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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The binding properties of surface receptors of immunoglobulins on mouse macrophages were studied with mouse myeloma proteins and normal peritoneal macrophages, thioglycollate-stimulated macrophages, and a macrophage cell line, P388D1. Primary cultures of mouse embryo fibroblasts served as controls. IgG2a proteins were bound strongly;IgG2b was bound weakly (one-twentieth as well as IgG2a);IgM, IgA, and IgG1 were not bound significantly. The number of binding sites per cell for IgG2a was 4 X 10(5) for thioglycollate-stimulated cells and 1 X 10(5) for normal and P388D1 cells. Binding was exothermal: with decreasing temperature the equilibrium (association) constants increased and dissociation rate constants decreased (at 37degreesC the respective values were 2 X 10(7) M-1 and 0.26 min-1, the latter value corresponds to a half time for dissociation of 2.6 min). From the rapidity of association and dissociation, it appears that the surface of the macrophage is in a dynamic equilibrium with IgG2a molecules in the cell's immediate microenvironment. The receptors for IgG2a are clearly specific for determinants in the immunoglobulin constant domain: two IgG2a proteins with greatly different isoelectric points (determined by isoelectric focusing) were bound with the same affinity to the same receptors; moreover, the Fc fragment was bound and Fab fragments were not. The Fc receptors for IgG2a proteins were readily eliminated by exposing macrophages briefly to trypsin. The receptors were regenerated during subsequent cultivation in serum-free medium; regeneration was inhibited totally by cycloheximide and partially by actinomycin D.
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PMID:Binding of monomeric immunoglobulins to Fc receptors of mouse macrophages. 119 57

Attempts to analyze bone marrow-derived macrophages (BMDM) by flow cytometry have been prohibited because of their high autofluorescence. Using an autofluorescence reduction method of Steinkamp and Stewart to reduce the autofluorescence of BMDM, we were able to examine several macrophage populations for their expression of I-A, I-J, and Mac-1 cell surface determinants. Bone marrow cells examined immediately after removal from the femur contain 50-60% Mac 1-positive cells (mainly granulocytes). During the next few days granulocytes and nonmacrophage precursor cells die, and the number of Mac 1-positive cells decrease. Once the bone marrow cells have been maintained in L cell conditioned medium (LCM) for 2 to 3 days, the number of cells expressing Mac 1 increases rapidly from 20% to 98% during the next 3 to 4 days. Bone marrow cells grown in LCM do not express I-J until these cells have been in culture 3 to 4 days, and the number of cells expressing I-J (up to 90% positive) parallels the increase in macrophages. Bone marrow cells maintained in LCM did not express detectable I-A during the 14 days these cells were examined. Two other macrophage populations often used in a variety of immunological studies were analyzed by flow cytometry. We found that the majority (up to 80%) of peritoneal cells expressed I-A, and only 20% of peritoneal cells had I-J cell surface determinants. On the other hand, peritoneal exudate cells collected 4 days after thioglycolate medium treatment were predominantly I-J positive (up to 70%), and only about 30% of these cells expressed I-A cell surface antigens. The binding of anti-I-J IgM antibody to BMDM was not to Fc receptors because pretreating these cells with up to 25 micrograms of an IgG2a myeloma protein did not block anti-I-J antibody binding. The addition of 25-200 micrograms of monoclonal anti-Fc receptor antibody was also ineffective in blocking the binding of a monoclonal anti-I-Jk antibody to BMDM. Pretreatment of BMDM with the IgM fraction of several control IgM antibody preparations did not block the specific binding of fluoresceinated anti-I-J IgM antibody. BMDM provide a pure population of macrophages that express a significant level of cell surface I-J antigens. Bone marrow cells grown in LCM are essentially devoid of other contaminating cells, and the increase in the number of I-J-positive cells parallels the increase in macrophages in these cultures.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Flow cytometric analysis of I-J expression on murine bone marrow-derived macrophages. 245 80

