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)

Human immunodeficiency virus-type 1 (HIV-1) replicates actively in infected individuals, yet cells with intracellular depots of viral protein are observed only infrequently. Many cells expressing the HIV-1 Gag protein were detected at the surface of the nasopharyngeal tonsil or adenoid. This infected mucosal surface contained T cells and dendritic cells, two cell types that together support HIV-1 replication in culture. The infected cells were multinucleated syncytia and expressed the S100 and p55 dendritic cell markers. Eleven of the 13 specimens analyzed were from donors who did not have symptoms of acquired immunodeficiency syndrome (AIDS). The interaction of dendritic cells and T cells in mucosa may support HIV-1 replication, even in subclinical stages of infection.
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PMID:Replication of HIV-1 in dendritic cell-derived syncytia at the mucosal surface of the adenoid. 896 79

The objective of the present study was to identify p24 antigenic domains recognized during natural human immunodeficiency virus type 1 (HIV-1) infection, the determination of the major epitopes of p24 having significant applications for both the improvement of diagnostic approaches and the development of vaccines. Reactivity of 20 HIV-1-infected patients and 8 HIV-1-negative patients was analyzed using an enzyme-linked immunosorbent assay (ELISA) developed with 45 overlapping synthetic pentadecapeptides, spanning amino acids 133 to 363 of HIV-1 p55gag precursor. Two peptides covering aa 178-192 and 288-302 of p55 were recognized by 40 and 45% of HIV-1 antibody-positive human samples, respectively. A peptide covering aa 272-322 of p55 was synthesized and recognized by most human sera in indirect ELISA. However, inhibition assays indicated that this sequence does not contain all of the immunodominant domains of p24 since it was not sufficient to block binding of human sera to whole p24. A three-dimensional model of p24 derived from the Mengovirus VP2 suggests that the two distant sequences recognized by human sera containing antibodies to HIV-1 could possibly be a part of a conformational epitope built up by two loops corresponding to aa 183-186 and 289-292.
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PMID:B cell epitopes of HIV type 1 p24 capsid protein: a reassessment. 867 7

Previous studies of asymptomatic human immunodeficiency virus (HIV) infection have shown that serum levels of soluble tumor necrosis factor receptors (sTNFR) are good predictors of disease progression and clinical outcome during zidovudine (ZDV) therapy. The present study of symptomatic HIV infection was designed to evaluate whether sTNFR p55 and p75 at weeks 0 (pretreatment) and 24 and 48 are predictors of death < or = 3 years after the start of ZDV 1,000 mg alone or combined with low-dose interferon-alpha (ZDV 500 mg + IFN-alpha 3 MIU three times weekly). CD4+ T-cell numbers and serum neopterin were analyzed in a similar way. Forty previously untreated symptomatic HIV-infected persons with CD4+ T-cell numbers > or = 150 x 10(6)/L were included. At baseline, in the nonsurvivor group, mean age (42.1 vs. 34.4 years, p = 0.002) and neopterin (24.7 vs. 18.0 nmol/L, p = 0.02) were higher, whereas mean CD4+ T-cell counts (202 vs. 295 x 10(6)/L, p = 0.02) were lower than in the survivors. All analyses were adjusted for age. For the pretreatment marker values, a significant relative risk (RR) for death was noted only in the univariate analysis for sTNFR-p55 > 1.7 ng/ml [RR 3.1; 95% confidence interval (CI) 1.1-8.8; p = 0.04]. During therapy, CD4+ counts < 200 x 10(6)/L at week 24 and 48 and neopterin > 20 nmol/ml at week 48 were independent predictors of survival in the uni- and multivariate analysis. Marker values relative to baseline were not predictive. sTNFR-p55 and p75 were of little use as surrogate markers for clinical efficacy during ZDV-containing drug regimens in symptomatic HIV-infected patients with CD4+ counts 150 x 10(6)/L.
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PMID:Predictive value for survival of soluble tumor necrosis factor receptors p55 and p75 during zidovudine-containing treatment in symptomatic human immunodeficiency virus type 1 infection. 875 25

AG1343 ([3S-(3R*,4aR*,8aR*,2'S*,3'S*)]-2-[2' hydroxy-3'-phenylthiomethyl-4'-aza-5'-oxo-5'-(2''-methyl-3''-hydro xy-phenyl) pentyl]-decahydroiso-quinoline-3-N-t-butylcarboxamide methanesulfonic acid) is a selective, nonpeptidic inhibitor of human immunodeficiency virus (HIV) protease (Ki = 2 nM) that was discovered by protein structure-based drug design methodologies. AG1343 was effective against the replication of several laboratory and clinical HIV type 1 (HIV-1) or HIV-2 isolates including pyridinone- and zidovudine-resistant strains, with 50% effective concentrations ranging from 9 to 60 nM. In reversibility studies, inhibition of gag (p55) proteolytic processing in HIV-1 particles from cells treated with AG1343 was maintained for up to 36 h after drug removal. The ability of virus to develop resistance to AG1343 was studied by serial passage of HIV-1 NL4.3 in the presence of increasing concentrations of drug. After 28 passages, a variant with a 30-fold reduction in susceptibility to AG1343 was isolated. Molecular analysis of the protease from this variant indicated a double change from a Met to Ile at residue 46 and an Ile to Val or Ala at residue 84 (M46I+I84V, A). Consistent with these findings, reductions in susceptibility were observed for recombinant viruses constructed to contain the single I84V change or the double M46I+I84V substitutions. Resistance, however, was not detected for recombinant viruses containing other key mutations in HIV-1 protease, including a Val to Ile change at residue 32 or a Val to Ala or Phe at residue 82. The potent anti-HIV activity of AG1343 against several isolates suggests that AG1343 should perform well during ongoing human phase II clinical trials.
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PMID:Antiviral and resistance studies of AG1343, an orally bioavailable inhibitor of human immunodeficiency virus protease. 883 68

