeys which were inoculated with the same dose of SIV became persistently infected and developed a decrease of the absolute numbers of CD4+ cells and showed a marked lymphadenopathy. Two out of four control animals died 58-265 days postinfection with an immunosuppressive disease. Immunohistochemical examination showed abundant viral antigen in lymph-node biopsies from the SIV-infected control monkeys but absence of SIV or HIV-2 antigens in the biopsies from the three HIV-2-preinfected and SIV-superinfected monkeys. The present study demonstrates possibilities for induction of immunity against immunodeficiency induced by a primate lentivirus, a concept with application also to HIV infection and AIDS in man.
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PMID:Infection of cynomolgus monkeys with HIV-2 protects against pathogenic consequences of a subsequent simian immunodeficiency virus infection. 197 45

A total of 70 human immunodeficiency virus type 1 (HIV-1) and 42 HIV-2 antibody-positive serum samples, collected from groups of individuals in which only one type of HIV prevails, were tested for cross-reactivity against HIV-2 and HIV-1 proteins by Western blot (WB) (immunoblot), radioimmunoprecipitation assay (RIPA), neutralization analysis, and enzyme-linked immunosorbent assay with as antigen synthetic peptides representing selected parts of the envelope (env) glycoproteins. Cross-reactions against the env glycoproteins were observed by WB in 10% (7 of 70) and by RIPA in 40% (28 of 70) of the HIV-1 antibody-positive serum samples and by WB in 29% (12 of 42) and by RIPA in 48% (20 of 42) of the HIV-2 antibody-positive serum samples. Testing by enzyme-linked immunosorbent assay against a 36-amino-acid peptide (Cys-301-Cys-336) of the external glycoprotein of strain HTLV-IIIB of HIV-1 (HIV-1HTLV-IIIB) (known to represent a dominating, linear neutralizing site) showed type-specific reactions in 67% (38 of 57) of HIV-1 antibody-positive serum samples. Type-specific reactions against a homologous 35-amino-acid peptide of strain SBL-6669 of HIV-2 (HIV-2SBL-6669) were found in 75% (30 of 40) of HIV-2 antibody-positive serum samples, and these reactions were correlated to neutralization against HIV-2SBL-6669. Cross-reactions against these peptides were seen in 23% (13 of 57) and 33% (13 of 40) of the HIV-1 and HIV-2 antibody-positive serum samples, respectively. These cross-reactions were correlated to cross-neutralization against HIV-1HTLV-IIIB and HIV-2SBL-6669. Cross-neutralization against one heterotypic virus strain was demonstrated in 16% (9 of 57) of HIV-1 antibody-positive serum samples and in 22% (5 of 22) of HIV-2 antibody-positive serum samples, but no correlation was found between cross-neutralization and env cross-reactivity in WB or RIPA.
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PMID:Envelope cross-reactivity between human immunodeficiency virus types 1 and 2 detected by different serological methods: correlation between cross-neutralization and reactivity against the main neutralizing site. 219 Nov 52

A category of viruses has been identified which is related to human immunodeficiency virus (HIV) but is more closely related to a group of simian retroviruses (STLV-III). These viruses named HTLV-IV, LAV-II, or SBL-6669, are prevalent in West-Africa. In this study, we analysed the cross-reactivity at the protein level between HTLV-IV and HIV (HTLV-IIIB). The results indicate that most people infected with HTLV-IV have antibodies that react to the major gag protein of HIV p 24. There is also a high degree of immunologic cross-reactivity between the pol gene products of HIV and HTLV-IV. Among these the endonuclease/integrase is more conserved than the reverse transcriptase. In contrast, the envelope glycoproteins that are the most frequently detected antigens by antibodies from exposed individuals are serotype specific. These data make the env gene products the most interesting antigens for serotype specific diagnosis of human retroviruses infections.
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PMID:A STLV-III related human retrovirus, HTLV-IV: analysis of cross-reactivity with the human immunodeficiency virus (HIV). 244 14

Ten healthy adult cynomolgus monkeys (Macaca fascicularis) were inoculated with two different isolates of human immunodeficiency virus type 2 (HIV-2), SBL-6669 and SBL-K135, to establish an animal model for HIV infection. HIV-2SBL-6669 had been propagated for a long time in continuous human cell lines whereas HIV-2SBL-K135 had been grown only in fresh human and monkey lymphocyte cultures or previously for a short time in a continuous cell line. Virus was isolated from three or four animals inoculated with HIV-2SBL-K135 but in none of six monkeys inoculated with HIV-2SBL-6669. All animals seroconverted although the antibody response was higher in SBL-K135 virus-infected monkeys. Varying degrees of lymphadenopathy were observed but there were no significant changes in the numbers of CD4+ and CD8+ T cells. The infection was transferred to two monkeys inoculated with blood from a previously SBL-K135 virus-infected monkey. Four animals inoculated with HIV-2SBL-K135, which had never been propagated in continuous human cell lines, showed strong antibody responses against both gag- and env- encoded proteins of HIV-2. None of the SBL-6669 infected monkeys showed antibodies to core proteins. HIV-2 infection of cynomolgus monkeys represents a useful experimental model for HIV vaccine trials and antiviral testing.
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PMID:Experimental infection of cynomolgus monkeys (Macaca fascicularis) with HIV-2. 252 70

