Viruses and the interferon (IFN) response : methods to improve production and to rapidly select IFN-sensitive viruses for vaccine development

摘要

Manipulation of a virus’s capacity to circumvent the interferon (IFN) responseudaids both fundamental studies as well as many practical applications includingudthe design of live-attenuated vaccines. However, these IFN-sensitive viruses areudoften difficult to grow to high titer in cells that produce and respond to IFN. Inudthe first part of this study we further characterised the use of the IFN inhibitor,udRuxolitinib (Rux) for its ability to block the IFN response and subsequentlyudenhance replication of IFN-sensitive viruses. This study has shown that i) Ruxudcould provide a more rapid and therefore more efficient alternative for theudgrowth of IFN-sensitive viruses than the current default option, growth in Veroudcells and ii) addition of Rux can increase growth of multiple viruses in numerousudcell-lines. These results indicate that as well as aiding fundamental studies theudaddition of Rux could become a valuable technique in a number of virologicaludapplications including live attenuated vaccine production and techniques toudisolate newly emerging viruses. In the second part of this study we developed audnovel method to isolate IFN-sensitive viruses from Paramyxoviruses, using PIV5ud(Parainfluenza virus 5) as an experimental model system to obtain selectionudparameters. We successfully isolated three mutant viruses (rPIV5mCh-α,udrPIV5mCh-β and PIV5 W3-γ) that each contain mutations within the IFNudantagonist V protein and the P protein which is essential for RNA replication.udSubsequently, both rPIV5mCh-α and PIV5 W3-γ were shown to contain non-udfunctional V proteins and exhibit IFN-sensitivity. Ultimately, this study is the firstudstep towards creating a general method to isolate various types of IFN-sensitiveudviruses that as well as aiding fundamental studies, may be further developed asudattenuated vaccines for clinically important viruses lacking vaccines.