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)

We have generated seven site-specific mutations in the genes encoding the variable region of the heavy chain domain (VH) of the phosphocholine-binding antibody S107. S107 is a member of a family of well-characterized highly homologous antibodies that bind phosphorylcholine mono- and diesters. Two of these antibodies, MOPC-167 and T15, have previously been shown to catalyze the hydrolysis of 4-nitrophenyl N-trimethylammonioethyl carbonate. Two conserved heavy-chain residues, Tyr-33 and Arg-52, were postulated to be involved in binding and hydrolysis of 4-nitrophenylcholine carbonate esters. To more precisely define the catalytic roles of these residues, three Arg-52 mutants (R52K, R52Q, R52C) and four Tyr-33 mutants (Y33H, Y33F, Y33E, Y33D) of antibody S107 were generated. The genes encoding the VH binding domain of S107 were inserted into plasmid pUC-fl, and in vitro mutagenesis was performed. The wild-type and mutant S107 antibodies were expressed in P-3X63-Ag8.653 (P-3) myeloma cells by using a modified SV2 shuttle vector. The catalytic properties of wild-type antibody S107 are similar to those of the phosphocholine-specific antibody T15, which has the same VH protein sequence. In general, mutations at Tyr-33 had little effect on catalytic activity, whereas mutations at Arg-52 that result in loss of the positively charged side chain significantly lower the catalytic activity of S107. One mutant, Y33H, catalyzed the hydrolysis of 4-nitrophenyl N-trimethylammonioethyl carbonate with a kcat of 5.7 min-1 and a Km of 1.6 mM at pH 7.5. These results not only demonstrate the importance of electrostatic interactions in catalysis by antibody S107 but also show that catalytic side chains can be introduced into antibodies to enhance their catalytic efficiency.
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PMID:A mutagenesis study of a catalytic antibody. 189 78

A series of mouse myeloma cell lines producing mutant gamma 2b immunoglobin heavy chains, which resemble heavy chain disease proteins, were analyzed for messenger RNA abundance as a function of mRNA alterations. A mutation effectively deleting the gamma 2b-CH1 domain of the mRNA had little or no effect on Ig heavy chain mRNA abundance on half-life (mutant 10.1). A mutation in the gamma 2b-CH2 and CH3 domain, causing premature termination of translation, had more deleterious effects on Ig heavy chain mRNA abundance and half-life (mutant I17). Substitution of the deleted portions of the gamma 2b mRNA with gamma 2a sequences by subclass switching in the cells (mutants K23 and K25) resulted in increased heavy chain abundance and half-life relative to the parent I17. In contrast, kappa light chain mRNA levels and half-lives remain constant among the mutants. The wild-type and mutant cell lines transcribed the Ig heavy chain gamma 2b locus equally when compared with an internal beta-actin standard by transcription run on studies. Therefore, half-life of the Ig heavy chain mRNA seems to be the principal determinant in cytoplasmic mRNA abundance in this system.
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PMID:Differential mRNA stabilities affect mRNA levels in mutant mouse myeloma cells. 190 Jan 33

A human immunoglobulin G1 (IgG1) antibody oligomer was isolated from a transfected myeloma cell line that produced a monoclonal antibody to group B streptococci. Compared to the IgG1 monomer, the oligomer was significantly more effective at protecting neonatal rats from infection in vivo. The oligomer was also shown to cross the placenta and to be stable in neonatal rats. Immunochemical analysis and complementary DNA sequencing showed that the transfected cell line produced two distinct kappa light chains: a normal light chain (Ln) with a molecular mass of 25 kilodaltons and a 37-kilodalton species (L37), the domain composition of which was variable-variable-constant (V-V-C). Cotransfection of vectors encoding the heavy chain and L37 resulted in production of oligomeric IgG.
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PMID:Effect of light chain V region duplication on IgG oligomerization and in vivo efficacy. 190 93

