Pegylated interferon beta in the treatment of the Theiler's murine encephalomyelitis virus mouse model of multiple sclerosis.

We evaluated the effects of pegylated-interferonβ-1a (pegIFNβ) therapy on intrathecal antibody responses, disability progression, and viral load in the CNS in mice infected with the Theiler's virus (TMEV), an animal model of progressive disability in Multiple Sclerosis (MS). The lack of a direct antiviral activity in the CNS, the absence of any effect upon the intrathecal immune response, and the failure to treat disease progression, indicate that the immunomodulatory effects of pegIFNβ-1a likely occur in the systemic circulation rather than within the CNS. These results may be relevant to the relative lack of effect of IFNβ in progressive MS relative to relapsing MS.