Tumor necrosis factor alpha (TNF-alpha) is a potent inducer of human immunodeficiency virus type 1 (HIV-1) expression in chronically infected cells. The aim of this study was to investigate the role played by the two known TNF-alpha receptors, TNFR-p55 and TNFR-p75, in the activation of HIV-1 expression. As a model system the latently infected human promonocytic cell line U1 was stimulated with wild-type TNF-alpha, with TNF-alpha muteins that specifically bind to one or the other receptor or with receptor-specific monoclonal antibodies. Induction of HIV-1 expression, measured by p24 core antigen capture enzyme-linked immunosorbent assay (ELISA), was found to be exclusively triggered by TNFR-p55 stimulation. However, our results also showed that the addition of TNFR-p75-specific ligands negatively modulated the HIV-1 expression induced via TNFR-p55.
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PMID:Tumor necrosis factor receptor p55 mediates induction of HIV type 1 expression in chronically infected U1 cells. 883 97

Although human immunodeficiency virus (HIV) infection is progressive, the rate of decline in CD4+ lymphocyte counts varies. The role of immune system components in limiting HIV infection has yet to be defined, but a previous report on the U.S. Navy HIV Seropositive Cohort reported that strong reactivity in the anti-p55 (core precursor), p24 (core) and p53 (reverse transcriptase) Western blot bands was associated with higher CD4+ lymphocyte counts at the first clinical evaluation for HIV. The previous report examined the cross-sectional association between Western blot banding patterns and initial CD4+ lymphocyte counts. This report examines the association between these banding patterns in individuals who progressed rapidly as compared with patterns of patients who did not, based on their trends in repeated CD4+ lymphocyte counts as a marker of progression. Rapid and slower progressors were identified from a cohort of 3414 Navy and Marine Corps personnel who had a first positive HIV Western blot during 1986-1991. For purposes of this study, rapid progressors were defined as individuals whose CD4+ lymphocyte counts declined to < 500 cells/mm3 within 1 year of seroconversion. A total of 325 individuals met these criteria. A comparison group of 63 slower progressors also was identified; this group consisted of those whose CD4+ lymphocyte counts remained at > or = 500 cells/mm3 for a minimum of 5 years of follow-up after their first positive Western blot. Rapid progressors were slightly younger than slower progressors and were more likely to be never married but did not differ significantly from slower progressors in race or sex. Rapid progressors had weaker reactivity in the anti-p55 core precursor (P < 0.0001), p15 core (P < 0.01), gp41 transmembrane (P < 0.01) and p31 endonuclease (P < 0.05) bands on the Western blot. The odds ratio for rapid progressor status associated with weak or absent reactivity was 7.8 in the anti-p55 band and ranged from 2.0 to 3.2 in the anti-p31, p15, and gp41 bands. These associations remained significant after adjustment for age, race, and sex. The p55 association persisted in repeated Western blots during routine clinical evaluation during a period of 5 years after the first positive Western blot. It was concluded that several possible explanations may account for the weaker reactivity of rapid progressors: (i) weak anti-p55 reactivity might have been a marker of early immune system damage; (ii) high concentrations of p55 or related proteins in the serum may have bound the available anti-p55 antibodies in rapid progressors, making them difficult to identify on the Western blot; or (iii) lack of anti-p55, p15, gp41, or p31 reactivity might have allowed more rapid progression.
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PMID:Western blot banding patterns of HIV rapid progressors in the U.S. Navy Seropositive Cohort: implications for vaccine development. Navy Retroviral Working Group. 887 45

The reactivities of 1,172 serum samples obtained from asymptomatic human immunodeficiency virus type 1 (HIV-1)-positive and HIV-1-negative individuals residing in Mexico to a synthetic disulfide-looped peptide from the HIV-1 gp41 (amino acids 602 to 616 [IWGCSGKLICTTAVP] were examined by an enzyme-linked immunoadsorbent assay (ELISA) procedure. Antibodies to the synthetic peptide were detected in 261 of 268 serum samples from HIV-positive individuals (sensitivity, 97.4%). The peptide also reacted with 12 of 904 serum samples from control HIV-negative individuals (specificity, 98.7%). Western blots (immunoblots) of four of the seven serum samples that produced false-negative results in the ELISA showed that three of them reacted weakly with gp41 and strongly with gp120, p55, and/or p24. Potential diagnostic difficulties raised by the reported C1q binding capacity of this peptide were also evaluated: few and weak false-positive results were found among sera from patients with rheumatoid arthritis (1 of 31) and neurocysticercosis (2 of 111). In fact, strong reactivity with the peptide spotted an undetected HIV infection underlying clinical neurocysticercosis.
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PMID:Serologic reactivity of a synthetic peptide from human immunodeficiency virus type 1 gp41 with sera from a Mexican population. 891 54

