Bombyx mori homolog of tumor suppressor p53 is involved in apoptosis-mediated antiviral immunity of B. mori cells infected with nucleopolyhedrovirus. (July 2018)

• Record Type: Journal Article
• Authors: Makino, Shizuka; Hamajima, Rina; Saito, Aya; Tomizaki, Moe; Iwamoto, Asako; Kobayashi, Michihiro; Yamada, Hayato; Ikeda, Motoko
• Is Part Of: Developmental and comparative immunology. Volume 84(2018)
• Page Start: 133
• Page End: 141
• Publication Date: 2018-07
• Subjects: Apoptosis -- p53 -- Bombyx mori -- Baculovirus -- Nucleopolyhedrovirus -- Cell culture; Immunology -- Periodicals; Developmental immunology -- Periodicals; 616.079
• DOI: 10.1016/j.dci.2018.02.009
• Languages: English
• ISSNs: 0145-305X

Abstract

Abstract: Apoptosis is important in antiviral immunity and affects viral multiplication and pathogenesis. Here, we showed that Bombyx mori cells transiently expressing B. mori homolog of the tumor suppressor p53 (Bm-p53) protein underwent apoptosis accompanied by elevated caspase-3-like protease activity and processing of B. mori Dronc (Bm-Dronc). RNAi-mediated silencing of bm-p53 expression, which significantly diminished accumulation of bm-p53 transcript and Bm-p53 protein, prevented apoptosis of B. mori cells infected with a recombinant B. mori nucleopolyhedrovirus defective in the anti-apoptotic p35 gene (vBmΔp35) and abolished the activation of caspase-3-like protease and processing of Bm-Dronc. Apoptosis in vBmΔp35-infected B. mori cells is associated with viral DNA replication, suggesting involvement of the DNA damage response. The Bm-p53 pro-apoptotic function is also found in Spodoptera frugiperda and Lymantria dispar cells. These results indicate that apoptosis induction in vBmΔp35-infected B. mori cells is a Bm-p53-mediated process promoted by the commencement of viral DNA replication. Highlights: Bombyx mori contains a homolog of tumor suppressor p53 (Bm-p53) protein. B. mori cells transiently expressing Bm-p53 protein undergo apoptosis. Bm-p53-mediated apoptosis is accompanied by caspase cascade activation. RNAi silencing of bm-p53 prevents apoptosis of vBmΔp35-infected B. mori cells. RNAi silencing significantly diminishes Bm-p53 protein levels in B. mori cells.