Fig. 3.

B1-8 and B1-8.H2-O^−/− B cells populate the GC equally in the presence of abundant T-cell help. (A) Schematic representation of experiment setup. Marked B1-8 and B1-8.H2-O^−/− cells were mixed at a 1:1 ratio and transferred into either naïve hosts or hosts that had been immunized 7 d prior with NP-CGG. The next day, mice were immunized with NP-CGG in alum for the first time (naïve) or second time (preimmunized), or were left unimmunized. (B) Size of T_FH population was examined on day 10 postimmunization. Plots shown are gated on CD4⁺ T cells. Numbers indicate size of gated population as percentage of CD4⁺ cells. (C) Quantification of data shown in B for multiple mice. (D) Contribution of WT and H2-O^−/− B1-8 cells to NP⁺ GC B-cell pool upon preimmunization. (E and F) Quantification of population defined in D as percentage of donor-derived NP⁺ GC B cells (E), and as a ratio of H2-O^−/− to WT populations, normalized to the ratio in the transferred mixture (F). Statistical significance was calculated using two-tailed paired t test in E and a two-tailed unpaired t test in C and F.