Fig 1. Generation of the recombinant MCMV expressing the ₅₃₃IYSTVASSL₅₄₁ epitope.

The sequence of IAV epitope ₅₃₃AAIYSTVASSL₅₄₁ (IVL_533-541) was introduced at the C-terminus of the MCMV ie2 gene, and the growth of the recombinant virus MCMV^IVL was tested in vitro and in vivo. (A) The location of the ie2 gene within the MCMV genome at ~186-187kb position is shown; the insertion site of the peptide IVL_533-541 and the corresponding nucleotide sequences are magnified. (B) MCMV^IVL and wild-type MCMV (MCMV^WT) growth at a multiplicity of infection of 0.1 was compared in NIH-3T3 cells. Virus titers in supernatants expressed as plaque-forming units (PFU) were established at indicated time points. Group means +/- standard error of the mean (SEM) are shown. The dashed line indicates the limit of detection. (C) BALB/c mice were i.p. infected with 2 x 10⁵ PFU of MCMV^IVL or MCMV^WT virus. Spleen, lung and liver homogenates were assayed for virus titers 5 days post-infection (dpi). Salivary-gland (SG) homogenates were assayed 21 dpi. Each symbol represents one mouse. Group means +/- standard error of the mean (SEM) are shown. The dashed line indicates the limit of detection.