concanavalin-a and Multiple-Myeloma

Topics: Agammaglobulinemia; alpha-Fetoproteins; Antibodies; Antibody Formation; Autoimmune Diseases; B-Lymphocytes; Concanavalin A; DNA; Epitopes; Genes, MHC Class II; Growth Inhibitors; Hybrid Cells; Hypersensitivity; Immune Tolerance; Immunity, Cellular; Immunoglobulins; Immunotherapy; Interferons; Lymphocyte Culture Test, Mixed; Multiple Myeloma; Nucleotides, Cyclic; Prostaglandins; T-Lymphocytes; T-Lymphocytes, Regulatory; Terminology as Topic; Thymus Hormones

ICSAT (Interferon Consensus Sequence binding protein for Activated T cells) is a lymphocyte-specific member of the interferon regulatory factor (IRF) family of transcription factors, originally identified through Southwestern screening of the ATL(Adult T-cell leukemia)-16T expression library. In this study, we created transgenic mice overexpressing ICSAT in lymphocytes. Although spontaneous tumorigenesis was not observed, IL-2 production with Concanavalin A stimulation was significantly increased in transgenic mice overexpressing ICSAT. ICSAT overexpression in lymphocytes seems insufficient for the leukemogenesis of ATL or multiple myeloma (MM), however, it may regulate T cell activation and its overexpression may lead to leukemogenesis via controlling IL-2 production.

Topics: Adult; Animals; Concanavalin A; DNA-Binding Proteins; Humans; Immunoglobulin G; Interferon Regulatory Factors; Interleukin-2; Leukemia, T-Cell; Lymphocytes; Mice; Mice, Transgenic; Multiple Myeloma; Thymus Gland; Transcription Factors

Multiple myeloma (MM) is a cancer of plasma cells, characterized by profound suppression of host immune responses. Here we show that MM cell lines significantly suppress the proliferation, blasting, response to interleukin-2 (IL-2), and expression of CD25 by concanavalin A (Con A)-activated or allostimulated peripheral blood T lymphocytes. T cells arrest in the G1 stage of the cell cycle, and do not enter the IL-2 autocrine growth pathway. T cell inhibition was mediated by a soluble factor. MM cell lines did not produce IL-10 but did produce large amounts of transforming growth factor beta1 (TGF-beta1). T cells were assessed for their ability to respond to IL-2 when co-cultured with MM cells in the presence or absence of the TGF-beta inhibitor, TGF-beta latency-associated peptide (LAP). MM cells suppressed IL-2 responses but this inhibition was completely reversed by TGF-beta LAP. A CD25-, IL-2-dependent blast cell line was not inhibited by MM cells or rhTGF-beta, confirming the specificity of the inhibition mechanism for the IL-2 autocrine growth pathway. We conclude that MM cells suppress T cells in their entry into the autocrine IL-2/CD25 pathway and in response to IL-2, and that TGF-beta has a significant role to play.

Topics: Adjuvants, Immunologic; Apoptosis; Cell Communication; Cell Cycle; Coculture Techniques; Concanavalin A; Humans; Interleukin-2; Lymphocyte Activation; Lymphocyte Culture Test, Mixed; Mitogens; Multiple Myeloma; Peptide Fragments; Protein Precursors; Proteins; Receptors, Interleukin-2; Recombinant Proteins; T-Lymphocytes; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tumor Cells, Cultured

Recurrent bacterial infections due to humoral immunodeficiency are an important cause of death in myeloma patients. Recent data indicate that CD8+ T lymphocytes and a reduction of T helper type 1 cells with disease progression may be involved in the regulation of polyclonal immunoglobulin secretion. In mixed lymphocyte cultures derived from peripheral blood mononuclear cells (PBMC) of 24 myeloma patients with reduced immunoglobulin serum levels we investigated the association of CD4+ and CD8+ T cell subsets and immunoglobulin-secreting B cells (ISC) upon mitogenic stimulation with pokeweed mitogen (PWM) and concanavalin A (Con A). In supernatants of cultured PBMC of myeloma patients the spontaneous secretion of the type 1 cytokine interferon-gamma was reduced. After PWM stimulation reduced numbers of polyclonal ISC were found in 79% of patients, and monoclonal ISC were observed in 12% of patients. After Con A stimulation, again formation of polyclonal ISC was reduced, but monoclonal ISC were found in 41% of patients. Elevation of monoclonal and reduction of polyclonal ISC after stimulation with Con A were associated with an increase of CD8+ CD11b+ Leu-8- T cells (P<0.05). We conclude that the elevated numbers of CD8+ CD11b+ Leu-8- T cells play a role in the stimulation of monoclonal and suppression of polyclonal immunoglobulin secretion in myeloma patients.

