Serial intravital microscopy reveals temporal dynamics of autoreactive germinal centers in the spleen

Abstract

The spleen plays a key role in clearing blood-borne infections and is involved in autoimmune and hematological disorders. It undergoes extensive remodeling during inflammation and immune reactions, but its localization in the peritoneal cavity has hampered studies of these dynamic changes. Here, we establish and validate a protocol for serial 2-photon microscopy of the murine spleen to capture dynamic processes in the living animal. As a proof-of-principle, we elucidate the expansion and contraction of autoreactive germinal centers (GCs) induced by epicutaneous application of the small-molecule TLR7 agonist resiquimod (R848). Leveraging a biocompatible abdominal imaging window, intravital labeling techniques, and fluorescent reporters, we follow GCs up to 180 {micro}m below the capsule for more than 2 weeks by tracking follicular dendritic cell (FDC) networks. This was accomplished without appreciable perturbation of normal physiology, paving the way for a deeper understanding of the biology of the spleen and its associated disease states. HighlightAn abdominal imaging window allowing the study of dynamic processes in the spleen of live mice over the course of several weeks.