The Experts below are selected from a list of 165 Experts worldwide ranked by ideXlab platform
Edward D. Ball - One of the best experts on this subject based on the ideXlab platform.
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Initial Trial of Bispecific Antibody-Mediated Immunotherapy of CD15-Bearing Tumors: Cytotoxicity of Human Tumor Cells Using a Bispecific Antibody Comprised of Anti-CD15 (MoAb PM81) and Anti-CD64/FcγRI (MoAb 32)
Journal of hematotherapy, 1992Co-Authors: Edward D. Ball, Paul M. Guyre, Mills Le, Jan L. Fisher, Nathan B. Dinces, Michael W. FangerAbstract:The high-affinity receptor for IgG, FcγRI, expressed on monocytes and interferon-γ (IFN-γ)-stimulated neutrophils, is a trigger molecule for cell-mediated cytotoxicity. We have prepared murine monoclonal antibodies (MoAb 22 and MoAb 32) that bind to FcγRI outside the ligand binding site and thus bind to and trigger cytotoxicity that is not competed by other immunoglobulins. Because of these properties, it seemed that these MoAbs would be very useful for the development of bispecific antibodies (BsAb) for targeting normal cellular immune defense mechanisms as a new form of immunotherapy for treatment of cancer. BsAbs incorporate into a single molecule the binding specificities of two different antibodies, and, thus, can be used to target myeloid cells to tumors, ensure activation of cellular cytotoxic mechanisms, and target cell lysis and/or phagocytosis. BsAbs were prepared using anti-FeγRI MoAb and an anti-myeloid cell MoAb, PM81, reactive with the CD15 Antigen, for studies of antibody-dependent cellular...
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expression of the CD15 Antigen on normal and leukemic myeloid cells effects of neuraminidase and variable detection with a panel of monoclonal antibodies
Molecular Immunology, 1991Co-Authors: Edward D. Ball, Lamia M Schwarz, Clara D BloomfieldAbstract:Abstract Normal and malignant myeloids cells are known to express cell surface molecules having in common the carbohydrate Antigen lacto- N -fucopentaose-III (LNF-III—termed CD15). We used flow cytometry to examine the variability of CD15 expression in normal cells and acute myeloid leukemia (AML) cells as detected by 24 murine monoclonal antibodies (mAb). Important differences in the levels of binding were observed with the various mAb. Titrations of each mAb were performed to confirm that these differences in binding were due to increased Antigen detection and not differences in concn. In studies of CD15 expression on AML cells selected from a large prospective study, anti-CD15-l (also known as PM-81) showed the highest binding to each case. Neuraminidase was added to cells from seven AML patients that we had previously found to be low in CD15 expression, in order to determine if cryptic CD15 was present on these cells. Neuraminidase enhanced binding of each of the entire panel of mAb on five patients' cells, thus demonstrating the ubiquitous expression of CD15 on AML cells. In two cases, binding of only some of the mAb was increased, indicating exposure of unusual epitopes on those cells. Subpopulations of normal peripheral blood lymphocytes, cells not associated with CD15 expression, also substantially increased their level of binding to some of the mAb after the addition of neuraminidase. Two-color flow cytometry was used to determine the immunologic phenotype of the lymphocytic population that expressed CD15. This technique revealed that 9.5% normal lymphocytes coexpressed the CD15 and CD3 (T cell) Antigens. In addition, by gating on large granular lymphocytes we found that 24.4% of these cells coexpressed CD15 (detected by PM-81) and CD2 (sheep erythrocyte receptor), while 50.3% expressed CD15 and CD16 (type III Fc receptor, natural killer cell-associated). This is consistent with the notion that sialylated CD15 is expressed on some natural killer cells and T cells.
Clara D Bloomfield - One of the best experts on this subject based on the ideXlab platform.
