MEASLES-VIRUS ANTISENSE SEQUENCES SPECIFICALLY CURE CELLS PERSISTENTLY INFECTED WITH MEASLES-VIRUS

Vectors expressing antisense mRNAs complementary to the measles virus (MV) nucleoprotein N or hemagglutinin H genes were used to transfect MV-permissive Vero cells, MV-nonpermissive C6 rat glioma cells, and C6 cells persistently infected with measles/SSPE virus (C6/SSPE cells). Transfected Vero cells infected with Mv showed a drastically reduced yield of infectious virus (90-99.99%). In plaque assays, plaque numbers and plaque size were significantly reduced compared with untransfected Vero cells. With an unrelated control virus, VSV, no effects were seen in the transfected Vero cells, underlining the specificity for MV. Following stable transfection with MV antisense vectors, C6 rat glioma cells, which are normally suitable to establish persistently MV-infected lines, can no longer be infected with the virus. In this case also, VSV infection was not influenced. Furthermore, antisense transfection of already persistently infected C6/SSPE cells leads to a loss of MV-specific immunofluorescence, concomitant with a disappearance of viral RNA. Single cell clones from the antisense-transfected CG/SSPE cells appear to be totally free of virus in cocultivation with Vero cells, suggesting that they are really cured. The effectiveness of even low amounts of antisense sequences suggests that they are good candidates for antisense oligonucleotide therapy in tissue culture and might eventually also be useful for in vivo application. (C) 1995 Academic Press, Inc.