Fig. 1.

Differentiation of human blood monocytes into functionally distinct Mϕ subsets, Mϕ-1 and Mϕ-2. (A) In contrast to mo.DCs, Mϕ-1 and Mϕ-2 highly expressed CD14 but showed no or only weak expression of CD1a or CD83 (the latter after activation by LPS) as determined by flow cytometry. Cytokine secretion was measured up to 72 h after stimulation with M. tuberculosis sonicate (myc) (▪), LPS (•), or medium control (♦). (B) Whereas activated Mϕ-1, similar to DCs, secreted high levels of IL-12p40, Mϕ-2 failed to secrete IL-12p40. (C) IL-10, in contrast, was most predominant in Mϕ-2. Similar cytokine profiles were obtained with cells from at least 10 independent donors.