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

An anti-I-Ab monoclonal antibody, designated K14.83-11, was produced in a fusion between SP 2/0 Ag-14 myeloma cells and spleen cells from a B10.D2/n mouse primed in vivo against C57BL/10. Unlike other anti-I-Ab monoclonal antibodies thus far described, K14.83-11 was found to have a combination of features involving specificity, isotype, and function, unique among existing anti-I-A reagents. K14.83-11 exhibited a strong binding to the I-Ab gene product, with only slight cross-reactivity to the I-Ap/q family of allelic products and no reactivity towards I-Ak,d. When analyzed for isotype, K14.83-11 was found to be of a rare IgG3 isotype. With respect to biologic activity, K14.83-11 not only failed to produce the expected inhibition of specific anti-I-Ab T cell reactivity in vitro, but instead produced a striking enhancement of T cell responses against the I-Ab gene product. The possible relationship of IgG isotype and function was suggested when the immunoenhancing effect of K14.83-11 on reactive T lymphocytes was reversed to that of suppression with highly purified F(ab)2 fragments obtained by pepsin digestion.
 ...
PMID:A novel anti-Ia monoclonal antibody which specifically enhances the corresponding T cell alloreactivity. 633 45

Intact rabbit immunoglobulin G molecules (IgGs) and their papain or pepsin fragments were radio-iodinated and injected into HeLa cells. Whole IgGs, Fab2, and Fc fragments were degraded with half-lives of 60-90 h, whereas half-lives of Fab fragments were 110 h. These results indicate that proteolytic cleavage in the hinge region of the IgG molecule is not the rate-limiting step in its intracellular degradation. The hingeless human myeloma protein, Mcg, was degraded at the same rate as bulk human IgG, providing further evidence that the proteolytically susceptible hinge region is not important for intracellular degradation of IgG molecules. SDS acrylamide gel analysis of injected rabbit IgG molecules revealed that heavy and light chains were degraded at the same rate. Injected rabbit IgGs and rabbit IgG fragments were also examined on isoelectric focusing gels. Fab, Fab2, and Fc fragments were degraded without any correlation with respect to isoelectric point. Positively charged rabbit IgGs disappeared more rapidly than their negative counterparts, contrary to the trend reported for normal intracellular proteins. The isoelectric points of two mouse monoclonal antibodies were essentially unchanged after injection into HeLa cells, suggesting that the altered isoelectric profile observed for intact rabbit IgG resulted from degradation and not protein modification. The intracellular distributions of IgG fragments and intact rabbit IgG molecules were determined by autoradiography of thin sections through injected cells. Intact IgG molecules were excluded from HeLa nuclei whereas both Fab and Fc fragments readily entered them. Thus, for some proteins, entry into the nuclear compartment is determined primarily by size.
 ...
PMID:Intracellular distribution and degradation of immunoglobulin G and immunoglobulin G fragments injected into HeLa cells. 640 51

