Wild type C57BL/6 or CD28-/- knockout mice infected with Smith MCMV (5 × 104 pfu) had liver and splenic tissues evaluated 2 days after infection. Total RNA were prepared and subjected to real-time PCR analysis for IL-1, IL-2, IL-12, IL-15, IL-17, IFN-γ, TNF-α and IFN-α. There were no significant differences in IL-1, IL-17 or TNF-α transcripts between wild type and CD28-/- mice either in liver or spleen (not shown). Data shown in are arbitrary transcripts units (relative to GAPDH) for IFN-α, IFN-γ, IL-2, IL-12 and IL-15 in liver or spleen 2 days pi. Significant differences are noted by p-values in this figure. Each data point represents mean ± standard error for 3 - 4 mice.