Topographic Gradient of Cell-Membrane Molecules in Avian Neural Retina Detected with Monoclonal Antibody

1981 ◽  
pp. 141-161
Author(s):  
G. David Trisler ◽  
Michael D. Schneider ◽  
Marshall Nirenberg
Keyword(s):  
Monoclonal Antibody ◽  
Cell Membrane ◽  
Neural Retina ◽  
Topographic Gradient

Monoclonal antibody immunoprecipitation of cell membrane glycoproteins

1987 ◽  
Vol 167 (2) ◽  
pp. 239-244 ◽  
Author(s):  
Gary A. Peltz ◽  
Byron Gallis ◽  
B. Matija Peterlin
Keyword(s):  
Monoclonal Antibody ◽  
Cell Membrane ◽  
Membrane Glycoproteins

A scale associated protein of Apedinella radians (Pedinellophyceae) and its possible role in the adhesion of surface components

1993 ◽  
Vol 104 (2) ◽  
pp. 391-398
Author(s):  
A. Koutoulis ◽  
M. Ludwig ◽  
R. Wetherbee
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Cell Membrane ◽  
Cell Surface ◽  
Immunofluorescence Microscopy ◽  
Endomembrane System ◽  
Thin Sections ◽  
Specific Location ◽  
Whole Cells

Monoclonal antibodies have been generated against cell surface components of the unicellular phytoflagellate Apedinella radians (Pedinellophyceae). One monoclonal antibody, designated Arg 1E5/1B1, labels a scale associated protein (SAP) of 145 kDa. Immunofluorescence microscopy of whole cells as well as immunoelectron microscopy of whole cell mounts and thin sections using Arg 1E5/1B1 have shown that the SAP is located on the proximal surface of body scales and spine-scales. Its specific location suggests that the SAP may play a role in the adhesion of these surface components to the cell membrane and/or to one another. The potential of monoclonal antibody Arg 1E5/1B1 as a tool to study cell surface morphogenesis and the role of the endomembrane system in A. radians is discussed.

A monoclonal antibody directed against an organ-specific liver cell membrane antigen in rabbits

1984 ◽  
Vol 68 (1-2) ◽  
pp. 341-348 ◽  
Author(s):  
T. Poralla ◽  
W. Dippold ◽  
H.P. Dienes ◽  
M. Manns ◽  
K.-H. Meyer zum Büschenfelde
Keyword(s):  
Monoclonal Antibody ◽  
Cell Membrane ◽  
Liver Cell ◽  
Liver Cell Membrane ◽  
Organ Specific ◽  
Cell Membrane Antigen

Membrane Remodeling By Pathogenic Antibodies Underlies Monocyte Activation in Heparin-Induced Thrombocytopenia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2244-2244
Author(s):  
Izabella Andrianova ◽  
Vincent M Hayes ◽  
Daria Madeeva ◽  
Rustem I. Litvinov ◽  
Douglas B. Cines ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Monoclonal Antibody ◽  
Flow Cytometry ◽  
Cell Membrane ◽  
Cell Activation ◽  
Monocyte Activation ◽  
Heparin Induced Thrombocytopenia ◽  
Scanning Electron

