Differential effect of IL-4 and IL-13 on CD44 expression in the Burkitt's lymphoma B cell line BL30/B95-8 and in Epstein-Barr virus(EBV) transformed human B cells: Loss of IL-13 receptors on Burkitt's lymphoma B cells

IL-4 and IL-13, cytokines with similar biological effects may influence gro wth and progression of B-cell tumors through regulation of key cell surface molecules important in intercellular communications. In this study, we dem onstrate that IL-4 and IL-13 exhibited differential effects on CD23 and CD4 4 expression and binding to hyaluronan in BL30/B95-8, a Burkitt's lymphoma (BL), and MK3.31, an Epstein-Barr virus transformed normal human B cell lin e (B-LCL). Studies conducted to understand the molecular mechanisms underly ing this differential effect show that IL-4 induced phosphorylation of JAK1 , JAK3, and STATE in BL30/B95-8 cells and of JAK3 and STATE in MK 3.31 cell s. In contrast, IL-13 failed to induce the phosphorylation of JAK kinases o r STATE proteins in these cell lines. The inability of BL30/B95-8 cells to respond to IL-13 was attributed to the loss of expression of IL-13R subunit s alpha1 and alpha2, a finding confirmed for a number of other BL cell line s examined. (C) 2001 Academic Press.