Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00492 (hypoxanthine-guanine phosphoribosyltransferase)
 2,385 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have selected mutations in genes encoding components of the signaling pathway for alpha interferon (IFN-alpha) by using a specially constructed cell line. The upstream region of the IFN-regulated human gene 6-16 was fused to the Escherichia coli guanine phosphoribosyltransferase (gpt) gene and transfected into hypoxanthine-guanine phosphoribosyltransferase-negative human cells. These cells express gpt only in the presence of IFN-alpha. They grow in medium containing hypoxanthine, aminopterin, and thymidine plus IFN and are killed by 6-thioguanine plus IFN. Two different types of mutants were obtained after treating the cells with mutagens. A recessive mutant, selected in 6-thioguanine plus IFN, was completely resistant to IFN-alpha but responded normally to IFN-gamma and, unexpectedly, partially to IFN-beta. A constitutive mutant, selected in hypoxanthine-aminopterin-thymidine alone, was abnormal in expressing endogenous genes in the absence of IFN. Both types revert infrequently, allowing selection for complementation of the defects by transfection.
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PMID:Use of a selectable marker regulated by alpha interferon to obtain mutations in the signaling pathway. 251 75

Sezary's syndrome is a leukemic proliferation of OKT4+ lymphocytes. Sezary cells were isolated by differential centrifugation and fused to CEM.8azar.C, and HGPRTase-lacking clone of CEM. The hybrid cells were studied for their ability to produce soluble mediators of human monocyte cytotoxicity. The product of a single clone, FtF3, which bore the surface phenotype of Sezary cells, was characterized. Monocyte cytotoxicity-inducing factor (MCF) was found to be stable at pH 2 for 1 hr, unlike IFN-gamma, and was found to be more heat stable as well. Moreover, treatment of MCF with antisera to IFN-gamma, IFN-alpha or a combination of IFN-gamma and IFN-alpha failed to neutralize its biologic activity. MCF binds to matrix gel Red A. MCF eluted from this dye-ligand was found to have an apparent m.w. of 11,500 by gel filtration and 14,700 by SDS-polyacrylamide gel electrophoresis. MCF produced by hybridized Sezary cells appear to be neither IFN-gamma nor an altered molecular form of IFN-gamma, yet is a potent inducer of human monocyte cytotoxicity.
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PMID:Identification of a human monocyte cytotoxicity-inducing factor from T cell hybridomas produced from Sezary's cells. 308 3

Rapamycin (RAP) disrupts signaling events implicated in cytokine-dependent proliferation of lymphocytes and other cells. This action is known to involve the formation of molecular complexes between the drug and intracellular binding proteins, termed FKBPs. However, the biochemical target(s) for the effector RAP-FKBP complexes remain uncharacterized. As an approach to explore the mechanism of action of RAP, we have isolated three independent sets of somatic mutants of the YAC-1 murine T cell line with markedly reduced sensitivity to the drug's inhibitory effects on proliferation and on IL-1-induced IFN-gamma production. These mutants were still fully sensitive to FK-506, an immunosuppressant structurally related to RAP whose mode of action also involves an interaction with FKBPs. Furthermore, the 12-kDa FKBP, FKBP12, was detectable in immunoblots from cytosolic extracts and eluates from RAP-affinity matrix in the mutants as in wild-type cells, suggesting that the resistance to RAP in the mutants is not due to a lack of FKBP12 expression. Cell fusion experiments were conducted to further define the nature of the alterations imparting RAP resistance in these mutants. Clones deficient in either thymidine kinase or hypoxanthine-guanine phosphoribosyltransferase, suitable as fusion partners for aminopterin-based selection of hybrids were generated from the wild-type or mutant lines. In most instances, the hybrids derived from the fusion between RAP-sensitive clones and RAP-resistant clones exhibited a RAP-resistant phenotype. Similar results were obtained with hybrids between RAP-resistant YAC-1 clones and the RAP-sensitive EL-4 cell line. Therefore, the mutations that confer resistance to RAP in the present system are dominant. Altogether, our observations are consistent with a model where pharmacologically relevant targets for the RAP-FKBP complex, rather than FKBP, might be altered in the mutants such that the inactivation of these targets by the effector complex is prevented.
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PMID:Dominant mutations confer resistance to the immunosuppressant, rapamycin, in variants of a T cell lymphoma. 753 11

