Fig 2: Controls for validation of memory B cell (MemB) clusters by flow cytometry.(A) FCRL5 and CD23 FMO gating strategies for Figure 6B. (B) FCRL5 and CD23 FMO gating strategies for Figure 6D. (C) FCRL5 and CD23 FMO gating strategies for Figure 6G. (D) Validation of intravenously (i.v.) staining with CD45 by conventional gating for FoB and MZB cells for the same chimeras in Figure 6G.

Fig 3: FCRL5+ and CD23+ fate-mapped memory B (MemB) cells have different preferential localization.(A) Experimental design to validate presence of fate-mapped FCRL5+ and CD23+ MemBs. (B) Identification of discrete populations of FCRL5+ and CD23+ MemB cells with Aicda-CreERT2-EYFP reporter mice by flow cytometry (n = 5 chimeras). (C) Experimental design for using S1pr2-CreERT2-tdTomato fate mapping in autoimmune chimeras. (D) Identification of discrete populations of FCRL5+ and CD23+ MemB cells with S1pr2-CreERT2-tdTomato fate mapping in autoimmune chimeras by flow cytometry (n = 3 chimeras). (E) Splenic localization of FCRL5+ S1PR2(Tomato)+ MemB cells by confocal microscopy. Overview of a spleen from autoimmune chimeras (Figure 3C), left, and selected area, center, delineates a bridging channel for a close-up examination of FCRL5+ S1pr2tomato+, right. Arrow points to FCRL5+ MemBs. Scale bars represent 100 µm (left), 50 µm (center), and 20 µm (right). Arrow heads point to FCRL5+ S1PR2(Tomato)+ cells. (F) Experimental design for in vivo marginal zone labeling. S1pr2-CreERT2-tdTomato:564Igi chimeras intravenously (i.v.) injected with 5 µg of anti-CD45-APC for 5 min before organ extraction. (G) Flow cytometry gate strategy to evaluate i.v. CD45 labeling between MemB FCRL5+ and MemB CD23+ cells. Statistical values correspond to one-tailed unpaired Student t-test (G).