Vancsok Catherine, Peñaranda M Michelle D, Raj V Stalin, Leroy Baptiste, Jazowiecka-Rakus Joanna, Boutier Maxime, Gao Yuan, Wilkie Gavin S, Suárez Nicolás M, Wattiez Ruddy, Gillet Laurent, Davison Andrew J, Vanderplasschen Alain F C
Immunology-Vaccinology, Department of Infectious and Parasitic Diseases, Fundamental and Applied Research for Animals and Health, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium.
Indian Institute of Science Education and Research Thiruvananthapuram, CET Campus, Thiruvananthapuram, India.
J Virol. 2017 Oct 13;91(21). doi: 10.1128/JVI.01209-17. Print 2017 Nov 1.
Virion transmembrane proteins (VTPs) mediate key functions in the herpesvirus infectious cycle. Cyprinid herpesvirus 3 (CyHV-3) is the archetype of fish alloherpesviruses. The present study was devoted to CyHV-3 VTPs. Using mass spectrometry approaches, we identified 16 VTPs of the CyHV-3 FL strain. Mutagenesis experiments demonstrated that eight of these proteins are essential for viral growth (open reading frame 32 [ORF32], ORF59, ORF81, ORF83, ORF99, ORF106, ORF115, and ORF131), and eight are nonessential (ORF25, ORF64, ORF65, ORF108, ORF132, ORF136, ORF148, and ORF149). Among the nonessential proteins, deletion of ORF25, ORF132, ORF136, ORF148, or ORF149 affects viral replication , and deletion of ORF25, ORF64, ORF108, ORF132, or ORF149 impacts plaque size. Lack of ORF148 or ORF25 causes attenuation to a minor or major extent, respectively. The safety and efficacy of a virus lacking ORF25 were compared to those of a previously described vaccine candidate deleted for ORF56 and ORF57 (Δ56-57). Using quantitative PCR, we demonstrated that the ORF25 deleted virus infects fish through skin infection and then spreads to internal organs as reported previously for the wild-type parental virus and the Δ56-57 virus. However, compared to the parental wild-type virus, the replication of the ORF25-deleted virus was reduced in intensity and duration to levels similar to those observed for the Δ56-57 virus. Vaccination of fish with a virus lacking ORF25 was safe but had low efficacy at the doses tested. This characterization of the virion transmembrane proteome of CyHV-3 provides a firm basis for further research on alloherpesvirus VTPs. Virion transmembrane proteins play key roles in the biology of herpesviruses. Cyprinid herpesvirus 3 (CyHV-3) is the archetype of fish alloherpesviruses and the causative agent of major economic losses in common and koi carp worldwide. In this study of the virion transmembrane proteome of CyHV-3, the major findings were: (i) the FL strain encodes 16 virion transmembrane proteins; (ii) eight of these proteins are essential for viral growth ; (iii) seven of the nonessential proteins affect viral growth , and two affect virulence ; and (iv) a mutant lacking ORF25 is highly attenuated but induces moderate immune protection. This study represents a major breakthrough in understanding the biology of CyHV-3 and will contribute to the development of prophylactic methods. It also provides a firm basis for the further research on alloherpesvirus virion transmembrane proteins.
病毒粒子跨膜蛋白（VTPs）在疱疹病毒感染周期中发挥关键作用。鲤疱疹病毒3型（CyHV-3）是鱼类异疱疹病毒的原型。本研究聚焦于CyHV-3的VTPs。通过质谱分析方法，我们鉴定出了CyHV-3 FL株的16种VTPs。诱变实验表明，其中8种蛋白对病毒生长至关重要（开放阅读框32 [ORF32]、ORF59、ORF81、ORF83、ORF99、ORF106、ORF115和ORF131），另外8种则并非必需（ORF25、ORF64、ORF65、ORF108、ORF132、ORF136、ORF148和ORF149）。在这些非必需蛋白中，缺失ORF25、ORF132、ORF136、ORF148或ORF149会影响病毒复制，而缺失ORF25、ORF64、ORF108、ORF
