IFN-alpha regulates IL 10 production by CML cells in vitro

High levels of spontaneous in vitro IL 10 secretion by a subset of untreate d chronic phase CML patients' cells are shown to be decreased in the presen ce of IFN-alpha. However. the lower level of spontaneous IL 10 secretion by healthy control cells are was not depressed by IFN-alpha. In contrast to i ts effects on IL 10 production, IFN-alpha increased the low spontaneous sec retion of IL 1 beta by patients' cells, bud did not further increase the hi gher levels of spontaneous IL 1 beta secretion by normal cells. It had no e ffect on secretion of TNF-alpha by patients or normals. Spontaneous secreti on of IL-1 alpha (or IFN-gamma) by patients' cells was not observed whether or not IFN-alpha was present. Therefore, one mechanism of action of IFN-al pha in vivo may involve decreasing endogenous IL 10 secretion (thereby redu cing suppressive effects on T cell reactivity) and increasing IL 1 beta sec retion (thereby enhancing antigen presentation).