Identification, isolation, and promoter-defined separation of mitotic oligodendrocyte progenitor cells from the adult human subcortical white matter

Previous studies have suggested the persistence of oligodendrocyte progenit or cells in the adult mammalian subcortical white matter. To identify oligo dendrocyte progenitors in the adult human subcortical white matter, we tran sfected dissociates of capsular white matter with plasmid DNA bearing the g ene for green fluorescence protein (hGFP), placed under the control of the human early promoter (P2) for the oligodendrocytic protein cyclic nucleotid e phosphodiesterase (P/hCNP2). Within 4 d after transfection with P/hCNP2: hGFP, a discrete population of small, bipolar cells were noted to express G FP. These cells were A2B5-positive (A2B5(+)), incorporated bromodeoxyuridin e in vitro, and constituted <0.5% of all cells. Using fluorescence-activate d cell sorting (FACS), the P/hCNP2-driven GFP(+) cells were then isolated a nd enriched to near-purity. In the weeks after FACS, most P/hCNP2: hGFP-sor ted cells matured as morphologically and antigenically characteristic oligo dendrocytes. Thus, the human subcortical white matter harbors mitotically c ompetent progenitor cells, which give rise primarily to oligodendrocytes in vitro. By using fluorescent transgenes of GFP expressed under the control of an early oligodendrocytic promoter, these oligodendrocyte progenitor cel ls may be extracted and purified from adult human white matter in sufficien t numbers for implantation and cell-based therapy.