RNA preparation was performed using NucleoSpin RNA II kit (Macherey-Nagel) according to the manufacturer's instructions. Quantitative real-time PCR was performed on a Mastercycler EP realplex S (Eppendorf). Primers for HPRT (housekeeping gene control), IFNb and IkBa mRNA expression were as follows: HPRT forward GTTGGATACAGGCCAGACTTTGTTG, HPRT reverse GAGGGTAGGCTGGCCTATTGGCT, IFNb forward 59-TCAGAATGAGTGGTGGTTGC-39, IFNb reverse 59-GACCTTTCAAATGCAGTAGATTCA-39; IkBa forward 59-GCAATTTCTGGCTGGTGGG-39, IkBa reverse 59GATCC-GCCAGGTGAAGGG-39. Data shown are representatives of at least three independent experiments.