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)

Twenty-eight paired blood and semen samples obtained from human immunodeficiency virus type 1 (HIV-1) seropositive men at various stages of disease progression were evaluated for titer and immunoglobulin (Ig) class by an enzyme-linked immunosorbent assay (ELISA). Blood antibody titers ranged from 40,000 to 4,000,000 with a median of 40,000. Semen titers ranged from 400 to 40,000 with a median of 400. HIV-1 antibody titers in matched semen and blood samples showed a strong positive correlation (r = 0.963). The ratio of semen:blood titers ranged from 1:1000 to 1:10 with a median of 1:100. There was no correlation between blood or semen antibody titer and stage of disease of the patients. However, there was a trend toward higher (greater than or equal to 4000) semen antibody titers in men with evidence of genital tract inflammation greater than 10(6) white blood cells/ml semen; 3/5 versus 5/23, p greater than 0.1 Fisher exact test). All HIV-1 antibodies detected were of the IgG class; no IgA or IgM class antibodies of titers greater than or equal to 40 were found in either blood or semen. Thirteen paired blood and semen samples from individual patients were analyzed for antibody specificity by Western blot. In some cases antibody profiles in semen were different from those in blood; strong antibody reactivity against the gp160 viral coat antigen band was consistently detected in semen and blood, whereas the prevalence of detectable antibody reactivity against the p55 and p17 HIV-1 antigen bands was significantly reduced in semen.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A comparison of HIV-1 antibody classes, titers, and specificities in paired semen and blood samples from HIV-1 seropositive men. 173 88

CD4(178)-PE40 is a genetically engineered hybrid toxin containing a portion of human CD4 linked to the translocation and ADP-ribosylation domains of Pseudomonas exotoxin A. In vitro, the molecule has been shown to selectively kill cells expressing the envelope glycoproteins of human immunodeficiency virus (HIV) or simian immunodeficiency virus (SIV), and to inhibit HIV spread. In this report we examine the activity of the hybrid toxin against cells expressing diverse forms of the HIV and SIV envelope glycoproteins, encoded by recombinant vaccinia virus vectors. The activity of CD4(178)-PE40 was found to be unaffected by mutations in the HIV-1 or HIV-2 envelope glycoprotein genes, which prevent normal proteolytic processing of the corresponding gp160 precursor molecules. Cells expressing a mutant HIV-1 envelope glycoprotein lacking most of the cytoplasmic tail of the gp41 transmembrane subunit were also sensitive to the hybrid toxin. Most interestingly, HIV-1, HIV-2, and SIVmac envelope glycoprotein molecules known to have widely differing affinities for CD4 were found to be comparably effective at mediating sensitivity to CD4(178)-PE40. By virtue of its ability to kill infected cells, the hybrid toxin inhibited the spread of SIVmac in vitro. These results indicate that CD4(178)-PE40 is active against cells expressing HIV and SIV envelope glycoproteins with a diverse array of structural differences.
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PMID:Activity of CD4-Pseudomonas exotoxin against cells expressing diverse forms of the HIV and SIV envelope glycoproteins. 173 90

Binding of the human immunodeficiency virus type 1 (HIV-1) external envelope glycoprotein (gp120) has been reported to alter the function and surface antigen expression of lymphocytes and monocytes in vitro. To determine whether these in vitro findings could be relevant in vivo, we searched for the presence of this antigen in the serum of patients with AIDS and the AIDS-related complex (ARC). Using an antigen capture enzyme-linked immunosorbent assay (ELISA) with polyclonal anti-gp120 antibody, we detected envelope antigens (gp160/120) in serum of 22 of 32 AIDS patients. In contrast, an ELISA using solid-phase recombinant CD4 to capture gp160/120 failed to detect any positives. A modification of the anti-gp120-based ELISA identified gp160/120-IgG immune complexes in all of 11 AIDS patients tested and in 4 ARC patients who were negative for gp160/120 antigen. We conclude that gp160/120, predominantly in the form of immune complexes, can be identified as circulating antigen in patients with AIDS. The potential pathogenic consequences of this antigenemia, its relation to soluble CD4 therapy, and its application as a clinical marker of disease merit further study.
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PMID:Identification of HIV-1 envelope glycoprotein in the serum of AIDS and ARC patients. 174 Jul 50