Type IV collagen is one of the main constituents of basement membranes, yet it is unknown whether the structural framework at different sites is assembled from one unique type of molecule or whether different type IV collagen molecules exist. To study the composition, chemical identity, and organization of this protein in different organs we have prepared monoclonal antibodies to a type IV collagen preparation from human placenta. Swiss Webster mice were hyperimmunized, and splenic cells were fused with the three different myeloma cell lines SP2/0, NS1, and U1. Type IV collagen-specific hybrids were selected and cloned by limiting dilution and on hard agar. Monoclonal antibodies secreted by two clones were extensively characterized by ELISA-inhibition assay, immunoprecipitation, rotary shadowing, and immunofluorescence techniques. Unlike conventionally raised antibodies in rabbits, both monoclonal antibody reagents show species-specific binding exclusively to native type IV collagen from human placenta but not to a similar preparation from calf lung or to other types of collagen. After heat denaturation of the antigen binding was no longer observed. The M3F7 antibody-binding site is located within the triple helical domain of the type IV molecule, approximately 900 A removed from the amino terminal end as visualized by a metal shadow casting technique. The monoclonal antibody M3F7 precipitates material from pepsin-derived and radiolabeled type IV collagen, and analysis of the polypeptide chains in the immunoprecipitate by sodium dodecyl sulfate polyacrylamide gel electrophoresis suggests that two major fragments are contained in the precipitate, which yield polypeptides of about 100 and 50 kilodaltons. After rotary shadowing of antigen-antibody mixtures native collagen fragments of two different size classes that bind antibody are visualized. One fragment is approximately 1500 A in length, and the other measures about 2700 to 3000 A. The localization of the antigenic site on these fragments suggests that both are generated by pepsin cleavage at a site about 900 A removed from the amino terminal end. In immunofluorescence experiments the monoclonal antibodies stained all basement membranes in kidney, lung, placenta, or skin, suggesting that at least the type IV collagen molecule recognized by these monoclonal antibodies is shared by a variety of vascular and epithelial basement membranes.
 ...
PMID:Methods in laboratory investigation. Monoclonal antibodies to type IV collagen: probes for the study of structure and function of basement membranes. 668 65

C3H mice were immunized with native, pepsin-extracted chick type V collagen, and their spleen cells were fused with myeloma cells from the cell line X63 Ag 8653. Several hybridoma cell clones were obtained and grown to mass culture which produced monoclonal antibodies reacting with native, but not or very little with denatured type V collagen, or isolated alpha 1(V) and alpha 2(V) chains in a radio-binding assay. No cross-reaction was found with native collagen types I, III and IV collagen; some clones showed a slight cross-reaction with types II and M collagen, and all clones cross-reacted with native collagen molecules containing 1 alpha, 2 alpha, and 3 alpha chains. This indicated that this collagen type probably carries similar antigenic sites and is closely related to type V collagen. Two clones were further characterized by SDS gel electrophoresis and radial immunodiffusion; the secreted antibodies belong to the IgG1 subclass. For immunofluorescence studies monoclonal antibodies were purified from culture medium or ascites fluid by ammonium sulfate precipitation or affinity chromatography on type V collagen. Type V collagen was localized in corneal stroma, bone matrix, mesodermal layer of the skin, muscle connective tissue and perichondrium. Short pretreatment of the tissue sections with pepsin was necessary in order to reveal fluorescence reactions.
 ...
PMID:Immunofluorescent localization of type V collagen in the chick embryo with monoclonal antibodies. 676 41

A murine BALB/c IgG2a (lambda 3) myeloma immunoglobulin SAPC-15 with binding activity for negatively charged polysaccharides has been purified by affinity chromatography, and its interaction with heparin and various other polyanionic antigens has been studied. The antigen-binding activity has been demonstrated to reside in the Fab part of the immunoglobulin. The S15 myeloma protein in 0.05 M Tris buffer at pH 7.4 precipitated dextran sulfate, heparin, chondroitin sulfate A, B and C, hyaluronic acid, H. influenzae type b polysaccharide, calf thymus DNA, Klebsiella polysaccharide K63 and poly-L glutamic acid. Of these antigens only dextran sulfate was precipitated in 0.01 M phosphate buffered saline (0.15M), pH 7.4. The pepsin S15 Fab fragment did not precipitate with any of these antigens. The intrinsic tryptophanyl fluorescence of S15 was changed maximally by the addition of heparin, and the binding affinity of the immunoglobulin for this antigen was high (greater than 10(6) L/M). S15 may resemble antibody molecules that react with antigens under non-physiological conditions or in pathological conditions or in the external environment as in the lumen of the gut. All the above interactions of S15 with antigens persisted in 0.05 M Tris buffer made physiologically isotonic by the addition of sucrose, and S15 could thus be used to identify these antigens on cell surfaces.
 ...
PMID:The interaction of mouse myeloma immunoglobulin S15 with negatively charged polysaccharide antigens. 681 62