The mouse heavy chain immunoglobulin promoter VH441 can lead in vitro to bidirectional transcription, due to a symmetrical organization of immunoglobulin heavy chain promoters with two TATA-like sequences bracketing the upstream promoter element ATGCAAAT (the so called octamer). We demonstrate here that divergent transcription also occurs in vivo in mature B cells from a myeloma which expresses the VH441 gene and even from the spleen of BALB/c mice. The level of VH441 divergent transcript increases in the spleen of BALB/c mice after immunisation by beta-(1,6)-galactan, showing that it is expressed in B cells which actively transcribe the VH441 gene. The divergent transcript has been characterized: its major transcription start site was mapped within 33 base pairs from the divergent TATA-like region, it is unspliced and not polyadenylated. In the light of these results, the functions of the divergent transcript and the bidirectional promoter are discussed.
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PMID:Demonstration of a divergent transcript from the bidirectional heavy chain immunoglobulin promoter VH441 in B-cells. 192 17

We describe a new method for amplification, by polymerase chain reaction (PCR), of rearranged segments encoding the variable part of light and heavy chains of an antibody (Ab) from the chromosomal DNA of hybridoma cells for the chimerization of Abs. A fundamental prerequisite for this is the knowledge of the exact sequences in the 5'-untranslated region of light and heavy chain mRNA, and of the joining segment used for rearrangement. This allows the design of nondegenerated oligodeoxyribonucleotides for PCR. The primer design permits directional cloning of the amplified, promoterless fragments into cassette vectors, in which they will be linked to the appropriate human constant domains and immunoglobulin (Ig) promoter/enhancer elements. The method is illustrated for chimerization of an Ab directed against the human T-lymphocyte antigen, CD4. The chimerized Ab is secreted in abundant quantities after transfection of the engineered plasmids into non-Ig-producing myeloma cells.
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PMID:Chimerization of antibodies by isolation of rearranged genomic variable regions by the polymerase chain reaction. 193 56

The junctional sequences corresponding to the complementarity determining region 3 (CDR3) of rearranged heavy chain Ig genes can provide allele-specific markers in the detection of B-lymphoid malignancies. Consensus oligonucleotide primers were used to amplify CDR3 regions of rearranged heavy chain alleles in clinical samples from myeloma, acute lymphocytic leukemia, and chronic lymphocytic leukemia patients. From the sequence of the amplified products, allele-specific primers were synthesized and used directly in polymerase chain reaction (PCR) amplification to detect the malignant clone. This method was both highly specific and sensitive to 1 malignant B-cell in a background of 10(5) normal cells. In addition, parameters that affect the linearity of PCR detection were determined and, by using titrations of malignant target cells to generate standard curves, quantitations of residual malignancies were determined. The application of this method is shown in an analysis of myeloma patients whose marrows were analyzed sequentially during therapy. Allele-specific oligonucleotide-PCR provided a rapid, highly specific and quantitative measure of residual disease, even in patients with clinical parameters indicating complete remission.
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PMID:Analysis of B-lymphoid malignancies using allele-specific polymerase chain reaction: a technique for sequential quantitation of residual disease. 195 87

The TH line was established by bringing tumour cells from a multiple myeloma patient into suspension culture and subsequently cloning them by limiting dilution. The cultured cells show marked heterogeneity; there are ultrastructural differences between small and large TH cells, particularly with respect to the rough endoplasmatic reticulum (RER). Karyotyping revealed chromosome numbers in the triploid range, with many structural abnormalities, at the 14q32 region among others. A t(14;18) could not be demonstrated. TH was shown to have germline and a rearranged allele for kappa light chain, and only a single rearranged gene for heavy chain immunoglobulin. TH expressed PCA-1, CD9, CD28 and CD38 antigens, HLA class II, RER and kappa light chain, but few or no other antigens associated with the B-cell lineage. Light chain kappa and trace amounts of IgG3 were found intracellularly as well as in culture supernatant. The addition of IL-6 to cultures of TH increased proliferation, as well as the secretion of kappa light chain and the membrane expression of CD28 and CD38 antigens. Because TH has relatively few B cell markers on its membrane, it may be useful for the induction of monoclonal antibodies specific for human plasma cells. It also provides a model for the demonstration that IL-6 can act as a paracrine growth and differentiation factor for cells of myelomal origin.
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PMID:Characterization of a human plasmacytoma line. 195 80

