Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.4.2.8 (hypoxanthine-guanine phosphoribosyltransferase)
 2,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have produced somatic cell hybrids between mouse myeloma cells deficient in hypoxanthine phosphoribosyltransferase IMP: pyrophosphate phosphoribosyltransferase; EC 2.4.2.8) and spleen cells derived from mice primed with either syngeneic or allogeneic cells transformed by simian virus 40. Such hybrids produced antibodies specific for simian virus 40 tumor (T) antigen. Only four of twelve independent hybrid cell cultures produced antibodies against simian virus 40 T antigen that crossreacted with the T antigen induced by BK virus, a human papovavirus isolated from patients who had undergone immunosuppressive therapy.
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PMID:Somatic cell hybrids producing antibodies specific for the tumor antigen of simian virus 40. 7 81

We have studied somatic cell hybrids between P3x63Ag8 mouse myeloma cells deficient in hypoxanthine phosphoribosyltransferase (EC 2.4.2.8) and either human peripheral lymphocytes or human lymphoblastoid or myeloma cells for the production of human immunoglobulin chains and for the expression of enzyme markers assigned to each of the different human chromosomes. Human chromosome 14 was the only human chromosome present in all independent hybrids producing mu, gamma, and alpha human heavy chains. In two of the independent hybrids that produced human heavy chains, human chromosome 14 was the only human chromosome present in the hybrid cells. Loss of human chromosome 14 from these hybrids resulted in the concomitant loss of their ability to produce human immunoglobulin heavy chains. In view of these results, we conclude that the genes for human immunoglobulin heavy chains are located on human chromosome 14 in immunoglobulin-producing human cells.
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PMID:Chromosomal location of the genes for human immunoglobulin heavy chains. 11 99

We describe an immunoglobulin gene recombination indicator in which a specific rearrangement via deletion results in the acquisition of a dominant phenotype. The indicator consists of the Escherichia coli xanthine/guanine phosphoribosyltransferase (gpt) gene, whose translation is prevented by the presence of an upstream initiation codon out of frame with respect to the gpt coding sequence. Flanking this barrier initiation codon are the heptamer-spacer-nonamer recognition sequences from a kappa chain variable region (V kappa) and from a kappa chain joining region (J kappa). A proper V-J joint results in the deletion of the translational barrier and allows expression of the selectable marker. When tested by transfection into fibroblasts, no rearrangements were detected and the presence of the barrier initiation codon was sufficient to completely abolish gpt expression in these cells. Similarly, no rearrangements were detected after transfer of the test gene into myeloma cells. However, when the construct was introduced into the pre-B-cell line 38B9, greater than 80% of the transfected cells showed evidence of a specific rearrangement. These rearrangements were associated with the translation of gpt, although no selection for its expression was needed. DNA sequence analysis of six different V-J joints revealed that the rearrangement proceeded with a high degree of accuracy. These results indicate that only very minimal DNA sequences (21 base pairs 5' of the V heptamer and 4 base pairs 3' of its nonamer; less than 45 base pairs 5' of the J nonamer and 3' of its heptamer) are required for efficient rearrangement and provide formal proof that kappa gene segments can rearrange by a deletional mechanism.
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PMID:High-frequency deletional rearrangement of immunoglobulin kappa gene segments introduced into a pre-B-cell line. 311 Jul 76

The cell surface antigen associated with the transformed state of cells that could grow in an anchorage-independent manner was analyzed by use of techniques of DNA transfection and hybridomas secreting the monoclonal antibody (MoAb). Spleen cells of C57BL/6 mice immunized with a highly tumorigenic, chemically induced murine cultured colon 36 tumor (C-C36) of BALB/c origin were hybridized with NS-1, a hypoxanthine phosphoribosyltransferase-deficient myeloma line of BALB/c mice. Screening of hybridomas revealed an antibody that reacted with C-C36 and transformed Swiss 3T3 cells growing in soft agar after transfection of 3T3 cells with C-C36 DNA. The hybridomas that did not react with nontransformed 3T3 and the less tumorigenic BALB/c hemangioendothelioma line D10 were then selected. An MoAb was designated "#71295." This MoAb immunoprecipitated the antigen that consisted of 65,000- and 14,000-molecular-weight components with soluble C-C36 membrane antigens. It also reacted with 2 other chemically induced syngeneic colon tumor lines, cultured colon 26 tumor line and cultured colon 51 tumor line, and with fibrosarcoma Meth A. However, #71295 was not found in NS-1, D14, and BALB/c normal thymus, liver, colon, and kidney tissues. In addition, this MoAb could not inhibit the anchorage-independent growth of C-C36 and transformed 3T3 cells. These results suggest that although the molecule defined by #71295 might not be associated with the anchorage independence of cell growth, it could be a newly expressed determinant on the cell surface that is related to the events of cell transformation.
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PMID:Identification of transformation-related antigen by monoclonal antibody on Swiss 3T3 cells induced by transfection with murine cultured colon 36 tumor DNA. 346 94

