B-lineage-intrinsic Smo activity is dispensable for primary and secondary humoral responses. (A) T-independent (TI) and T-dependent (TD) immunization protocols. Wild-type and SmoC mice were immunized at time points labeled Ag with TNP-Ficoll or TNP-KLH to elicit TI and TD immune responses, respectively. Pre-immune (day −3) and immune (days 7 and 21) sera were collected as indicated. (B) Primary TI and TD IgM response. Wild-type or SmoC mice were immunized with TNP-Ficoll or TNP-KLH as in panel A, and IgM responses to TNP were measured by ELISA (n = 3, mean and SD). (C) Secondary responses to TD immunization. wild-type or SmoC mice were immunized with TNP-KLH as in panel A. Secondary IgM, IgG1, IgG2a, IgG2b, and IgG3 responses to TNP were measured by ELISA (n = 5, mean and SEM). Serum dilution titrations are provided in supplemental Figure 4.