Topics: Agammaglobulinemia; Aged; B-Lymphocytes; CD8-Positive T-Lymphocytes; Concanavalin A; Female; Humans; Immunoglobulins; Interferon-gamma; Interleukin-6; L-Selectin; Lymphocyte Activation; Macrophage-1 Antigen; Male; Middle Aged; Multiple Myeloma; Pokeweed Mitogens

Idiotype-specific T cells were characterized in patients with multiple myeloma stage I by analysing idiotype-induced DNA synthesis (3H-thymidine incorporation), IL-2 and IFN-gamma production at the single cell level (ELISPOT) (in vitro tests) and delayed type hypersensitivity (DTH) skin reaction (in vivo test). In seven out of eight patients at least one of the four tests was positive. In five patients three or more tests were positive. One patient was negative in all four tests. Six patients had both IL-2 and IFN-gamma-secreting cells and three of them also a DTH response. Furthermore, those three patients with a proliferative response also had IL-2 and IFN-gamma-secreting cells induced by the idiotype. The data indicate that part of the idiotype-specific T cell fraction belongs to the CD4 Th1 cell population. Whether CD8-specific T cells also were present could not be ruled out. The present study provides further support for the existence of idiotype-specific T cells in multiple myeloma. Such cells might be an important target for an immune-mediated therapeutic approach.

Topics: Aged; Antibodies, Neoplasm; Antibody Specificity; Cell Division; Cells, Cultured; Concanavalin A; Dose-Response Relationship, Immunologic; Female; Humans; Hypersensitivity, Delayed; Immunoglobulin G; Immunoglobulin Idiotypes; Interferon-gamma; Interleukin-2; Male; Middle Aged; Multiple Myeloma; T-Lymphocytes

A one-step non-radioactive assay to determine the proliferation of murine lymphocytes, lymphoid tumor cells and hybridoma cells is described. This assay requires the addition of Alamar Blue dye to cell cultures and the degree of change in its color, which is reflective of the extent of cellular proliferation, can be determined by an ELISA plate reader. Alamar Blue must be added during the initial phase of cell culture. The pattern of concanavalin A (ConA) or anti-CD3 antibody-induced proliferative response of murine lymphocytes as assessed by Alamar Blue was similar to that of a [3H]thymidine assay. Similarly, the spontaneous proliferation curve of anti-CD3 antibody secreting cell line (YCD3-1), monocytic macrophage cell lines (PU5-1.8, P388D1, J774.1) and myeloma cells (Sp2/0) as determined by Alamar Blue closely resembled that of the [3H]thymidine assay. The minimum detectable number of proliferating cells was comparable in Alamar Blue and [3H]thymidine assays. Since cell lysis/extraction and washing procedures are not involved in the Alamar Blue assay, this approach has several distinct advantages over currently available assays (eg. [3H]thymidine). First, it allows daily monitoring of proliferation without compromising the sterility of cultures. An indication of proliferation can be evaluated (spectrophotometrically or visually) as early as 24 h after ConA stimulation. Second, unlike previously reported assays, Alamar Blue permits further analysis of proliferating cells by other methods. Analysis of cells in culture with Alamar Blue for various surface antigens (CD44, CD45RB, CD4, heat stable antigen) by flow cytometry revealed that the fluorescent profile and relative percentage of cells in cultures with the Alamar Blue were comparable to those without this reagent. The salient advantages of Alamar Blue assay over the [3H]thymidine assay include: (i) non-radioactivity; (ii) simplicity; (iii) less costly; (iv) non-labor intensive; (v) rapidity of assessment of proliferation of large number of samples; (vi) non-toxicity; (vii) usefulness in determining the kinetics of cell growth of hybridomas; and (viii) non-interference of secretion of antibodies by a hybridoma cell line.

Topics: Animals; Antibody Formation; CD3 Complex; Cell Line; Cell Survival; Cells, Cultured; Coloring Agents; Concanavalin A; Flow Cytometry; Hybridomas; Kinetics; Lymphocyte Activation; Macrophages; Mice; Mice, Inbred C57BL; Monocytes; Multiple Myeloma; Oxazines; Spleen; T-Lymphocytes; Thymidine; Thymus Gland; Tumor Cells, Cultured; Xanthenes

Blood monocytes (BMs) from 139 subjects (70 malignant melanoma patients, 31 breast cancer patients, 38 healthy controls) were cultured for at least 7 days. The formation of multinucleated giant cells (MGCs), which was checked during the whole time of culture, was observed in all cases. By the seventh day MGCs represented 25-50% and during the second and third month more than 90% of all cells. Lymphokines and/or concanavalin A stimulation (16-34 cases respectively) of BMs was performed as well. This stimulation greatly accelerated MGC formation. There were no differences either in spontaneous or in stimulated fusion between the different groups compared.

