Neonatal microglia can be skewed toward a DC-like or macrophage-like
phenotype by GM-CSF or M-CSF. (A) Neonatal microglia
express c-kit, but not flt3, as analyzed by flow cytometry (c-kit,
clone 2B8; flt3, A2F10.1). (B) Phenotypic markers are
differentially expressed on neonatal microglia after administration of
myeloid growth factors. Neonatal microglia were cultured with or
without 5 ng/ml GM-CSF or 1 ng/ml M-CSF from the beginning of the
mixed glial culture. (Upper) Phase-contrast confocal
microscopy of microglia skewed as described above (magnification:
microglia, ×69; GMCSF and MSCF, ×100). (Lower)
Cell-surface expression of CD11b (clone M1/70), CD11c (clone HL3),
mannose receptor (clone Dec205), B7–1 (clone 16–10A1), and B7–2
(clone GL1) was analyzed by flow cytometry.