BM DCs express a range of complement components, regulators, and receptors and C3a is generated locally. BM DCs were prepared from WT C57BL/6 mice. (A) Conventional RT-PCR was performed in DCs with 24-hour LPS stimulation. The typical agarose gels show the PCR products for C1q, C3, fB, properdin, and 18S (internal control, upper gel), and CR3, CR4, C3aR, C5aR, and 18S (lower gel). The 50-bp DNA markers (M) are shown along side the gels. (B) qPCR was performed in DCs with or without 24-hour LPS stimulation. (C) Detection of C3a in the supernatants from different stages (days 4, 6, and 7) of WT DC culture by ELISA. Activated mouse serum (1 of 10 000 dilution) was used as C3a positive control, and the supernatant from C3^−/− DC culture at day 7 was used as a negative control. All results are representative of at least 3 independent experiments. Data in panels B and C are means plus or minus SEM (n = 9). Data were analyzed by Student t test. P values are for comparisons between no LPS and LPS treatment (**P < .001; ***P < .0001).