An increased expression of the LPS receptor complex on target cells, may contribute to the enhanced reactivity to LPS [73, 74] . We therefore investigated whether macrophages of Ad infected mice overexpress the receptor components mCD14 and TLR4/ MD-2. We found that splenic macrophages from Ad infected mice overexpress mCD14 in an IFN-ab dependent manner (Fig. 11D ) but the expression of TLR4/MD-2 was only minimally affected (Fig. S14D) . Furthermore, we found increased acetylation levels of histone H4 at the TNF-a promoter in Ad-infected wt, but not in IFNabR-deficient macrophages (Fig. 11E ). This suggests that Adinduced IFN-ab increases LPS-induced TNF-a production, at least in part by epigenetic changes at the TNF-a promoter.