A recombinant vaccinia virus in which the transcription of the human immunodeficiency virus type 1 (BRU isolate) env gene is driven by the 11K late vaccinia promoter yields about 10-fold higher amounts of gp160 env protein upon infection of monkey cells than does a recombinant in which gp160 is expressed using the 7.5K early-late promoter. The gp160 was purified from detergent lysates of infected cells by lentil lectin affinity chromatography followed by immunoaffinity chromatography, and was obtained in yields of 1-2 mg/10(9) cells of material estimated to be about 70% pure. Pairs of rabbits were immunized with purified gp160 using either one of five different adjuvants or an immunostimulating complex. In all cases a substantial humoral immune response was obtained after boosting, including an activity that neutralized the homologous (BRU) isolate of HIV-1. In some cases, this activity also neutralized two distantly related isolates, SF2 and MN.
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PMID:Cross-neutralizing antibodies in rabbits immunized with HIV-1 gp160 purified from simian cells infected with a recombinant vaccinia virus. 174 74

Passive immunity is conferred to the fetus by maternal antibodies, the majority of which are transported across the placenta during the third trimester of pregnancy. To determine the placental transport of anti-HIV-1 antibodies, serum from 5 women infected with human immunodeficiency virus (HIV) and their abortuses were examined for anti-HIV-1 antibodies. The gestational age of the abortuses ranged from 18 to 24 weeks and following polymerase chain reaction amplification, HIV-1 gag DNA was detected in tissue from 2 of the abortuses. The concentration of total IgG antibodies present in cord blood ranged from 2.9% to 12.5% of maternal levels. Antibodies directed against the envelope proteins, gp160 and gp120, the reverse transcriptase protein, p66, and the capsular protein, p24, were present in fetal and maternal serum. Although IgG1 was the predominant subclass antibody generated in response to HIV-1 proteins, IgG2, IgG3, and IgG4 directed against HIV-1 proteins were also detected. There were large differences in the antigens recognized by the antibodies produced in the mothers, and the IgG subclasses of the antibodies produced. HIV-1 proteins recognized by antibodies present in cord blood were similar to those recognized by paired maternal serum and IgG1, IgG2, IgG3 recognizing HIV-1 proteins were detected in fetal serum. However, there was a dichotomy in placental transport of IgG subclass antibodies to HIV-1 proteins. The role of these antibodies in prevention of vertical transmission of HIV-1 has yet to be determined.
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PMID:Characterization of IgG and IgG subclass antibodies present in paired maternal and fetal serum which are directed against HIV-1 proteins. 174 77

Sera were obtained from 50 individuals infected with human immunodeficiency virus type 1 or from HIV-1-uninfected individuals before or after vaccination with recombinant gp160. These sera were evaluated for activity antagonistic to the cell-killing activity of the chimeric Pseudomonas exotoxin hybrid protein, sCD4-PE40. For these studies, Chinese hamster ovary (CHO) cells were transfected with a chimeric plasmid encoding the tat, rev, and envelope genes of HIV-1 and a cell line was selected for stable expression of the envelope glycoproteins at the cell surface (CHO-env). Cytotoxicity of sCD4-PE40 for CHO-env in the presence or absence of added human serum was quantitated spectrophometrically following enzymatic reduction of a tetrazolium bromide within the mitochondria of viable cells (MTT assay). Several HIV+ sera inhibited the cytotoxic activity of sCD4-PE40; the antagonist had properties consistent with those of immunoglobulins in that it was heat stable, absorbed by protein A, and reversible by increasing the concentration of sCD4-PE40. Of 15 HIV+ sera which strongly reacted with gp120, 11 (73%) also potently inhibited sCD4-PE40 cytotoxicity, and cytotoxicity was inhibited by sera from some HIV- individuals after, but not before, immunization with gp160. These data suggested a role for antibody to gp120 in the antagonistic activity. However, not all sera with antibody to gp120 antagonized sCD4-PE40 cytotoxicity and high levels of antagonist activity were frequently (40%) found in HIV+ sera lacking immunoblot-detectable antibody to gp120, or antibody to either CD4 or PE40. Grouping of the HIV+ sera according to the patients' absolute number of CD4+ cells revealed that the degree of inhibition of sCD4-PE40 cytotoxicity approached a Gaussian distribution, suggesting that persons with CD4+ cell counts between 200 and 700/mm3 may be more likely to possess significant levels of serum antagonist. This data have implications for the clinical development of sCD4-PE40 or other sCD4-based therapeutics in the management of HIV-1 infection.
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PMID:Soluble CD4-PE40 is cytotoxic for a transfected mammalian cell line stably expressing the envelope protein of human immunodeficiency virus (HIV-1), and cytotoxicity is variably inhibited by the sera of HIV-1-infected patients. 174 81

