Knockdown of DAI by siRNA in vivo hampers the ALD-DNA-induced macrophage activation.
In vivo transfection of peritoneal cells with siDAI was performed to block the DAI expression in peritoneal macrophages in mice. A and B, the peritoneal macrophages purified from siDAI or siControl-treated mice were stimulated with ALD-DNA (4 μg/ml) in vitro. A, 12 h later, the mRNA level of DAI was analyzed by real-time PCR. B, 24 h later, levels of TNF-α, IL-6, IL-10, and MCP-1 in the culture supernatants was analyzed by ELISA. Data are mean ± S.E. of three independent experiments. *, p < 0.05; **, p < 0.01; ***, p < 0.001. C, peritoneal macrophages purified from siDAI- or siControl-treated mice were cocultured with CD4+ T cells and CD19+ B cells isolated from the SLE mice, and stimulated with ALD-DNA for 6 days. Anti-dsDNA IgG levels in the culture supernatants were evaluated by ELISA. Data are mean ± S.E. of three independent experiments, n = 4. ***, p < 0.001.