Fig. 5

Migration of activated NP-specific B cells from the SED to GC regions of the Peyer’s patch following oral immunization. a Schematic representation of the model used to detect movements of B cells in the PP by photoactivation. B1–8^hi B cells expressing PA-GFP or CFP were adoptively transferred into AID^Cre/+ Rosa26^{fl-stop-fltdTomato} mice that were subsequently orally immunized with NP-CT. At 10 days after transfer, PPs were exposed and SED or GC areas were photoactivated based on CFP and tdTomato expression and the position of the photoactivated cells was subsequently analyzed 4 h later. b Photoactivation was guided to the SED region based on the presence of CFP⁺ cells. Four hours after activation approximately 40% of the GFP⁺ B cells had left the photo-converted area in SED. These were often found close to or within the GC at this point (marked with white arrowheads). In addition, macrophages were evident by auto-fluorescence (marked with orange arrowheads; also see Supplementary Fig. 5a). c The GC was detected based on the large density of tdTomato⁺ cells in the area. Four hours after photoactivation most of the PA-GFP⁺ B cells remained within the GC area. d The percentage of B cells that had migrated from the photoactivated area within 4 h. The analysis represents one experiment performed on three distinct PP. Photoactivated areas are marked with dashed line rectangles and close up areas with normal line quadrants. Similar results were obtained in 3 independent experiments. Scale bar = 80 µm. Source data are provided as a Source Data file