Figure 4. SCARF1 regulates AC-induced phosphorylation of MAPK and STAT Kinases.

(A) Upregulation of STAT genes in SCARF1⁺ BDCA1⁺ DCs. PBMCs were isolated from healthy controls and treated with apoptotic cells for 4 hours. Live CD11c⁺BDCA1⁺ DCs were sorted into SCARF1 negative (SCARF1^Lo) or SCARF1 positive (SCARF1^Hi) groups. mRNA was extracted, and the genetic profiling was measure by Nanostring immunology panel. Unbiased heatmap depicting the regulation of kinases. Gene expression as log 2 after normalization using Morpheus software. Representative heatmap of single Nanostring assay (n=4). U-unstimulated. P values by Students t-test. (B-I) SCARF1 is partly responsible for phosphorylation of kinases. PBMCs from healthy controls (1x10⁶/mL) were treated with SCARF1-blocking antibody for 30 min or left untreated, then Live/Dead-UV-labeled apoptotic cells were added for 15 or 30 minutes. Cells were immediately fixed and stained for flow cytometry. Cells were gated on CD11c⁺BDCA1⁺SCARF1⁺ in the presence or absence of apoptotic cells. Left panel: MFI quantification, Right panel: Representative histograms (B-C) p-MAPK p38 Thr180/Tyr182, (D-E) p-STAT3 Tyr705, (F-G) p-STAT1 Tyr701, (H-I) p-ERK p44/42 Thr202/Tyr204. MFI, mean fluorescent intensity. Data represent the mean (±SEM) of 2 independent experiments n= 4 independent individuals. P *(<0.02), ns (not significant) by the Mann-Whitney test.