Human cell lines were infected with different strains of human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2) as well as with a simian immunodeficiency virus SIVmac isolate and used as targets in an antibody-dependent cellular cytotoxicity (ADCC) assay. Sera from HIV-1- or HIV-2-infected subjects provided the antibody, and lymphocytes from normal donors provided the effector cells. About 60% of HIV-1 antibody-positive sera mediated ADCC when tested against any given HIV-1 isolate-infected target cell (human T-cell lymphotropic virus type IIIB, B40, A2587), and about 75% of HIV-2 antibody-positive sera mediated ADCC when tested against target cells infected with HIV-2 isolates (lymphadenopathy-associated virus type 2 and SBL-6669) or simian immunodeficiency virus from macaques. Within each type, individual sera showed different reactivity patterns, and the probability that a serum was ADCC positive was higher when it was tested against several strains. When the ADCC reactivity of sera against different strains was compared, diversity as detected by ADCC appeared to be greater among HIV-1 strains than among HIV-2 strains. For HIV-1, 54 to 67% of the sera gave concordant ADCC reactions, whereas for HIV-2 and SIVmac, 91% of the sera gave concordant results. Almost no strain-specific differences were seen between SBL-6669 and lymphadenopathy-associated virus type 2. As we determined previously, HIV-1 and HIV-2 did not cross-react in ADCC. The results indicated that HIV-1 and HIV-2 antibody-positive sera mediate both strain- and type-specific ADCC. HIV-2 antibody-positive sera seem to mediate ADCC with broader reactivity and to a higher frequency compared with HIV-1 antibody-positive sera.
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PMID:Antibody-dependent cellular cytotoxicity detects type- and strain-specific antigens among human immunodeficiency virus types 1 and 2 and simian immunodeficiency virus SIVmac isolates. 274 34

A new primate retrovirus, STLV-IIIAGM, has been recently isolated from healthy African green monkeys and is apparently nonpathogenic in its natural host. However, spontaneous infection as well as inoculation of STLV-IIIAGM into macaques induces a disease with clinical features that resemble human AIDS. Independent isolates of human retroviruses, serologically closely related to STLV-IIIAGM, have been obtained from healthy individuals (HTLV-IV) and patients with immunodeficiency (LAV-2FG and SBL 6669) from West Africa. The latter have also been referred to as HIV-2 because, like HTLV-III/HIV-1, they may be associated with immune deficiency, or as West African human retroviruses because of their prevalence and probable origin from that region. We have molecularly cloned the STLV-IIIAGM genome and have generated probes from the gag-pol and envelope genes to analyze the genetic relatedness of these simian and human retroviruses. Our results indicate that all these retroviruses are genetically closely related to each other, HTLV-IV and STLV-IIIAGM differing only by a few restriction enzyme sites while LAV-2FG and SBL 6669 exhibit greater polymorphism from HTLV-IV/STLV-IIIAGM. These data mirror the variable degree of relatedness among members of the first subgroup of human retroviruses, HTLV-III/HIV.
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PMID:Genetic analysis of a new subgroup of human and simian T-lymphotropic retroviruses: HTLV-IV, LAV-2, SBL-6669, and STLV-IIIAGM. 304 52

A new human retrovirus of West African origin (SBL-6669) has been isolated from a patient with immunological and clinical signs of immunodeficiency. Using radioimmunoprecipitation assays (RIPA) and Western blot (WB) tests with human sera, the new virus isolate has been compared with HTLV-IV, LAV-II, and the HTLV-IIIB prototype strain of the human immunodeficiency virus (HIV). The West African isolates appeared to be members of the same virus group since their glycoproteins were antigenically indistinguishable. West African sera showed no detectable cross reaction with HTLV-IIIB glycoproteins. The external glycoprotein in the different virus strains only showed minor variations in size. The size of the transmembranous protein was not unambiguously defined. In the West African virus isolates a 30-35 kD protein was seen similar to the protein previously described possibly to represent this component. However, in SBL-6669 a distinct 41 kD protein was also identified. There were interstrain variations in the size of several viral proteins among the West African virus isolates. Only minor differences were seen between SBL-6669 and LAV-II. The variations were most pronounced in two core proteins corresponding to the 19 kD and 24 kD proteins of HTLV-IIIB. In addition, West African human retroviruses appear to differ in pathogenicity. LAV-II and SBL-6669 are associated with immunodeficiency, whereas HTLV-IV was isolated from healthy individuals. Since further spread of these viruses to other parts of the world is imminent, it is necessary to consider their antigenic and immunogenic properties in serodiagnosis of HIV infections and in planning for immunoprophylactic interventions.
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PMID:A new human retrovirus isolate of West African origin (SBL-6669) and its relationship to HTLV-IV, LAV-II, and HTLV-IIIB. 304 53

Enzyme-linked immunosorbent assays (ELISA) were developed for the demonstration of antibodies to HIV-2 using disrupted virions of the SBL-6669 isolate of HIV-2 and the so-called human T-lymphotropic virus type IV (HTLV-IV), recently found to be identical with the simian immunodeficiency virus (SIVmac), as antigens. Three hundred sera from West African subjects, attending an outward clinic in Bissau for examination of suspected tuberculosis, were tested by these two assays as well as by a commercially available anti-HIV-2 ELISA (ELAVIA II). Fifty of these sera were positive in all three ELISAs as well as in Western blot tests against HTLV-IV. Thirty-eight of these positive sera were also tested by an anti-HIV-2 Western blot kit (LAV-Blot II) with positive results. The ELISAs based on SBL-6669 and HTLV-IV antigens had a specificity of 99.6% (one false positive among 250 negative sera) whereas the specificity of ELAVIA II was 94.6% using the recommended cut-off value and 98.4% using a higher cut-off value. Another 58 sera from West African patients, clinically suspected of having AIDS or HIV-related disease, were tested for HIV-2/HTLV-IV antibodies by Western blot and by ELISA against SBL-6669 and HTLV-IV antigens; all of the 30 sera which were positive by Western blot were found to be positive in both ELISAs.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Enzyme immunoassays for the demonstration of antibodies to HIV-2SBL-6669 and HTLV-IV (SIVmac). 313 13


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