Figure 6

Germinal center B cells are increased in SLAM¹²⁹but not RIIB^−/−mice. (A, Left) Slight splenomegaly in female RIIB^−/− mice. Spleen weights were measured for each line of both genders (F, female; M, male) and are presented as the ratio of the weight per body weight. Horizontal bars indicate mean values, excepting the plot of RIIB^−/−SLAM¹²⁹ male for single determination. ***P <0.001. Student’s t-test. (A, Right) Total splenic lymphocytes in each line. Horizontal bar represents the mean number of total splenocytes, excepting the plot of RIIB^−/−SLAM¹²⁹ male for single determination. N.S., not significant. Student’s t-test. (B) Germinal center formation in naïve B6, N22 female RIIB^−/−, and female and male SLAM¹²⁹ mice at 45 weeks of age. Frozen spleen sections were stained with GL7-Alexa488 and Alexa546-labeled anti-mouse IgD antibodies. Scale bar =10 μm. (C) Flow cytometric determination of germinal center (GC) B cells of B6, female SLAM¹²⁹ and N22 female RIIB^−/− mice at 45 week of age. Splenocytes were gated with anti-CD19-APC, and analyzed for anti-Fas-PE and GL7-FITC. (D) Total GC cells and GC B cells are not significantly increased in female RIIB^−/− mice. The percentage of GC B cells in splenic CD19⁺ cells (Left), and the absolute number of splenic GC B cells (Right) of each line of both genders (F, female; M, male) are shown. *P <0.05; ***P <0.001; N.S., not significant. Student’s t-test.