A monoclonal antibody, anti-Z-1, was established by fusion of spleen cells from mice immunized with guinea pig thioglycollate-induced peritoneal macrophages (TGC-M phi s) with mouse myeloma cells, P3-X63-Ag8-6.5.3. The Fab' fragments of anti-Z-1 bound to almost all of the TGC-M phi s with a high association constant (6.0 +/- 0.8) X 10(8) M-1, and effectively inhibited phagocytic activities of the cells for unopsonized zymosan and serum-treated zymosan. On the contrary, neither the phagocytic activity for rabbit IgG antibody-sensitized sheep erythrocytes nor that for periodate-treated sheep erythrocytes was inhibited by anti-Z-1. Immunoprecipitation analysis revealed that the antigen recognized by anti-Z-1, which was named Z-1 antigen, consists of a polypeptide chain with a molecular weight of 140,000 (alpha chain) noncovalently associated with a polypeptide chain of 95,000 (beta chain). The epitope with which anti-Z-1 reacts was found to be on the alpha chain by Western blotting. Furthermore, it was found that Z-1 antigen solubilized from the cells with nonionic detergent was capable of binding to unopsonized zymosan, suggesting that Z-1 antigen may function as a receptor for zymosan. These findings show the structural and functional similarities of Z-1 molecules on guinea pig peritoneal macrophages to the third complement receptor on human and mouse leukocytes.
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PMID:Characterization of a monoclonal antibody to guinea pig peritoneal macrophages that inhibits phagocytosis of unopsonized zymosan: structural and functional similarities of the antigen to human and mouse CR3. 246 9

A new monoclonal antibody, M1-8, that recognizes murine interdigitating cells (IDC) and Langerhans cells was obtained from a hybridoma prepared by fusion of SP2/0 mouse myeloma cells with splenic cells of rats immunized with IDC-rich cell suspension obtained from lymph nodes of athymic nude mice (BALB/c nu/nu). The specificity was assessed immunohistochemically on frozen sections of lymph nodes and epidermal sheets from both nude and normal mice. M1-8 reacted with paracortical IDC, veiled cells of the marginal sinus, and epidermal Langerhans cells in both normal and nude mice. In simultaneous staining by M1-8 and nonspecific esterase or anti-Ia or anti-Thy-1,2 antibody, the same epidermal dendritic cells were positive for all these antigens except Thy-1,2. Immunoelectron microscopy of the lymph node suspension using gold colloid particles revealed the attachment of gold particles to the cell membrane of IDC. Analysis by flow cytometry of the lymph node cell suspension showed 14 or 6% of M1-8-positive cells in nude or normal mouse, respectively. Immunohistochemical analysis showed that M1-8 also reacted with dendritic cells in the thymus and spleen and had a different distribution from F4/80. M1-8 also reacted with monocytes in bone marrow and peripheral blood, alveolar macrophages, and thioglycollate-stimulated peritoneal exudate macrophages. The antibody belongs to the immunoglobulin M class, reacts immunochemically with a glycoprotein in the cell membrane, and has a molecular mass of approximately 15 kDa.
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PMID:New monoclonal antibody that specifically recognizes murine interdigitating and Langerhans cells. 247 79

Three hybridoma clones were isolated after hybridization of a mouse myeloma line with splenocytes from rats immunized with Forssman glycosphingolipid (Fo). Two of these clones produced Fo-specific monoclonal antibodies (MAB) of the IgM class, one MAB of the IgG2c class. In complement-dependent depletion experiments and immunofluorescence studies on the nature of Fo-positive leukocytes in CBA/J mice the following results were obtained: whereas blood monocytes, polymorphonuclear leukocytes, and lymphocytes were Fo negative, 5 to 10% of suspended spleen cells were positive. The majority of these were macrophage-like, glass- and nylon-adherent, nonspecific esterase-positive phagocytizing cells carrying Ia and globoside markers. These cells participated as accessory cells in the mixed lymphocyte culture reaction. In cell suspensions from axillary and inguinal lymph nodes, 2% were Fo positive. They were enriched up to 70% in the glass-adherent, esterase-positive population from this source. In contrast, no Fo-positive cells were detected in mesenteric lymph nodes, and less than 0.1% of the resident peritoneal macrophages bore this marker. The percentage of Fo-positive cells increased to 1% in thioglycollate-elicited peritoneal cells. Immunostaining of cryosections of lung and liver tissue showed alveolar macrophages and Kupffer cells, respectively, to be Fo negative.
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PMID:Forssman glycolipid, an antigenic marker for a major subpopulation of macrophages from murine spleen and peripheral lymph nodes. 349 90

