Cutting Edge: Tyk2 Is Required for the Induction and Nuclear Translocation of Daxx Which Regulates IFN-α-Induced Suppression of B Lymphocyte Formation

IFN-alpha inhibits B lymphocyte development, and the nuclear protein Daxx has been reported to be essential for this biological activity. We show in this study that IFN-alpha inhibits the clonal proliferation of B lymphocyte progenitors in response to IL-7 in wild-type, but not in tyk2-deficient, mice. In addition, the IFN-alpha-induced up-regulation and nuclear translocation of Daxx are completely abrogated in the absence of tyk2. Therefore, tyk2 is directly involved in IFN-alpha signaling for the induction and translocation of Daxx, which may result in B lymphocyte growth arrest and/or apoptosis.