Figure 4.

α-GalCer acts in vivo and in vitro to suppress colony formation. C57BL/6 mice were injected i.p. with α-GalCer 100 μg·kg⁻¹ in a 400 μL volume of PBS containing 2% DMSO (vehicle), once, 24 h before killing and bone marrow collection Controls received vehicle in the same conditions Bone marrow cells (2 × 10⁵ cells mL⁻¹, in Iscove's modifed Dulbecco's medium with 20% FCS) were pre-incubated for 2 h in the presence of GM-CSF (2 ng·mL⁻¹ final concentration), alone (GM-CSF) or together with α-GalCer 10⁻⁸M (GM-CSF+α-GalCer) before mixing with agar (0.3% final concentration) and plating in triplicate. Total myeloid colonies were scored at day 7 under an inverted microscope. Data are mean ± SEM (n = 4 for all groups). *P ≤ 0.05, **P < 0.01, significantly different as indicated.