A hybridoma clone secreting rat monoclonal antibody (MAB) designated as 3F3.5F and which reacted with a population of activated tumoricidal mouse peritoneal macrophage (M phi) was produced by the fusion of mouse myeloma cells with rat spleen cells immunized against adherent BCG-activated mouse peritoneal exudate cells (adherent BCG-PEC). The antibody was cytotoxic and of the rat IgM class. The specific reactivity of the antibody with mouse primary cells and cell lines was examined by complement-dependent cytotoxicity and indirect immunofluorescence flow cytometry analysis. The antibody was found to bind to about 40% of the adherent BCG-PEC activated in vivo and elicited peritoneal macrophages activated in vitro by lymphokine and lipopolysaccharide (LPS), to about 35% of polymorphonuclear neutrophils (PMN) 15 hr after intraperitoneal injection of BCG, to about 30% of bone marrow cells from BCG-infected mice, to about 10% of P815 mastocytoma cells and to thioglycollate-induced PEC to some degree. It did not bind to other cells tested including BCG-induced peritoneal lymphocytes, non-tumoricidal PEC, thymocytes, spleen cells, resting bone marrow cells from normal mice, lymphomas, myelomas, fibroblasts, or macrophage-cell lines. Pretreatment of adherent BCG-PEC with MAB 3F3.5F and rabbit complement caused a considerable decrease in tumor cytotoxicity toward P815 cells, but the same pretreatment of non-adherent BCG-PEC had no inhibitory effect on natural killer activity for YAC-1 cells.
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PMID:A novel rat monoclonal antibody directed against a population of activated mouse peritoneal macrophages. 374 66

Protein 460 is a mouse myeloma gamma A(2) protein that competitively binds two small haptens, 2,4-epsilon-dinitrophenyl-L-lysine (Dnp-Lys) and 2-methyl-1:4-naphthaquinone thioglycollate (MenTG), to the antibody-combining region. The intact protein has a relatively inaccessible sulfhydryl group on each heavy chain. When it is substituted with a bulky reagent the binding affinity for MenTG decreases, while the binding of Dnp-Lys remains the same. Guanidine.HCl selectively reduces binding of Dnp-Lys; dimethylsulfoxide selectively reduces binding of MenTG. Papain digestion of protein 460 followed by column chromatography gave two fractions: one contained both binding activities and the other contained the sulfhydryl group. The affinity for Dnp-Lys of the first fraction is the same as that of the whole molecule, while affinity for MenTG is decreased. Since selective alteration of one or the other binding activity can occur in different ways, it seems likely that even though the haptens compete with each other, there is some spatial separation between the groups of contact amino-acid residues involved in the binding of these two haptens. These findings do not support the hypothesis that an immunoglobulin molecule carries combining sites complementary only to a single hapten or to a structurally related series of haptens, but rather suggests that the antibody-combining site may be a polyfunctional region capable of binding several structurally dissimilar haptens. We discuss a mechanism whereby polyfunctional combining sites can give rise to an antibody population (immune serum) that has a high degree of specificity to a single hapten.
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PMID:Contact regions for dinitrophenyl and menadione haptens in an immunoglobulin binding more than one antigen. 411 41

Two monoclonal antibodies, M3/31 and M3/38, were obtained by fusion of mouse myeloma cells with rat spleen cells immunized to immunoadsorbent-purified macrophage glycoproteins. Co-precipitation experiments show that antigenic determinants recognized by these two antibodies reside on the same molecular species, termed Mac-2, Mac-2, an antigen of 32,000 Mr, is synthesized by and expressed on the surface of thioglycollate-elicited macrophages as shown by [35S]-methionine and 125I labeling. Saturation binding experiments show that thioglycollate-elicited macrophages express 1.7 X 10(5) Mac-2 sites/cell. Thioglycollate-elicited macrophages are strongly absorptive for 125I-labeled M3/38 MAb. Kidneys are also absorptive; however, evidence is presented pointing to the nonspecificity of this absorption. Lymph node and thymus are negative, whereas spleen and bone marrow are weakly absorptive, probably due to stromal cells. Nonlymphoid tissues, such as lung, liver, heart, and brain, exhibit slight or no absorbing capacity. Cell suspensions from spleen, bone marrow, thymus, and peripheral lymph node are greater than 99% Mac-2- by immunofluorescent flow cytometry. In contrast, thioglycollate-elicited macrophages are greater than 96% strongly positive for Mac-2. Only 20% of peptone-elicited cells are weakly positive, whereas resident peritoneal macrophages and other macrophage elicited by Listeria monocytogenes, Con A, or LPS are greater than 98% negative. SDS-PAGE of [35S]-methionine-labeled Mac-2 shows that thioglycollate-elicited macrophages synthesize 10- to 30-fold more Mac-2 than other peritoneal macrophage subpopulations, whereas all types of peritoneal macrophages synthesize and express on their surfaces similar amounts of the Mac-1 antigen. Mac-2 antigen is therefore induced in macrophages only in response to specific differentiative signals.
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PMID:Mac-2, a novel 32,000 Mr mouse macrophage subpopulation-specific antigen defined by monoclonal antibodies. 617 26

