Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A synthetic peptidemimetic substrate of the human immunodeficiency virus 1 (HIV-1) protease with a nonhydrolyzable pseudodipeptidyl insert at the protease cleavage site was prepared. The peptide U-81749 inhibited recombinant HIV-1 protease in vitro (inhibition constant Ki of 70 nanomolar) and HIV-1 replication in human peripheral blood lymphocytes (inhibitory concentration IC50 of 0.1 to 1 micromolar). Moreover, 10 micromolar concentrations of U-81749 significantly inhibited proteolysis of the HIV-1 gag polyprotein (p55) to the mature viral structural proteins p24 and p17 in cells infected with a recombinant vaccinia virus expressing the HIV-1 gag-pol genes. The HIV-1 like particles released from inhibitor-treated cells contained almost exclusively p55 and other gag precursors, but not p24. Incubation of HIV-like particles recovered from drug-treated cultures in drug-free medium indicated that inhibition of p55 proteolysis was at least partially reversible, suggesting that U-81749 was present within the particles.
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PMID:A synthetic HIV-1 protease inhibitor with antiviral activity arrests HIV-like particle maturation. 240 86

A murine monoclonal antibody (MoAb), VAK 4, has been known to specifically react with a major core protein (p24) as well as with its precursor (p55-57) and intermediate precursor (p40) of human immunodeficiency virus strain IIIB (HTLV-IIIB). Radioimmunoprecipitation assays revealed that VAK 4 MoAb precipitated a major core protein and its precursors from a variety of strains of HIV and also from simian immunodeficiency virus (SIV), although the molecular weights of the precursor proteins in each viral strain were slightly different. A protein synthesized by transfected Escherichia coli containing amino acid sequences corresponding to residues 121-436 of the HTLV-IIIB gag gene was reactive with VAK 4 MoAb, but the protein carrying only residues 121-309 was not reactive, suggesting that the epitope recognized by VAK 4 MoAb resides at the carboxyl terminus of p24 protein. A competitive enzyme-linked immunosorbent assay showed that patient sera containing anticore protein antibody inhibited the binding of VAK 4 to HTLV-IIIB. These findings suggested that VAK 4 MoAb recognized an immunogenic and conserved epitope belonging to a major core protein of HIV-related viruses.
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PMID:Conserved immunogenic region of a major core protein (p24) of human and simian immunodeficiency viruses. 246 60

In order to optimize detection of human immunodeficiency virus-1 (HIV-1)-infected cells, the temporal appearance of virus antigens in newly infected H9 cell cultures was examined. Analyses were accomplished by indirect immunofluorescence labeling with each of 10 monoclonal antibodies and evaluation by flow cytometry. Of the antibodies examined, those specific for HIV-1 capsid protein p24, matrix protein p17, or their precursor molecule p55 allowed the earliest and most sensitive detection in infected cells fixed to allow detection of intracellular antigen. Discrimination of infected cells from uninfected cells was much less sensitive when three antibodies specific for HIV-1 glycoproteins were used to detect intracellular or cell surface antigen. In several experiments involving the time course of infection, we observed no differences in cell numbers between infected and uninfected H9 cultures initiated at identical cell concentrations. We hypothesized that it might be possible to quantitate infectious HIV-1 virions from the kinetics of infected cell appearance. Straight-line relationships between the log p24-positive cells and the time after infection were observed. These quantitative observations were employed to calculate the number of infectious units originally added to the culture that were capable of infecting H9 cells. The production of infectious virus, but not of cytopathic effects, was required. The results of this novel approach to the titration of infectious HIV-1 particles agreed well with those from median cell culture infective dose determination. This method could be employed with other infectious agents for which detection of cell-associated antigens is possible in cell cultures not destroyed by infection.
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PMID:Kinetics of infected cell appearance as a determinant of number of human immunodeficiency virus-1 infectious units. 249 63

HIV-Western blot (WB) testing of sequential sera from a blood donor revealed identical bands in the p24 and p55 positions. Additional testing using indirect immunofluorescence antibody technique, radioimmunoprecipitation assay and an HIV p24 antigen immunoassay were negative. During a 5-year follow-up period the blood donor has remained apparently healthy and no signs of disease have developed. We conclude that sera from this blood donor show a false positive HIV WB reactivity. The nature of this reactivity remains obscure but has practical implications for the routine HIV screening of blood donors.
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PMID:Long-term persistence of false positive antibody reactivity in HIV western blot testing of sera from a healthy blood donor. 249 39

Serum specimens which originally exhibited a narrow (indeterminate) 24-kilodalton core protein (p24) or p24/p55 pattern of reactivity with human immunodeficiency virus (HIV) in the Western blot (immunoblot) test were studied to gather information on antibody specificity. A total of 12 specimens were initially reevaluated with an indirect immunofluorescence assay (IFA), three enzyme-linked immunosorbent assays (ELISAs), and Western blot analyses. Five of the specimens were IFA positive and contained anti-gp160/gp120 antibodies which were observed only when an HIV Western blot antigen rich in gp160 and gp120 was used. The remaining seven serum specimens were nonreactive by IFA and showed variable reactivity in HIV antibody ELISAs. The specimens did not cross-react with core antigens for human T-cell leukemia virus types 1 and 2 or contain detectable levels of HIV p24 antigen. The p24/p55 reactivity of six of the seven indeterminate specimens could be reduced or eliminated by preincubating the specimens with disrupted, HIV-infected H9 cells but not with uninfected H9 cells. The six specimens also exhibited discernible reactivity with recombinant HIV p24 antigen. When an additional 23 indeterminate specimens were assayed, all of the serum specimens were nonreactive by IFA while 65% (15 of 23) showed various degrees of reactivity with the recombinant p24 protein. There was no indication that any of the HIV core antibody reactivity was caused by HIV infection. Indeterminate results for five patients with specific p24 reactivity, who were retested after a period of weeks or months, remained indeterminate for HIV antibody with no significant change in ELISA or Western blot reactivity.
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PMID:Investigation of atypical western blot (immunoblot) reactivity involving core proteins of human immunodeficiency virus type. 250 54