Topics: Breast Neoplasms; Cell Fusion; Cell Transformation, Neoplastic; Cells, Cultured; Concanavalin A; Giant Cells; Humans; Lymphokines; Monocytes; Multiple Myeloma

Two-dimensional gel electrophoresis with the 125I-Con A overlay and affinity purification with Con A-agarose revealed the presence of an abundant ubiquitous 100-kDa glycoprotein (GP100) in nucleated mammalin cells. The amount in cultured human and murine cells varies from 3 to 20 X 10(6) molecules per cell making GP100 the most abundant glycoprotein in nucleated cells. Peptide mapping shows that it is different from erythrocyte Band III protein. Several properties of GP100 suggest that it could play a structural role in nucleated cell membranes.

Topics: Animals; Anion Exchange Protein 1, Erythrocyte; Cell Line; Cell Nucleus; Cells; Chromatography, Affinity; Concanavalin A; Glycoproteins; HeLa Cells; Humans; Isoelectric Point; Mast-Cell Sarcoma; Mice; Molecular Weight; Multiple Myeloma

Early transmembrane events of tumour cells (mouse myeloma X5563 and lymphoma RDM4) after binding of a monoclonal antibody against mouse MHC antigen and a mitogenic lectin, Con A, were examined by stopped-flow fluorometry with 3 different fluorescent probes. The results showed that membrane fluidities of the cells increased first after binding of anti H-2Kk monoclonal antibody (11-4.1), then calcium was released from intracellular stores into the cytoplasma, and lastly calcium influx occurred from the external medium into the cytoplasma. While Con A only induced calcium influx from the external medium into the cytoplasma.

Topics: Animals; Antibodies, Monoclonal; Biological Transport, Active; Calcium; Cell Line; Cell Membrane; Concanavalin A; Cytoplasm; H-2 Antigens; Lymphoma; Membrane Fluidity; Mice; Multiple Myeloma; Neoplasms, Experimental; Spectrometry, Fluorescence

We investigated the subcellular sites of glycoprotein oligosaccharide maturation by using lectin conjugates to stain lightly-fixed, saponin-permeabilized myeloma cells. At the electron microscopic level, concanavalin A-peroxidase stains the cisternal space of the nuclear envelope, the rough endoplasmic reticulum, and cisternae along the proximal face of the Golgi stack. Conversely, wheat germ agglutinin-peroxidase stains cisternae along the distal face of the Golgi stack, associated vesicles, and the cell surface. These observations confirm the existence of two qualitatively distinct Golgi subcompartments, show that the lectin conjugates can be employed as relatively proximal or distal Golgi markers under conditions of excellent ultrastructural preservation, suggest that the asymmetric distribution of qualitatively distinct oligosaccharides is a property of underlying cellular components and not simply of the principal secretory product, and suggest that the oligosaccharide structure recognized by wheat germ agglutinin is attained during transport from the proximal toward the distal face of the Golgi stack.

Topics: Animals; Binding Sites; Cell Line; Concanavalin A; Endoplasmic Reticulum; Golgi Apparatus; Lectins; Multiple Myeloma; Nuclear Envelope; Oligosaccharides; Peroxidases; Rats; Staining and Labeling; Wheat Germ Agglutinins

