Introduction B cell Chronic lymphocytic leukemia (BCLL) is characterized by the accumulation of monoclonal malignant CD5+ B cells that show resistance to apoptosis in vivo, but are susceptible to apoptosis when incubated in vitro. A number of cytokines have been reported to protect against apoptosis in vitro, but it is not clear whether the effects of these cytokines are mediated in similar ways. We have therefore studied the regulation of apoptosis in B-CLL cells in vitro, in response to various cytokines.

Methods B-CLL cells were purified and incubated with the following agents; Interferon-gamma, IL-4, IL-10, IL-13, TNF-alpha and GM-CSF, each at 3 different concentrations. Apoptosis was measured after 70 hours by Annexin/PI staining and analysed for early apoptosis (Annexin V positive), late apoptotic (Annexin V and PI positive), and necrotic (PI positive).

Results The percentage of live cells in unstimulated B-CLL cells was 42.4±2.3%. Co-incubation of B-CLL cells with IL-4 at 100ng/ml increased the percentage of live cells to 63.2±8.4%, while in the presence of interferon-gamma the percentage of live cells was 48.7±5.9%. In contrast, co-incubation with TNF-alpha reduced the percentage of live cells to 30.8±6.8%. IL-10, IL-13 and GM-CSF had no effect on B-CLL cells survival at any of the concentrations used.. No significant differences in the pattern of early/late apoptosis or necrosis were seen between the different cytokines used.

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Topics:
chronic b-cell leukemias, chronic lymphocytic leukemia, cytokine, annexin a5, granulocyte-macrophage colony-stimulating factor, interferon type ii, interleukin-10, interleukin-13, interleukin-4, recombinant granulocyte-macrophage colony-stimulating factors

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2005, The American Society of Hematology
2004
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