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 (HIV) strains can be separated into two types: HIV and HIV-related West African viruses. Site-directed serology using synthetic peptides offers possibilities for the determination of type-specific antibodies. A 22-amino-acid peptide with the sequence Ala-Ile-Glu-Lys-Tyr-Leu-Glu-Asp-Gln-Ala-Gln-Leu-Asn-Ala-Trp-Cys-Ala-Phe-Arg-Gln - Val-Cys representing a conserved region of the transmembranous protein of simian T-cell lymphotropic virus-type III (STLV-III; related to West African HIV) was used as antigen in an enzyme-linked immunosorbent assay (ELISA). In parallel, tests were performed with a pair of previously described peptides, including the homologous region of the glycoprotein (gp) 41 of the HIV strain HTLV-IIIB. In tests with three groups of 20 sera it was shown that the different peptide ELISAs allowed a categorical distinction of antibodies to the two types of HIV. Tests using peptide antigens may provide excellent opportunities for large-scale testing for type-specific antibodies against HIV. The tests are simple, sensitive and specific and are readily standardized.
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PMID:Discrimination between antibodies to HIV and to related retroviruses using site-directed serology. 304 Dec 32

Alterations in polymorphonuclear leucocyte (PMN) function are frequently associated with intraoral disease. The purpose of this study was to evaluate if alterations exist in three early stimulatory events of PMN function in individuals with intraoral manifestations of human immunodeficiency virus (HIV) infection. Peripheral PMNs were isolated from nine HIV-seropositive male homosexuals with HIV-associated periodontitis and intraoral candidiasis and healthy HIV-seronegative age-matched heterosexuals (controls). Phagocytosis was assessed using fluorescent microspheres, oxidative burst was assessed via hydrolysis of 2',7'-dichlorofluorescein (FCDH) to 2',7'-dichlorofluorescein (FCDA) with PMA stimulation, and F-actin formation was assessed with NBD-phallacidin stain after stimulation with f-Met-Leu-Phe. Compared to controls, seven of nine HIV-seropositive patients demonstrated a significant increase in the percentage of phagocytic cells while seven of nine HIV-seropositive patients demonstrated a 5-59% increase in number of beads per cell. In the oxidative burst assay, seven of seven HIV-seropositive patients demonstrated a significant increase over controls in FCDA stain with PMA stimulation. In the F-actin assay, four of five HIV-seropositive patients demonstrated a significant increase over controls in NBD-phallacidin staining after f-Met-Leu-Phe stimulation.
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PMID:Elevated phagocytosis, oxidative burst, and F-actin formation in PMNs from individuals with intraoral manifestations of HIV infection. 321 15

In order to define the protease domain of human immunodeficiency virus 1, various regions of the pol open reading frame were cloned and expressed in Escherichia coli. Antiserum directed against the conserved retroviral protease active site was used to identify pol precursor and processed species containing the presumed protease domain. The smallest product that accumulates is about 11 kDa as measured by NaDodSO4/PAGE. This size agrees with that predicted from the presence in this region of two Phe-Pro sequences, which is one of the cleavage sites recognized by HIV protease. DNA encoding only the predicted 11-kDa protein was cloned, bypassing the need for autoprocessing, and the protein was expressed to a high level in E. coli. This form is active as demonstrated by its ability to specifically cleave protease-deficient pol protein in vivo in E. coli. Extracts of E. coli containing the 11-kDa protease also process human immunodeficiency virus gag substrates in vitro. These results demonstrate that the 11-kDa protease is sufficient for enzymatic activity and are consistent with a major role for this form in virus maturation.
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PMID:An 11-kDa form of human immunodeficiency virus protease expressed in Escherichia coli is sufficient for enzymatic activity. 328 30

A protein corresponding to the putative protease of the human immunodeficiency virus 1 (HIV-1) has been prepared by total chemical synthesis. This 99 residue synthetic enzyme showed specific proteolytic activity on fragments of the natural gag precursor and on synthetic peptide substrates, two of which released fragments corresponding to the N terminus and C terminus of the protease molecule itself. The observed substrate specificity was not restricted to cleavage at Phe/Tyr-Pro bonds. Inhibition studies provided direct evidence that the HIV-1 protease belongs to the family of aspartic proteases. The availability of the HIV-1 protease as a defined molecular species has important implications for the design of specific inhibitors that do not interfere with the host cell metabolism as a possible route to antiviral agents against acquired immunodeficiency syndrome (AIDS).
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PMID:Enzymatic activity of a synthetic 99 residue protein corresponding to the putative HIV-1 protease. 329 1

