FIGURE 3.

CD155 induction in response to both IL-4 and LPS is dependent on AhR. (A) The PVR region upstream of the transcriptional start site contains a DRE identified as an AhR responsive site by JASPAR analysis. (B) THP-1 cells were pre-treated with AhR inhibitor SR1 24h prior to stimulation with IL-4 or LPS, fractionated, and analyzed for AhR levels by immunoblot. (C) THP-1 cells were treated as in (B) and RT-qPCR was performed to examine (AhR transcriptional target) AhRR and CYP1B1 transcript levels (n=5). (D) THP-1s were treated as in (B, C). CD155, PD-L1 levels and the STAT1, STAT6, p38 signaling response were analyzed by immunoblot. (E) THP-1 cells were pre-treated with β-catenin inhibitor JW-67 analyzed as in (D). (F) Transient AhR depletion with siRNA prior to IL-4 stimulation abrogated CD155 induction in THP-1 cells (n=4). (G) MDMs were pre-treated with AhR inhibitors SR1, GNF-351 (GNF), and CH223191 (CH), and CD155 expression was measured and quantified using immunoblot (n=3). Data in (B), (D), and (E) are representative of three repeats