Supplementary Figure 7: Functional consequences of the ablation of FRCs.
From: B cell homeostasis and follicle confines are governed by fibroblastic reticular cells
(a) Ccl19-Cre x iDTR mice were injected with DTxn, followed by passive immunization with rabbit anti-phycoerythrin. 18 h later, mice received phycoerythrin (PE) in the footpad and the popliteal node was imaged 6 h later for B220, FDCM1 and PE. (n=3 mice). (b) Serum was collected from Ccl19-Cre x iDTR mice 3 days after DTxn administration and levels of circulating BAFF were determined by flow cytometry-based bead assay. Each dot represents a mouse. (c,d) Ccl19-Cre x iDTR mice were injected in the footpad with 0.5 ng/g DTxn and numbers of FRCs and B cells were determined by flow cytometry 72 h later. Data are representative of two independent experiments (mean+/-sd, n=3 mice/group per experiment). (e) After enzymatic digestion of lymph nodes, cell suspensions were left untreated in complete medium or treated with protease inhibitors at room temperature. BAFF staining was evaluated by flow cytometry at different time points. Data are representative of three independent experiments. (f) CFSE-labeled purified B cells were cultured in vitro for 5 days in contact with FRCs, separated from FRCs by a transwell filter (TW), or with FRC-conditioned culture supernatant. B cell proliferation was determined as CFSE dilution in B220+ cells. NS non significant, * p<0.001
