An AAAG-Rich Oligodeoxynucleotide Rescues Mice from Bacterial Septic Peritonitis by Interfering Interferon Regulatory Factor 5.

A previous study found that an AAAG-rich Oligodeoxynucleotide (ODN), designated as MS19, could lessen the acute lung inflammatory injury (ALII) in mice infected by influenza viruses. Bioinformatics analysis found that MS19 is consensus with the binding site of interferon regulatory factor 5 (IRF5) in the regulatory elements of pro-inflammatory genes. This study established a septic peritonitis model in Institute of Cancer Research (ICR) mice infected with Escherichia coli (E. coli), and found that MS19 prolonged the survival of the mice and down-regulated the expression of inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-alpha). In cultured RAW264.7 cells, MS19 significantly reduced the expression of iNOS, IRF5, IL-6, and TNF-alpha and inhibited the nuclear translocation of IRF5. This data may provide a new insight for understanding how MS19 reduces the excessive inflammatory responses in sepsis.