Ovine IFN-tau modulates the expression of MHC antigens on murine cerebrovascular endothelial cells and inhibits replication of Theiler's virus

Interferon-beta (IFN-beta) has been used successfully to treat patients wit h relapsing-remitting multiple sclerosis (MS). IFN-tau is a new class of ty pe I IFN that is secreted by the trophoblast and is the signal for maternal recognition of pregnancy in sheep. IFN-tau has potent immunosuppressive an d antiviral activities similar to other type I IFN but is less cytotoxic th an IFN-alpha/beta. The current investigation concerns the effect of recombi nant ovine IFN-tau (rOvIFN-tau) on the modulation of MHC class I and II exp ression on cloned mouse cerebrovascular endothelial (CVE) cells. IFN-tau in duced tyrosine phosphorylation of Stat1 and upregulated the expression of M HC class I on CVE. One proposed action by which type I IFN reduce the relap se rate in MS is via interference with IFN-gamma -induced MHC class It expr ession. IFN-tau was shown to downregulate IFN-gamma -induced MHC class It e xpression on CVE and, hence, may be of potential therapeutic value in downr egulating inflammation in the central nervous system (CNS). IFN-tau did not upregulate the expression of MHC class II on CVE. IFN-tau also inhibited t he replication of Theiler's virus in CVE. These in vitro results suggest th at IFN-tau may be of therapeutic value in the treatment of virus-induced de myelinating disease.