Fig. 5: TFAM is required for GC B cell commitment.
a, Representative flow cytometry plots depicting the gating of CD38+IgD+ APs and CD38−IgD− GC B cells in the CD19+tdTomato+ population. Quantification of AP and GC B cell percentages from NP-CGG immunized Aicda-WT (n = 8) and Aicda-Tfam (n = 9) mice. Data were pooled from two independent experiments and are representative of four independent experiments. b, Representative Airyscan IHC images of GCs from Aicda-WT and Aicda-Tfam mice. The arrowheads indicate tdTomato+IgD+ APs. Scale bar, 50 μm. Representative of two independent experiments. c, Schematic of the experimental design for the iGB culture and adoptive transfer to assess in vivo GC entry and recruitment. d, Flow cytometric characterization of GC entry of adoptively transferred WT and Tfam−/− iGB cells in SRBC-immunized CD45.1 congenic hosts on day 10. GC B cells were defined as BCL6+GL-7+. Representative of two independent experiments. e, Quantification of d (n = 6 mice per group). f, Confocal images of splenic sections depicting tdTomato+ WT and Tfam−/− iGB cells adoptively transferred as in c but into separate congenic hosts. The arrowheads indicate transferred tdTomato+ iGB cells. Representative of two independent experiments. g, Representative confocal images of the splenic TFH cell compartment in NP-CGG immunized Aicda-WT and Aicda-Tfam mice. Scale bar, 50 μm. Representative of three independent experiments. h, TFH cell counts per GC from immunized Aicda-WT (n = 21 GCs) and Aicda-Tfam (n = 18 GCs) mice (as in g). Each symbol represents one GC pooled from n = 4 mice. Representative of three independent experiments. i, Schematic of the experimental design of the TFH-B coculture. j, Percentages of in vitro TFH-induced Rosa26-tdTom Tfam WT (Rosa-WT) or TfamloxP (Rosa-Tfam) GC B cells (GL-7+tdTomato+IgG1+) of the total viable cells. Technical replicates of n = 2 mice are shown. Representative of two independent experiments with n = 3 mice in total. Statistical significance was calculated using an unpaired two-tailed t-test (a,j) and a two-tailed Mann–Whitney U-test (e,h). Data are presented as the mean ± s.e.m.
