Figure 3. Tolerant B cells exhibit cell-intrinsic dysfunction.

(A) Experimental design. Enriched B cells (2 × 10⁷) isolated from naive (N-B) or tolerant (Tol-B) mice were transferred into MD4 hosts and challenged with F1(B/c × B6) heart allografts the following day. (B) F1 heart-graft survival in MD4 mice receiving N-B cells or Tol B cells. n = 6/group. (C) DSA-IgG (MFI) analyzed at the time of graft rejection. n = 6/group. (D) Experimental design. Purified 2 × 10⁷ N-B cells or Tol-B cells were adoptively transferred (AdTr) together with 5 × 10⁶ enriched B6 T cells and 1 × 10³ TCR75 T cells into MD4 mouse (mse) hosts, followed by immunization with 2 × 10⁷ B/c donor spleen cells (DSCs). (E) Total number of TCR75 T cells/mouse analyzed on day 14. n = 4–8/group. (F) Total TCR75-Tfh cells/mouse. n = 4–8/group. (G) DSA-IgG (MFI) from N-B–cell or Tol-B–cell recipients immunized with or without 2 × 10⁷ B/c DSCs with or without CpG (100 μg/mouse i.v. given on day 0, and 50 μg/mouse i.p. on days 1 and 2) plus anti-CD40 (αCD40; 100 μg/mouse i.v. on days 0 and 7) on day 14 after AdTr. n = 4–11/group. Data were pooled from 2 or more independent experiments. Data are presented as the mean ± SEM. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001 by 1-way ANOVA with Bonferroni’s post hoc test.