Involvement of autocrine M-CSF consumption in M2d generation. (A) At the indicated times, M-CSF was quantified in the SNs of monocytes cultured in CM without or with LIF, IL-6, or OSM. Results are expressed in ng/mL as means plus or minus SD; n = 4. (B) At day 2, M-CSF was quantified in the SNs of monocytes activated with 10 to 100 ng/mL LIF or IL-6. Results are expressed in ng/mL as mean plus or minus SD; n = 4. (C) PCR analysis of M-CSF, M-CSF-R, IL-6, LIF, and OSM mRNA expression in monocytes cultured for 16 hours in CM without or with IL-6, LIF, or OSM. Results are representative of 1 of 3 experiments. (D-F) Monocytes were cultured in CM without or with IL-6, LIF, or M-CSF without or with neutralizing anti–M-CSF and/or anti–IL-6 mAbs or control mAbs. On day 5, LPS was added and CD86 expression (D) and IL-12 production (E) were analyzed 48 hours later. After LPS stimulation, macrophages were cultured with allogenic CD4⁺ T cells, and [³H]-thymidine incorporation was measured at day 4 (F). Results are expressed as the percentages of restoration (mean ± SD; n = 4). (G) Monocytes were cultured in CM without (dotted line) or with (full line) IL-6, and M-CSF-R expression was analyzed by FACS after 24 hours. Results are representative of 1 of 4 experiments. Shaded areas correspond to the control mAb. (H) Monocytes were cultured in CM without or with LIF or IL-6, and M-CSF-R expression was analyzed by FACS after 24 and 48 hours. Results are expressed in MFI (mean ± SD; n = 4). (I) At the indicated times, IL-6 was quantified in the SNs of monocytes maintained in CM without or with LIF, OSM, or M-CSF. Results are expressed in ng/mL as means plus or minus SD; n = 4. *P < .05.