TRAF3 mice exhibit enhanced humoral responses to TD and TI antigens. (A) Mice were challenged with TNP-BSA (T-dependent antigen) in complete Freund adjuvant or with TNP-LPS (T-independent antigen). Blood was collected before and after injection of TRAF3 mice (◇) and wild-type littermates (■) with antigens at the days indicated. Titers of anti-TNP IgM and anti-TNP IgG₂ were determined by ELISA using TNP-KLH–coated plates. Data represent mean (± standard error of the mean [SEM]; n = 4). (B) B-cell antibody responses to TLR agonists. B cells were cultured in 12-well plates (2 × 10⁵ cells/mL) and either untreated or treated with 2 μg/mL LPS or 1 μM CpG (ODN1826). Culture supernatants were collected at various days, and secreted IgM, IgG₁, and IgG_2a were quantified. Data represent mean (± SEM) for TRAF3 mice (n = 5, ) and wild-type littermates (n = 4, ■).