A variety of commercial DNA arrays specific for humans and rodents are widely available; however, microarrays containing well-characterized genes to study pathway-specific gene expression are not as accessible for domestic animals, such as cattle, sheep and pigs. Therefore, a small-scale application-targeted bovine immune-endocrine cDNA array was developed to evaluate genetic pathways involved in the immune-endocrine axis of cattle during periods of altered homeostasis provoked by physiological or environmental stressors, such as infection, vaccination or disease. For this purpose, 167 cDNA sequences corresponding to immune, endocrine and inflammatory response genes were collected and categorized. Positive controls included 5 housekeeping genes (glyceraldehydes-3-phosphate dehydrogenase, hypoxanthine phosphoribosyltransferase, ribosomal protein L19, beta-actin, beta2-microglobulin) and bovine genomic DNA. Negative controls were a bacterial gene (Rhodococcus equi 17-kDa virulence-associated protein) and a partial sequence of the plasmid pACYC177. In addition, RNA extracted from un-stimulated, as well as superantigen (Staphylococcus aureus enterotoxin-A, S. aureus Cowan Pansorbin Cells) and mitogen-stimulated (LPS, ConA) bovine blood leukocytes was mixed, reverse transcribed and PCR amplified using gene-specific primers. The endocrine-associated genes were amplified from cDNA derived from un-stimulated bovine hypothalamus, pituitary, adrenal and thyroid gland tissues. The array was constructed in 4 repeating grids of 180 duplicated spots by coupling the PCR amplified 213-630 bp gene fragments onto poly-l-lysine coated glass slides. The bovine immune-endocrine arrays were standardized and preliminary gene expression profiles generated using Cy3 and Cy5 labelled cDNA from un-stimulated and ConA (5 microg/ml) stimulated PBMC of 4 healthy Holstein cows (2-4 replicate arrays/cow) in a time course study. Mononuclear cell-derived cytokine and chemokine (IL-2, IL-1alpha, TNFalpha, IFN-gamma, TGFbeta-1, MCP-1, MCP-2 and MIP-3alpha) mRNA exhibited a repeatable and consistently low expression in un-stimulated cells and at least a two-fold increased expression following 6 and 24 h ConA stimulation as compared to 0 h un-stimulated controls. In contrast, expression of antigen presenting molecules, MHC-DR, MHC-DQ and MHC-DY, were consistently at least two-fold lower following 6 and 24 h ConA stimulation. The only endocrine gene with differential expression following ConA stimulation was prolactin. Additionally, due to the high level of genetic homology between ovine, swine and bovine genes, RNA similarly acquired from sheep and pigs was evaluated and similar gene expression patterns were noted. These data demonstrate that this application-targeted array containing a set of well characterized genes can be used to determine the relative gene expression corresponding to immune-endocrine responses of cattle and related species, sheep and pigs.
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PMID:Construction and application of a bovine immune-endocrine cDNA microarray. 1526 89

In order to quantify in vivo the mRNAs of cytokines which play important roles in leptospirosis, we have developed quantitative real-time PCR assays for interleukin-2 (IL-2), IL-4, IL-10, IL-12p40, tumor necrosis factor alpha (TNF-alpha), gamma interferon (IFN-gamma), transforming growth factor beta, and two housekeeping genes (encoding beta-actin and hypoxanthine phosphoribosyltransferase). We used a lethal hamster model reflecting severe leptospirosis in humans. The LightCycler system was used to quantify the gene expression levels with the SYBR green I detection format using external standard curves for each target. We compared the expression levels of cytokine mRNA in the peripheral blood mononuclear cells of both control (uninfected) hamsters and Leptospira interrogans-inoculated hamsters from 1 to 24 h and then 1 to 4 days postinfection. In this kinetic study, there was pronounced expression of Th1 cytokine mRNA (TNF-alpha, IFN-gamma, and IL-12), with transcripts being detected as early as 1 h postinfection. Expression of anti-inflammatory cytokines, such as IL-4 and IL-10, was prominent in delayed samples from 1 to 4 days postinfection in response to infection with Leptospira interrogans. Our data are the first to establish that pathogenic leptospires can stimulate in vivo the production of type 1 cytokines involved in cellular immunity by using this informative animal model. Measuring and assessing cytokine profiles may provide a useful method for accurate study of the mechanisms of anti-Leptospira immunity, indications of prognosis factors, and prospective evaluation of leptospirosis vaccine efficacy in humans.
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PMID:Proinflammatory and immunomodulatory cytokine mRNA time course profiles in hamsters infected with a virulent variant of Leptospira interrogans. 1679 Jul 92

A microarray for demonstration of a limited number of porcine cytokines was initiated. Polymerase chain reaction (PCR) products were synthesized for four house-keeping genes, cyclophilin, beta-actin, hypoxanthine phosphoribosyltransferase (HPRT) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and the following cytokines: interleukin (IL)-1beta, IL-4, IL-6, IL-8, IL-10, IL-12 p35, IL-12 p40, IL-18, interferon (IFN)-alpha, IFN-beta, IFN-gamma, tumour necrosis factor (TNF)-alpha, macrophage inhibition factor (MIF) and granulocyte/macrophage colony-stimulating factor (GM-CSF). Cytokine production was induced by incubation of porcine peripheral blood mononuclear cells (PBMC) with Concanavalin A (ConA) or oligodeoxynucleotide (ODN) 2216. RNA was isolated after 6 or 24 h from stimulated cells or unstimulated control cells and from intestinal biopsies. Cytokine expression was analysed using a 3-DNA Array 350(TM) labelling kit from Genisphere. Data were normalized using external control genes and analysed with the genepix pro 5.0 software. All the cytokines could be induced in PBMC and expressed on the array and the cytokines IL-6 and IFN-alpha were also analysed at protein level. All but one cytokine were expressed in samples from intestinal biopsies. Densitometric analyses of PCR products of the house-keeping genes were performed to validate the results from the microarray. Thus, this microarray will enable analyses of the cytokine profile during local and systemic infections in the pig.
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PMID:Development of a microarray for studying porcine cytokine production in blood mononuclear cells and intestinal biopsies. 1738 82