Retroviral envelope glycoproteins interact with cell receptors and are targets for antiviral immune responses in infected hosts. Macaque simian immunodeficiency virus (SIVmac) is a T-lymphocytopathic lentivirus which causes an AIDS-like disease in rhesus macaques. The envelope gene of SIVmac encodes a precursor glycoprotein (gp160) which is cleaved into an external domain (gp130) and a transmembrane domain (gp32). To investigate the functional and immunological properties of the SIV external envelope glycoprotein, we have used genetically engineered mammalian cells to produce recombinant gp130 (rgp130). The rgp130 has the appropriate molecular weight, is glycosylated, and has native conformation as determined by binding to the cell receptor for SIV, the CD4 antigen. Rhesus macaques immunized with purified rgp130 formulated in muramyl dipeptide adjuvant generated high titers of antienvelope antibodies. Antibodies from these macaques were tested for in vitro virus neutralization; very low or undetectable levels of neutralization were observed. In contrast, neutralizing antibodies were readily detected in sera from goats immunized with rgp130. With respect to cell-mediated immunity, proliferative responses to rgp130 were demonstrated in peripheral blood monocyte cells (PBMC) from macaques immunized with the recombinant glycoprotein as well as in PBMC from SIV-infected animals. These results show that rgp130 is functional and immunogenic; the potential of rgp130 for protective immunization remains to be determined.
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PMID:Functional and immunological characterization of SIV envelope glycoprotein produced in genetically engineered mammalian cells. 176 Feb 29

Anti-human immunodeficiency virus type 1 (Anti-HIV-1) antibody response was compared in four groups of mice following inoculation with HIV-1 gp160, with live recombinant vaccinia virus expressing HIV-1 envelope glycoproteins, or with both immunogens in alternate orders for primary or secondary immunizations. Both subunit and recombinant virus immunogens induced similar levels of antibody response following primary immunization. However, after secondary immunization, mice primed with live recombinant virus and then boosted with subunit gp160 immunogen showed significantly higher antibody response than those in the other three groups. Neutralizing antibodies were generated only in this group of mice and were shown to neutralize both the homologous virus (BRU) and a divergent isolate (SF2) of HIV-1. On the other hand, their reactivities to peptide sequences from the principal neutralizing determinant (PND) of gp120 were limited to the BRU isolate, not SF2 or MN, indicating that the cross-neutralizing activities were directed against determinants other than the linear epitope(s) within the PND. These results also indicate that combined immunization by priming with liver recombinant virus and boosting with subunit immunogen may be more effective than immunization by either immunogen alone.
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PMID:Neutralizing antibodies against HIV-1 BRU and SF2 isolates generated in mice immunized with recombinant vaccinia virus expressing HIV-1 (BRU) envelope glycoproteins and boosted with homologous gp160. 176 63

The envelope (env) glycoprotein of human immunodeficiency virus 1 (HIV-1), initially synthesized as a precursor molecule termed gp160, is cleaved into two noncovalently associated subunits prior to delivery to the plasma membrane. We have studied the oligomeric structure of this protein using chemical cross-linking, velocity gradient sedimentation, and SDS-resistance. We find that gp160 forms stable homodimers after synthesis. After cleavage to gp120/gp41 the molecule becomes less stable to detergent solubilization and centrifugation but remains dimeric. Interactions between the 129 amino terminal residues in the ectodomains of adjoining gp41 subunits are both sufficient and necessary for assembly. In addition, tetramers composed of two dimers were also formed. Larger structures were not observed. The tetrameric paramyxovirus F protein, which has structural and functional similarities to the HIV-1 env protein, also forms a dimer of dimers.
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PMID:The assembly of the HIV-1 env glycoprotein into dimers and tetramers. 178 45

Analysis of human immunodeficiency virus-1 (HIV-1) gp160 amino acid sequences by computer programs that provide information on the possible conformation, hydrophilicity, and surface probability was used to identify possible functional domains. Amino acid domains that serve as signals for transfer of the polypeptide chain through the cell membrane were identified. Stop-transfer amino acid domains present in gp160 made possible the identification of the membrane anchorage hydrophobic amino acid sequence. The characterization of amino acid domains that serve as signals for proteolytic cleavage suggest that gp41 might be cleaved in a number of positions in the polypeptide chain, releasing parts of the carboxy-terminus amino acid sequence from that part of gp41 anchored in the cell membrane. The computer analysis deals with the mode of insertion of gp160 into the cell membrane by the cellular signal recognition protein system and subsequent processing of the gp160 to gp120 and gp41 (and subpeptides). The model for the positioning of these peptides is used to predict the organization of the processed envelope proteins in the viral envelope. The possible function of domains in gp120 and gp41 during the interaction with host cells during virus infection is discussed.
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PMID:Computer analysis of human immunodeficiency virus-1 envelope glycoprotein: functional topogenic domains as signals for transfer and cleavage. 179 51


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