A conventionally produced antibody specific for hamster lung macrophages was prepared by immunizing guinea pigs with lung macrophages from LSH (inbred) hamsters. Specificity was achieved by absorbing the resulting serum with hamster blood cells and peritoneal macrophages. This antibody was used to precipitate antigen from detergent lysates of hamster lung macrophages. To produce monoclonal antibodies, F1 hybrids of Balb C X C57Bl6 mice were immunized with these immunoprecipitates. Fusion of splenic lymphocytes from these mice with NS-1 myeloma cells produced 4 hybrid cell lines. Subcloning yielded 18 lines producing antibody reacting only with lung macrophages, and 2 lines secreting nonreactive antibody. Screening used lung and peritoneal macrophages and an ELISA assay. Using gel electrophoresis and lysates of 125I-labeled lung macrophages, all 18 lines reacted with the same antigen, a protein of 102,000 daltons. Subclasses of these monoclonal antibodies included IgG2b kappa and IgG1 kappa. Quantitative ELISA assays showed that the antibody reacted with lung macrophages of LSH and LVG (outbred) hamsters, but not with hamster resident peritoneal macrophages, spleen cells, or bone marrow cells. The antibody did not cross-react with lung or resident peritoneal macrophages from mice, rats, or guinea pigs. By flow cytometry, no reaction was detected with resident, thioglycollate-elicited, or BCG-stimulated peritoneal macrophages. When frozen sections of lung and other organs were examined by indirect immunofluorescence and immunoperoxidase methods, only alveolar macrophages were stained.
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PMID:Monoclonal antibody to an alveolar macrophage surface antigen in hamsters. 646 78

Macrophages have been obtained from the peritoneal cavities of C57BL/6 mice following treatment with C. parvum, MVE-2, mineral oil, or thioglycollate. Cell populations were primarily composed of mononuclear phagocytes as determined by a latex bead uptake assay. Macrophages obtained from C. parvum or MVE-2 were activated as judged by enhanced cytostatic activity against two tumor cell target lines. Thioglycollate-elicited macrophages demonstrated much lower cytostatic ability. Rats were immunized with activated MVE-2 macrophages. Hybridomas were prepared by fusion with a non-secreting myeloma cell line followed by cloning. Cell supernates were selected on the basis of binding to activated but not elicited macrophages. The monoclonal antibody produced has been characterized by flow cytometry. The antibody does not react with syngeneic erythrocytes, thymocytes, or spleen cells. Reaction with thioglycollate macrophages is very low. Alternatively, intense binding is found on activated macrophages. This antigen which accompanies macrophage activation for tumor cell cytostasis is designated as macrophage activation antigen-1 (MAA-1). Several important physiological changes accompany the process of macrophage activation. For example, activated macrophages demonstrate enhanced microbicidal, phagocytic, secretory, and tumoricidal activity (for reviews see refs. 1,2). Concommitant alterations in cell surface properties have been observed. These include: (a) changes in surface morphology and spreading (3-5), (b) altered lipid and protein content (6,7), (c) decreases in 5'-nucleotidase activity and alkaline phosphodiesterase (8), increases in leucine aminopeptidase (8), decreases in mannose receptors (11,12), and antigen F4/80 (11), (d) increases in Ia antigens (11,12), and (e) increased tumor cell binding (13). These structural and functional modifications indicate that activated macrophages represent a unique class of functionally differentiated cells (9). Antigenic modifications accompanying macrophage differentiation are of special interest. Markers for specific macrophage classes might be useful in defining differentiation pathways, dissecting type-specific functional activities such as tumor cytotoxicity, and providing a means to identify macrophage subsets in heterogeneous cell populations. In the present work we have taken the first step in this direction by defining a cell surface macrophage activation antigen.
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PMID:Characterization of a monoclonal antibody defining a macrophage activation-specific cell surface antigen. 674 39


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