Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recombinant full-length human CD23 has been incorporated into fluorescent liposomes to demonstrate the existence of a ligand for CD23 that is different from the previously known ligand, immunoglobulin E (IgE). The novel ligand for CD23 is expressed on subsets of normal T cells and B cells as well as on some myeloma cell lines. The interaction of full-length CD23 with its ligand is specifically inhibited by anti-CD23 monoclonal antibodies and by IgE, and it is Ca2+ dependent. Moreover, tunicamycin treatment of a CD23-binding cell line, RPMI 8226, significantly reduced the binding of CD23 incorporated into fluorescent liposomes, and a sugar, fucose-1-phosphate, was found to inhibit CD23-liposome binding to RPMI 8226 cells, suggesting the contribution of sugar structures on the CD23 ligand. In addition, CD23-transfected COS cells were shown to form specific conjugates with the cell line RPMI 8226. These data demonstrate that CD23 interacts with a ligand, which is different from IgE, and that CD23 can be considered as a new surface adhesion molecule involved in cell-cell interactions.
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PMID:Demonstration of a second ligand for the low affinity receptor for immunoglobulin E (CD23) using recombinant CD23 reconstituted into fluorescent liposomes. 138 72

Utrophin, the autosomal dystrophin-related protein (DRP), is expressed in HeLa cells, smooth muscle-like BC3H1 cells from mouse brain, COS monkey kidney cells, the P388D1 monocyte-macrophage cell line and untransformed human skin fibroblasts, as well as in rat C6 glioma and Schwannoma cells. It was undetectable, however, in the Sp2/O mouse myeloma cell line and in hybridoma lines derived from it. Dystrophin was not detected in any of these cell lines. Although all utrophin-containing cells were capable of forming monolayers in culture, no major effects of either attachment to substratum or length of time in culture (2-17 days) on utrophin levels were observed. After subcellular fractionation of BC3H1 or glioma cells, nearly all of the utrophin was found in the Triton-soluble fraction, suggesting an association with cell membranes.
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PMID:Utrophin, the autosomal homologue of dystrophin, is widely-expressed and membrane-associated in cultured cell lines. 142 62

The kappa-chain of the myeloma MOPC 21 is an unusual L chain, in that it is not secreted unless complexed with a H chain. This nonsecreted kappa-chain seems to be retained in the endoplasmic reticulum in association with the protein BiP/GRP78, both in myeloma cells and when expressed in COS-1 fibroblasts. By assaying the fate of the MOPC 21 kappa-chain and its mutated derivatives in COS-1 cells, we show that the cause of the nonsecreted phenotype is the presence of histidine in position 87 of the variable domain. When this amino acid is changed back to the tyrosine that usually occupies position 87, secretion of the unassembled kappa-chain is restored. As in B lymphoid cells, co-expression of gamma H chains in COS-1 cells complements the mutation in the L chain, and rescues secretion of the arrested kappa. Thus, the presence of histidine at position 87 creates a conditional L chain secretory mutant: it is not compatible with normal transport of free L chain, but can be rescued in the presence of H chain.
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PMID:A conditional secretory mutant in an Ig L chain is caused by replacement of tyrosine/phenylalanine 87 with histidine. 151 62

We present a strategy to study functional and/or developmental processes occurring in the nervous system, as well as in other systems, of mice. This strategy is based on the local expression of specific monoclonal antibodies (mAbs) by cells of the nervous system. As an application of this strategy, we report the cloning of the anti-substance P rat mAb NC1/34HL. Functional substance P-binding antibodies were reconstituted from the cloned variable domains by using vectors for expression in myeloma cells. With these and other vectors a general system for the cloning and expression of mAbs under a series of promoters (of the rat VGF8a gene, the neurofilament light-chain gene, and the methallothionein gene) has been created. The activity of these plasmids was confirmed by expressing the recombinant NC1/34HL mAb in GH3 pituitary cells, PC12 pheochromocytoma cells, and COS cells. DNA from the described constructs can be used to target the expression of the NC1/34HL mAb to the central nervous system of transgenic mice. This procedure will allow us to perturb substance P activity in a controlled way in order to dissect its multiple roles.
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PMID:Neuroantibodies: molecular cloning of a monoclonal antibody against substance P for expression in the central nervous system. 171 2

Human prothymosin alpha, virtually alone among proteins, is recovered from the aqueous phase of phenol-extracted cell lysates prepared from human myeloma cells or COS cells that were transfected with the human prothymosin alpha gene. This observation forms the basis for purification of the protein to homogeneity in two steps--phenol extraction followed by electrophoresis in sodium dodecyl sulfate polyacrylamide gels to remove residual contaminants consisting chiefly of carbohydrate and RNA.
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PMID:Human prothymosin alpha: purification of a highly acidic nuclear protein by means of a phenol extraction. 213 39