Abstract Heparin induced thrombocytopenia (HIT) is an iatrogenic antibody-mediated disorder with a paradoxically high propensity for thrombosis. We have shown previously that human HIT IgGs and the HIT-like monoclonal antibody (MAb) KKO bind to platelet factor 4 (PF4) complexed with glycosaminoglycans (GAGs) on the surface of platelets and monocytes, initiating cell activation in vitro, thrombocytopenia in a transgenic mouse model, and thrombus formation in a laser microvascular injury model in vivo even in the absence of exogenous heparin. Monocytes bind PF4 and HIT Ab more readily than platelets because they express higher affinity GAGs, heparan sulfate and dermatan sulfate, in addition to chondroitin sulfate found on both cell types. To study changes in the structure of the monocytes that accompany HIT, we used scanning electron microscopy, confocal microscopy and flow cytometry to characterize the morphology and function of isolated human monocytes and mouse transgenic Fcg receptor IIA positive (FcγRIIA+) or wt (FcγRIIA-) monocytes in the absence or presence of platelets. We show by scanning electron microscopy that upon binding of pathogenic HIT Abs to PF4/GAG complexes on FcgRIIA expressing monocytes, they initiate profound remodeling of the cell membrane. Addition of 100 μg/ml recombinant human PF4 in the absence of HIT Abs initiates the activation process with the appearance of 177 ± 53 nm "knobs" on the surface of 70% of monocytes. Subsequent addition of the HIT-like monoclonal antibody KKO at 50 μg/ml dramatically alters the cellular surface with the appearance of large 701 ± 208 nm membrane "blebs" that were not seen on FcγRIIA-mouse monocytes. These large, membrane-associated structures likely engage FcγRIIA, clustering them in proximity to cell-bound immune complexes, which promotes cell activation that leads to thrombosis. These blebs increase in size over time and are then shed from the cells as monocyte-derived microparticles, which self-aggregate. As a result of shedding of these blebs, the monocytes lose much of their typical ruffled surface (only 67% of monocytes maintain ruffles in the presence of PF4 plus KKO, compared to 97% of control monocytes) and appear smoother, sometimes with pores indicating degranulation. In the presence of platelets, monocytes exposed to PF4 and KKO formed heterocellular aggregates in addition to these subcellular changes. In contrast to KKO, addition of the non-pathogenic MAb RTO not only did not induce blebbing, but largely inhibited PF4-induced changes in the monocyte surface. This suggests that RTO might prevent monocyte activation by interfering with PF4 tetramerization. Structural analysis of the shed microparticles by microscopy revealed that they had an average diameter of 356 ± 307 nm, with many larger particles and aggregates. Flow cytometry confirmed that the shed particles contain cell membrane lipids and receptors. Confocal microscopy showed uniform binding of labeled PF4 to the monocyte cell membrane followed by rapid clustering into large complexes after the addition of KKO, but not RTO. These studies affirm the centrality of cell surface PF4/GAG complexes in the pathogenesis of HIT and provide quantitative morphometric characteristics of the changes in the monocyte membrane structure. We propose that PF4 released from activated platelets binds to the surface of GAG-expressing monocytes in vivo, forming clusters of PF4/GAG complexes that likely promote antibody binding and cause monocyte activation through FcγRIIA along with large-scale remodeling of the cell membrane and shedding of procoagulant microparticles. Disclosures No relevant conflicts of interest to declare.

scholarly journals Impacts of a Proliferation-Inducing Ligand on Current Therapeutic Monoclonal Antibody-Induced Cytotoxicity Against Human Multiple Myeloma Cells

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3105-3105 ◽  
Author(s):  
Liang Lin ◽  
Shih-Feng Cho ◽  
Kenneth Wen ◽  
Tengteng Yu ◽  
Phillip A Hsieh ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Monoclonal Antibody ◽  
Cell Membrane ◽  
Nk Cell ◽  
Cell Lysis ◽  
Advisory Board ◽  
Dependent Manner ◽  
Effector Cells ◽  
Human Multiple Myeloma ◽  
Dose Dependent

