Figure 3. Regulation of the AM14 Response by cDCs Requires Fas.

(A) Experiment design. 8-9 × 10⁶ Fas-sufficient AM14.MRL.Fas^lpr/+ B cells were transferred into Fas-sufficient MRL.Fas^lpr/+ recipients that either lacked cDCs (ΔDC) or into littermate controls (Cntrl) on day 0. The AM14 B cell response was activated with PL2-3 on days 0, 2 and 4, or left untreated (no Ag). Some mice did not receive cell transfer or Ag (no Tfr). Spleens were harvested on day 6.

(B) Number of AM14 B cells (4-44⁺) per spleen.

(C) Number of AM14 plasmablasts (4-44⁺, CD22^lo, CD44^hi) per spleen.

(D, E, & F) ELISpot assays for the number of 4-44⁺, IgM⁺, IgG2a⁺, or IgG2b⁺ AFCs per spleen. Data were combined from 5 experiments to obtain 15-29 mice per group receiving PL2-3 and 2-7 mice in the other groups. Bars represent mean and SEM. ****p < 0.0001 by Mann-Whitney U test.

(G) Immunofluorescence histology was performed on spleens from experimental mice. Images were taken at a magnification of 100x. Red, AM14 B cells (4-44⁺); green, B cell follicles (B220⁺); blue, T cell zones (CD4⁺). White scale bars are 200 μm. See also Figures S4 and S5.