Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P13232 (Interleukin-7)
 580 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Incubation of human T lymphocytes with saturating concentrations of combinations of certain anti-CD2 and -CD4 mAb results in reciprocal down-regulation of the cell surface density expression of the respective CD molecules. Such reciprocal down-regulation occurs at 0 degrees C in the presence of sodium azide and appears selective for CD2 and CD4 molecules because mAb identifying various other CD T cell surface molecules (anti-Leu2a, -OK-CLL, -W6/32, -beta 2-microglobulin, -4B4) do not modulate CD2 or CD4 R density, and because anti-CD2 mAb (anti-OKT11 and -D66 clone-1) do not alter CD8 R density (anti-OKT8, -Leu2a) and vice versa. Down-regulation of CD2 by mAb specific to CD4 is epitope-specific but does not vary on the basis of the antibody isotype used. The anti-CD4 mAb, Leu3a, was the strongest CD2 down-regulator examined followed by OKT4F. mAb specific to other CD4 epitopes (B, C, D, and E) caused only slight down-regulation of CD2 expression whereas anti-OKT4 and -OKT4A mAb had no significant regulatory effect. Also, mAb specific to the 9.6 (anti-OKT11) and D66 (anti-D66 clone 1) epitopes of the CD2 molecule down-regulated CD4 density detectable with Leu3a, OKT4, and OKT4A anti-CD4 mAb. Down-regulation of CD2 by anti-CD4 mAb also occurred with the transformed T cell line, KE-37, which demonstrates that such effects can occur without mononuclear phagocytic accessory cells. From these data it can be concluded that important T cell immunoregulatory signals may be transmitted intramembranally between CD2 and CD4 glycoproteins.
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PMID:Cytofluorometric analyses of human T cell CD2/CD4 inter-molecular interactions. 296 74

Prostaglandin E1 (PGE1) has a stimulatory effect both on the growth and the expression of differentiated function of Madin Darby Canine Kidney (MDCK) cells in a hormonally defined medium (Medium K-1). While the stimulatory effect of PGE1 on MDCK cell growth is observed in subconfluent cultures, the effect of PGE1 on differentiated function (i.e., dome formation) is observed at confluency. PGE1 may possibly affect growth and such differentiated functions by separate mechanisms. In order to examine this possibility, dibutyryl cyclic AMP resistant variants of MDCK were selected. All of the variants were partially resistant to the growth inhibitory effects of dibutyryl cyclic AMP and theophylline. The cyclic AMP dependent protein kinase activity of four of the five variant clones studied was significantly reduced as compared with normal MDCK cells. The dependence of the kinase activity of several of the dibutyryl cyclic AMP resistant variants (DBr2 and DBr3) on the cyclic AMP concentration in the reaction mixture was compared with that of normal MDCK cells. At all of the cyclic AMP concentrations tested DBr2 and DBr3 cells had reduced protein kinase activity as compared with normal MDCK cells. This reduced activity could be attributed to a decrease in the Vmax for kinase in the two variants, rather than to a change in the Km of kinase for cyclic AMP. The cyclic AMP phosphodiesterase activity of dibutyryl cyclic AMP resistant variants was also studied. Unlike PGE1 independent clone 1, DBr2 and DBr3 cells did not differ significantly from normal MDCK cells with regard to their ability to degrade cyclic AMP. The growth and functional responsiveness of DBr2 and DBr3 cells to PGE1 was also examined. DBr2 and DBr3 cells were shown to retain a normal growth response to PGE1. However the capacity of DBr2 and DBr3 cells to form domes in response to PGE1 was dramatically reduced as compared with normal MDCK cells. Nevertheless DBr3 cells were shown to still retain the capacity to form domes in response to other inducers. The effect of PGE1 on one of the functional parameters involved in dome formation (the activity of the Na+/K+ATPase) was examined. The rate of ouabain-sensitive Rb+ uptake was observed to be elevated in confluent monolayers of normal MDCK cells maintained in Medium K-1, as compared with monolayers maintained in Medium K-1 minus PGE1.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Dibutyryl cyclic AMP resistant MDCK cells in serum free medium have reduced cyclic AMP dependent protein kinase activity and a diminished effect of PGE1 on differentiated function. 299 25

