HDAC inhibition enhances the production of IFN-β. (A-D) RNA and cell culture supernatants were collected from BMDMs preincubated for 1 hour with (+) or without (−) TSA (100nM) before exposure to LPS (100 ng/mL) or Pam₃CSK₄ (100 ng/mL). (A-B) IFN-β mRNA and protein expression was quantified by RT-PCR and ELISA. Results are expressed as the ratio of Ifnb mRNA level to that of GAPDH. Data are mean ± SD of triplicate samples from 1 experiment representative of 2 experiments. (C-D) Ifna4 (C), Ccl2, Ccl5, Ccl8, Ccl12, Cxcl10, Nos2, Irf7, and Irf8 (D) mRNA contents were quantified by RT-PCR. Results are expressed as the ratio of mRNA level of the gene of interest to that of GAPDH. Data are representative of 2 independent experiments. A.U. indicates arbitrary units. (E-F) Splenocytes were incubated with TSA and LPS (5 μg/mL), Pam₃CSK₄ (5 μg/mL), CpG ODN (CpG, 0.5μM), E coli (5 × 10⁷ CFU/mL), staphylococcal enterotoxin B (SEB, 1-5 μg/mL), toxic shock syndrome toxin-1 (TSST-1, 0.4-2.0 μg/mL), and concanavalin A (5 μg/mL). (E) Proliferation was measured by ³H-thymidine incorporation. Data are mean ± SD of triplicate samples and are representative of 2 independent experiments. (F) IFN-γ production was quantified by ELISA in cell culture supernatants collected after 48 hours. Data are representative of 2 independent experiments.