Murine T-lymphomas and Thy-1- mutants were labeled overnight with [3H]ethanolamine to detect proteins which possess a glycophospholipid anchor. When labeled cells were treated with 10% trichloroacetic acid and then analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography, both Thy-1 and a second intensely labeled protein (46 kDa) were observed. The presence of the radiolabeled 46-kDa protein in wild type and class E Thy-1 negative cells (cells in which Thy-1 is synthesized but cannot be labeled with [3H]ethanolamine) suggested incorporation into a distinct moiety. Labeling of the 46-kDa protein with [3H]ethanolamine is rapidly inhibited by cycloheximide. Further characterization of the 46-kDa protein by subcellular fractionation and Triton X-114 partitioning indicated that the protein is located in the cytosol. The protein is basic and does not bind to either concanavalin A or wheat germ agglutinin. Labeling of a 46-kDa protein has also been demonstrated in Chinese hamster ovary, COS, rat myeloma, cloned human T-lymphocytes, and HeLa cells. Pronase digestion of the [3H]ethanolamine-labeled 46-kDa protein of wild type lymphoma cells generated a nonbasic and polar labeled fragment which is labile to strong acid and base ([3H]ethanolamine is liberated), insensitive to periodate oxidation and alkaline phosphatase, and does not bind to concanavalin A or wheat germ agglutinin. Judging from methylation studies, the labeled ethanolamine residue does not contain a free amino group. Based on these results, we report a novel post-translational modification of selected protein(s) by the covalent addition of [3H]ethanolamine.
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PMID:Extensive labeling with [3H]ethanolamine of a hydrophilic protein of animal cells. 337 24

The immunoglobulin kappa light chain produced by the CH12 lymphoma is unusual because it is not secreted when expressed in the absence of a heavy chain. Instead, it undergoes rapid intracellular degradation. This degradation is selective, as another light chain expressed in the same cell is not degraded. It is also a property of the CH12 kappa chain itself, since it is degraded rapidly when expressed either in another myeloma cell or in COS-1 fibroblasts. When provided a heavy chain, this kappa chain assembles into IgM and is then protected from proteolysis. The degradation of kappa requires ATP, is sensitive to reduced temperature and to the thiol reagent diamide. Of all the proteolytic inhibitors tested, 3,4-dichloroisocoumarin, L-1-tosylamido-2-phenylethyl chloromethyl ketone, and to a lesser extent 1-chloro-3-tosylamido-7-amino-2-heptanone, inhibit kappa degradation, suggesting the involvement of a serine protease. The degradation of kappa does not require transport to the Golgi complex, nor is it sensitive to a variety of lysosomotropic agents. Both immunofluorescence and the observed association with the endoplasmic reticulum (ER) stress proteins GRP78/BiP and GRP94 indicate that the kappa chain is localized mostly in the ER. When a point mutation which blocks transport to the Golgi complex is introduced into this kappa chain, the association with the stress proteins is enhanced but the rate of degradation is not significantly decreased. We conclude that the CH12 kappa chain is a particularly good substrate for an ER degradation machinery, and that its sensitivity to the protease(s) is governed by its state of assembly. This ER degradation provides a possible quality control mechanism during the differentiation of B lymphocytes.
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PMID:Rapid degradation of an unassembled immunoglobulin light chain is mediated by a serine protease and occurs in a pre-Golgi compartment. 824 27

Enzymatically active granule-associated serine protease ("granzyme") B has been purified from human NK cell lysates, using novel granzyme B-specific monoclonal antibodies. Two antibodies, designated 2C5 and 1D10, were produced following immunization of BALB/c mice with a nineteen amino acid peptide synthesized according to the sequence deduced from a granzyme B cDNA clone. Of several peptide-reactive culture supernatants that resulted from cell fusion of splenocytes with NS-1 myeloma cells, clones 2C5 (IgG2a) and 1D10 (IgG1) produced antibodies which detected a approximately 32kDa molecule in human NK cell lysates by Western blotting. This reactive species was detectable in lysates of IL-2-stimulated peripheral blood mononuclear cells, the human NK leukemia cell line YT, the rat NK leukemia cell line RNK-16, but not in the mouse cytotoxic T cell line CTLL-R8 or a variety of non-cytolytic hemopoietic tumor cell lines. The specificity of reactivity with granzyme B was demonstrated by the reaction of the monoclonal antibody with active granzyme in the lysate of COS-7 cells transfected with human granzyme B cDNA, but not with granzyme H expressed in an identical fashion. Western blotting on Percoll-fractionated IL-2 activated human peripheral blood lymphocyte lysates and YT demonstrated reactivity of the monoclonal antibody with a approximately 32kDa species only in those fractions with granzyme A (BLT esterase) and B (Asp-ase) activities. Moreover, 2C5/1D10 antibodies coupled to Protein A-sepharose beads immunoprecipitated enzymatically active granzyme B from YT cell lysates. Scale up of this procedure should yield a means of purifying the large quantities of natural or recombinant granzyme B required to study the function of this granzyme in cellular cytotoxicity.
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PMID:Immunopurification of functional Asp-ase (natural killer cell granzyme B) using a monoclonal antibody. 837 25

