(A and B) Primary CD4+ T cells (A) and B220+ B cells (B) from the spleen of WT and Msn KO mice were treated with cyclohexamide at the indicated times and surface TβRII analyzed by flow cytometry. (C) Flow cytometry analysis of primary CD4+ T cells isolated from the spleen of WT and Msn KO mice, and treated with brefeldin A (BFA), 20 μg/ml, for up to 5 hours and then washed. Cell surface TβRII was left to recover for up to 12 hours prior to analysis. (D) Reconstituted 1:1 mix of WT (CD45.1, black) and Msn KO (CD45.2, red) bone marrow chimeric mice treated as in C. Data represent the mean ± SD of 3 independent experiments in triplicate. *P < 0.05, ***P < 0.001 by 2-way ANOVA.