Figure 7. Alloreactive tolerant B cells suppress naive B cell proliferation and GC responses, but do not suppress donor-specific Tfh responses.

Spleen and lymph nodes (inguinal, axillary, and branchial) were harvested from CD45.1/IgH_a recipients receiving donor naive B (N-B) or tolerant B (Tol-B) cells from CD45.2/IgH_b immunized with B/c DSCs and analyzed on days 14 to 21 after AdTr. (A) Percentage Ki-67⁺ donor anti-tetramer (αTet) B cells. (B) Total number of Ki-67⁺ donor αTet B cells/mouse (mse). (C) Percentage GC⁺ donor αTet B cells. (D) Total number of GC⁺ donor αTet B cells/mouse. (E) Percentage Ki-67⁺ host αTet B cells. (F) Total number of Ki-67⁺ host αTet B cells/mouse. (G) Percentage GC⁺ host αTet B cells. (H) Total number of GC⁺ host αTet B cells/mouse. n = 9–13/group. Data are pooled from more than 2 independent experiments. (I) Percentage pK^d:IA^b CD4⁺ T cells. (J) Total number of pK^d:IA^b CD4⁺ T cells/mouse. (K) Percentage pK^d:IA^b CD4⁺ Tfh cells. (L) Total pK^d:IA^b CD4⁺ Tfh cells/mouse. n = 5–8/group. Data are pooled from 2 or more independent experiments. (M) Experimental design. Enriched B cells (2 × 10⁷) isolated from naive or Tol mice were transferred into MD4 hosts, followed by immunization with F1(C3H × B/c) DSCs. DSA-IgG was collected on day 14 after AdTr. (N and O) Normalized MFI of (N) αB/c IgG and (O) αC3H IgG produced by AdTr N-B or Tol-B cells. n = 5/group. MFIs were normalized to MD4 mice that received N-B cells without F1(C3H × B/c) DSCs. Data are pooled from 2 or more independent experiments and 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.