Figure 5.
Antibody production after stimulation with toll-like receptor (TLR) ligands. (A) Spontaneous and induced IgM responses by B cell subsets. The B cell subsets P1–P4 defined as shown in Figure 2 were FACS-sorted, cultured at 0.5 × 106 cells/ml and stimulated with resiquimod in the absence or presence of interleukin-2 (IL-2) and B-cell activating factor (BAFF) for 5 days. IgM production in the supernatants was quantified by ELISA. (B) TLR-induced IgM production induced of full PBMCs, of plasmacytoid dendritic cell (pDC)-depleted PBMCs (C), and of PBMCs reconstituted with pDC following sorting (D). (E–G) FMDV-specific IgG-antibody levels detected in the same setup as in (B–D). (B–G) Cells were cultured for 7 days. Six biological replicates of two independent experiments are shown. Statistical significance was calculated using ANOVA followed by Tukey’s test (****P < 0.0001; ***P < 0.001; **P < 0.01; *P < 0.05).