Abstract
LeuM5 antigen (CD11c, p150.95) expression, widely used as an immunodiagnostic marker for B-cell hairy cell leukemia, was examined on benign, normal peripheral blood T cells before and after stimulation in vitro with phytohemagglutinin and on a large, diverse panel of 73 T-cell neoplasms. Resting T cells lacked LeuM5. Intracytoplasmic LeuM5 was detectable at 3 to 4 days and surface membrane LeuM5 was detectable continuously between 5 and 17 days on greater than or equal to 20% CD3 cells (maximum, 42% CD3 cells at 10 days) after activation. Two-color flow cytometric analysis of the activated T cells demonstrated that a maximum of 60% CD8 but only 25% CD4 cells expressed LeuM5; the mean percentage of LeuM5+ CD8 cells was 44% compared with 12% LeuM5+ CD4 cells. A variable proportion of the neoplastic T cells in 19 of 73 (26%) T-cell neoplasms were LeuM5+. Twelve of 18 CD4-CD8+ (67%) but only 5 of 40 CD4+ CD8- T-cell neoplasms expressed LeuM5. These studies demonstrate that the LeuM5 antigen is 1) expressed in association with T-cell activation, 2) preferentially expressed by activated CD8 cells, and 3) variably expressed by neoplastic T cells, but particularly by those exhibiting the CD4- CD8+ phenotype.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Antigens, Differentiation / immunology*
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Antigens, Differentiation, Myelomonocytic / genetics
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Antigens, Differentiation, Myelomonocytic / immunology
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Antigens, Differentiation, Myelomonocytic / metabolism*
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Antigens, Differentiation, T-Lymphocyte / immunology
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Antigens, Neoplasm / genetics
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Antigens, Neoplasm / immunology
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Antigens, Neoplasm / metabolism
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CD8 Antigens
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Gene Expression
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Humans
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Integrin alphaXbeta2
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Leukemia, Hairy Cell / immunology*
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Leukemia, Lymphoid / immunology
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Leukemia, Lymphoid / metabolism
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Leukemia, Lymphoid / pathology
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Lymphocyte Activation / drug effects
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Lymphocyte Activation / immunology
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Lymphoma / immunology
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Lymphoma / metabolism*
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Lymphoma / pathology
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Phytohemagglutinins / pharmacology
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Receptors, Leukocyte-Adhesion / immunology*
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Skin Neoplasms / immunology
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Skin Neoplasms / metabolism*
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Skin Neoplasms / pathology
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T-Lymphocytes / immunology*
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T-Lymphocytes / pathology
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Tumor Cells, Cultured / immunology
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Tumor Cells, Cultured / metabolism
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Tumor Cells, Cultured / pathology
Substances
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Antigens, Differentiation
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Antigens, Differentiation, Myelomonocytic
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Antigens, Differentiation, T-Lymphocyte
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Antigens, Neoplasm
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CD8 Antigens
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Integrin alphaXbeta2
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Phytohemagglutinins
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Receptors, Leukocyte-Adhesion