MCMV Smith strain was used in all experiments. This strain was prepared as a salivary gland-passaged stock from CD1 mice. Moderate dose infection (5610 4 PFU per mouse) was initiated on day 0 by intraperitoneal injection. In vivo responses were measured at indicated time points. For infectious viral titer quantification, organs were weighed, homogenized in cold supplemented DMEM (Invitrogen Life Technologies) and supernatants were collected following centrifugation. Serially diluted samples were used to inoculate confluent monolayers of bone marrow stromal cells (ATCC M2-10B4) in 24-well tissue culture plates and incubated for one hour at 37uC, 5% CO 2 . Following incubation, inoculums were removed and monolayers were overlaid with a 16DMEM/0.5% low-melt agarose solution. Cells were incubated for 7 days at 37uC, 5% CO 2 , then fixed in 10% buffered formalin and stained with crystal violet. Plaques were counted to determine viral titer as previously described [22, 24, 26] .