Type I interferon induces a novel mRNA (Yo-antigen) in human blood cells

Interferons are known to induce 20 or more proteins following treatment of cells in culture. However, the functions of only few of these proteins are known. Following a 24-h type I interferon treatment of human blood in vitro, we have isolated and characterized 27 potentially novel induced mRNAs. Of the mRNAs characterized, one was found to code for the Yo-antigen. This protein contains a leucine zipper sequence, suggesting that it may bind DNA. The Yo-antigen was originally identified in female patients with paraneoplastic cerebellar degeneration. In this study, the Yo-antigen message was detected in the treated blood of three out of the four male subjects, whereas the protein was detected in only one blood sample. A two- to threefold increase of this protein was observed in Daudi and HL-60 cell lines following interferon-alpha treatment. These findings suggest the possibility that the Yo-antigen protein is involved in interferon-inducible gene regulation, and that its induction may relate to some of the side effects often noted in patients undergoing high-dose interferon treatment.