Figure S1.

STIM proteins are required for effective competition in GC. Related to Fig. 1. (A) Frequency of CD45.1⁺CD45.2⁺Aicd^Cre/+ and CD45.2⁺Stim1^f/fStim2^f/fAicd^Cre/+ cells in indicated parental populations in the spleen of mixed BM chimeric mice immunized with NP-CGG in alum. Total B, follicular (FO) B, and NP-specific GC B cells are defined as B220⁺, CD21^lowCD23^highB220⁺, and NIP⁺FAS⁺GL7⁺B220⁺ cells, respectively. Data are presented as mean ± SEM for five or six mice. Data are representative of two independent experiments. NS, not significant. *, P < 0.05 versus Aicd^Cre/+ cells (two-way ANOVA). (B) Mixed BM chimeric mice (CD45.1⁺ mice lethally irradiated and reconstituted with 50% CD45.1⁺CD45.2⁺Mb1^Cre/+ (control) plus 50% CD45.2⁺Stim1^f/fStim2^f/fMb1^Cre/+ (Stim1/2 BKO) BM cells) were immunized with NP-CGG in alum. Frequency of W33L⁺ clones among single NP-specific IgG1⁺ plasma cells (NIP⁺CD138⁺TACI⁺IgG1⁺) in mixed BM chimeric mice immunized with NP-CGG for 14 days. Numbers along the perimeter indicate percentages of W33L⁻ (white) and W33L⁺ (orange) clones. Data are representative of two independent experiments.