FIG. 10.

The S and N genes of MHV-A59 are not responsible for the induction of TNF-α. (A) Schematic diagram of the MHV genome highlighting the differences in S and N genes in the recombinants Penn-98-1 and icA59/2N with respect to the parental MHV-A59 and MHV-2. (B and C) Induction of TNF-α and IL-6 in primary astrocytes by MHV infection. Primary astrocytes were infected with the recombinant viruses Penn-98-1 and icA59/2N or the parental viruses MHV-A59 and MHV-2 at an MOI of 5, and the cell culture supernatants were collected at 24 h p.i. The protein levels of TNF-α and IL-6 were determined by ELISA and are expressed as mean numbers of picograms per milliliter in three independent experiments. The error bars indicate standard deviations of the means. The asterisks indicate statistical significance between the pairs (P < 0.05).