INTERLEUKIN-3 (IL-3) AND GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR (GM-CSF) CAN INDUCE DIFFERENTIATION OF CHRONIC B-CELL LEUKEMIA EXPRESSING THE ALPHA-SUBUNIT OF IL-3 AND GM-CSF RECEPTOR
M. Shiiba et al., INTERLEUKIN-3 (IL-3) AND GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR (GM-CSF) CAN INDUCE DIFFERENTIATION OF CHRONIC B-CELL LEUKEMIA EXPRESSING THE ALPHA-SUBUNIT OF IL-3 AND GM-CSF RECEPTOR, International archives of allergy and immunology, 111, 1996, pp. 12-15
Interleukin-5 (IL-5), IL-3 and granulocyte-macrophage colony-stimulati
ng factor (GM-CSF) exhibit similar functions on eosinophils, and these
common functions are believed to be mediated by the shared beta chain
of receptors. IL-5 shows activity on the murine chronic B cell leukem
ia cell line BCL(1)-B20, inducing differentiation into IgM-secreting c
ells, but IL-3 and GM-CSF do not have such activity. To elucidate whet
her the lineage specificity of IL-5 is due to restricted expression of
the IL-5 receptor a chain (IL-5R alpha), transfectants of BCL(1)-B20
were established that express IL-3 receptor alpha (BCL(1)-3R) or GM-CS
F receptor alpha (BCL(1)-GMR). BCL(1)-3R and BCL(1)-GMR acquired respo
nsiveness to IL-3 and GM-CSF, respectively, to an extent similar to IL
-5 stimulation, resulting in IgM-secreting cells. Thus, the differenti
ation of BCL(1)-B20 into IgM-secreting cells can be equally supported
by either IL-3 or GM-CSF, suggesting that intracellular signaling thro
ugh IL-5R can be replaced by signaling from IL-3R and GM-CSFR. These r
esults support the notion that the lineage specificity of IL-5 is main
ly due to the restricted expression of IL-5R alpha. Regulation of IL-5
R alpha, IL-3R alpha and GM-CSFR alpha expression in the developmental
stage appears to be important for understanding the unique function o
f these cytokines on a particular cell type.