scholarly journals Cell surface phenotyping of megakaryoblasts

Blood ◽  
1987 ◽  
Vol 69 (3) ◽  
pp. 957-960 ◽  
Author(s):  
T Koike ◽  
S Aoki ◽  
S Maruyama ◽  
M Narita ◽  
T Ishizuka ◽  
...  
Keyword(s):  
Cell Surface ◽  
Acute Leukemia ◽  
Peroxidase Activity ◽  
Down’S Syndrome ◽  
Phenotypic Characterization ◽  
Target Cells ◽  
Monocytic Cells ◽  
Transient Abnormal Myelopoiesis ◽  
Hla Dr

Abstract Surface phenotypic characterization of megakaryoblasts, identified by platelet peroxidase activity, was investigated in four patients who showed increased proliferation of megakaryoblasts: one patient with typical features of acute leukemia, one presenting with acute myelofibrosis, and two with Down's syndrome in whom blasts disappeared spontaneously (transient abnormal myelopoiesis, TAM). MY10 and/or MY9 antigens were expressed on the surface of some megakaryoblasts, but MY7, and MY4, antigens specific to granulocytic or monocytic cells, were not. Some megakaryoblasts were positive for only anti-HLA-DR antibodies. It was speculated that, during the differentiation of the megakaryocytic lineage, MY9 antigen appears transiently on the surface of megakaryoblasts that have lost HLA-DR antigens and have gained the glycoprotein IIb/IIIa antigen. This study also demonstrated that the proliferating blasts in some patients with TAM were mainly megakaryoblasts and suggested that the target cells in TAM are CFU-GEMM.

scholarly journals Cell surface phenotyping of megakaryoblasts

Blood ◽  
1987 ◽  
Vol 69 (3) ◽  
pp. 957-960
Author(s):  
T Koike ◽  
S Aoki ◽  
S Maruyama ◽  
M Narita ◽  
T Ishizuka ◽  
...  
Keyword(s):  
Cell Surface ◽  
Acute Leukemia ◽  
Peroxidase Activity ◽  
Down’S Syndrome ◽  
Phenotypic Characterization ◽  
Target Cells ◽  
Monocytic Cells ◽  
Transient Abnormal Myelopoiesis ◽  
Hla Dr

Surface phenotypic characterization of megakaryoblasts, identified by platelet peroxidase activity, was investigated in four patients who showed increased proliferation of megakaryoblasts: one patient with typical features of acute leukemia, one presenting with acute myelofibrosis, and two with Down's syndrome in whom blasts disappeared spontaneously (transient abnormal myelopoiesis, TAM). MY10 and/or MY9 antigens were expressed on the surface of some megakaryoblasts, but MY7, and MY4, antigens specific to granulocytic or monocytic cells, were not. Some megakaryoblasts were positive for only anti-HLA-DR antibodies. It was speculated that, during the differentiation of the megakaryocytic lineage, MY9 antigen appears transiently on the surface of megakaryoblasts that have lost HLA-DR antigens and have gained the glycoprotein IIb/IIIa antigen. This study also demonstrated that the proliferating blasts in some patients with TAM were mainly megakaryoblasts and suggested that the target cells in TAM are CFU-GEMM.

scholarly journals Phenotypic characterization of human cytolytic T lymphocytes in mixed lymphocyte culture.

1981 ◽  
Vol 153 (1) ◽  
pp. 213-218 ◽  
Author(s):  
A Moretta ◽  
M C Mingari ◽  
B F Haynes ◽  
R P Sekaly ◽  
L Moretta ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Cell Surface ◽  
Mixed Lymphocyte Reaction ◽  
Mixed Lymphocyte Culture ◽  
Lymphocyte Culture ◽  
Phenotypic Characterization ◽  
Cytolytic T Lymphocytes ◽  
Activated T Cells

