LDNs express detectable levels of TLR7 and undergo TLR7-induced NETosis. (A) Gating strategy showing that NET-appendant neutrophils detected by Sytox Orange and DAPI positivity were increased following R848 treatment in LDNs but not HDNs. (B) Cumulative data showing R848-induced NETosis in LDNs and HDNs from 10 SLE patients and 16 healthy controls. (C, D) Correlative assessment of R848-induced LDN NETosis with SLE disease activity and treatment. (E) RNA-seq analysis of TLR7 mRNA expression in circulating HDNs and T CD4⁺ Th1, CD4⁺ Th2 and CD4⁺ Th17 T cells (green), naïve and switched memory (SM) B cells (blue), and pDCs (red). (F) Meta-analysis of TLR7 mRNA expression in LDNs and HDNs from three microarray and RNA-seq gene expression datasets. (G) Quantitative RT-PCR analysis of TLR7 mRNA expression in HDNs and LDNs in healthy controls (n = 5) and SLE patients (n = 10). Significance was determined using two-way analysis of variance, Spearman’s rank-order correlation and Wilcoxon signed-rank test (^#). *^/#P < 0.05 and ***P < 0.001