Figure 6.

Reconstituted antibodies colocalize and activate complement. Colocalization of (A) IgM and C3d, and (B) IgG and C3d shows increased antibody binding and complement activation in Rag1 recipients reconstituted with pooled serum of CS mice. Antibody and complement colocalization can be seen on epithelial and endothelial cells in a pattern not dissimilar to that seen in allograft transplants. n = 3 in all groups. IgM, IgG, and C3d immunofluorescent staining was quantified in all groups. Note the significant in increase in (C) IgM, (D) IgG, and (E) C3d in CS serum-reconstituted mice as compared with NS and CS Ig-depleted serum-reconstituted mice. ^#P < 0.01 for NS versus CS; ^##P < 0.001 for CS versus CS IgM- and IgG-depleted serum.