B-cell–intrinsic role of Rictor in antibody responses. B cells purified from Cre-ER^T2Rictor^fl/fl mice pretreated with tamoxifen, or controls, were transferred together with equal mixed fractions of normal CD4⁺ T cells from WT and OT-II TCR transgenic mice into Rag2^−/− recipients. Sera of these recipient mice were analyzed 3 weeks after immunization with NP-conjugated ovalbumin. (A) Mean (± SEM) results from ELISA detecting NP-specific IgM and IgG1 (n = 6 vs 6). (B-D) Spleen cells were analyzed by flow cytometry, and donor-derived cell numbers (mean ± SEM; n = 6 vs 6) were calculated.