(A) α-NP IgM (left) and α-NP IgG3 (right) serum response of relfl/flCD19-Cre, relfl/+CD19-Cre and CD19-Cre mice to NP-ficoll immunization before (Pre), and 7d after immunization (Post) with NP-ficoll (left). (B) α-NP IgM (left) and α-NP IgG3 (right) serum response of relafl/flCD19-Cre, relafl/+CD19-Cre and CD19-Cre mice to NP-ficoll immunization before (Pre), and 7d after immunization with NP-ficoll (left). (C) α-NP IgM (left) and α-NP IgG3 (right) serum response of relfl/flCD19-Cre, relfl/+CD19-Cre and CD19-Cre mice to NP-LPS immunization before (Pre), and 7d after immunization with NP-LPS (left). (D) α-NP IgM (left) and α-NP IgG3 (right) serum response of relafl/flCD19-Cre, relafl/+CD19-Cre and CD19-Cre mice to NP-LPS immunization before (Pre), and 7d after immunization with NP-LPS (left). (A-D) Data are cumulative from independent experiments (n=2-7 per group), with each symbol representing a mouse. Data are shown as mean ± standard deviation. Statistical significance was determined by Student's t test (*, P<0.05; **, P<0.01; ***, P<0.001).