R-848 induces transiently reduced availability of PBLs (TRAP) in an MyD88-dependent fashion. Mice were bled from the tail vein immediately before injection of PBS or R-848. Between 24 hours and 48 hours after injection the same mice were bled again. Blood samples were cleared of erythrocytes by osmotic shock and the samples analyzed by flow cytometry for the presence of mononuclear cells (A). The same samples were also analyzed for the presence of CD4⁺, CD8⁺, GR-1⁺, or B220⁺ cells. Shown are time courses of the amount of these cell types in the blood relative to the amount present before injection of PBS or R-848 in wild-type (wt) (B) or MyD88 knock-out (ko) animals (C). Each point in panels B and C represents data of at least 3 individually measured animals (compare Table 1). Error bars indicate standard deviation.