Interleukin-10 and gp130 cytokines in human multiple myeloma

Interleukin (IL)-10 is a critical cytokine involved in the terminal differe ntiation of B cells into plasma cells. IL-10 is also involved in multiple m yeloma, a malignant plasma cell disorder. IL-6 and, more generally the cyto kines activating the gp130 IL-6 transducer, are major survival and prolifer ation factors of myeloma cells. IL-10 is also a growth factor of malignant plasma cells, produced by myeloma cells from about half the patients and is detected in the plasma of patients with plasma cell leukemia or solitary p lasmacytoma. The myeloma cell growth activity of IL-10 is mediated through a gp130 cytokine, oncostatin M (OSM), that is frequently produced by myelom a cells. Myeloma cells fail to express OSM receptors but IL-IO, by inducing it, confers on them the sensivity to OSM.