Figure 3.

Functional elimination of IRAK4 prevents splenomegaly and associated leukocyte expansion observed in lupus-prone mice. Sle1, Sle1IRAK4^KD/KD, Sle1Tg7, and Sle1Tg7IRAK4^KD/KD female mice were aged to 6–7 months and analyzed for characteristic autoimmune immunological traits. (A) Frequency of the indicated splenic leukocytes evaluated by flow cytometry. (B) Representative flow plots of plasma cells (CD138⁺B220⁻) from spleens of Sle1Tg7 and Sle1Tg7IRAK4^KD/KD mice with cumulative data from all strains. (C) GC B cell frequency measured by flow cytometry as GL7⁺Fas⁺ cells, represented as % B cells (CD19⁺B220⁺). (D) Representative immunofluorescent images of splenic GC staining, 300 x scale bar represents 50 μm, with anti-GL7 (blue), anti-CD4 (red) and anti-IgD antibodies (green). (E) Cumulative frequency of marginal zone (MZ) B cells (CD21⁺CD23⁻) across all strains (represented as % of CD19⁺B220⁺ B cells). (F) Representative flow plots of age-related B cells (CD11b⁺CD11c⁺) with cumulative data (represented as % of CD19⁺B220⁺ B cells). (G) Cumulative data of CD4⁺ CXCR5⁺PD1⁺ T follicular helper (T_FH) cells, and (H) the frequencies of naïve (CD44^lowCD62L^high) and effector memory (CD44^highCD62L^low) (represented as % of CD3⁺CD4⁺ T cells). (I) Frequencies of splenic CD11b⁺CD11c⁺MHC-II⁺ DCs and CD11b⁺CD11c⁺MHC-II⁻ cells. Flow cytometry data is from 17 to 23 mice per group. Parametric data were assessed by 1-way ANOVA (with Bonferroni's multiple comparisons test) and non-parametric data with Kruskal-Wallis (with Dunn's multiple comparisons test) ^*P < 0.05, ^**P < 0.01, ^***P < 0.001, ^****P < 0.0001. Additional comparisons between two groups were made with a Student's t test or Mann-Whitney test for parametric and non-parametric data, respectively, indicated by # (^#P < 0.05, ^##P < 0.01).