Pure secretory immunoglobulin A was isolated from human milk by fractionation in gradients of pH and (NH4)2SO4 concentration followed by gel filtration. The hinge region containing all the O-glycosidically linked oligosaccharides was isolated en bloc after trypsin and pepsin hydrolysis and separated by gel filtration. The mixture of O-glycosidically linked oligosaccharides contained N-acetylneuraminic acid (NeuAc), fucose (Fuc), galactose (Gal), N-acetylglucosamine (GlcNAc) and N-acetylgalactosamine (GalNAc) in the molar ratio of 0.2:0.5:2.5:2:1 respectively. After beta-elimination several oligosaccharides were separated by a combination of ion-exchange chromatography and gel-filtration chromatography. The complete structure of four of these oligosaccharides was determined by methanolysis, methylation and mass spectrometry. The structure of the four oligosaccharides which are linked to serine or threonine residues of the hinge region are as follows: beta-Gal-(1 leads to 3)-GalNAc-ol; alpha-HeuAc-(2 leads to 3)-beta-Gal-(1 leads to 3)-GalNAc-ol; beta-Gal-(1 leads to 3)-[beta-GlcNAc-(1 leads to 6)]-GalNAc-ol; beta-Gal-(1 leads to 3)-[beta-Gal-(1 leads to 4)-beta-GlcNac-(1 leads to 6)]-Gal-NAc-ol. These oligosaccharides are more complex and heterogenous than the oligosaccharides linked to serine residues of the hinge region from myeloma serum immunoglobulin A1.
 ...
PMID:Heterogeneity of the glycans O-glycosidically linked to the hinge region of secretory immunoglobulins from human milk. 721 51

Kidney tubule dysfunction and lesions are frequent complications of myeloma, related to unknown properties of the monoclonal light chain. We have analyzed protease sensitivity and binding properties of urinary light chains from four patients with Fanconi's syndrome, 12 with cast nephropathy, and four control patients without myeloma-associated tubulopathy. All light chains were normal-sized, monomeric and/or dimeric, and none was N-glycosylated. Kinetic studies of light chain digestion by pepsin and the lysosomal enzyme cathepsin B showed the generation of a protease-resistant 12 kDa fragment, corresponding to the V domain of the kappa chain in the four Fanconi's syndrome patients; in two out of four the V domain was also completely resistant to trypsin. Western and dot blots revealed similar patterns of reactivity of light chains from patients with the Fanconi's syndrome towards other light chains. Properties of cast-nephropathy light chains were more heterogeneous but clearly differed from those of Fanconi's syndrome: (i) 9 out of 12 were of the lambda-type; (ii) only four yielded a transient 12 kDa fragment after cathepsin B digestion, but all showed some resistance to proteolysis of the entire molecule or a fragment thereof to at least one protease, at variance with control light chains; (iii) they displayed various patterns of reactivity with other light chains; (iv) 7 out of 12 reacted specifically with Tamm-Horsfall protein (THP) by ELISA, in contrast with those of Fanconi's syndrome. In one patient who presented with cast nephropathy and the Fanconi's syndrome, the light chain exhibited both partial resistance of the V kappa domain to cathepsin B and the highest reactivity with THP.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Protease resistance and binding of Ig light chains in myeloma-associated tubulopathies. 756 94

