IN-VIVO AND IN-VITRO INTERFERON INDUCTION IN CHICKENS BY S-28828, AN IMIDAZOQUINOLINAMINE IMMUNOENHANCER

Imiquimod and its analogs belonging to a class of imidazoquinolinamine s, activate immune system via cytokine induction, and have antitumor a nd antiviral effects in mammals. In this study, we showed that a relat ed analog, designated S-28828, induced interferon (IFN) and macrophage activating cytokine(s) (macrophage activating factor, MAF) in chicken s in vivo, ex vivo, and in vitro. IFN and MAF were detectable in the s erum of chickens following oral administration. Serum IFN levels were the highest at 2 h after treatment. Although there was no detectable I FN in sera of chickens at 8, 24, and 48 h after treatment, high levels of interferon inducible enzyme, 2'-5' oligoadenylate synthase (2'5' O AS) were present at these time points. In vitro and ex vivo studies sh owed that spleen cells, bone marrow (BM) cells, and peripheral blood l eukocytes (PBL) were capable of producing IFN and MAF, although spleen cells produced the highest levels. Our results suggest that S-28828 a dministered orally may be a useful immunoenhancing and antiviral agent for chickens.