All-trans retinoic acid induces TLR-5 expression and cell differentiation and promotes flagellin-mediated cell functions in human THP-1 cells

All-Trans Retinoic Acid Enhances Bacterial Flagellin-Stimulated Proinflammatory Responses in Human Monocyte THP-1 Cells by Upregulating CD14

“…e cell surface expression of TLR5 was gradually reduced in a time-dependent manner upon treatment with 1 μM ATRA, and the expression level at 48 h after ATRA treatment was approximately 45% of that of the control (Figure 5(c)). e present results suggest that the ATRA-enhanced inflammatory responses against flagellin in THP-1 cells may not be due to the increased cell surface levels of TLR5, opposing the findings of the previous report which indicated that ATRA enhances cell surface expression of TLR5 in THP-1 cells [14].…”

“…To determine agonist effects, RARα agonist BMS753 and RXRα agonist LG100268, which were purchased from Sigma-Aldrich, were used. Cells were treated with agonist for 24 h and then stimulated with 10 or 100 ng/ml of flagellin from S. typhimurium for 24 h. We chose concentrations of ATRA and flagellin according to established protocols [14,15]. To determine antagonist effects, RARα antagonist BMS195614 (Sigma-Aldrich) and RXRα antagonist UVI 3003 (Santa Cruz Biotechnology, Dallas, Texas, USA) were used.…”

“…In addition, ATRA significantly inhibited LPS-induced prostaglandin E2 production and cyclooxygenase-2 expression in mouse peritoneal macrophages, as well as TNF-α release in rat peripheral blood mononuclear cells [13]. To the best of our knowledge, only one study has reported on the immune potentiating effects of ATRA, which increases the flagellinmediated immune response of human monocytes by inducing TLR5 expression [14].…”

Retinoic acid receptor β deficiency reduces splenic dendritic cell population in a conditional mouse line

“…These authors confirm that TLR2 and TLR4 mRNAs expression levels were positively correlated with both the levels of proteins and their function. On the other hand, it was previously shown that treatment of primary human monocytes with retinoic acid does not affect TLR1 or TLR4 expression [53,54]; similarly, in RAR␤ L−/L− mouse model we did not observe altered TLR1 or TLR4 mRNA expression in spleen of RAR␤ deficient mice. However, we observed that TLR2 expression was diminished in the spleen of RAR␤ conditional mice, but not in CD11c + DCs.…”

Targeting of folate receptor β on acute myeloid leukemia blasts with chimeric antigen receptor–expressing T cells

“…Notably, ATRA is known to induce differentiation of THP1 and HL60 44,45 as measured by greater cytokine production and co-stimulatory molecule expression. 46 ATRAmediated differentiation of AML cells may have heightened the allogeneic T-cell response. However, the largest differences in reactivity were observed when m909 CAR T cells were incubated with ATRAtreated FRb 1 AML, suggesting that greater antigen density played the dominant role in mediating increased m909 CAR T-cell reactivity.…”