O6-alkylguanine DNA alkyltransferase is induced by human recombinant interferon-alpha A/D in mouse liver.

Treatment of C57Bl or BALB/C mice with human interferon-alpha A/D (HuIFN-alpha A/D) significantly increased hepatic levels of the DNA repair enzyme O6-alkylguanine DNA alkyltransferase (AT). The maximum induction was seen 24 h after a single dose of 50-100 micrograms/kg IFN-alpha A/D. No induction was observed in rat liver hepatocytes cultured in vitro. Liver AT was also induced by poly(I:C), which is a potent IFN inducer. By increasing AT levels, IFN could protect against the potentially mutagenic alkylation at guanine O6 position caused by some carcinogens. Moreover this finding suggests a link between immune response and the DNA repair system, possibly acting in concert to defend the body from potentially toxic compounds.