ANTISENSE RNA-MEDIATED INHIBITION OF MOUSE HEPATITIS-VIRUS REPLICATION IN L2 CELLS

We have successfully used antisense RNA to inhibit replication of the mouse hepatitis virus (MHV) in a cell culture system. MHV is a single- stranded RNA virus of positive polarity. Mouse L2 cells were stably tr ansfected with an antisense construct that targets regions of genes 5 and 6 of the virus, High levels of expression from this construct, whi ch is under control of the human elongation factor 1 alpha promoter, w ere found. After infection of the antisense cell lines with MHV, repli cation of the virus was significantly reduced compared with control ce lls, In a viral plaque assay, smaller plaques were found in the antise nse cell lines, In addition, up to a 92% inhibition in the number of v iral particles produced in one antisense cell line could be seen. This inhibitory effect decreased at longer (>16 hour) infection times. It was possible to both increase the amount of inhibition and prolong the inhibitory effect by reducing the multiplicity of infection. Our resu lts suggest that antisense RNA may be an effective tool to slow down p rogression of MHV infection in mice.