Abstract
In patients with chronic lymphocytic leukemia (CLL), numbers of CD8 + CD45RA +/- CD27- effector T cells are expanded. We investigated whether this expansion is also present in other B cell malignancies and the possible mechanism underlying these changes. Whereas an increase in total CD4+and CD8+ T cell numbers was found only in CLL, numbers of CD4+ and CD8+ effector T cells were significantly increased in both CLL and indolent lymphoma, but not aggressive lymphoma and myeloma. Interestingly, PD-1 expression was decreased on effector T cells and inversely correlated with effector T cell numbers, suggesting a functional role for PD-1 in regulating T cell homeostasis. In vitro experiments revealed impaired up-regulation of PD-1 upon T cell activation in the presence of malignant but also healthy B cells. Our data suggest that in CLL and indolent lymphoma, the malignant B cells affect PD-1 expression on effector T cells, resulting in an expansion of these subsets.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Aged
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B-Lymphocytes / immunology
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B-Lymphocytes / metabolism
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B-Lymphocytes / pathology
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CD4-Positive T-Lymphocytes / immunology
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CD4-Positive T-Lymphocytes / metabolism
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CD4-Positive T-Lymphocytes / pathology
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CD8-Positive T-Lymphocytes / immunology
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CD8-Positive T-Lymphocytes / metabolism
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CD8-Positive T-Lymphocytes / pathology
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Cell Proliferation*
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Cells, Cultured
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Cytomegalovirus / immunology
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Cytomegalovirus Infections / immunology
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Cytomegalovirus Infections / metabolism
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Cytomegalovirus Infections / pathology
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Flow Cytometry
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Humans
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Leukemia, Lymphocytic, Chronic, B-Cell / immunology*
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Leukemia, Lymphocytic, Chronic, B-Cell / metabolism
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Leukemia, Lymphocytic, Chronic, B-Cell / pathology
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Leukocyte Common Antigens / immunology
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Leukocyte Common Antigens / metabolism
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Lymphocyte Activation / immunology
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Lymphoma, B-Cell / immunology*
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Lymphoma, B-Cell / metabolism
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Lymphoma, B-Cell / pathology
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Middle Aged
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Programmed Cell Death 1 Receptor / immunology*
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Programmed Cell Death 1 Receptor / metabolism
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T-Lymphocytes / immunology*
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T-Lymphocytes / metabolism
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T-Lymphocytes / pathology
Substances
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PDCD1 protein, human
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Programmed Cell Death 1 Receptor
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Leukocyte Common Antigens