Ig light (L) chains are secreted not only as part of assembled Ab molecules, but also as free L chains, the latter process being involved in the pathology of several diseases. The secretion competence of free L chains distinguishes them from free subunits of other oligomeric proteins, which are usually retained intracellularly. We used several techniques to test the idea that secretion of free L chains is dependent on dimerization. Coexpression of pairs of L chains, differing in only one amino acid, which alters the secretory phenotype, shows that these L chains behave independently: the wild-type chains are secreted, whereas the mutants are retained intracellularly. A survey of kappa- or lambda-producing cell lines by nonreducing gel electrophoresis shows that a negligible fraction of these L chains exists as disulfide-bonded dimers. Moreover, chemical cross-linking and density gradient centrifugation demonstrate that there is no significant pool of noncovalent L chain dimers. Noncovalent heterodimers can be detected readily between a kappa-chain and a chimera consisting of a heavy chain variable domain linked to the kappa-chain constant domain. This confirms that noncovalent L chain homodimers would have been detected if they were present. These findings about the association state of free L chains are independent of the host cell, as they are observed in both myeloma cells and COS fibroblasts. We conclude that L chain dimerization is a rare event that neither facilitates secretion nor is required for it.
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PMID:Ig light chains are secreted predominantly as monomers. 881 4

Interactions between P-selectin and P-selectin glycoprotein ligand-1 (PSGL-1) mediate the earliest "rolling" of leukocytes on the lumenal surface of endothelial cells at sites of inflammation. Previously, PSGL-1 has been shown to be the primary mediator of interactions between neutrophils and P-selectin, but studies on the ability of PSGL-1 to mediate interactions between P-selectin and other subsets of leukocytes have yielded variable and conflicting results. A novel IgG monoclonal antibody (MoAb) to human PSGL-1 was generated, and the specificity of this MoAb was confirmed by both flow cytometric analysis and Western blotting of cells transfected with human PSGL-1. This newly developed MoAb, KPL1, inhibited interactions between P-selectin expressing COS cells and either HL60 cells, neutrophils, or lymphocytes. Furthermore, KPL1 completely inhibited interactions between P-selectin and either purified CD4 T cells or neutrophils in a flow assay under physiological conditions, but had no effect on interactions of T cells or neutrophils with E-selectin. In addition, KPL1 blocked interactions between lymphoid cells transfected with L-selectin and COS cells expressing PSGL-1. The KPL1 epitope was mapped to a site within a consensus tyrosine sulfation motif of PSGL-1, previously shown to be essential for interaction with P-selectin and now shown to be essential for interaction with L-selectin, and to be distinct from the epitope identified by the PL1 function blocking anti-PSGL-1 MoAb. Two-color flow cytometry of normal leukocytes showed that while natural killer (NK) cells (CD16(+)), monocytes, CD4 and CD8 T cells, and alpha/beta and gamma/delta T cells were uniformly positive for PSGL-1, B cells expressed low levels of the KPL1 epitope. This low level of KPL1 staining was also observed immunohistologically in germinal centers, which had no detectable KPL1 staining, whereas T-cell areas (interfollicular region) were positive for KPL1. Interestingly, plasma cells in situ and interleukin-6-dependent myeloma cell lines were KPL1(+). Thus, PSGL-1 is expressed on essentially all blood neutrophils, NK cells, B cells, T cells, and monocytes. Variation in tyrosine sulfation during B-cell differentiation may affect the ability of B cells to interact with P- and L-selectin.
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PMID:A novel P-selectin glycoprotein ligand-1 monoclonal antibody recognizes an epitope within the tyrosine sulfate motif of human PSGL-1 and blocks recognition of both P- and L-selectin. 941 80


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