The ability of activated T cells to suppress ongoing IgE synthesis in vitro was assessed using U266--a human myeloma cell line spontaneously producing IgE. T cells were able to inhibit U266 IgE synthesis in the presence of 10 micrograms/ml of Con A by 41.8% (p less than 0.01). T cells preincubated with 10 or 50 micrograms/ml of Con A and washed extensively were still able to inhibit U266 IgE synthesis in the absence of Con A by 41 and 46% (p less than 0.05 and p less than 0.02, respectively). The decrease in IgE measured was due to inhibition of newly formed IgE by U266, as shown by control experiments with cycloheximide. The inhibition was not due to the simple depletion of nutrient growth factors by the activated T cells, as it did not occur with MOLT-4, T cells that are very active metabolically; nor could it be reversed with medium containing IL 2 and B cell growth factors. Culture supernatants of Con A-activated T cells were also able to suppress IgE synthesis by U266 (21%; p less than 0.01), which suggests that upon appropriate activation, T cells secrete material(s) with inhibitory properties for IgE synthesis. Activation of T cells by mixed lymphocyte culture using puromycin-treated lymphoblastoid cell lines as stimulators also generated T cells that had suppressive activity for IgE synthesis. T cells activated with Con A and subsequently incubated with IgE demonstrated a diminished ability to suppress IgE synthesis. This observation is in agreement with the finding that patients with high levels of IgE may lack isotype-specific suppressor T cells for spontaneous IgE secretion. However, T cells from such patients have so far shown variable loss of IgE suppressive function. These results suggest that human IgE synthesis is susceptible to inhibition at a very differentiated stage, and this may be important in expression of allergic diseases.

Topics: Adult; Concanavalin A; Humans; Immunoglobulin A; Immunoglobulin E; Immunoglobulin G; Interleukin-2; Lymphocyte Activation; Lymphocyte Culture Test, Mixed; Multiple Myeloma; Prednisone; T-Lymphocytes, Regulatory

Topics: Animals; Cell Adhesion; Cell Membrane; Cells, Cultured; Concanavalin A; Kidney; Male; Methylmannosides; Mice; Multiple Myeloma; Sertoli Cells; Spermatids; Spermatocytes; Spermatozoa

Normal and leukaemic lymphoid cells, both human and murine, were stained for specific carbohydrates with three fluorescein-labelled lectins: Aprotinin for sialyl (or uronyl) groups: Ricinus agglutinin for galactosyl groups; and Concanavalin A for mannosyl (or glucosyl) groups. The method gives permanent preparations of sections from methanol fixed, paraffin embedded tissues, from blood and bone marrow films or touch preparations of lymph nodes that were methanol fixed. Whereas normal lymphocytes and lymphoblasts reacted strongly for sialyl groups, lymphoblasts of acute lymphoblastic leukaemia and lymphocytes of chronic lymphocytic leukaemia gave a much weaker reaction. The same was the case of the lymphocytes of the Sézary variant and the lymphocytes of macroglobulinaemia. The fine processes of the cells of hairy cell leukaemia stained well for sialyl groups. No obvious differences were detected between normal monocytes and the cells of monocytic leukaemia, nor between normal plasma cells and those of myeloma.

Topics: Animals; Aprotinin; Carbohydrates; Concanavalin A; Fluoresceins; Humans; In Vitro Techniques; Lectins; Leukemia; Leukemia, Hairy Cell; Leukemia, Lymphoid; Leukemia, Monocytic, Acute; Lymphoid Tissue; Mice; Multiple Myeloma; Waldenstrom Macroglobulinemia

Topics: Adult; Cells, Cultured; Concanavalin A; Dactinomycin; Humans; Leucine; Leukemia, Plasma Cell; Lymphocyte Activation; Lymphocytes; Male; Multiple Myeloma; Phytohemagglutinins; Plasma Cells; Pokeweed Mitogens; Thymidine

Twelve 14C-acetylated glycopeptides have been subjected to affinity chromatography on concanvalin A (Con A)--Sepharose at pH 7.5. The elution profiles could be classified into four distinct patterns. The first pattern showed no retardation of glycopeptide on the column and was elicited with a glycopeptide having three peripheral oligosaccharide chains: (abstract:see text). Such glycopeptides have only a single mannose residue capable of interacting with Con A--Sepharose; an interacting mannose residue is either an alpha-linked nonreducing terminal residue or an alpha-linked 2-O-substituted residue. The second type of profile showed a retarded elution of glycopeptide with buffer lacking methyl alpha-D-glucopyranoside (indicative of weak interaction with the column) and was given by glycopeptides with the structures: (abstract: see text) where R1 is either H or a sialyl residue. The third profile type showed tight binding of glycopeptide to Con A--Sepharose and elution as a sharp peak with 0.1 M methyl alpha-D-glucopyranoside; glycopeptides giving this pattern had the structures: (abstract: see text) where R2 is either H, glcNAc, Gal-beta 1,4-GlcNAc, or sialyl-Gal-beta 1,4-GlcNAc. These glycopeptides all have two interacting mannose residues, the mimimum required for binding to the column; one of these mannose residues must, however, be a terminal residue to obtain tight binding and sharp elution. The fourth profile type showed tight binding of glycopeptide to the column but elution with 0.1 M methyl alpha-D-glucopyranoside resulted in a broad peak indicating very tight binding; glycopeptides showing this behaviour had the structures: (abstract: see text) where R3 is either GlcNAc,Gal-beta 1,4-GlcNAc, or sialyl-Gal-beta 1,4-GlcNAc. Therefore it can be concluded that although a minimum of two interacting mannose residues is required for binding to Con A--Sepharose, the residues linked to these mannoses can either strengthen or weaken binding to the column.

