Fig. 2.
Mef2c is required for efficient humoral immune response against T-dependent antigens. (A) Mef2c B-cell conditional KO (ko, blue circles) mice exhibit reduced NP-specific IgG1 titers compared with control (ctrl, red circles) mice at 14 and 21 days after immunization with NP-chicken gamma globulin. (B) Immunohistochemistry on sections from lymph nodes depicts a reduced GC response (PNA, green) at 14 days after immunization in Mef2c B-cell KO (bottom row) mice compared with control (top row) mice (white arrows indicate GCs). Lymphoid follicle structure (IgD, red) remained intact in both groups. (C) Quantification of the GC defect by flow cytometry shows a ≈80% reduction in total PNA+, FAS+, B220+ GC B cells in lymph nodes of Mef2c B-cell KO mice compared with control mice.