Fig. 5

VIP inhibits TLR2 and TLR4 upregulation in LPS-stimulated human THP1 monocytes. a Unstimulated THP1 cells cultured for 24 h following conversion to monocytes by vitamin D3 (monocytic THP1 cells); b monocytic THP1 cells cultured with P. Gingivalis W50 LPS (100 ng/ml) for 24 h with a subsequent 35% increase in TLR2^high expressing cell population; c monocytic THP1 cells cultured with P. gingivalis W50 LPS (100 ng/ml) and VIP (10⁻⁸ M) for 24 h, showing a 10% increase in TLR2^high expressing cell population (25% reduction due to VIP). d monocytic THP1 cells cultured with E. coli 0111:B4 LPS (100 ng/ml) for 24 h with a subsequent 32% increase in TLR4^high expressing cell population; c monocytic THP1 cells cultured with E. coli 0111:B4 LPS (100 ng/ml) and VIP (10⁻⁸ M) for 24 h, showing a 6% increase in TLR4^high expressing cell population (26% reduction due to VIP). Arrows highlight CD14^high/TLR2^high and CD14^high/TLR4^high population. Data is representative of results obtained from 10 replicate experiments