摘要
Cholesterol-25-hydroxylase(CH25H)has been identified as an interferon-stimulated gene(ISG)in mammals that exerts its antiviral effects by catalyzing the conversion of cholesterol to 25-hydroxycholesterol(25HC).However,invertebrates lack an antiviral system homologous to vertebrate interferons(IFNs)because the genomes of invertebrates do not encode IFN-like cytokines.Nevertheless,CH25H is present in insect genomes and it therefore deserves further study of whether and by which mechanism it could exert an antiviral effect in invertebrates.In this study,the Bombyx mori CH25H(BmCH25H)gene,of which the encoded protein has high homology with other lepidopteran species,was identified and located on chromosome 9.Interestingly,we found that the expression of BmCH25H was significantly upregulated in B.mori nucleopolyhedrovirus(BmNPV)-infected BmN cells and silkworm(B.mori)larvae at the early infection stage.The inhibitory effect of BmCH25H on BmNPV replication was further demonstrated to depend on its catalytic residues to convert cholesterol to 25HC.More importantly,we demonstrated that during BmNPV infection,BmCH25H expression was increased through the Janus kinase–signal transducer and activator of transcription(JAK–STAT)pathway,similar to the induction of ISGs following virus infection in vertebrates.This is the first report that CH25H has antiviral effects in insects;the study also elucidates the regulation of its expression and its mechanism of action.
基金
supported by the Natural Science Foundation of Guangdong Basic and Applied Basic Research Fund(2022A1515012657)
Guangzhou Science and Technology Plan Project(202002030218)
National Natural Science Foundation of China(31872426)
South China Agricultural University high-level talent launch project
Guangdong Provincial Promotion Project on Preservation and Utilization of Local Breed of Livestock and Poultry(No.2018-143)
Innovation and Entrepreneurship Training Program for College Students in Guangdong Province(S202110564098).
