| Abstract: |
We investigated the growth and differentiation of leukaemic B cells from patients with B‐cell chronic lymphocytic leukaemia (CLL) in response to proliferation and differentiation factors present in conditioned medium and to anti‐immunoglobulin antibodies. Highly purified E‐rosette negative (E) B cells from 5 out of 15 patients with CLL exhibited moderate proliferative responses to Ml or 10 or 15 μ/ml of F(ab′)2 fragments of rabbit anti‐human μ‐chain specific antibody. Conditioned medium (CM), derived by stimulating human peripheral blood mononuclear leucocytes with PHA. induced significant proliferative responses of purified E cells in 13 out of 14 patients examined. The extent of these proliferative responses varied substantially, and was in the range of 2.6‐ to 91‐fold. Stimulation of purified L cells trom patients with CLL with both anti‐μ and CM resulted in significant proliferative in all l5 patients examined. These responses were significantly higher than thosc induced by CM alone (P<0.02). Synergism between CM and anti‐μ in inducing proliferative responses was observed in 11 out of 15 patients. Largely loukaemic B cell populations expressing on the cell surface more than one immunoglolobulin heavy chain isotype, exhibited significantly higher (P<0.009) proliferaiive response to CM and anti‐μ than those expressing IgM only. Highly purified E‐ peripheral blood or tonsil lymphocytes from all normal donors examined responded by proliferation to anti‐μ alone or to CM alone. Synergism in inducing prolifcrative responses was aiso observed when the cells were stimulated with both CM and anti‐μ. In addition to inducing proliferative responses, culture with CM of purified E‐rosctte negative, largely leukaemic, B cells from patients with CLL for 6 days at 37°C resulted in differentiation into immunoglobulin synthesizing and secreting cells. Synthesis and secretion of IgM were observed in 7 out of 10 patients examined. A switch to IgG production was observed in three patients. Morphological examination of E cells from patients wiih CLL after treatment wiih CM dcmonstrated thai these cells were differentiated into plasma‐like cells. These results suggest that leukaemic B cells from palicnls with CLL can be induced to proliferate and differentiate in response to growth and differentiation factors derived by mononuclear Icucocytes. in a manner similar to that of normal B cells. Copyright © 1987, Wiley Blackwell. All rights reserved |
| Keywords: |
clinical article; leukemia; human cell; lymphocyte proliferation; cell division; biological model; cell differentiation; b lymphocyte; b-lymphocytes; lymphocyte differentiation; plasma cell; cell culture; rosette formation; chronic lymphatic leukemia; cytochemistry; culture media; immunoglobulin m antibody; etiology; antibodies, anti-idiotypic; leukemia, lymphocytic; human; priority journal; support, non-u.s. gov't; support, u.s. gov't, p.h.s.; conditioned medium; immunoglobulins, mu-chain
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