Myeloma, hybridoma, and thymoma cell lines have been successfully transfected for the Escherichia coli xanthine-guanine phosphoribosyltransferase gene (gpt) by using the plasmid vector pSV2-gpt. The transformed cells synthesize the bacterial enzyme 5-phospho-alpha-D-ribose-1-diphosphate:xanthine phosphoribosyltransferase (XGPRT; EC 2.4.2.22) and have been maintained in selective medium for over 4 months. Lymphoid cell lines expressing a K immunoglobulin light chain were obtained by transfecting cells with pSV2-gpt containing a rearranged K light chain genomic segment from the S107 myeloma cell line. The S107 light chain is synthesized in gpt-transformed J558L myeloma cells and is identical to the light chain synthesized by the S107 myeloma cell line, as judged by immunoprecipitation and two-dimensional gel electrophoresis. Furthermore, this light chain is synthesized and secreted as part of an intact antibody molecule by transformed hybridoma cells that normally secrete an IgGl (gamma, K) antibody molecule. No light chain synthesis was detected in a similarly transformed rat myeloma or a mouse thymoma line.
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PMID:Immunoglobulin gene expression in transformed lymphoid cells. 640 77

Drug-specific monoclonal antibodies and their antigen-binding Fab fragments reverse acute desipramine toxicity in a rat experimental model by inducing a redistribution of drug from cardiac tissue into serum and extracellular fluid. In order to investigate the use of smaller recombinant antibody fragments such as single chain Fv (sFv) as an antidote, an efficient murine NS/O myeloma expression system was developed. The variable light (VL) and variable heavy (VH) domains of a murine anti-desipramine monoclonal antibody were cloned and sequenced. A 270 amino acid VH-(Gly4Ser)3-VL sFv was prepared by overlapping polymerase chain reaction (PCR) amplification of VH with heavy chain leader peptide, VL, and the linker. This construct was subcloned into a mammalian expression vector which utilizes the SR alpha promoter, a hybrid promoter consisting of the SV40 early promoter with portions of the human T-cell leukemia virus type I long terminal repeat and also containing the Escherichia cloi xanthine-guanine phosphoribosyltransferase gene for selection. NS/O myeloma cells were transfected by electroporation. Stable recombinant NS/O clones were screened for expression of sFv using reverse transcriptase-PCR to detect mRNA and an enzyme-linked immunosorbent assay (ELISA) to detect sFv. Secreted sFv from clones capable of growth to a cell density of 2-4 x 10(6) viable cells/mL was purified in a single step using a desipramine affinity column resulting in 12-39 mg/L of purified sFv. Affinity-purified sFv had comparable desipramine binding activity to Fab when evaluated by competitive ELISA.
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PMID:Cloning, expression, and purification of an anti-desipramine single chain antibody in NS/O myeloma cells. 880 32

Fusions were made between thymidine kinase deficient (TK-) Friend Cells inducible for hemoglobin production, and immunoglobulin-producing, hypoxanthine-guanine phosphoribosyltransferase-deficient (HGPRT-) myeloma cells. Hybrids were selected in hypoxanthine-aminopterin-thymidine (HAT) and identified by isozyme analysis and chromosome counts. All hybrids resembled the myeloma cell line in mode of growth and were immunoglobulin secretors. All hybrids did not express hemoglobin and were uninducible for hemoglobin production with dimethyl sulfoxide (DMSO). Hybridization of genomic globin DNA probes with hybrid-derived nuclear and cytoplasmic mRNAs blotted to nitrocellulose filter indicated that lack of expression of the globin genes in the hybrids was due to lack of transcription.
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PMID:Transcriptional control of the expression of mouse globin genes in myeloma x erythroleukemia cell hybrids. 973 46