DNA from a human laryngeal carcinoma was molecularly cloned in Lambda L47. The gene library was screened for human papillomavirus (HPV)-related sequences by hybridization analysis with 32P-labelled HPV 16 DNA at conditions of low stringency (Tm -40 degrees C). One of the clones (4-5) with an insert of 7.8 kb showed cross-hybridization with most of the known HPV types (Tm -40 degrees C), and with several of them even under more stringent conditions (Tm -30 degrees C). No signal was detected under high-stringency conditions (Tm -20 degrees C). The co-linear alignment of clone 4-5 with HPV 16 DNA could be demonstrated by hybridization experiments and also by partial DNA sequence analysis. We conclude that clone 4-5 represents a new HPV type tentatively designated HPV 30. HPV 30 DNA was also detected in 2 genital lesions but not in 41 laryngeal carcinomas analyzed so far. Its presence in other tumor DNA is now under investigation.
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PMID:Molecular cloning and characterization of the DNA of a new human papillomavirus (HPV 30) from a laryngeal carcinoma. 300 Sep 55

We previously isolated spontaneous env gene mutants of Friend spleen focus-forming virus that are nonleukemogenic in adult mice but form leukemogenic revertants in newborns; we found that the revertants contain secondary env mutations. To identify sites in the encoded membrane glycoprotein that are important for its pathogenic function, we molecularly cloned and partially sequenced the env genes of two mutant viruses (clone 63 and clone 4) and one revertant (clone 4REV). Clone 63 contained three noncontiguous point mutations that caused nonconservative amino acid substitutions of Gly-119----Arg-119, Cys-180----Tyr-180, and Gly-203----Arg-203 in the xenotropic-related domain of the env glycoprotein. These substitutions were presumably responsible for the altered electrophoretic and pathogenic properties of the mutant glycoprotein. The presence of these and several other G-A nucleotide substitutions at different sites in one spontaneous mutant provided striking evidence that error-rich proviruses can form during retroviral replication. Clone 4 contained a point mutation that generated a premature termination condon at amino acid residue 304 (Gln-304----Ochre-304). This termination codon was located immediately after the proposed xenotropic-ecotropic recombination site and eliminated the ecotropic-related domain, including the putative membrane anchor of the glycoprotein. Clone 4REV was a true revertant derived from clone 4 in which the premature termination codon had back-mutated to re-form the wild-type sequence. These results confirm an essential role for the env gene in Friend spleen focus-forming virus pathogenesis and suggest that the encoded membrane glycoprotein contains different domains that contribute to its pathogenic function.
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PMID:Role of a membrane glycoprotein in Friend virus erythroleukemia: nucleotide sequences of nonleukemogenic mutant and spontaneous revertant viruses. 300 85

The biological activities of Epstein-Barr virus (EBV) from a human epithelial hybrid cell line derived from a nasopharyngeal carcinoma (NPC-KT) were studied. Low concentrations of virus from the NPC-KT cell line stimulated DNA synthesis of human cord blood lymphocytes (CBL) and induced CBL to form EBV nuclear antigen-positive continuous cell lines. The CBL exposed to higher doses of virus showed stimulated DNA synthesis 2 days after infection, followed by cell lysis. Virus from the NPC-KT cell line induced EBV-specific antigens in nonproducer Raji cells and reduced the colony-forming ability of the super-infected cells. The ratio of transforming activity to early antigen-inducing ability was not constant during cell passage. The data obtained suggest that NPC-KT clone 1 cells are producing virus with cytotoxic and transforming properties.
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PMID:Heterogeneity of Epstein-Barr virus derived from a nasopharyngeal carcinoma that has transforming and lytic properties. 301 75

Human cytotoxic T cell (CTL) clones generated against a DQw3-positive EBV-transformed B cell line were analyzed in terms of immunological characteristics. The cytolytic activities of clones 1-18 and 3-34 were inhibited by anti-DQw3 monoclonal antibodies (HU-18 and HU-23), but they were not affected by anti-DR (HU-4 and HU-20) and anti-HLA-A, B, C (W6/32) monoclonal antibodies. In contrast to that the clone 1-18 cytolyzed all the human B cell lines typed as DQw3, the clone 3-34 reacted only with DR4/Dw4 and DR5-positive cells that were positive for HU-23 and typed as TA10. In addition, the clone 3-34 were cross-reactive to DQw2-typed cells. These results show that there are two epitopes that CTL recognize on the same DQw3 molecules; one is the public epitope among DQw3 antigens, and the other is the private epitope that HU-23 recognizes. This is the further evidence for CTL recognition of HLA-DQ antigens.
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PMID:[Human cytotoxic T cell clones that recognize HLA-DQw3 antigens]. 302 17

