Formation of virus-like particles from cloned cDNAs of Thogoto virus

Thogoto virus (THOV) is the type species of tick-transmitted orthomyxovirus es. Here, we describe the generation of virus-like particles (VLP) of THOV from cloned cDNAs. To synthesize the six structural proteins of THOV in mam malian cells, we used T7-controlled expression plasmids and a recombinant v accinia virus producing T7 RNA polymerase. A minireplicon encoding a report er gene flanked by THOV promoter sequences was expressed by the cellular RN A polymerase I. The recombinant proteins were functional in encapsidation, amplification and transcription of the minireplicon RNA. Furthermore, the a rtificial nucleocapsids were packaged into THO-VLPs that transferred the mi nireplicon to indicator cells. This system should be helpful in generating recombinant THOV entirely from cloned cDNAs.