B6 recipients were treated or not with clodronate, followed by splenic harvest 24 hours later. Spleens were frozen, sectioned, and fixed as previously described.12 (link),22 (link) Sections were then stained foe IgD, MARCO, and SIGNR1, then mounted using Prolong Gold antifade mounting media (ThermoFisher Scientific). A Leica SP8 multiphoton confocal microscope was used to capture images, with image analysis using Leica Application Suite software.