Conclusion
PlGF enhances TLR-signaling upstream of IKK and contributes to an exaggerated pathologic pro-inflammatory state in response to activation of maternal and fetal mononuclear phagocytes by specific TLR agonists.
Results
PlGF significantly enhanced the magnitude and duration of TNF messenger RNA and protein production by TLR-7/8-activated monocytes, and increased subsequent production of TNF-independent inflammatory cytokines. This PlGF/TLR effect involved multiple inflammatory cytokines/chemokines and was seen with the majority of TLR agonists. PlGF enhanced phosphorylation of IkappaB kinase (IKK) in monocytes stimulated with the TLR-7/8 agonist R848, and IKK inhibition completely suppressed the PlGF effect.