Figure 1. T cells utilize MyD88 signaling to coordinate germinal center responses.

(A–C) GC-T_FH cells from PPs, defined by CD3⁺CD4⁺B220⁻CXCR5^hiPD-1^hi, were measured by flow cytometry. (A) Representative plots were previously gated on CD3⁺CD4⁺B220⁻ cells. (B) Frequency and (C) absolute numbers of GC-T_FH cells (n= 21 WT, n=18 T-MyD88^−/−).

(D–F) GC B cells, defined by B220⁺IgD^lowFas⁺GL-7⁺, from PPs were measured by flow cytometry. (D) Representative plots were previously gated on B220⁺IgD^low cells. (E) Frequency and (F) absolute numbers of GC B cells (n=21 WT, n=18 T-MyD88^−/−).

(G–J) IgA⁺ plasmablasts, defined as B220⁻CD138⁺IgA⁺, within the siLP and cLP were measured by flow cytometry (G), Representative plots were previously gated on CD138⁺ B220⁻ cells from siLP. (H) Frequencies of IgA⁺ plasmablasts in siLP (n=6 WT, n=7 T-MyD88^−/−). (I) Representative plots were previously gated on CD138⁺ B220⁻ cells from cLP. (J) Frequencies of IgA⁺ plasmablasts in cLP (n=8 WT, n=5 T-MyD88^−/−). Unpaired two-tailed Student’s t-tests were used for all comparisons. P-value<0.05 (*); P-value<0.01 (**); P-value<0.001 (***). Lines in scatterplots represent means. See also Figures S1–4.