Immobilized C1q differentially modulates LPS-induced cytokine release by human phagocytic cells according to their differentiation state. Cytokine levels were measured by Luminex multiplex analysis of the supernatant of phagocytic cells plated on LabTek chamber slides coated with 8 μg/ml C1q (□) or HSA control (■) and stimulated with 0 or 10 ng/ml LPS for 18 h. Data are mean values from a single experiment using donor-matched monocytes, HMDMs, and iDCs, performed in triplicate ± SD, and representative of data obtained in three experiments using different donors. *, p < 0.05; **, p < 0.005, Student's t test.