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)

The enzyme-linked immunosorbent assay (ELISA) was used to survey human sera for antibodies to Encephalitozoon cuniculi using spores obtained from in vitro cultures as antigen. Sera were obtained from patients with tropical diseases, neurological and renal disorders, patients who were HIV positive and those who had been tested for HIV but found to be negative. Sera from inhabitants of the village of Jali, The Gambia and from healthy blood donors were also examined. Numerous sera from all groups except the blood donors gave positive ELISA reactions at dilutions of 1:400. On titration, those with titres of 1:400 were reclassified as negative. Antibody titres of 1:800 and above were considered to be indicative of past or present infections with E. cuniculi. Many of these ELISA seropositives were also positive by IFAT or PAP. When examined by Western blotting of SDS-PAGE protein profiles of E. cuniculi spores, sera from many patients who had a tropical association reacted with the characteristic profiles shown by known positive mouse and rabbit sera. Others in the tropical group showed antibody binding to some but not all of the immunodominant polypeptides and yet others were negative in spite of their reactivity in the ELISA, IFAT or PAP test. Less agreement between ELISA and Western blotting results was obtained with the other groups of patients, although reactivity with one or more of the major polypeptide bands was sometimes seen. Serum from one blood donor, examined by ELISA and Western blotting, was positive. Differences in the methods of antigen preparation and of epitopes recognized by individuals may account for different reactivities in the tests. It is concluded that infections of E. cuniculi are common in the tropics and that reactivations of these infections might be a hazard to AIDS patients.
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PMID:Evidence for widespread occurrence of antibodies to Encephalitozoon cuniculi (Microspora) in man provided by ELISA and other serological tests. 190 78

An enzyme immunoassay (EIA) with a single incubation step has been developed to detect the HIV-1 major core polypeptide p24 in human blood specimens and in cell culture supernatants. In this assay, the solid phase is coated with monoclonal antibodies to p24, and the specimen is incubated simultaneously with peroxidase labelled polyclonal anti-HIV(Fab'). If HIV-1 p24 antigen is present in a specimen it will form a sandwich complex with the capture and tracer antibodies during the incubation step. The sensitivity of the assay for p24 antigen, 20 pg/ml, was equal to that of two commercial HIV antigen detection EIAs, when human blood specimens and virus isolation cell culture supernatants were analyzed. However, the assay described is simpler to perform than those previously reported, since only one incubation step is needed. Moreover this assay minimizes the handling of material containing potentially infectious HIV.
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PMID:Sensitive one-step enzyme immunoassay for HIV-1 p24 antigen in human blood specimens and cell culture supernatants. 190 66

AIDS is a progressive disease associated with steady loss of helper T cells and several other functions. As the disease evolves, cytopathogenic human immunodeficiency (HIV) variants of increasing virulence can be isolated from the host. The HIV is an unusually variable genome by virtue of a low replication fidelity. In this report we describe our effort to test the hypothesis that there is a correlation between virus variability and cytopathogenicity, and further, that there is an "impact" of the virus infection on the expression of host cellular genes. To search for such a relationship, we infected H-9 cells (human CD4+ lymphoblastoid cell line) with each of 5 isolates of HIV of distinct origin and cytopathogenicity. To measure the influence of the virus infection on the expression of host cellular genes, shortly after infection, (3 h or 13 h), cells were radiolabeled and the radioactive polypeptides separated by two-dimensional gel electrophoresis. Radiofluorographs were prepared and analyzed to determine relative rates of biosynthesis of cellular polypeptides. To organize the large amounts of data found, cluster analysis and principal component analysis were used to expose the data in formats that allowed a model construction. The rates of biosynthesis of many cellular polypeptides were altered upon viral infection in terms of both enhancements and impairment of biosynthesis. Some of the variation in polypeptide synthesis was isolate-specific, while most alterations were of modest magnitude. There appears to be no "overall effect" associated with infection by a cytopathic variant of the virus. Polypeptides affected by the cytopathic variants were determined as targets for further investigation. The method used promotes the measurement of "ensemble" information that is characteristic of the process and it promotes the creation of models of virus action.
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PMID:Global analysis of lymphocyte gene expression: perturbation of H-9 cells by infection with distinct isolates of human immunodeficiency virus--an exposition by multivariate analysis of a host-parasite interface. 191 48

