Figure 7. B cell-intrinsic TLR7 and TLR9 exert opposing effects on IC glomerulonephritis.

(A) Left panels: Representative examples of glomeruli from B^WAS−/−, B^{W/TLR7−/−} and B^{W/TLR9−/−} chimeras stained with Jones’ methenamine silver-Periodic acid-Schiff stain. Right panel: Glomerular inflammation scored as: (0+) minimal mesangial expansion consistent with radiation injury; (1+) focal glomerular changes with moderate mesangial expansion, GBM thickening/reduplication and glomerular hypercellularity; or, (2+) diffuse glomerular changes with severe mesangial expansion, GBM thickening/reduplication and glomerular hypercellularity. Pathology was scored by two observers blinded to genotype. (B–D) Glomerular immune-complex deposits were determined by immunofluorescence staining for: (B) IgG (C) IgG2c, and (D) complement C3. Representative images are shown (left), together with intensity of glomerular fluorescent staining (right) scored from 0–3+ by two independent, blinded observers. (E) Left panels: Representative images of immunohistochemistry staining for glomerular MAC-2⁺ macrophages. Right panel: MAC-2⁺ area as a percentage of total glomerular area determined using Image Pro Plus (Media Cybernetics, Inc.). 4 independent kidney sections were examined per mouse. Bars, 50μm. (A–E) Results are mean ± s.e.m. *, P<0.05; **, P<0.01; ***, P<0.001. Total mice analyzed (A–D, E): B^WT (n=6, 4), B^WAS−/− (n=14, 6), B^{W/TLR7−/−} (n=11, 9), and B^{W/TLR9−/−} (n=15, 8), from 3 (A–D) and 2 (E) independent experimental cohorts.