Induction of Blood 2′,5′-Oligoadenylate Synthetase Activity in Mice by Gastric Administration of Ovine IFN- τ

Abstract

Interferon-τ (IFN-τ) is a member of the type I IFN family. Although its distribution is restricted to ruminants, IFN-τ is active against cells of humans and mice. It has been reported that oral administration of ovine IFN-τ (OvIFN-τ) prevents both acute and chronic relapsing forms of murine experimental allergic encephalomyelitis (EAE). Here, we examined the effect in mice of peroral gastric administration of OvIFN-τ on the induction of 2′,5′-oligoadenylate synthetase (OAS) activity in whole blood. Before administration, mice were deprived of food and drink for 6 h, and IFN was given by either intraperitoneal (i.p.) injection or per-oral gastric administration. When administered gastrically, IFN was introduced directly into the upper part of the stomach using an oral feeding needle. OAS activity in whole blood increased dependent on dose (0-105 U) and time (0-24 h), with no significant difference in the level of activity between the two routes. An increase in the activity of OAS in blood following administration of OvIFN-τ was observed in ICR, BALB/c, C57BL/6, NZW/N, and SJL/J mice, although the extent of the increase varied with the strain. Blood OAS levels also increased on administration of murine IFN-α (MuIFN-α). However, higher levels were detected after i.p. injection than after gastric administration.