CD1 molecules are refolded in vitro.

This step of the new maturation protocol involves maturation with TNF-alpha, IFN-gamma, and PGE2.

Differentiation of monocytes into dendritic cells is promoted by addition of granulocyte-macrophage colony-stimulating factor (GMCSF 1000U/ml, Chemicon) and recombinant IL-4 (1000U/ml, R&D Systems) for 5 days.