A phase 1 trial of a candidate human immunodeficiency virus type 1 (HIV-1) vaccine was done in 25 healthy seronegative subjects. The antigen, env2-3 (SF2), was a nonglycosylated polypeptide representing the gp120 region of the env gene of the HIV-1(SF2) isolate. It was produced in genetically engineered yeast as a denatured molecule incapable of binding CD4. A synthetic lipophilic muramyl tripeptide (MTP-PE) was used as an adjuvant. Ten subjects received adjuvant alone and 15 received 50- or 250-micrograms doses of env2-3 (SF2) administered intramuscularly in two immunization regimens. In general, adjuvant and vaccine were well tolerated. Antibody responses to both the homologous antigen, env2-3 (SF2), and antigens from other highly divergent HIV isolates were elicited in the majority of vaccine recipients. However, antibody titers were low, without neutralizing activity. In 9 of 11 subjects who received the complete vaccine immunization series, a significant specific T lymphocyte response was observed.
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PMID:Safety and immunogenicity of a genetically engineered human immunodeficiency virus vaccine. 198 6

Parts of the gag p24 and the gp41 transmembrane protein of the human immunodeficiency virus HIV-1 were expressed as fusion proteins in Escherichia coli, using an expression vector carrying aa 1-375 of the lac-Z gene linked to the recognition sequence for the blood coagulation factor Xa. Fusion proteins were cleaved into the bacterial and viral portion and the viral polypeptide was purified by a molecular sieve column. The purified viral antigens were tested with 288 human sera in the enzyme-linked immunosorbent assay (ELISA) technique. Comparison with commercially available tests showed comparable sensitivity and a higher specificity of the gag/env-ELISA for borderline reactive sera.
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PMID:Cleavage and purification of prokaryotically expressed HIV gag and env fusion proteins for detection of HIV antibodies in the ELISA. 198 91

The beta 2-Microglobulin is a polypeptide present on the surface membrane of both B and T cells and is integrated into the structure of HLA antigenes. The beta 2-Microglobulin concentration have been used as a reliable indicator of glomerular and tubular function of the kidney. Increased serum concentration of beta 2-Microglobulin are observed also in lymphoproliferative disorders with high cell proliferation rates. More recently, increased concentration of beta 2-Microglobulin was shown in patients with anti-HIV antibodies with or without symptomatic AIDS. We have determined beta 2-Microglobulin in 61 subjects: 40 between the ages of 25 and 35 and seemingly healthy, 21 patients between the ages of 22 and 32 and intravenous drug abuser with anti-HIV antibodies and at high-risk for AIDS. In all subjects we have tested: BUN, creatinine, beta 2-Microglobulin and T4/T8 ratio. In 40 subjects as normal controls, beta 2-Microglobulin average was means = 1.07 mg/L (SD = 0.39), T4/T8 ratio average: means = 1.06 (SD = 0.119). In 21 patients drug abuser with anti-HIV antibodies, the beta 2-Microglobulin average was cleanly increased: means = 4.72 mg/L (SD = 2.23), the T4/T8 ratio average cleanly decreased: means = 0.54 (SD = 0.21). We believe the beta 2-Microglobulin quantitation, even if not specific for patient with symptomatic AIDS, used in conjunction with other laboratory tests, principally T4/T8 ratio, will be a useful marker for recognizing persons with possible asymptomatic AIDS who are members of populations known to be at high-risk for AIDS.
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PMID:[Increase of beta 2-microglobulin in drug addicts with anti-HIV antibodies and high risk of AIDS]. 200 Jan 73

Using a lambda gt11 cDNA library constructed from the seeds of the bitter melon (Momordica charantia), we have obtained a full length cDNA containing the entire sequence of alpha-momorcharin by immunoscreening. The length of this cDNA is 1044 basepairs long and it consists of an open reading frame coding for a polypeptide of 286 amino acids. The first 23 residues of this polypeptide probably code for a signal sequence. The N-terminal sequence of the deduced protein is exactly identical to that determined by peptide sequencing. The sequence identity between alpha-momorcharin and other ribosome inactivating proteins, such as trichosanthin and ricin A chain, is high, i.e., 34-63%. Examination of the predicted secondary structure of alpha-momorcharin and trichosanthin indicates that these proteins have regions of high structural similarities and this may account for the common biological activities that they share, viz., abortificant, immunosuppressive, antitumor and inhibition of HIV-1.
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PMID:Cloning of the cDNA of alpha-momorcharin: a ribosome inactivating protein. 200 4

