Fig. 7. Tmbim4 restoration rescues IgG1⁺ GC B cell positive selection.

(A) Schematic design of the retroviral vectors for Tmbim4 restoration and control.

(B) Left, representative Ca²⁺ flux dynamics for Indo-1 stained iGB cells upon restoration (Miz1^KO-Tmbim4) or not (Miz1^KO-ctrl) of Tmbim4 in MIZ1^KO cells. Right, cumulative data for Ca²⁺ flux shown as “Peak” = highest cytoplasmatic levels after stimulation.

(C) Schematics of the experimental workflow for the restoration of Tmbim4 levels in vivo.

(D) Representative plots of ex vivo GC B cells displaying restoration (Miz1^KO-Tmbim4) or not (Miz1^KO-ctrl) of Tmbim4.

(E) Gating strategy for IgG1⁺ and IgM⁺ GC B cell subsets generated from donor-derived reporter positive B cells.

(F) Dynamic changes of the percentages of IgG1⁺ and IgM⁺ B cell subsets in retrovirally transduced GC B cell on day 4 and day 7.

(G) Cumulative data for IgG1⁺ B cell percentages within GC B cells upon restoration (Miz1^KO-Tmbim4) or not (Miz1^KO-ctrl) of Tmbim4 in MIZ1^KO cells. Left, day 4 after cell transfer; right, day 7 after cell transfer.

(H) Cumulative data for IgG1⁺ B cell percentages within GC B cells upon restoration (Miz1^KO-Tmbim4) or not (Miz1^KO-ctrl) of Tmbim4 in MIZ1^KO cells. Left, day 4 after cell transfer; right, day 7 after cell transfer.

Each symbol (B: MIZ1^KO-ctrl n = 6, MIZ1^KO-Tmbim4 n = 6; E-H: day 4 n = 4; day 7 n = 3) represents an individual mouse. Data in (B) is from two independent experiments, data in (E - F) is one representative from two independent experiments. *, P ≤ 0.05; **, P ≤ 0.01 (unpaired two-tailed Student’s t test in (B); paired multiple t test (F); paired t test (G-H)).