ENCAPSIDATION OF A RECOMBINANT LUIII PARVOVIRUS GENOME BY H1 VIRUS AND THE FIBROTROPIC OR LYMPHOTROPIC STRAINS OF MINUTE VIRUS OF MICE

We previously constructed a recombinant LuIII parvovirus genome lackin g viral coding sequences and used it to generate luciferase-transducin g virions, by cotransfection of cells with a helper plasmid expressing LuIII viral proteins. Here, we describe similar cotransfections using alternative, replication-defective helpers encoding the non-structura l and capsid proteins of parvovirus H1, or of either the fibrotropic o r lymphotropic parvovirus strain of minute virus of mice [MVM(p) or MV M(i)]. Each cotransfection generated transducing virus which directed luciferase expression after infection of HeLa cells. The transducing a ctivity of virus produced using either LuIII or H1 helper plasmids cou ld be specifically neutralized by antiserum raised against the corresp onding infectious virus. When the recombinant LuIII parvovirus was pse udotyped with MVM(p) or MVM(i), the resulting virions efficiently expr essed luciferase after infection in human or murine cells known to be permissive for both MVM strains. The MVM(p) pseudotyped virus also exp ressed this reporter efficiently when infected into the murine A9 fibr oblast line. In contrast, the recombinant virus generated with an MVM( i) helper gave luciferase expression that was barely detectable after infection of A9 cells which are highly restrictive for MVM(i) producti ve infection. These results support the notion that the allotropic det erminant of these MVM strains functions through their capsid proteins. Pseudotyping of recombinant parvovirus genomes should be useful in co ntrolling their host range as vectors, and in studying mechanisms infl uencing the permissiveness of parvovirus infections.