Fig. 6.
Precursor cells for multinuclear osteoclasts exist in the Flt-1+CD11b+ cell fraction obtained from CD34+Flt-1− cord blood mononuclear cells.
Flt-1+CD11b+ and Flt-1++CD11b++ cell fractions obtained from CD34+Flt-1− cord blood mononuclear cells after a 2-week incubation (A) were further cultured with M-CSF and ODF/sRANKL cytokines (see “Materials and methods”). Flt-1+CD11b+ cells but not Flt-1++CD11b++ cells (B) efficiently differentiated into multinuclear osteoclasts, which are negative for phagocytic activity but positive for expression of VNR. Scale bar indicates 100 μm in length. The numbers of the multinuclear (▪) and mononuclear (░) osteoclasts started from 3 × 104Flt-1+CD11b+ or Flt-1++CD11b++ cells are indicated in panel C.