Reovirus effect on stem cells. (A) Lack of reovirus effect on cultured stem cells. CD34⁺ cells were isolated using negative selection columns and cultured in StemSpan medium in the presence or absence of reovirus (40 MOI). Cells were harvested 0, 1, 2, and 5 days after virus infection, and CD34⁺ cells were enumerated by flow cytometry. Error bars indicate the standard deviation of the mean of 3 replicates. (B) Lack of reovirus effect on stem cell progenitor assay. Stem cells (CD34⁺) were selected and treated with reovirus as described. Samples taken at the days indicated were cultured in methylcellulose and scored for CFU-GMs, BFU-Es, and CFU-GEMMs. NV indicates no virus; LV, live virus. Error bars indicate the standard deviation of the mean of 3 replicate plates. (C) Lack of reovirus protein synthesis detected by [³⁵S]-methionine labeling in apheresis product primed with G-CSF. Apheresis product cells were primed with G-CSF and pulse labeled with [³⁵S]-methionine with or without reovirus treatment (40 MOI). At time points indicated in the figure, cellular proteins were harvested and subjected to SDS-PAGE. Reovirus marker proteins (λ, μ, and σ) are indicated in lane 1. Note the absence of viral protein bands at all time points after virus infection.