A tetradecapeptide, H-Arg-Lys-Asp-Val-Tyr-Val-Glu-Leu-Tyr-Leu-Gln-Ser-Leu-Thr-OH, corresponding to amino acids 32 to 45 of thymopoietin II and its six analogs by replacing the amino acid residue in position 37, was prepared. These peptides were synthesized using conventional synthesis in solution and were tested for their effect on impaired T-cell transformation by phytohemagglutinin (PHA) in the common variable immunodeficiency. The tetradecapeptide had increasing activity on the T-cell transformation by PHA. Among the tetradecapeptide analogs, several analogs in which Val37 was replaced by Leu or Phe exhibited potent activity which was more than that of the parent peptide fragment. On the other hand, replacement of Val37 by Pro, beta Ala, or sarcosine had no effect at concentrations as high as 3.5 X 10(-4) M. One analog whose Val37 was replaced by Gly showed activity one-third that of the parent peptide fragment. On the basis of these results, the structure-activity relationship for the tetradecapeptide is discussed.
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PMID:Syntheses and effects of a thymopoietin II fragment and its analogs on the impaired T-cell transformation in a patient with common variable immunodeficiency. 387 89

Lymphocyte and neutrophil locomotion were studied in 23 patients with well defined, primary immunodeficiencies. These included eight patients with common variable immune deficiency, three patients with X-linked agammaglobulinaemia, two patients with the Wiskott-Aldrich syndrome, three patients with ataxia telangiectasia, three patients with immunodeficiency and normal serum immunoglobulin concentrations, one patient with immune deficiency and hyper-IgM syndrome, two patients with Job syndrome and one patient with a granulocyte adherence defect. Random and stimulated lymphocyte and neutrophil migration were evaluated. C5a and casein were used to stimulate lymphocyte migration and C5a and formyl-methionyl-leucyl-phenylalanine (f-MLP) were used to stimulate neutrophil migration. Significantly depressed lymphocyte migration in response to casein and C5a was observed in patients with common variable immune deficiency, patients with immune deficiency and normal immunoglobulin concentration, and patients with Job syndrome. No consistent defect in lymphocyte locomotion was observed in the other patients studied. Neutrophil migration in response to C5a and f-MLP was depressed in Job syndrome, the patient with a granulocyte adherence defect, one of the six patients with common variable immune deficiency and none of the remaining patients. No significant correlation of skin test reactivity and lymphocyte migration was noted, but a correlation between the degree of lymphocyte proliferation in response to phytohaemagglutinin and lymphocyte migration in response to casein was observed. The results presented indicate that aberrations in lymphocyte migration occur in several types of immunodeficiency diseases and that defects in lymphocyte and neutrophil migration can occur simultaneously or totally independent of each other.
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PMID:Abnormalities of lymphocyte locomotion in immunodeficiency disease. 661 60

The metabolic fate of SK&F 107461 [Cbz-Ala-Ala-Phe psi [CHOHCH2] Gly-Val-Val-OMe], a potent and specific inhibitor of the protease encoded by human immunodeficiency virus type 1, in male Sprague-Dawley rats is described. SK&F 107461 is a hexapeptide analog containing a hydroxyethylene linkage in place of one of the peptide bonds, and in which the amino terminus is blocked with a carbobenzyloxy group and the carboxy terminus is modified to a methyl ester. The major metabolites of SK&F 107461 found in bile and urine after intravenous administration of 3H-labeled compound were characterized by LC/MS using either thermospray or continuous flow/FAB models of ionization. Approximately 80% of the administered radioactivity was recovered in the bile of bile duct-exteriorized rats following an intravenous dose. Radiochromatographic profiling indicated that SK&F 107461 was subject to extensive biotransformation. Structures were determined for three major biliary and five major urinary metabolites. Two of the major circulating plasma metabolites observed after intravenous bolus administration had similar retention times to metabolites that were observed in both bile and urine. A pathway for the biotransformation of SK&F 107461 in the rat is proposed. The parent molecule underwent two primary modes of metabolism. Hydrolysis of the carboxy-terminal ester or hydrolysis of the Ala-Ala peptide bond near the amino terminus were the primary metabolic events. All of the other metabolites characterized can be accounted for by exopeptidase activity subsequent to one or both of these primary events. There were no major metabolites observed resulting from anything other than hydrolysis of the ester or peptide bonds in the parent molecule.
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PMID:Characterization of the metabolites of the peptidomimetic human immunodeficiency virus type 1 protease inhibitor SK&F 107461 in rats using liquid chromatography/mass spectrometry. 749 45

