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Fig. 1 | Arthritis Research & Therapy

Fig. 1

From: Cytokine production by activated plasmacytoid dendritic cells and natural killer cells is suppressed by an IRAK4 inhibitor

Fig. 1

Regulatory effect of hydroxychloroquine (HCQ) and the interleukin-1 receptor associated kinase 4 inhibitor (IRAK4i) I92 on tumor necrosis factor (TNF)-α and interferon (IFN)-α production. ad Cocultures of plasmacytoid dendritic cells (pDC) and natural killer (NK) cells from healthy donors were stimulated with RNA-containing immune complexes (RNA-IC) for 5 h (a,b) or 9 h (c,d) in the absence or presence of HCQ or I92. The frequencies of TNF-α- and IFN-α-producing NK cells (blue) and pDCs (red) were determined by flow cytometry. The dot plots represent one representative individual donor from two (HCQ) and four (IRAK4i) donors analyzed. e,f pDCs or NK cells were cultivated separately or in coculture in the presence of RNA-IC with or without I92 or HCQ. Cytokine levels were measured by immunoassays after 20 h. No IFN-α is produced by NK cells (data not shown). No cytokines were detected in the cell cultures in the absence of RNA-IC. Bars represent the mean with standard error of the mean (SEM) of nine donors from at least three independent experiments. Friedman’s test, uncorrected Dunn’s test; *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. BDCA blood dendritic cell antigen

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