Interferon-alpha induces transient suppressors of cytokine signalling expression in human T cells

The suppressors of cytokine signalling (SOCS) proteins comprise a newly ide ntified family of negative feedback regulators of cytokine signalling. SOCS expression is differentially induced upon cytokine stimulation in differen t cell types. Here we show that interferon-alpha (IFN alpha) is a potent in ducer of SOCS expression in human T cells, as high expression of CIS, SOCS- 1, SOCS-2, and SOCS-3 was detectable after IFN alpha stimulation. After 4 h of stimulation, CIS, SOCS-1, and SOCS-3 expression had returned to baselin e levers, whereas SOCS-2 expression had not declined. In contrast, after IL -2 induction neither CIS, SOCS-1, nor SOCS-2 expression levels declined aft er 6 h. In conclusion, we provide the first evidence that IFN alpha induces SOCS expression in human T cells. Moreover, we show that IFN alpha and IL- 2 induce distinct patterns of expression kinetics, suggesting that dynamic changes in cytokine sensitivity might be mediated via induction of SOCS exp ression with different kinetics in T cells. Copyright (C) 2001 S. Karger AG , Basel.