Figure 4. Counter-selection by IgG1 BCR for memory cell fate.
(A and B) Diagrams of allele combinations used to assess IgG1-mediated counter-selection in the memory cell fate in C–E. (C and D) IgMa and IgMb were examined by flow cytometry 21 days after immunization with APC in CFA in the antigen-specific GC (C) and memory (D) compartments of indicated mice. (E) Fraction of antigen-specific YFP+ memory B cells expressing the Ighb allotype in indicated mice 40 days after immunization with APC in CFA. Lines represent means. (F) Mean number of antigen-specific GC (upper panels) and YFP+ memory (lower panels) B cells of indicated genotype per 106 total B cells of the donor genotype in bone marrow chimeras immunized with PE in CFA. Results represent 3 independent experiments with a total of 8–10 mice of each genotype in (C) and (D); two independent experiments with a total of 6–8 mice total of each genotype in (E); and two independent experiments with a total of 6–7 mice per group at each time point in (F). Error bars = SEM. ** p = 0.0022; *** p ≤ 0.0007. Two-tailed Mann-Whitney test was used to assess significance. See also Figure S3.