Diagram showing proposed interaction between complement and the TLR pathways. PAMPs such as LPS and zymosan can activate both pathways. Activated complement regulates TLR signaling through the G-protein-coupled anaphylatoxin receptors C5aR and C3aR, MAPKs, NF-κB, and likely other transcription factors. In the absence of the complement regulatory protein DAF, complement activation and its effect on TLR signaling is amplified. The absence of DAF may be mimicked by strong complement activators such as CVF or pathological conditions such as sepsis.