Interleukin-2 (IL-2) plays an essential role in the clonal expansion of antigen-activated T lymphocytes (T cells). In fact, the expression of both IL-2 and IL-2 receptor (IL-2R, p55, CD25) genes is transiently induced upon T cell activation through the interaction of antigen/major histocompatibility complex (MHC) and T cell receptor complex. To elucidate the mechanism(s) of the induced gene expression for IL-2 and IL-2R, we have investigated for the presence of potential transcription factors that specifically interact with regulatory cis-elements. Here, we demonstrate that one such factor mediates the induced expression of both genes. Interestingly, the recognition sequences by this factor are significantly diverse in these two genes and are related to those of immunoglobulin (Ig) kappa chain and MHC class I genes. We provide evidence that this factor indeed binds to the IL-2, IL-2R, and Ig sequence elements with different affinities, thereby affecting the magnitude of gene expression. Interestingly, this factor also binds to other cytokine genes, such as interleukin-6 (IL-6), interferon-gamma (IFN-gamma), and HIV-1 and HTLV-1 LTR sequences.
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PMID:Involvement of a common transcription factor in the regulated expression of IL-2 and IL-2 receptor genes. 251 55

The sequences encoding the core proteins p55, p25, and p18 of the human immunodeficiency virus (HIV-1) have been inserted into the vaccinia virus genome. Infection of cultured cells with the live recombinant viruses led to the expression of proteins that were recognized by sera from HIV-seropositive individuals. Immunization of mice with the recombinant virus expressing the HIV p25 protein and the p55 precursor yielded high levels of antibodies directed against the corresponding HIV antigens. The data obtained are discussed in terms of the possible use of these live recombinant viruses in the development of a strategy toward an AIDS vaccine.
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PMID:HIV-1 core proteins expressed from recombinant vaccinia viruses. 271 65

Between May 1986 and April 1987 routine screening for anti-HIV antibody was performed by enzyme immunoassay (EIA) on 3344 serum samples. The 1160 samples found positive or borderline were further analysed in Western blot (Wb). We analysed the frequency of different patterns of 'intermediate' Wb reactions (1-3 'specific' bands) and tried to determine their significance by searching for possible modifications of the pattern of reaction a few months later. Of 1160 Wb, 461 were clearly positive, 489 negative and 210 'intermediate'. The latter consisted of: 92 sera with anti-p24 (associated or not), 23 with anti-gp 120 and 160, 16 with anti-p55, 12 with anti-p41, 10 with anti-p65, eight with anti-p17 and four with anti-p31. A non-specific pattern was observed in the remaining 45. Of these sera, 46% were obtained from high risk subjects, 38% from persons without risk and in 16% no reliable information was available. In 30 subjects (24 with p24 and 6 with p41), a second sample was obtained about three months later. The reaction persisted in nine, was replaced by another in five, and disappeared in 15. One subject with anti-p41 in the first sample became clearly positive. In one of the 15 samples with disappearance of the reaction, the antigen p24 was present as the only sign of HIV infection. Later samples of this subject showed clear seroconversion. In many subjects with and without risk of exposure to HIV, the Wb gives an intermediate pattern of reactions (1-3 specific bands), that does not permit definitive conclusion on one single sample. Later controls are therefore necessary. Most of these reactions do not correspond to HIV infection.
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PMID:Serological diagnosis of HIV infection: incidence, outcome and significance of partial reactions found in western blot analysis. 275 92

The authors, after reviewing the current literature about the serological pattern of anti-HIV antibodies detected with Western Blot and the research of the viral antigen in AIDS, report the study of the above mentioned parameters in two HIV seropositive drug addicts. Case 1 (symptomless seropositive) presented a reactivity against p24 and p55 a month after an acute HIV infection and a more delayed reactivity to the whole anti-HIV antibody pattern. Case 2 (which developed full-blown AIDS), together with clinical and immunological deterioration, had a decline and disappearance of antibodies to p24 and persistence of reactivity against gp41 and detection of viral antigen. Diagnostic and prognostic significance of these results are discussed.
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PMID:[Diagnostico-prognostic significance of the analysis of anti-HIV antibodies and viral antigens in acquired immunodeficiency syndrome. Presentation of 2 paradigmatic cases]. 275 65

HUT-78 cells were infected with a reverse transcriptase (RT)-positive supernatant of a culture of peripheral blood lymphocytes (PBL) from an AIDS patient and then cloned. Of these clones, two have been isolated and characterized. Clone D10 is persistently and productively infected with an HIV variant. The clone F12, in spite of the presence of an integrated full-length HIV provirus, does not release virus particles in the medium. D10 and F12 clones substantially differ in terms of protein pattern; that is, D10 is super-imposable to infected HUT-78 cells, whereas F12 exhibits a decreased uncleaved p55 gag precursor and the presence of uncleaved gp160 and of a unique p19, although they do not show qualitative or quantitative differences in viral RNA synthesis. Restriction patterns of F12 proviral DNA do not show major genomic deletions. These results indicate that F12 clone cells carry an HIV genome with minor mutations that probably affect the correct production of viral proteins at a posttranscriptional level. In addition, the F12 clone is resistant to high-multiplicity superinfection with HIV-1 or HIV-2.
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PMID:Biologic and molecular characterization of producer and nonproducer clones from HUT-78 cells infected with a patient HIV isolate. 276 97


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