Beta-2-microglobulin (beta 2m) is a polypeptide composing HLA antigens on the surface of nucleated cells. Its serum concentration is increased mainly in patients with lymphoproliferative disorders and during viral infections, and reflects probably accelerated activation and turnover of T cells. In this paper we report on abnormalities of beta 2m serum levels in HIV-infected patients. 17 asymptomatic HIV-carriers and 16 persons with clinically overt disease were examined and compared with 20 healthy controls. Patients with confirmed AIDS or ARC were found to have significantly raised beta 2m levels. We found elevated values of beta 2m in asymptomatic HIV-carriers even with normal T4/T8 lymphocytes ratio. There were statistically significant differences in mean beta 2m values between these groups and healthy individuals. beta 2m can be considered as an early, non-specific marker of HIV infection, even in the absence of clinical manifestations of AIDS.
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PMID:[Beta-2 microglobulin as a non-specific marker of immunodeficiency in individuals infected with human immunodeficiency virus (HIV)]. 205 18

Three different human immunodeficiency virus type I (HIV-1) envelope derived recombinant proteins and the full length human CD4 polypeptide were expressed in Spodoptera frugiperda (Sf9) cells. DNA constructs encoding CD4, gp120, gp160, and gp160 delta (full length gp160 minus the transmembrane and cytoplasmic region of gp41) were cloned into the baculovirus expression vector pVL941 or a derivative and used to generate recombinant viruses in a cotransfection with DNA from Autographa californica nuclear polyhedrosis virus (AcMNPV). Western blotting of cell extracts of the recombinant HIV-1 proteins showed that for each construct two major bands specifically reacted with anti-HIV-1 envelope antiserum. These bands corresponded to glycosylated and nonglycosylated versions of the HIV proteins as determined by 3H-mannose labeling and tunicamycin treatment of infected cells. A time course of HIV envelope expression revealed that at early times post-infection (24 hours) the proteins were fully glycosylated and soluble in nonionic detergents. However, at later times postinfection (48 hours), expression levels of recombinant protein reached a maximum but most of the increase was due to a rise in the level of the nonglycosylated species, which was largely insoluble in nonionic detergents. Thus, it appears that Sf9 cells cannot process large amounts of glycosylated recombinant proteins efficiently. As a measure of biological activity, the CD4 binding ability of both glycosylated and nonglycosylated recombinant HIV envelope proteins was tested in a coimmunoprecipitation assay. The results showed that CD4 and the glycosylated versions of recombinant gp120 or gp160 delta specifically associated with one another in this analysis. Nonglycosylated gp120 or gp160 delta proteins from tunicamycin-treated cultures did immunoprecipitate with anti-HIV-1 antiserum but did not interact with CD4. We conclude that production of native HIV envelope proteins, as measured by addition of carbohydrate side chains and ability to bind CD4, peaks early after infection in baculovirus-infected insect cells.
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PMID:Temporal expression of HIV-1 envelope proteins in baculovirus-infected insect cells: implications for glycosylation and CD4 binding. 207 45

The envelope proteins of retroviruses are derived from a polypeptide precursor protein by cleavage adjacent to a cluster of basic amino acids. Site-specific mutagenesis was used to construct a mutant of the human immunodeficiency virus type 1 (HIV-1) in which the arginine residue at the carboxy-terminus of the gp120 was changed to a threonine residue. This single substitution was sufficient to abolish all detectable cleavage of the gp160 envelope precursor polypeptide as well as virus infectivity. The gp160 was produced in normal quantities from a biologically active clone of the mutant virus after transfection into cos-1 cells. The mutant gp160 contained N-linked oligosaccharide chains with mannose-rich cores similar to those of the gp160 produced by the wild-type clone. Immunofluorescence assays showed that gp160 was transported to the surface of transfected CD4+ HeLa cells. No envelope proteins of known size could be detected in the media of cells transfected with the mutant virus, suggesting that functional virions were not formed. Binding of the mutant gp160 to the CD4 receptor molecule was unimpaired. Despite this and the presence of gp160 on the cell surface, neither growth of mutant-transfected CD4+ HeLa cells nor cocultivation of transfected cos-1 cells with H9 cells resulted in significant syncytium formation. The data indicate that the carboxy-terminal arginine residue of HIV-1 gp120 is necessary for envelope protein cleavage and suggest cleavage is important in the virus life cycle in both functional virus release and membrane fusion.
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PMID:Characterization of an HIV-1 point mutant blocked in envelope glycoprotein cleavage. 210 82


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