Mixed lymphocyte reaction (MLR)-activated T cells were analyzed according to the expression of various cell surface markers by the specific cytotoxic T lymphocytes (CTL) generated in the MLR. CTL were found exclusively in a population of MLR-activated T cells that lacked detectable Fc gamma R but that expressed a surface antigen recognized by the 4F2 monoclonal antibody. In contrast, CTL were found in both the Ia-positive and Ia-negative cells after MLR activation. Thus, the specific CTL generated in the allogeneic MLR can be identified and isolated by virtue of the expression of a particular cell surface marker.

scholarly journals A Cell-Based Internalization and Degradation Assay with an Activatable Fluorescence–Quencher Probe as a Tool for Functional Antibody Screening

2015 ◽  
Vol 20 (7) ◽  
pp. 869-875 ◽  
Author(s):  
Yan Li ◽  
Peter Corbett Liu ◽  
Yang Shen ◽  
Marshall D. Snavely ◽  
Kaori Hiraga
Keyword(s):  
Cell Surface ◽  
Target Cells ◽  
Receptor Endocytosis ◽  
Drug Conjugates ◽  
Anti Cancer ◽  
A Cell ◽  
Rapid Characterization ◽  
Fluorescence Quencher ◽  
Culture Supernatants

For the development of therapeutically potent anti-cancer antibody drugs, it is often important to identify antibodies that internalize into cells efficiently, rather than just binding to antigens on the cell surface. Such antibodies can mediate receptor endocytosis, resulting in receptor downregulation on the cell surface and potentially inhibiting receptor function and tumor growth. Also, efficient antibody internalization is a prerequisite for the delivery of cytotoxic drugs into target cells and is critical for the development of antibody–drug conjugates. Here we describe a novel activatable fluorescence–quencher pair to quantify the extent of antibody internalization and degradation in the target cells. In this assay, candidate antibodies were labeled with a fluorescent dye and a quencher. Fluorescence is inhibited outside and on the surface of cells, but activated upon endocytosis and degradation of the antibody. This assay enabled the development of a process for rapid characterization of candidate antibodies potentially in a high-throughput format. By employing an activatable secondary antibody, primary antibodies in purified form or in culture supernatants can be screened for internalization and degradation. Because purification of candidate antibodies is not required, this method represents a direct functional screen to identify antibodies that internalize efficiently early in the discovery process.

ER-MP12 antigen, a new cell surface marker on mouse bone marrow cells with thymus-repopulating ability: II. Thymus-homing ability and phenotypic characterization of ER-MP12-positive bone marrow cells

1993 ◽  
Vol 5 (9) ◽  
pp. 1099-1107 ◽  
Author(s):  
Walentina A. T. Slieker ◽  
Johannes C. M. van der Loo ◽  
Marella F. T. R. de Rlik-de Bruijn ◽  
Dale I. Godfrey ◽  
Pieter J. M. Leenen ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cell Surface ◽  
Bone Marrow Cells ◽  
Surface Marker ◽  
Cell Surface Marker ◽  
Phenotypic Characterization ◽  
Mouse Bone Marrow ◽  
Mouse Bone Marrow Cells ◽  
Marrow Cells

Phenotypic characterization of acute leukemia with monoclonal antibodies using the microlymphocytotoxicity assay

1983 ◽  
Vol 8 (4) ◽  
pp. 255-263 ◽  
Author(s):  
Ephraim Gazit ◽  
Shlomit Orgad ◽  
Shoshana Lison ◽  
Nurit Kornbrut ◽  
Rina Zaizov ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Acute Leukemia ◽  
Phenotypic Characterization

Phenotypic characterization of alveolar monocyte recruitment in acute respiratory distress syndrome

2000 ◽  
Vol 279 (1) ◽  
pp. L25-L35 ◽  
Author(s):  
Simone Rosseau ◽  
Peter Hammerl ◽  
Ulrich Maus ◽  
Hans-Dieter Walmrath ◽  
Hartwig Schütte ◽  
...  
Keyword(s):  
Acute Respiratory Distress Syndrome ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Distress Syndrome ◽  
Phenotypic Characterization ◽  
Ki67 Staining ◽  
Hla Dr ◽  
Monocyte Recruitment ◽  
Patient Groups

