N-WASP deletion protects mice from autoimmune manifestations. (A) Anti-single-stranded DNA (ssDNA) and anti-double-stranded DNA (dsDNA) IgG antibodies as measured by enzyme-linked immunosorbent assay and (B) detection of IgG autoantibodies by protein array in the serum of indicated mice. Results are shown for autoantibodies with significantly decreased reactivity (as assessed by significance analysis of microarray with false discovery rate <1) in B/DcKO mice compared with B/WcKO mice. Shown are heat maps of net fluorescence intensity ratios between each mouse and the average plus 2 standard deviations for the net fluorescence intensity ratios for WT mice for each antigen. Range is from 0 (blue) to 1 (black) to 5 (yellow). Sera from systemic lupus erythematosus–prone MRL-lpr/lpr mice were used as a positive control. (C) Periodic acid–Schiff staining of formalin-fixed paraffin-embedded kidney sections reveals severe hypercellularity and capillary wall thickening in WKO and B/WcKO mice, but not in B/DcKO mice age 7 to 14 months. Representative tissue pathology of 8 to 15 mice per group is shown. (D) Blinded pathological glomerular scoring (ranging from 0 [no glomerular pathology] to 3 [severe glomerular pathology]) performed by a nephropathologist, confirming kidney damage in WKO and B/WcKO, but not in B/DcKO mice. Statistical significance was assessed by Mann-Whitney test (enzyme-linked immunosorbent assay detection of autoantibodies and pathological score) and significance analysis of microarray (protein array). *P < .05, **P < .01, ***P < .001).