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expression of the CD15 Antigen on normal and leukemic myeloid cells effects of neuraminidase and variable detection with a panel of monoclonal antibodies
Molecular Immunology, 1991Co-Authors: Edward D. Ball, Lamia M Schwarz, Clara D BloomfieldAbstract:Abstract Normal and malignant myeloids cells are known to express cell surface molecules having in common the carbohydrate Antigen lacto- N -fucopentaose-III (LNF-III—termed CD15). We used flow cytometry to examine the variability of CD15 expression in normal cells and acute myeloid leukemia (AML) cells as detected by 24 murine monoclonal antibodies (mAb). Important differences in the levels of binding were observed with the various mAb. Titrations of each mAb were performed to confirm that these differences in binding were due to increased Antigen detection and not differences in concn. In studies of CD15 expression on AML cells selected from a large prospective study, anti-CD15-l (also known as PM-81) showed the highest binding to each case. Neuraminidase was added to cells from seven AML patients that we had previously found to be low in CD15 expression, in order to determine if cryptic CD15 was present on these cells. Neuraminidase enhanced binding of each of the entire panel of mAb on five patients' cells, thus demonstrating the ubiquitous expression of CD15 on AML cells. In two cases, binding of only some of the mAb was increased, indicating exposure of unusual epitopes on those cells. Subpopulations of normal peripheral blood lymphocytes, cells not associated with CD15 expression, also substantially increased their level of binding to some of the mAb after the addition of neuraminidase. Two-color flow cytometry was used to determine the immunologic phenotype of the lymphocytic population that expressed CD15. This technique revealed that 9.5% normal lymphocytes coexpressed the CD15 and CD3 (T cell) Antigens. In addition, by gating on large granular lymphocytes we found that 24.4% of these cells coexpressed CD15 (detected by PM-81) and CD2 (sheep erythrocyte receptor), while 50.3% expressed CD15 and CD16 (type III Fc receptor, natural killer cell-associated). This is consistent with the notion that sialylated CD15 is expressed on some natural killer cells and T cells.
Michael A Kerr - One of the best experts on this subject based on the ideXlab platform.
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expression of CD15 Antigen in urinary bladder transitional cell carcinoma
Journal of Clinical Pathology, 1990Co-Authors: D M Parham, K Morton, G Coghill, A J Robertson, Michael A KerrAbstract:The biopsy specimens of 91 patients between the ages of 38 and 94 with transitional cell carcinoma of the bladder were retrospectively reviewed to determine if the expression of CD15 Antigen detected by a monoclonal antibody MC2 was correlated with prognosis. Expression was variable, ranging from strong expression of the Antigen by only the superficial cells in well differentiated papillary lesions to weak expression by most cells in solid or invasive tumours. In the invasive component there was a correlation between MC2 expression and tumour type, suggesting that the cell surface carbohydrate detected by MC2 may have a role in cell adhesion. There was no correlation between staining and survival. It is concluded that tumour type, grade, and stage remain the best prognostic indicators of urothelial tumours.
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expression of the CD15 differentiation Antigen 3 fucosyl n acetyl lactosamine lex on putative neutrophil adhesion molecules cr3 and nca 160
Biochemical Journal, 1990Co-Authors: S C Stocks, M Albrechtsen, Michael A KerrAbstract:The expression of the carbohydrate Antigen 3-fucosyl-N-acetyl-lactosamine (CD15, LeX) on human neutrophil glycoproteins has been studied by immunoprecipitation and immunoblotting by using monoclonal antibody MC2. The Antigen is expressed on membrane glycoproteins of approximate molecular mass 165 and 105 kDa. These glycoproteins include the complement receptor and adhesion molecule, CR3, in which the β-chain (CD18, 105 kDa) shows much greater expression than the alpha-chain (CD11b, 165 kDa). Most of the 165 kDa CD15 Antigen is accounted for by expression on the carcinoembryonic Antigen (CEA)-related molecule NCA160. Other members of this family, NCA95, NCA90 and NCA55, which are also found in neutrophils, do not express the CD15 Antigen. There is a marked increase in the surface expression of CD15, CR3 and the Antigen recognized by anti-CEA antibodies upon activation of neutrophils by the chemotactic peptide N-formylmethionyl-leucylphenylalanine.
Gilbert G Haas - One of the best experts on this subject based on the ideXlab platform.