In 49 acute respiratory distress syndrome (ARDS) patients, the phenotype of alveolar macrophages (AMs) was analyzed by flow cytometry. Bronchoalveolar lavage (BAL) was performed within 24 h after intubation and on days 3– 5, 9– 12, and 18– 21 of mechanical ventilation. The 27E10high/CD11bhigh/CD71low/ 25F9low/HLA DRlow/RM3/1lowAM population in the first BAL indicated extensive monocyte influx into the alveolar compartment. There was no evidence of increased local AM proliferation as assessed by nuclear Ki67 staining. Sequential BAL revealed two distinct patient groups. In one, a decrease in 27E10 and CD11b and an increase in CD71, 25F9, HLA DR, and RM3/1 suggested a reduction in monocyte influx and maturation of recruited cells into AMs, whereas the second group displayed sustained monocyte recruitment. In the first BAL from all patients, monocyte chemoattractant protein (MCP)-1 was increased, and AMs displayed elevated MCP-1 gene expression. In sequential BALs, a decrease in MCP-1 coincided with the disappearance of monocyte-like AMs, whereas persistent upregulation of MCP-1 paralleled ongoing monocyte influx. A highly significant correlation between BAL fluid MCP-1 concentration, the predominance of monocyte-like AMs, and the severity of respiratory failure was noted.

scholarly journals Human Immunodeficiency Virus Type 1 Attachment to HeLa CD4 Cells Is CD4 Independent and gp120 Dependent and Requires Cell Surface Heparans

1998 ◽  
Vol 72 (5) ◽  
pp. 3623-3634 ◽  
Author(s):  
Isabelle Mondor ◽  
Sophie Ugolini ◽  
Quentin J. Sattentau
Keyword(s):  
Human Immunodeficiency Virus ◽  
Cell Surface ◽  
Hela Cells ◽  
Target Cells ◽  
Cd4 Cells ◽  
Virus Binding ◽  
Hla Dr ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The binding of human immunodeficiency virus type 1 (HIV-1) (Hx10) virions to two different cell lines was analyzed by using a novel assay based on the detection, by anti-HLA-DR-specific antibodies, of HLA-DR+ virus binding to HLA-DR− cells. Virion attachment to the CD4+-T-cell line A3.01 was highly CD4 dependent in that it was potently inhibited by CD4 monoclonal antibodies (MAbs), and little virus binding to the CD4−sister A2.01 line was observed. By contrast, virion binding to HeLa cells expressing moderate or high levels of CD4 was equivalent to, or lower than, binding to wild-type CD4− HeLa cells. Moreover, several CD4 MAbs did not reduce, but enhanced, HIV-1 attachment to HeLa-CD4 cells. CD4 was required for infection of HeLa cells, however, demonstrating a postattachment role for this receptor. MAbs specific for the V2 and V3 loops and the CD4i epitope of gp120 strongly inhibited virion binding to HeLa-CD4 cells, whereas MAbs specific for the CD4bs and the 2G12 epitopes enhanced attachment. Despite this, all gp120- and gp41-specific MAbs tested neutralized infectivity on HeLa-CD4 cells. HIV-1 attachment to HeLa cells was only partially inhibited by MAbs specific for adhesion molecules present on the virus or target cells but was completely blocked by polyanions such as heparin, dextran sulfate, and pentosan sulfate. Treatment of HeLa-CD4 cells with heparinases completely eliminated HIV attachment and infection, strongly implicating cell surface heparans in the attachment process. CD4 dependence for HIV-1 attachment to target cells is thus highly cell line specific and may be replaced by other ligand-receptor interactions.

scholarly journals Model System for Phenotypic Characterization of Sequence Variations in the LDL Receptor Gene

2006 ◽  
Vol 52 (8) ◽  
pp. 1469-1479 ◽  
Author(s):  
Trine Ranheim ◽  
Mari Ann Kulseth ◽  
Knut Erik Berge ◽  
Trond Paul Leren
Keyword(s):  
Flow Cytometry ◽  
Cell Surface ◽  
Ldl Receptor ◽  
Model System ◽  
Phenotypic Characterization ◽  
Sequence Variant ◽  
Ldlr Gene ◽  
Coated Pits ◽  
Sequence Variations