The expression of several surface antigen genes in Trypanosoma brucei is mediated by the duplicative transposition of a basic-copy variant surface glycoprotein (VSG) gene into an expression site. We determined that the appearance of variant 118, in a parasitemia, resulted from at least four independent duplicative transpositions of the same VSG 118 gene. Variants 117 and 118 both appeared at specific periods but resulted from multiple independent activations. Antigenic variants thus occur in an ordered manner. We show that in the duplicative transpositions of VSG genes, the ends of the transposed segments were homologous between the basic copy and the expression site. Sequences other than the previously reported 70-base-pair (bp) repeats could be involved. In one variant, 118 clone 1, the homology was between a sequence previously transposed into the expression site and a sequence located 6 kilobases upstream of the VSG 118 gene. In variant 118b the homology was presumably in 70-bp repeat arrays, while in a third 118 variant yet another sequence was involved. The possibility that the 70-bp repeats are important in the initial steps of the recombinational events was illustrated by a rearrangement involving a 70-bp repeat array. The data provide strong evidence for the notion that gene conversion mediates the duplicative transposition of VSG genes. We discuss a model that explains how the process of duplicative transposition can occur at random and still produce an ordered appearance of variants.
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PMID:Frequent independent duplicative transpositions activate a single VSG gene. 303 67

Four Neurospora crassa genomic clones have been selected as hybridizing much more strongly to labelled mRNA isolated from acetate-grown mycelium than to mRNA from sucrose-grown mycelium. Hybridization of restriction fragments with acetate-specific mRNA or cDNA has been used to delimit the transcribed region(s) of each clone. The transcription of all four clones is strongly induced by transfer of growing mycelium from sucrose to acetate as sole carbon source. In wild-type mycelium, mRNAs corresponding to the four clones reach maximum levels after four hours of induction. They accumulate more rapidly and reach higher levels in an acetate non-utilizing mutant, acu-7, which has been found to overproduce enzymes of the glyoxylate cycle and to have a partial block in the TCA cycle. Molecular transformation of a Neurospora acu-5 mutant and of an Aspergillus nidulans acuE mutant by DNA of clone 2 and clone 1, respectively, strongly suggests that clone 2 codes for acetyl-coenzyme A synthetase and that clone 1 codes for malate synthase. The transcribed segments of clones 1 and 2 each hybridize to corresponding clones from Aspergillus nidulans (R. A. Sandeman and M. J. Hynes, personal communication).
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PMID:Molecular cloning, identification and transcriptional analysis of genes involved in acetate utilization in Neurospora crassa. 305 23

The monocytoid tumor cell line U-937 and five derived subclones were infected with the HTLV-IIIB isolate of the human immunodeficiency virus (HIV). Susceptibility to infection and sensitivity to the cytopathic effects correlated with the expression of the T4 antigen on the cell surface. On the basis of these characteristics the lines could be divided into three groups. Less than 10% T4 positive cells were present in the parental line and clone 4; hence productive infection could only be established after a long latency or with a high virus inoculum. These lines showed no or only marginal cytopathic effect. Clone 16 contained more than 95% T4 positive cells and was the most sensitive line to infection with HTLV-IIIB and its cytopathic effect. Cell death was so extensive following infection that no continuous virus producer line could ever be established from clone 16 cells. Cultures with intermediate T4 expression (50-70% T4+ cells) also had intermediate susceptibility to virus infection. Cytopathic changes, even if pronounced, could be overcome in the infected cultures by the addition of uninfected cells and, in each case, a producer line could be established. HTLV-IIIB infection of clone 16 cells could be blocked by preincubation with monoclonal anti-T4 antibodies indicating a close similarity between the HTLV-IIIB receptor on T4 positive T cells and monocytoid cells. The results thus show that T4 positive monocytoid cells can function as target cells for the HIV.
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PMID:Susceptibility to infection by the human immunodeficiency virus (HIV) correlates with T4 expression in a parental monocytoid cell line and its subclones. 310 30

Mice with an established syngeneic T cell tumor (RBL5) received short term adoptive chemoimmunotherapy with CTL clone 1.B6 and murine rIFN-gamma. In comparison with treatment with either agent alone, the combination of 1.B6 and rIFN-gamma was associated with a dramatic increase in long term survival. No direct effects of rIFN-gamma on tumor cell proliferation, MHC Ag expression, or susceptibility to CTL-mediated lysis could be demonstrated to explain the prolongation of survival. However, rIFN-gamma induced a distinct increase in broad-spectrum cytolytic capacity of peritoneal exudate cells and further increased class II MHC expression on peritoneal macrophages. The explanation for enhanced adoptive chemoimmunotherapy after combined short term administration of a CTL clone and rIFN-gamma is uncertain. Potential mechanisms include direct tumor lysis by activated cells, indirect tumor lysis via sensitization to other lymphokines or monokines, improved Ag-specific activation of transferred CTL clones, and/or more effective development of de novo host anti-tumor immunity.
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PMID:Adoptive immunotherapy of syngeneic murine leukemia is enhanced by the combination of recombinant IFN-gamma and a tumor-specific cytotoxic T cell clone. 312 13


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