M-CSF treatment increases DC numbers in vivo. FLKO mice were treated for 5 consecutive days with 10 μg/day M-CSF i.p. in 0.01% BSA in PBS or with vehicle alone (control). DC were purified from FLKO spleens and stained with CD11c and CD45RA and shown gated in (A). Total splenocytes and pDC and cDC populations were enumerated and are shown as a -fold increase compared with vehicle-treated mice (B). Data are pooled from 3 individual mice within 2 separate experiments compared with control mice analyzed the same day.