Topics: Carbohydrates; Chromatography, Affinity; Concanavalin A; Glycopeptides; Humans; Immunoglobulin G; Molecular Conformation; Multiple Myeloma; Sepharose

Bone marrow mononuclear cell populations were studied in 35 patients without myeloma, 39 patients with multiple myeloma, and 15 patients with benign monoclonal gammopathy. Bone marrow mononuclear cell receptors, responses to mitogens or allogeneic stimuli, and suppressive effects on in vitro peripheral blood lymphocyte (PBL) function were studied. In bone marrow cell populations from patients with untreated multiple myeloma, the percent of complement receptor-bearing cells and the pokeweed mitogen- and concanavalin A-stimulated responses were significantly greater than were those in bone marrow cell populations from patients without myeloma. Sheep red blood cell receptor-bearing cells were significantly greater in marrow populations from treated multiple myeloma patients compared to those from untreated multiple myeloma patients. Sheep red blood cell receptor-bearing cells from the bone marrow of multiple myeloma patients suppressed responses of the multiple myeloma patients' PBL's to autologous mitomycin C-treated bone marrow plasma cells and to allogeneic stimuli in one-way mixed leukocyte culture. Complement receptor-bearing cells suppressed the response to pokeweed mitogen. The presence of lymphocytes in the marrow compartment that are capable of suppressing the response of myeloma patients' PBL's to plasma cell antigens may be significant in the pathogenesis of multiple myeloma.

Topics: Bone Marrow; Complement System Proteins; Concanavalin A; Female; Humans; Hypergammaglobulinemia; Immunity; Immunosuppression Therapy; Lymphocyte Activation; Lymphocyte Culture Test, Mixed; Male; Multiple Myeloma; Phytohemagglutinins; Pokeweed Mitogens; Rosette Formation; T-Lymphocytes

A copper.protein complex present in the serum of a hypercupremic myeloma patient has been purified to homogeneity using gel filtration, DEAE-cellulose chromatography, and concanavalin A/Sepharose affinity chromatography. Immunoelectrophoresis and hemagglutination inhibition tests showed the copper-bound protein to be an IgG1-type immunoglobulin with lambda light chains. The immunoglobulin is of normal molecular weight (150,000) with normal size light and heavy chains (28,000 and 56,000, respectively). The carbohydrate portion of the molecule appears to be abnormal in that it interacts with concanavalin A, whereas most immunoglobulins of the gammaG-type do not. The copper in the native copper.IgG complex is in an EPR-indeterminable valence state. Copper was efficiently removed from the copper.IgG complex by dialysis against 0.1 M potassium cyanide. The apo-IgG was separated from the copper.cyanide complex by gel filtration. The copper complex was reconstituted by equilibrating the apo-IgG with 7.7 muM cupric ions.

Topics: Carrier Proteins; Concanavalin A; Copper; Electron Spin Resonance Spectroscopy; Humans; Immunoelectrophoresis; Immunoglobulin G; Macromolecular Substances; Molecular Weight; Multiple Myeloma; Myeloma Proteins; Protein Binding; Protein Conformation; Spectrophotometry

The reactivity of peripheral blood lymphocytes from patients with advanced malignancy was assessed by mitogen-induced stimulation of protein synthesis as measured by 3H-leucine incorporation. It was confirmed that the lymphocyte response of patients was depressed. Furthermore, the lymphocytes of 15 out of 27 cancer patients, selected because of their low responses, inhibited the reactivity of normal lymphocytes in co-cultures. The lymphocytes from one patient with Hodgkin's disease were also inhibitory. In contrast, lymphocytes from healthy subjects, patients with chronic lymphocytic leukaemia, lymphosarcoma or multiple myeloma caused no suppression. Experiments with purified cell populations from patients with carcinoma indicated that purified T cells responded to mitogens while unseparated lymphocytes failed to respond and that the inhibitory activity was due to adherent cells, presumably monocytes. There was no evidence for B-cell-mediated suppression. However, in two cases inhibition was caused by isolated T cells of the patients and not by adherent cells. These experiments suggested that one mechanism for the depression of cell-mediated immunity seen in patients with advanced cancer may be the nonspecific suppresssion of certain T-cell functions by circulating monocytes.

