The contribution of IRF7 to a TLR7-driven FcγRIIB ^−/− model of SLE. (A–H) B and T cell responses were evaluated in the spleens of FcγRIIB^−/−yaa (RIIB^−/−yaa) and FcγRIIB^−/−yaaIRF7^−/− (RIIB^−/−yaaIRF7^−/−) mice at 2 and 4 mo of age. (A) Spleen weight of RIIB^−/−yaa and RIIB^−/−yaaIRF7^−/− mice. (B and C) (B) Flow cytometry gating strategy and (C) frequency and number of B220⁺GL-7⁺CD95⁺ GC B cells of total B220⁺ B cells. (D and E) (D) Number and (E) flow cytometry gating strategy and frequency of CD138⁺TACI⁺ PCs in IgD⁻ B cells. (F) Frequency of IgD⁻CD11b⁺CD11c⁺ ABCs of B220⁺CD19⁺ B cells in the spleen. (G and H) Frequency of (G) CD4⁺CD44⁺CD62L⁻ Teffs of total CD4⁺ cells and (H) CD4⁺CD44⁺CD62L⁻CXCR5⁺PD-1⁺ Tfh of total CD4⁺ cells. (I) Serum IgG and IgG2c anti-SmRNP antibodies were measured by ELISA. (J and K) High-dimensional flow cytometry analysis of kidney immune cell infiltrates identifying following populations: total CD45⁺ cells, CD45⁺CD11b⁻CD19⁺B220⁺ B cells, CD45⁺CD19⁻CD11b⁻CD11c⁺B220⁺CD317⁺ pDCs, CD45⁺CD19⁻B220⁻CD56⁻CD11b⁺CD11c⁺MHCII^hi iDCs, CD45⁺CD19⁻B220⁻CD56⁻CD11b⁺CD11c⁺Ly6c⁺Ly6G⁻ moDCs, CD45⁺CD19⁻B220⁻CD56⁻CD11b⁻CD11c⁺MHCII⁺ cDCs, CD45⁺CD19⁻B220⁻CD56⁻CD11b⁺Ly6C⁺Ly6G⁻ monocytes, CD45⁺CD19⁻B220⁻CD56⁻CD11b⁺Ly6C⁺Ly6G⁺ neutrophils, CD345⁺B220⁻CD19⁻CD56⁻CD11b⁺F4/80⁺MHCII⁺ macrophages, CD45⁺CD19⁻B220⁻CD11b⁻CD4⁺ CD44⁺CD62L⁻ CD4⁺ Teffs, CD45⁺CD11b⁻B220⁻CD19⁻CD4⁻CD8⁻CD56⁺ NK cells, and CD45⁺CD19⁻B220⁻CD11b⁻CD8⁺CD44⁺CD62L⁻ CD8⁺ Teffs. (L and M) (L) BUN and (M) creatinine levels were measured in sera collected from 4-mo-old mice. (N) The percentage of survival in RIIB^−/−yaa and RIIB^−/−yaaIRF7^−/− mice. Each symbol represents an individual mouse, and data are presented as means ± SEM. Data in panels A–I and N (n = 7–13 mice per group) represent three experiments. Data in panels J–M (n = 5–11 mice per group) represent two to three experiments. P values were calculated via two-way ANOVA with Dunn–Sidak correction (A–K), an unpaired Student’s t test (L), Mann–Whitney test (M), or log-rank (Mantel–Cox) test (N) (*, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001). NS, not significant; cDCs, conventional DCs; moDCs, monocyte-derived DCs.