Expression of parvovirus LuIII NS1 from a Sindbis replicon for production of LuIII-luciferase transducing virus.

In order to develop an alternative packaging system for recombinant parvoviruses, the gene for the major nonstructural protein (NS1) of parvovirus LuIII was inserted into a Sindbis replicon vector. Cells infected with recombinant SinNS1 virus produced NS1 RNA from the Sindbis 26S promoter and expressed NS1 protein which was able to transactivate a parvovirus P38 promoter. Co-transfections of Sindbis-NS1 RNA together with a packageable LuIII transducing genome and a coat protein expression plasmid generated detectable levels of LuIII-luciferase transducing virus. These levels could be increased by a capsid expression plasmid that was also capable of expressing NS2. These results show that a multi-functional parvovirus protein expressed from a Sindbis RNA molecule can be used to produce recombinant parvoviruses.