Activation of interferon-inducible genes in vivo by synthetic double-stranded RNA, poly rI:rC.

We analyzed the effects of synthetic dsRNA (poly rI:rC) treatment on the expression in vivo of two interferon (IFN)-inducible genes. DBA/2 mice were injected i.p. with poly rI:rC and its effect on the levels of the following mRNAs was determined; 202, 2'-5' oligoadenylate synthetase (2-5A synthetase) and beta-actin. After poly rI:rC treatment the levels of the 202 and 2-5A synthetase mRNAs in the spleen and in bone marrow peaked between 12 and 24 h and decreased thereafter, whereas beta-actin levels remained unchained unchanged. Pretreatment of DBA/2 mice with sheep anti-murine IFN-alpha/beta antibodies before rI:rC injection strongly diminished the induction of 202 mRNA indicating that IFN-alpha/beta mediated this induction.