Differentiation of purified malignant B cells induced by PMA or by activated normal T cells.
We studied the in vitro differentiation (immunoglobulin production) of purified malignant B cells of 21 patients with different B-cell malignancies, including chronic lymphocytic leukemia (CLL), prolymphocytic leukemia (PLL), hairy cell leukemia (HCL) and non-Hodgkin lymphoma (NHL). Direct activation of purified malignant B cells with phorbol myristate acetate (PMA) resulted in the differentiation of most CLL cells, but not of the other types of B-cell malignancies. This differentiation required the presence of interleukin 4 (IL-4). In contrast, with the use of anti-CD2-stimulated normal T cells and IL-2, immunoglobulin M (IgM) could be detected in the supernatant of all but one of the purified malignant B-cell populations. However, by analysis of the light chains of the IgM produced, monoclonality could be demonstrated in only 13/21 cases: 8/11 CLL, 3/3 PLL, 0/3 HCL, and 2/4 NHL. In two patients additional proof that the malignant B cells were the source of the IgM production could be obtained in an idiotype-specific ELISA. Apart from IgM, also the production of IgG antibodies could be detected. However, only for 2/3 HCL patients, we could confirm a monoclonal IgG production. Since HCL is a malignancy of mature B cells, already carrying IgG on the membrane, this IgG production is not the result of a switch process. In all other cases where IgG production was polyclonal, we have no indications for the induction of Ig switch. The fact that the more mature B-cell malignancies were T-cell-dependent for their differentiation might be a reflection of the in-vivo situation. The efficient induction of malignant B-cell differentiation described in this paper allows investigation of the antigen specificity of these antibodies.
van Kooten
C
C
Central Laboratory of The Netherlands Red Cross Blood Transfusion Service, Amsterdam.
Rensink
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I
Aarden
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L
van Oers
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R
D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology; D001402:B-Lymphocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D018801:CD2 Antigens; D002454:Cell Differentiation / Q000187:drug effects; D016207:Cytokines / Q000494:pharmacology; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D015448:Leukemia, B-Cell / Q000473:pathology*; D007943:Leukemia, Hairy Cell / Q000473:pathology; D015463:Leukemia, Prolymphocytic / Q000473:pathology; D008213:Lymphocyte Activation / Q000187:drug effects; D016393:Lymphoma, B-Cell / Q000473:pathology*; D011971:Receptors, Immunologic / Q000502:physiology; D013268:Stimulation, Chemical; D013601:T-Lymphocytes / Q000187:drug effects / Q000502:physiology*; D006377:T-Lymphocytes, Helper-Inducer / Q000187:drug effects / Q000502:physiology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D000888:Antibodies, Anti-Idiotypic; D000945:Antigens, Differentiation, T-Lymphocyte; D018801:CD2 Antigens; D016207:Cytokines; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011971:Receptors, Immunologic; D013755:Tetradecanoylphorbol Acetate