In a series of compounds containing (2S,3S)-3-amino-2-hydroxy-4-phenylbutanoic acid (AHPBA), a transitionstate mimetic, R-87366:(2S,3S)-3-[N-(quinoxaline-2-carbonyl)-L-asparaginyl]amino- 2-hydroxy-4-phenylbutanoyl-L-proline tert-butylamide, was found to be a potent human immunodeficiency virus protease inhibitor (Ki value was 11 nM) and anti-HIV agent (IC90 value was 0.5 microM for HIV-1IIIB acutely infected cells) with moderate water-solubility (4.2 mg/ml at 25 degrees C). The compound was also active in chronically infected Molt-4/HIV-1IIIB cells, and inhibited the proteolytic processing of p55 into p17, suggesting that its anti-HIV activity was derived from HIV protease inhibition. The compound showed more potent activity (IC90 value was 0.03-0.25 microM) against clinical isolates of HIV in 5 out of 6 patients examined with varying clinical status in an ex vivo assay. One isolate, however, from the sixth patient, was less sensitive to R-87366 (IC90 value was 0.5 microM). In experiments with this strain, R-87366 showed comparatively low efficacy in acutely infected peripheral blood mononuclear cell (PBMC). This result suggests that the diversity of sensitivity shown in the ex vivo assay could be caused by the viral property itself. As a result of the determination of nucleic acid sequences in the clinical isolates, some amino acids were found to be substituted in the protease region, in contrast to the HIV-1 clade B consensus sequence, and some of them have been reported to contribute to the susceptibility of HIV protease inhibitors.
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PMID:In vitro and ex vivo anti-human immunodeficiency virus (HIV) activities of a new water-soluble HIV protease inhibitor, R-87366, containing (2S,3S)-3-amino-2-hydroxy-4-phenylbutanoic acid. 905 82

Syphilis has once again become a public health issue with the advent of human immunodeficiency virus (HIV) infection. We report a 28-year-old Chinese man with recently acquired HIV infection together with early neurosyphilis. His presentation of acute mononucleosis-like syndrome, lymphadenopathy, aseptic meningitis, positive central nervous syndrome and reactive Venereal Disease Research Laboratory test in his cerebrospinal fluid helped to reach the diagnosis. Paired serum Western blot tests for HIV infection performed 1 month apart revealed either a new appearance or an increasing intensity of bands for p17, p24, p31, gp41, p52, p55, p68, gp120 and gp160 suggesting recently acquired HIV infection. The lymphadenopathy disappeared spontaneously and the neurosyphilis responded well to 14 days of penicillin G therapy. The Western blot pattern, clinical course, laboratory data, and therapeutic response indicated that the acute retroviral syndrome and early central nervous system involvement caused by Treponema pallidum occurred concomitantly.
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PMID:Concomitant human immunodeficiency virus infection and syphilitic meningitis. 906 8

The mechanisms of cell death in CD4+ T cells mediated by human herpesvirus 6 (HHV-6) were investigated. The frequency of cell death in the human CD4+ T-cell line JJHAN, which had been inoculated with HHV-6 variant A or B, appeared to be augmented by tumor necrosis factor alpha (TNF-alpha). Agarose gel electrophoresis of DNA from HHV-6-inoculated cells showed DNA fragmentation in multiples of the oligonucleosome length unit. The degree of DNA fragmentation increased when HHV-6-inoculated cells were cultured in the presence of TNF-alpha. Flow cytometry and Scatchard analysis of TNF receptors revealed an increase in the number of the p55 form of TNF receptors on JJHAN cells after HHV-6 inoculation. It also appeared that treatment with anti-Fas monoclonal antibody (MAb) induced marked apoptosis in HHV-6-inoculated cells. Transmission electron microscopy showed characteristics of apoptosis, such as chromatin condensation and fragmentation of nuclei, but virus particles were hardly detected in apoptotic cells. Two-color flow cytometric analysis using anti-HHV-6 MAb and propidium iodide revealed that DNA fragmentation was present predominantly in uninfected cells but not in productively HHV-6-infected cells. In addition, JJHAN cells incubated with UV light-irradiated and ultracentrifuged culture supernatant of HHV-6-infected cells appeared to undergo apoptosis. The present study demonstrated that both HHV-6 variants A and B induce apoptosis in CD4+ T cells by indirect mechanisms, as reported recently in human immunodeficiency virus type 1 infection.
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PMID:Induction of T-cell apoptosis by human herpesvirus 6. 909 50


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