A proliferation inducing ligand (APRIL) is a natural ligand for B cell maturation antigen (BCMA) and transmembrane activator and CAML interactor (TACI), two receptors overexpressed in human multiple myeloma (MM) patient cells. Specifically, BCMA is highly expressed in plasma cells of all MM patients and BCMA-based immunotherapies has recently shown impressive response rates in patients with relapsed and refractory diseases. APRIL, mainly secreted by myeloma-supporting bone marrow (BM) accessory cells, i.e., macrophages, osteoclasts (OC), promotes MM cell progression in vitro and in vivo. It further induces survival and function of regulatory T cells (Treg) via TACI, but not BCMA, to support an immunosuppressive MM BM microenvironment (Leukemia. 2019;33:426). Here, we study effects of APRIL in current immunotherapies in MM and determine whether APRIL influences antibody-dependent cellular cytotoxicity (ADCC) induced by therapeutic anti-BCMA (J6M0) or anti-CD38 (daratumumab) mAbs via FcR-expressing immune effector cell-dependent mechanisms. Using anti-human IgG1 to detect J6M0 binding to the cell membrane BCMA, we first showed that APRIL, in a dose-dependent manner (31-500 ng/ml), competed with J6M0 for binding to BCMA. Such effects were inhibited by the blocking anti-APRIL monoclonal antibody (mAb) (Apry-1-1), as confirmed by flow cytometry and confocal microscopy. APRIL still inhibited J6M0 binding to BCMA at 4°C, arguing against that APRIL induces shedding of BCMA receptor. Using PE labeled anti-FLAG to detect APRIL-FLAG bindings to MM cell surface BCMA, J6M0 (0.25-4 µg/ml) did not alter APRIL binding to BCMA following 2h or 1d incubation. High concentrations of J6M0 (>10 µg/ml) only blocked ~50% of APRIL (0.2 µg/ml)-induced NFκB activity as determined by specific DNA binding assays, indicating that APRIL-induced signaling cascade via BCMA or TACI in MM cells is not completely blocked by J6M0. In parallel, data analysis using mRNA-seq identified 594 or 355 differentially expressed genes (Log2-Fold-change > 1.5 and adjusted p < 0.05) in APRIL- and BCMA-overexpressed RPMI8226 MM cell transfectants, respectively, when compared with control parental cells. KEGG and Reactome pathway enrichment analysis further defined that these differentially expressed genes are enriched in cell adhesion, migration, chemokine signaling pathways, and JAK/STAT signaling pathways, in addition to proliferation and survival in MM cells. We next asked whether overnight treatment with APRIL in MM cell lines decreased their baseline lysis by FcR-expressing effector cells, i.e., NK, monocytes. In a dose-dependent manner, APRIL (10-200 ng/ml) downregulated baseline MM cell lysis mediated by these effector cells. Importantly, in a similar fashion, ADCC was decreased against all APRIL-treated vs control MM cell lines induced by J6M0 or daratumumab. Conversely, blocking anti-APRIL mAbs reverted APRIL-suppressed cytotoxicity against MM cells induced by J6M0 or daratuzumab. These results were validated by decreased J6M0-induced NK cell degranulation following co-incubation with APRIL-treated vs control MM cells. In contrast, anti-APRIL neutralizing mAbs specifically blocked APRIL-inhibited NK cell membrane CD107a expression. Furthermore, co-cultures with MM-supporting OCs or macrophages decreased ADCC against MM cells by NK cells; conversely the neutralizing anti-APRIL mAb significantly blocked APRIL-reduced MM cell lysis by J6M0- or Daratumumab. Finally, APRIL reduced J6M0-induced patient MM cell lysis when freshly isolated BM mononuclear cells from MM patients (n=10) were incubated with NK cells from the same individual. Anti-APRIL mAbs still blocked APRIL blockade in J6M0-induced autologous patient MM cell lysis. Taken together, our data further indicate that therapies directed at the APRIL/BCMA and APRIL/TACI axes may simultaneously target MM cells and counteract APRIL-reduced MM cell lysis induced by therapeutic mAbs targeting MM cells. These results thus support combination strategies of blocking APRIL mAbs with BCMA- or CD38-directed immunotherapies to further overcome MM cell-induced immunosuppressive BM microenvironment, thereby enhance Disclosures Munshi: Abbvie: Consultancy; Abbvie: Consultancy; Celgene: Consultancy; Takeda: Consultancy; Takeda: Consultancy; Oncopep: Consultancy; Janssen: Consultancy; Janssen: Consultancy; Oncopep: Consultancy; Amgen: Consultancy; Amgen: Consultancy; Adaptive: Consultancy; Adaptive: Consultancy; Celgene: Consultancy. Anderson:Gilead Sciences: Other: Advisory Board; Janssen: Other: Advisory Board; Sanofi-Aventis: Other: Advisory Board; OncoPep: Other: Scientific founder ; C4 Therapeutics: Other: Scientific founder .

Hapten-mediated identification of cell membrane antigens using an anti-FITC monoclonal antibody

1994 ◽  
Vol 169 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Péter Balogh ◽  
György Szekeres ◽  
Péter Németh
Keyword(s):  
Monoclonal Antibody ◽  
Cell Membrane ◽  
Membrane Antigens ◽  
Cell Membrane Antigens

scholarly journals Topography of N-CAM structural and functional determinants. II. Placement of monoclonal antibody epitopes.

1986 ◽  
Vol 103 (5) ◽  
pp. 1729-1737 ◽  
Author(s):  
A L Frelinger ◽  
U Rutishauser
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Cell Membrane ◽  
Biological Properties ◽  
Peptide Chain ◽  
Functional Domains ◽  
Peptide Fragments ◽  
Antigenic Sites ◽  
Cell Biol ◽  
Antibody Epitopes

The accompanying report (Watanabe, M., A. L. Frelinger III, and U. Rutishauser, 1986, J. Cell Biol., 103:1721-1727) describes a set of monoclonal antibodies (mAbs) directed against N-CAM epitopes representing the known major structural and functional domains of the molecule. In this study, we have generated and separated a variety of peptide fragments from N-CAM, and then used their size and reactivity with each antibody to position the antigenic sites along the peptide chain. This epitope map, together with the biological properties of the antibodies and previous studies on N-CAM, have been used to construct a topographical model for the molecule in the cell membrane.

scholarly journals Modeling bispecific monoclonal antibody interaction with two cell membrane targets indicates the importance of surface diffusion

mAbs ◽  
2016 ◽  
Vol 8 (5) ◽  
pp. 905-915 ◽  
Author(s):  
Bram G. Sengers ◽  
Sean McGinty ◽  
Fatma Z. Nouri ◽  
Maryam Argungu ◽  
Emma Hawkins ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Cell Membrane ◽  
Surface Diffusion ◽  
Bispecific Monoclonal Antibody
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