Race between virus and inflammasomes: inhibition or escape, intervention and therapy.

The inflammasome is a multiprotein complex that further regulates cell pyroptosis and inflammation by activating caspase-1. The assembly and activation of inflammasome are associated with a variety of diseases. Accumulative studies have shown that inflammasome is a key modulator of the host's defense response to viral infection. Indeed, it has been established that activation of inflammasome occurs during viral infection. At the same time, the host has evolved a variety of corresponding mechanisms to inhibit unnecessary inflammasome activation. Therefore, here, we review and summarize the latest research progress on the interaction between inflammosomes and viruses, highlight the assembly and activation of inflammosome in related cells after viral infection, as well as the corresponding molecular regulatory mechanisms, and elucidate the effects of this activation on virus immune escape and host innate and adaptive immune defenses. Finally, we also discuss the potential therapeutic strategies to prevent and/or ameliorate viral infection-related diseases via targeting inflammasomes and its products.

[Mechanism of MBL inhibiting the LPS-induced DC maturation].

The study was aimed to investigate the mechanism of mannan-binding lectin (MBL) on bacterial lipopolysaccharide (LPS)-induced human peripheral blood monocyte-derived dendritic cell (DC) maturation. The monocytes were prepared from the peripheral blood of healthy adult volunteers. The immature dendritic cells (imDC) were induced by 5-day-culture in medium supplemented with rhGM-CSF and rhIL-4. FACS was used to investigate the interaction of MBL with imDC and the impact of MBL on LPS binding to imDC. ELISA and Western blot was used to analyze the interaction of MBL with soluble TLR4 ectodomain protein (sTLR4); Western blot was used to detect LPS-induced NF-κB translocation in imDC. The results showed that MBL could directly bind to imDC in the presence of calcium. sTLR4 protein or LPS could competitively inhibit the binding of MBL to imDC. ELISA and Western blot showed that MBL could evidently bind to sTLR4 protein in a concentration-dependent manner. FACS showed that MBL could competitively inhibit the binding of LPS to imDC by binding to imDC directly. Western blot showed that MBL decreased LPS-induced NF-κB translocation in imDC. It is concluded that MBL may competitively inhibit the binding of LPS to imDC by binding to TLR4 expressed on imDC, resulted in inhibition of LPS-induced DC maturation, suggesting that MBL can regulate DC maturation through ligand-binding. This study provides the good foundation to clarify the mechanism of MBL inhibiting the LPS-induced DC maturation.