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expression of CD15 lewisx Antigen on human sperm and its role in sperm egg interaction
American Journal of Reproductive Immunology, 1997Co-Authors: Osmond J Dcruz, Hovey Lambert, Gilbert G HaasAbstract:PROBLEM: The carbohydrate epitope 3-fucosyl-N-acetyllactosamine (CD15) is a constituent of cell surface glycoconjugates that has been implicated in cell-cell adhesion mediated by carbohydrate-specific ligands. The present study was designed to investigate whether CD15 is present on human sperm and whether it plays a role in human sperm-egg interaction. METHODS: Fluorescent flow cytometry was used to quantitate the binding of monoclonal antibodies (mAb) to sperm-bound CD15 and CD46 Antigens on acrosome-intact (AI) and acrosome-reacted (AR) sperm. The location of the binding site of these mAbs was assessed by fluorescence microscopy. The effects of anti-CD15 and anti-CD46 mAbs on gamete interaction were tested utilizing both homologous (human zona binding and penetration) and heterologous (zona-free hamster egg binding and penetration) systems. RESULTS: The mean percentage of capacitated sperm which bound anti-CD15 or anti-CD46 mAbs was low (4.8% and 5.1%, respectively). Exposure to calcium ionophore A23187 (CaI) resulted in an increase in anti-CD15 (38.6 ± 4%) and anti-CD46 (83.4 ± 2%) binding to sperm. Both anti-CD 15 and anti-CD46 binding sites were localized by fluorescence microscopy on the sperm acrosomal region. In four experiments, the percent of zona-free hamster eggs penetrated by human sperm were medium control 93% (62/66), irrelevant mAb 74% (70/94), anti-CD46 0% (0/107), and anti-CD15 10% (9/90). One hundred percent (6/6) of human zona were penetrated by human sperm exposed to medium control, 88% (8/9) following exposure to irrelevant mAb, 0% (0/11) following exposure to anti-CD46, and 50% (5/10) following exposure to anti-CD 15. The mean (± SD of tightly bound sperm to hamster eggs were medium control 57 ± 18%, irrelevant mAb 64 ± 16%, anti-CD46 37 ± 13%, and anti-CD15 19 ± 10%. The corresponding values for human zona were: medium control 118 ± 14%, irrelevant mAb 61 ± 11%, anti-CD46 39 ± 18%, and anti-CD15 99 ± 19%. CONCLUSION: CD15 Antigen is expressed on human sperm that have undergone acrosomal loss. mAb to CD15 was shown to inhibit significantly sperm binding and penetration of zona-free hamster eggs and penetration of human zona pellucida. These findings suggested that sperm-egg interaction may be mediated in part by the CD15 Antigen. Capsule: Acrosome-reacted human sperm bind monoclonal antibodies specific for CD15 (Lewisx) epitope. The binding sites were located on the sperm head. Anti-CD15 antibody impaired both the binding and penetration of zona-free hamster eggs and the penetration of human zona by human sperm.
Haruo Tsuji - One of the best experts on this subject based on the ideXlab platform.
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Nitric oxide induced by tumor cells activates tumor cell adhesion to endothelial cells and permeability of the endothelium in vitro
Clinical & Experimental Metastasis, 1997Co-Authors: Kazuo Yudoh, Hisao Matsui, Haruo TsujiAbstract:Human fibrosarcoma HT1080 cell surface phenotype analysis revealed the expression of "cluster of differentiation 15" (CD15) Antigen and to a lesser extent, of "very late Antigen-4" (VLA-4). Expression of "endothelial-leukocyte adhesion molecule-1" (ELAM-1) was negligible on resting human umbilical vascular endothelial cells (HUVECs), but its expression could be induced by HT1080 conditioned medium. HT1080 cell adhesion to HUVECs was partially dependent on CD15/ELAM-1 adhesion molecules. HT1080 cell adhesion to HUVECs induced the enhancement of nitric oxide (NO) production from HUVECs. Exogenous NO and NO from HUVECs enhanced ELAM-1 expression on HUVECs, HT1080 cell adhesion to HUVECs, permeability of the HUVEC monolayer, and HT1080 cell invasion through the HUVEC monolayer. These enhancements were not induced by NO synthase inhibitor, N^G-nitro-L-arginine methyl ester (L-NAME). These results suggest that NO expression induced by tumor cells via the CD15/ELAM-1 adhesion system may contribute to enhancement of tumor cell adhesion to endothelial cells and hyperpermeability of the endothelium, facilitating tumor cell invasion.