The specificity of IgE binding to a human basophil-like cell line (KU812) was studied by flow cytometry. Four IgE myeloma proteins, representing both light-chain types, one chimeric IgE protein, and polyclonal serum IgE blocked the direct binding of FITC-labeled IgE(DES) myeloma protein to KU812 cells in a dose-dependent and nearly equimolar way. Although not as efficiently as human IgE (from five to eight times less on a molar basis), both rat and mouse IgE blocked IgE(DES)-FITC binding to KU812 cells. In sharp contrast, all four human IgG subclasses, both IgA subclasses, and IgM myeloma proteins, as well as monomeric and heat-aggregated polyclonal human IgG, were unable to block significantly IgE(DES)-FITC binding to KU812 cells (< 0.5% on a molar basis). The cytophilic epitope on IgE was heat-susceptible (56 degrees C, 2 h), lost after reduction alkylation, and resident in the papain-derived Fc epsilon-fragment, but not in the papain-derived Fab epsilon- and Fc'epsilon-fragments nor in the pepsin-derived F(ab')2 epsilon- and Fc"epsilon-fragments. Washing and displacement experiments indicated that a major part of IgE reacted with high affinity to KU812 cells. The results indicate that the binding of IgE to KU812 cells is highly specific and involves the classical high-affinity Fc epsilon RI-receptor. Although the density of receptors is low, this human cell line offers a unique model to study IgE/Fc epsilon RI interactions.
 ...
PMID:Demonstration of specific high-affinity Fc epsilon-receptors on the human basophil-like leukemia cell line KU812 by flow cytometry. 774 Nov 91

Monoclonal free L chains secreted in immunoproliferative disorders are frequently involved in renal complications, including a specific proximal tubule impairment, the Fanconi's syndrome, which is generally featured by intracellular crystallization of L chain-related material. In a patient with myeloma-associated Fanconi's syndrome, hexagonal crystals (most surrounded by smooth membranes) were found in kidney proximal tubular cells and bone marrow plasma cells and phagocytes. The sequence of the patient's monoclonal kappa-chain was deduced from that of identical kappa-cDNA clones from the tumoral plasma cells. Small protein-enriched gel filtration fractions from urine yielded crystals morphologically similar and with the same 60 A periodicity on electron micrographs as those found in the cells. N-terminal sequencing and mass spectrometry studies showed that the crystals contained a 107-amino acid fragment (with a C-terminal lysine) corresponding to the V domain together with a low proportion of the entire kappa-chain. In vitro trypsin and pepsin treatment of the native entire kappa-chain yielded a homogeneous V domain fragment which, contrary to other monoclonal kappa-chains, was completely resistant to further proteolytic attack. The patient's kappa-chain also displayed an unusual self-reactivity, as demonstrated by a Western blot technique. The peculiar proneness of the V domain to resist proteolysis and to form crystals might prevent the normal cell catabolism of the L chain and lead to crystallization and renal impairment.
 ...
PMID:Monoclonal Ig L chain and L chain V domain fragment crystallization in myeloma-associated Fanconi's syndrome. 846 90

A 49-year-old man with multiple myeloma (IgG-lambda Bence-Jones protein positive) presented a bleeding tendency: characterized intramuscular hemorrhage. Coagulation studies showed a von Willebrand factor (vWF) defect (Duke bleeding time > 20 min; ristocetin cofactor activity [vWF:RC] < 6%; significant reduction of large multimers of vWF. Mixing study suggested the presence of inhibitor directed against vWF:RC activity and collagen binding activity of vWF. The inhibitor was identified as an antibody of the IgG class. The inhibitor blocked the interaction of vWF with glycoprotein Ib in the presence of ristocetin, as did the pepsin-digested fragment of the inhibitor [F(ab)2'], but neither blocked botrocetin-mediated interaction of vWF with glycoprotein Ib. They also inhibited the binding of vWF to immobilized collagen type I. The inhibitor and the F(ab)2' reacted strongly with native vWF and fragment I (amino acids 911-1365) and with the 39/34 kDa fragment (amino acids 480/481-718), but not with fragment II (amino acids 1366-2050) and fragment III-T2 (heavy chains, amino acids 273-511; light chains, amino acids 674-728). We conclude that the IgG antibody inhibits both vWF:RC activity and the binding of vWF to collagen by reacting with the epitopes present on the A1 loop and A3 domains of vWF.
 ...
PMID:Autoantibody inhibits binding of von Willebrand factor to glycoprotein Ib and collagen in multiple myeloma: recognition sites present on the A1 loop and A3 domains of von Willebrand factor. 960 24


<< Previous 1 2 3 4 5 Next >>