Figure 9.

Schematic diagram of the putative antiviral mechanism by which BmSirt5 inhibited BmNPV proliferation in the silkworm. (A) BmSirt5 expression was significantly induced by BmNPV infection in the fat body or midgut, together with the activation of other host antiviral pathways such as STING. (B) The innate immune pathway mediated by BmRelish can induce the production of downstream antimicrobial peptide (AMP) genes and other antiviral genes to resist BmNPV infection. (C) Nuclear translocation of Relish may be stimulated by de-succinylation or de-acetylation activities of BmSirt5. (D) Inhibition of the NAD⁺-dependent de-acetylase activity of BmSirt5 by Suramin could interfere with the activation of BmRelish, for instance by inhibition of its transfer to the nucleus.