Theiler's virus as a vector for foreign gene delivery into the CNS

We reported that DA strain of Theiler‘s murine encephalomyelitis virus(TMEV)grows in macrophages where persists in the chronic stage if infection，therefore maintaining the genome.On the other hand，GDVII strain of TMEV does not grow there，and cannot maintain the genome(J Virol71：729-733，1997)。Such a strain-specific，host cell-dependent virus growth was observed only in macrophages，but not in other types of cells(Microbiol Immunol，43：885-892，1999)。Recombinant and mutant virus study also demonstrated that L I D1*I D 1 protein，which is out-of-frame with the polyprotein and translated from the alternative AUG within the L coding region，plays an important role for this phenomenon(J Virol 72：4950-4955，1998)。We finally inserted lymphotoxin(LT)gene into the L coding region of DA strain of TMEV and generated the recombinant virus。Western blotting and enzyme-linked immunosorbent assay demonstrated the expression of LT in BHK-21cells infected with the recombinant virus。In addition，the expressed LT showed cytotoxicity against L-929 cells.Therefore，the present study provides a beginning of the use of TMEV as a vector for foreign gene delivery into the CNS。

We reported that DA strain of Theiler's murine encephalomyelitis virus (TMEV) grows in macrophages where persists in the chronic stage if infection, therefore maintaining the genome. On the other hand, GDVII strain of TMEV does not grow there, and cannot maintain the genome (J Virol 71 : 729-733, 1997). Such a strain-specific, host cell-dependent virus growth was observed only in macrophages, but not in other types of cells (Microbiol Immunol, 43 : 885-892, 1999). Recombinant and mutant virus study also demonstrated that LィイD1*ィエD1 protein, which is out-of-frame with the polyprotein and translated from the alternative AUG within the L coding region, plays an important role for this phenomenon (J Virol 72 : 4950-4955, 1998). We finally inserted lymphotoxin (LT) gene into the L coding region of DA strain of TMEV and generated the recombinant virus. Western blotting and enzyme-linked immunosorbent assay demonstrated the expression of LT in BHK-21 cells infected with the recombinant virus. In addition, the expressed LT showed cytotoxicity against L-929 cells. Therefore, the present study provides a beginning of the use of TMEV as a vector for foreign gene delivery into the CNS.