FIGURE 6.

B cell deficiency reduced intragraft macrophages. A, Quantitative immunohistochemistry demonstrated increased levels of CD68 within allogeneic allografts compared to syngeneic allografts. Sensitized recipients had greater levels of CD68 within the allograft compared to allogeneic recipients. B^−/− allogeneic recipients had reduced levels of CD68 compared to sensitized recipients. P<0.0001 by 1-way ANOVA. B, Representative histology of CD68 deposition (brown stain, indicated by arrows) within the allograft is shown (magnification x200). C, CD68 protein was measured by immunoblot of kidney lysates and reported as relative protein level normalized to GAPDH. CD68 protein was increased in allogeneic compared to syngeneic allografts. Similarly, CD68 protein levels were greater in sensitized compared to allogeneic allografts. CD68 protein levels were decreased in allografts from B^−/− allogeneic recipients compared to allogeneic recipients at 6 months and compared to sensitized recipients at 3 and 6 months. P=0.0003 by 1-way ANOVA. D, The mean number of CD68⁺ cells per glomerulus were determined. There were fewer CD68⁺ cells per glomerulus in B^−/− allogeneic recipients compared to sensitized allogeneic recipients. P=0.002 by 1-way ANOVA. Data presented as mean ± standard deviation. Data points on graph represent individual animals. *P<0.05, **P<0.01 Syn, syngeneic; Allo, allogeneic; Sens Allo, sensitized allogeneic; B^−/− Allo, B cell deficient allogeneic