Figure 1.

Modulation of LPS‐induced pro‐inflammatory cytokine production in human PDL cells. Vitamin D/VDR presumably attenuates cytokine production at the transcriptional level. The antimicrobial peptide LL‐37 can bind and neutralize LPS extracellularly, but it may also interact with the synthesis of cytokines downstream of NF‐κB, leading to reduced cellular cytokine production. Secretory leukocyte protease inhibitor (SLPI) is a protein expressed in PDL cells, and it seems to act as a negative regulator of cytokine production via interaction with TLR4 expression and NF‐κB activity. Glucocorticoids (GC) reduce PDL cell production of pro‐inflammatory cytokines probably through inhibition of NF‐κB activity. Please, note that TLR4 is a plasma membrane receptor