title: Functional characterization of viral tumor necrosis factor receptors encoded by cyprinid herpesvirus 3 (CyHV3) genome.
abstract: Cyprinid herpesvirus 3 (CyHV3) is a large double-stranded DNA virus of Alloherpesviridae family in the order Herpesvirales. It causes significant morbidity and mortality in common carp and its ornamental koi variety, and threatens the aquaculture industries worldwide. Mimicry of cytokines and cytokine receptors is a particular strategy for large DNA viruses in modulating the host immune response. Here, we report the identification and characterization of two novel viral homologues of tumor necrosis factor receptor (TNFR) encoded by CyHV3-ORF4 and -ORF12, respectively. CyHV3-ORF4 was identified as a homologue of HVEM and CyHV3-ORF12 as a homologue of TNFRSF1. Overexpression of ORF4 and ORF12 in zebrafish embryos results in embryonic lethality, morphological defects and increased apoptosis. Although we failed to identify any interaction between the two vTNFRs and their potential ligands in zebrafish TNF superfamily by yeast two-hybrid system, the expression of some genes in TNF superfamily or TNFR superfamily were mis-regulated in ORF4 or ORF12-overexpressing embryos, especially the death receptor zHDR and its cognate ligand DL1b. Further studies showed that the apoptosis induced by the both CyHV3 vTNFRs is mainly activated through the intrinsic apoptotic pathway and requires the crosstalk between the intrinsic and extrinsic apoptotic pathway. Additionally, using RT-qPCR and Western blot assays, the expression patterns of the both vTNFRs were also analyzed during CyHV3 productive infection. Collectively, this is the first functional study of two unique vTNFRs encoded by a herpesvirus infecting non-mammalian vertebrates, which may provide novel insights into viral immune regulation mechanism and the pathogenesis of CyHV3 infection.
authors.affiliation: MOE Key Laboratory of Aquatic Food Safety/State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yi
authors.affiliation: MOE Key Laboratory of Aquatic Food Safety/State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Hemei
authors.initials: H
authors.lastname: Qi
authors.affiliation: MOE Key Laboratory of Aquatic Food Safety/State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Jimin
authors.initials: J
authors.lastname: Yuan
authors.affiliation: MOE Key Laboratory of Aquatic Food Safety/State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.affiliation: MOE Key Laboratory of Aquatic Food Safety/State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou 510275, People's Republic of China.
authors.forename: Shaoping
authors.initials: S
authors.lastname: Weng
authors.affiliation: MOE Key Laboratory of Aquatic Food Safety/State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou 510275, People's Republic of China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, People's Republic of China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: He
authors.affiliation: MOE Key Laboratory of Aquatic Food Safety/State Key Laboratory for Bio-control, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou 510275, People's Republic of China. Electronic address: dongchfu@mail.sysu.edu.cn.
authors.forename: Chuanfu
authors.initials: C
authors.lastname: Dong
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002347:Carps; D002460:Cell Line; D005260:Female; D005393:Fish Diseases / Q000235:genetics* / Q000378:metabolism / Q000821:virology; D005786:Gene Expression Regulation; D006564:Herpesviridae / Q000235:genetics / Q000502:physiology*; D006566:Herpesviridae Infections / Q000235:genetics / Q000378:metabolism / Q000662:veterinary* / Q000821:virology; D008297:Male; D016366:Open Reading Frames; D053240:Receptors, Tumor Necrosis Factor, Member 14 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment / Q000662:veterinary; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015027:Zebrafish
chemical_list: D053240:Receptors, Tumor Necrosis Factor, Member 14; D047888:Receptors, Tumor Necrosis Factor, Type I; D014764:Viral Proteins
keywords: Apoptosis; Cyprinid herpesvirus 3 (CyHV3); Immune regulation; Koi herpesvirus (KHV); TNF receptor; Zebrafish embryos