Topics: Adult; Aged; Carcinoma, Bronchogenic; Cells, Cultured; Concanavalin A; Hodgkin Disease; Humans; Immune Adherence Reaction; Lectins; Leukemia, Lymphoid; Lymphocyte Activation; Lymphocyte Transfusion; Lymphocytes; Lymphoma, Non-Hodgkin; Middle Aged; Mitogens; Multiple Myeloma; Neoplasm Proteins; Neoplasms; T-Lymphocytes

Topics: Amino Acids; Chromatography, Affinity; Concanavalin A; Glycopeptides; Humans; Immunoglobulin A; Molecular Weight; Multiple Myeloma; Myeloma Proteins; Protein Binding

Agglutination by two lectins, Concanavalin A (Con A) and Ricinus communis agglutinin (RCA), has been investigated in a human lymphoid cell system. The main conclusions of this study are: (1) no systematic correlation exists between the neoplastic state and sensitivity to Con A or RCA; (2) cells of neoplastic lines vary unsystematically in their surface properties as evaluated by Con A agglutination, with the possible exception that presence of Epstein-Barr virus (EBV) is associated with a high degree of agglutination and (3) cells of diploid lymphoblastoid lines and phytohemagglutinin (PHA)-stimulated lymphoctes agglutinate similarly and significantly better than unstimulated T- or B-lymphocytes. The relatively simple Con A agglutination assay can be used as an adjunct in classification of human lymphoid cell lines.

Topics: Agglutination; Cell Line; Concanavalin A; Humans; Hyaluronoglucosaminidase; Lectins; Leukemia; Lymphocyte Activation; Lymphocytes; Lymphoma; Multiple Myeloma; Neoplasms; Neuraminidase; Plant Lectins; Plants, Toxic; Ricinus; Stimulation, Chemical; Trypsin

Topics: Animals; Cell Line; Concanavalin A; DNA, Neoplasm; Galactosamine; Galactose; Lectins; Leukemia, Myeloid; Lipopolysaccharides; Lymphoma; Mannose; Methylglycosides; Mice; Mitogens; Multiple Myeloma; Neoplasms, Experimental; Polysaccharides, Bacterial; Ricin; RNA, Neoplasm; Salmonella typhi; T-Lymphocytes

Topics: Adult; Aged; Antigen-Antibody Reactions; B-Lymphocytes; Cell Line; Complement System Proteins; Concanavalin A; Cytotoxicity Tests, Immunologic; DNA; Erythrocytes; Humans; Immune Adherence Reaction; In Vitro Techniques; Lectins; Liver; Lymphocytes; Melphalan; Middle Aged; Mitogens; Multiple Myeloma; Prednisolone; T-Lymphocytes

Topics: Adult; Aged; Antigen-Antibody Reactions; Carbon Isotopes; Cell Line; Chromium Isotopes; Concanavalin A; Cytotoxicity Tests, Immunologic; DNA; Humans; In Vitro Techniques; Lectins; Liver; Lymphocyte Activation; Lymphocytes; Melphalan; Middle Aged; Mitogens; Multiple Myeloma; Prednisolone

Topics: Animals; Azo Compounds; Biphenyl Compounds; Concanavalin A; Cyanosis; Edema; Forelimb; gamma-Globulins; Humans; Immunotherapy; Lectins; Mice; Mice, Inbred Strains; Multiple Myeloma; Necrosis; Paresis; Skin Diseases; Time Factors; Vaccines

Ferritin conjugates of two plant agglutinins, concanavalin A and ricin, have been used as specific electron microscopic stains for covalently-bound saccharide residues on membrane fragments from a myeloma-cell homogenate. The results indicate that different saccharide residues are uniformly localized to a single surface of each membrane fragment. In particular, the ferritin-concanavalin A conjugate binds exclusively to the cisternal side of membrane fragments of the rough endoplasmic reticulum. If it is postulated that the biogenesis of eukaryotic plasma membranes involves an assembly-line process from precursor intracellular membranes, these observed asymmetric distributions of saccharides on cell membranes can be explained.

Topics: Animals; Cell Line; Cell Membrane; Concanavalin A; Ferritins; Mice; Mice, Inbred BALB C; Microscopy, Electron; Multiple Myeloma; Myeloma Proteins; Oligosaccharides; Plasmacytoma; Protein Binding; Ricin; Staining and Labeling