Abstract Background: Sequence variations in the LDL receptor (LDLR) gene cause defects of LDLR protein production and function through different molecular mechanisms. Here we describe a cell model system for the phenotypic characterization of sequence variations in the LDLR gene. Well-known sequence variations belonging to LDLR classes 2 to 5 (p.G565V, p.I161D, p.Y828C, and p.V429M) were studied in CHO and HepG2 cells. Methods: Expression of LDLR protein on the cell surface was detected by use of fluorescence-conjugated antibodies against the LDLR and the LDLR activity was measured by incubating the cells with fluorescently labeled and radiolabeled LDL. The intracellular locations of the LDLR mutants and wild-type were also investigated. Results: The class 2A p.G565V sequence variant exhibited an intracellular distribution of LDLR with no active receptors on the cell surface. Both the class 3 p.I161D and class 4 p.Y828C sequence variants gave surface staining but had a reduced ability to bind or internalize LDL, respectively. By determining the intracellular locations of the receptors we were able to visualize the accumulation of the class 5 p.V429M sequence variant in endosomes by means of a specific marker, as well as confirming that the class 4 p.Y828C variant was not localized in clathrin-coated pits. Flow cytometry allowed us quantitatively to determine the amount and activity of receptors. To confirm the results of binding and cell association of fluorescently labeled LDL analyzed by flow cytometry, assays using 125I-labeled LDL were performed. In addition to a useful and valid alternative to radiolabeled LDL, the unique properties of fluorescently labeled LDL allowed a variety of detection technologies to be used. Conclusions: This new approach enables phenotypic characterization of sequence variations in the LDLR gene. The assays developed may be valuable for confirming the pathogenicity of novel missense sequence variations found throughout the LDLR gene.

scholarly journals Functional and phenotypic characterization of a protein from Lactobacillus acidophilus involved in cell morphology, stress tolerance and adherence to intestinal cells

Microbiology ◽  
2010 ◽  
Vol 156 (11) ◽  
pp. 3360-3367 ◽  
Author(s):  
Sarah J. O'Flaherty ◽  
Todd R. Klaenhammer
Keyword(s):  
Cell Surface ◽  
Stress Tolerance ◽  
Cell Morphology ◽  
Surface Protein ◽  
Gene Replacement ◽  
Probiotic Bacteria ◽  
Phenotypic Characterization ◽  
Replacement System

Structural components of the cell surface have an impact on some of the beneficial attributes of probiotic bacteria. In silico analysis of the L. acidophilus NCFM genome sequence revealed the presence of a putative cell surface protein that was predicted to be a myosin cross-reactive antigen (MCRA). As MCRAs are conserved among many probiotic bacteria, we used the upp-based counterselective gene replacement system, designed recently for use in L. acidophilus, to determine the functional role of this gene (LBA649) in L. acidophilus NCFM. Phenotypic assays were undertaken with the parent strain (NCK1909) and deletion mutant (NCK2015) to assign a function for this gene. The growth of NCK2015 (ΔLBA649) was reduced in the presence of lactate, acetate, porcine bile and salt. Adhesion of NCK2015 to Caco-2 cells was substantially reduced for both stationary-phase (∼45 % reduction) and exponential-phase cells (∼50 % reduction). Analysis of NCK2015 by scanning electron microscopy revealed a longer cell morphology after growth in MRS broth compared to NCK1909. These results indicate a role for LBA649 in stress tolerance, cell wall division and adherence to Caco-2 cells.

Phenotypic characterization of macrophages in the BMB sample of human acute leukemia

2020 ◽  
Vol 99 (3) ◽  
pp. 539-547
Author(s):  
Jian-Xin Song ◽  
Yan Wen ◽  
Rui-Wei Li ◽  
Ting Dong ◽  
Yi-Fei Tang ◽  
...  
Keyword(s):  
Acute Leukemia ◽  
Phenotypic Characterization
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