We have studied the phenotype and the immunoglobulin gene configuration of blood B cells from 15 patients with stage III multiple myeloma (MM) at diagnosis. Highly purified B cells (greater than 90% CD20 positive cells) were obtained after L-leucine methyl ester monocyte depletion and elimination of T cells by rosetting. The percentage of B cells with surface immunoglobulin (sIg) featuring the same light and heavy chain isotype as the serum monoclonal immunoglobulin was very low, except in one patient, in whom 25-30% of B cells displayed surface and cytoplasmic immunoglobulin (cIg) sharing idiotypic determinants with the serum monoclonal IgG kappa. In all cases but one the percentage of circulating plasma cells accounted for less than 2% of the enriched B cell preparations. In one patient purified B cell population contained 30% of plasma cells and the immunoglobulin gene study revealed a rearranged JH hybridizing fragment identical in bone marrow and blood B cell DNA samples. In the other 14 cases no rearranged fragment was detected although we used a technique allowing the detection of at least 2% clonal cells. The absence of clonal cells in the patient whose B cells contained a high percentage of cells featuring surface IgG molecules was confirmed on purified sIgG-positive cells. In addition CD20-positive cells from this patient did not contain gamma mRNA. Therefore the IgG molecules were clearly extrinsic. Although the existence of clonal B lymphocytes or of myeloma idiotype related B cells cannot be ruled out, they escape detection by sensitive genetic studies of immunoglobulin genes.
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PMID:Phenotype and immunoglobulin gene configuration of blood B cells from patients with multiple myeloma. 204 22

We found M-proteins with two peaks by agarose electrophoresis in the serum of a myeloma patient. The M-proteins were identified as both IgG 1-kappa type, and classified as IgG-F (fast mobility) and IgG-S (slow mobility). 1) The possibility that the two M-proteins were derived from the post translational differences of sugar moieties of the same IgG molecule was unlikely, because no migration changes were observed in IgG-F and IgG-S after the treatment with 4 different sugar enzymes. 2) Fab fractions of IgG-F and IgG-S were analyzed. After papain or pepsin digestion, western blotting with anti-Fab antiserum revealed that the Fab fraction of IgG-F and IgG-S had identical mobility by agarose electrophoresis. However the Fc fractions of IgG-F and IgG-S analyzed by the same procedures with anti-Fe antiserum, were different. 3) Anti-idiotype antiserum prepared in rabbits against IgG-S, or -F, and absorbed by normal IgG and normal human serum showed a fused precipitin line with IgG-F and IgG-S. These findings suggest that two M-proteins with both IgG 1 and kappa type, have the same VH and VL regions but have different constant regions of heavy chain. Since one copy of IgG 1 constant gene is found in each human haploid gene. It is speculated that the switching of the rearranged VDJ gene to constant region gene occurred not only between cis chromosome but also between trans chromosome.
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PMID:[Immunochemical analysis of two peak M proteinemia derived from structural differences of IgG Fc region]. 205 1

The construction, synthesis and secretion of a genetically engineered antibody-cytokine fusion molecule is described. To target tumor necrosis factor (TNF) to tumor cells, recombinant antibody techniques were used to produce a Fab-like antibody-TNF conjugate. At the gene level, the heavy chain gene of an antitransferrin receptor antibody was linked to a synthetic TNF gene encoding human TNF. Transfection of the heavy chain-TNF gene into a myeloma derived cell line which was producing the light chain of the same antibody, allowed the isolation of a cell line secreting a fusion protein of the expected molecular weight and composition. The culture supernatant of the cell line contained TNF cytotoxic activity towards murine L929 cells and human MCF-7 cells. Cytotoxicity towards the human cancer cells was inhibited by an excess of the original antitransferrin receptor antibody, indicating that the antibody-TNF molecules are targeted to the transferrin receptor rich tumor cells. Since the antibody genes used are chimeric (i.e. composed of mouse variable and human constant regions) and since DNA encoding human TNF was used, the hybrid protein is an example of a humanized immunotoxin-like molecule. These results illustrate the possibilities of antibody engineering technology to create and produce improved agents for cancer therapy. Furthermore, they demonstrate for the first time the ability of myeloma cells to secrete an antibody-cytokine chimeric molecule.
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PMID:Targeting of tumor necrosis factor to tumor cells: secretion by myeloma cells of a genetically engineered antibody-tumor necrosis factor hybrid molecule. 206 6


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