Protein expression profiling of cytokines and cytokine receptors on purified chronic lymphocytic leukemia cells from patients with favourable prognostic indicators

Chronic lymphocytic leukemia (CLL) cells rapidly undergo apoptosis when cultured in vitro, which contrasts with their prolonged survival in vivo. Multiple cytokines and cytokine receptors are believed to work together to regulate the survival of CLL cells. The aim of the current study was to measure the endogenous expression and secretion of cytokines and cytokine receptors in CLL cells when exogenous cytokines are minimized. We demonstrated that the intracellular and secreted levels of 174 cytokines and cytokine receptors of purified CLL B-cells were not significantly different from those of normal B-cells except for the secreted levels of IL-6 and eotaxin. IL-6 was 3.0 times lower (p = 0.038) whereas eotaxin was 2.2 times higher (p = 0.027) in CLL conditioned medium than in normal B-cell conditioned medium. Our results suggest that, except for IL-6 and eotaxin, CLL B-cells and their normal counterparts produce and secrete similar amounts of cytokines and cytokine receptors in vitro.