ATF7 mediates lipopolysaccharide-induced epigenetic changes in macrophages involved in innate immunological memory (expression)

Immunological memory is generally thought to be mediated exclusively by lymphocytes such as memory T and B cells. However, enhanced innate immune responses caused by a previous infection increase protection against reinfection suggesting the presence of innate immunological memory. Here, we describe expression profile of peritoneal macrophages from wild-type mice pre-administrated with TLR ligands or from ATF7 knockout mice. ATF7 suppresses a group of innate-immunity genes in macrophage by recruiting H3K9 dimethyltransferase G9a. TLR ligands induce ATF7 phosphorylation, leading to release of ATF7 from chromatin and reduction in H3K9me2 level. Partially disrupted chromatin structure and increased basal expression on target genes are maintained for a long period, increasing resistance pathogens. Therefore we speculate ATF7 is important factor in controlling innate immunological memory.

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Yoshida K, Maekawa T, Zhu Y, Renard-Guillet C, Chatton B, Inoue K, Uchiyama T, Ishibashi K, Yamada T, Ohno N, Shirahige K, Okada-Hatakeyama M, Ishii S