The initiation of human immunodeficiency virus type 1 (HIV-1) reverse transcription occurs by the extension of a tRNA(3Lys) primer bound near the 5' end of the genomic RNA at a position termed the primer binding site (PBS). The PBS is an 18-nucleotide sequence of the HIV-1 genome which is complementary to the 3'-terminal 18 nucleotides of the tRNA(3Lys). To investigate the sequence specificity of the interaction between tRNA(3Lys) and the PBS, we have constructed proviral genomes containing mutations in the PBS region. A mutant PBS was constructed in which the 18 nucleotides complementary to tRNA(3Lys) were substituted with 18 nucleotides predicted to be complementary to the 3'-terminal bases of a tRNA(Phe) molecule [pHXB2PBS(phe)]. A second proviral genome was constructed in which the PBS complementary to tRNA(Phe) was changed such that the first six nucleotides correspond to the wild-type PBS [pHXB2PBS(pheC)]. In all models of reverse transcription, the complementarity between the minus- and plus-strand PBS DNA facilitates the template switch and elongation of plus-strand DNA, resulting in a complete proviral genome. To test this model, we have inserted a five-nucleotide sequence 6 bp 3' of the mutant PBSs, which corresponds to the last five nucleotides of the wild-type PBSs [pHXB2PBS(phe+5) and pHXB2PBS(pheC+5)]. Transfection of plasmids containing the wild-type or mutant proviral genomes into COS-1 cells resulted in similar levels of intracellular expression of HIV-1 gag and env gene products as determined by immunoprecipitation with sera from AIDS patients and release of virus as determined by p24 assay. Transfection of pHXB2PBS(phe) or pHXB2PBS(phe+5) did not result in the production of infectious virus, while replication-competent viruses from cells transfected with pHXB2PBS(pheC) were detected very infrequently. Transfection of pHXB2PBS(pheC+5), however, consistently resulted in the production of infectious virus, although the appearance of the virus was delayed compared with those from cells transfected with pHXB2(wild type). Reinfection of SupT1 cells with equal amounts of p24 antigen resulted in similar kinetics of replication. PCR was used to amplify the PBS, and individual DNA products were subcloned into M13mp18. Sequence analysis of the PBS region of integrated proviruses derived from transfection of pHXB2PBS(pheC+5) revealed that the 18-nucleotide PBS complementary to tRNA(3Lys) was regenerated with a deletion of 6 bp 3' to the PBS region in all phage clones examined.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Minimal sequence requirements of a functional human immunodeficiency virus type 1 primer binding site. 750 99

High level resistance to 3'-azido-3'-deoxythymidine (AZT, zidovudine or Retrovir) is conferred by the presence of four or five mutations (Met-41-->Leu; Asp-67-->Asn; Lys-70-->Arg; Thr-215-->Tyr or Phe; Lys-219-->Gln) in the human immunodeficiency virus (HIV) reverse transcriptase. The order of appearance of these five mutations in asymptomatic patients during therapy has been studied. This has enabled us to propose a model for the acquisition of zidovudine resistance mutations during the treatment of high-risk asymptomatic HIV-infected individuals. A consistent acquisition pattern of mutations at codons 41, 70 and 215 was observed in 17 individuals. Complex mixtures of HIV species containing different combinations of single and linked double resistance mutations were present early in zidovudine therapy in isolates from two patients studied in detail. From these mixtures the linked Leu-41/Tyr-215 genotype outgrew all others initially. The development of each new virus population is likely to be mediated primarily by the increase in the level of drug resistance rather than changes in the growth kinetics of the virus. This leads us to conclude that one major driving force in the outgrowth of different mutant viruses is the selective advantage conferred by higher levels of drug resistance.
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PMID:Zidovudine treatment results in the selection of human immunodeficiency virus type 1 variants whose genotypes confer increasing levels of drug resistance. 750 70

The crystal structure of a complex between a 24-amino acid peptide from the third variable (V3) loop of human immunodeficiency virus-type 1 (HIV-1) gp 120 and the Fab fragment of a broadly neutralizing antibody (59.1) was determined to 3 angstrom resolution. The tip of the V3 loop containing the Gly-Pro-Gly-Arg-Ala-Phe sequence adopts a double-turn conformation, which may be the basis of its conservation in many HIV-1 isolates. A complete map of the HIV-1 principal neutralizing determinant was constructed by stitching together structures of V3 loop peptides bound to 59.1 and to an isolate-specific (MN) neutralizing antibody (50.1). Structural conservation of the overlapping epitopes suggests that this biologically relevant conformation could be of use in the design of synthetic vaccines and drugs to inhibit HIV-1 entry and virus-related cellular fusion.
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PMID:Crystal structure of the principal neutralization site of HIV-1. 751 Dec 53


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