SELF-RENEWING CANINE OLIGODENDROGLIAL PROGENITOR EXPANDED AS OLIGOSPHERES

We have previously shown that oligodendroglial progenitors (OP) can be generated from multipotent rat neural precursor cells. We now report the generation of a homogeneous culture of canine OP from neural precu rsor cells. In non-adherent cultures, homogeneous OP cultures were obt ained in 6-8 weeks of treatment with B104 cell conditioned medium (B10 4CM), In adherent cultures where astrocytes grew as a layer of substra te, colonies of OP invariably appeared at 10-14 days in vitro (DIV) an d the colonies were expanded as free-floating spheres (oligospheres), in the presence of B104CM, suggesting that astrocytes facilitate the g eneration of canine OP. The oligosphere cells were characterized by se lf-renewal in the presence of B104CM and by terminal differentiation i nto oligodendrocytes after withdrawal of B104CM, Transplantation studi es indicated that the extensively expanded oligosphere cells retained myelination capacity. The oligospheres thus provide a valuable source for experimental cell therapy studies. J. Neurosci. Res. 54:181-190, 1 998. (C) 1998 Wiley-Liss, Inc.