Engulfment of mast cell secretory granules on skin inflammation boosts dendritic cell migration and priming efficiency.

Background: Mast cells (MCs) are best known as key effector cells of allergic reactions, but they also play an important role in host defense against pathogens. Despite increasing evidence for a critical effect of MCs on adaptive immunity, the underlying mechanisms are poorly understood.

Objective: Here we monitored MC intercellular communication with dendritic cells (DCs), MC activation, and degranulation and tracked the fate of exocytosed mast cell granules (MCGs) during skin inflammation.

Mast Cells Are Critical Regulators of Bone Fracture-Induced Inflammation and Osteoclast Formation and Activity.

Mast cells, important sensor and effector cells of the immune system, may influence bone metabolism as their number is increased in osteoporotic patients. They are also present during bone fracture healing with currently unknown functions. Using a novel c-Kit-independent mouse model of mast cell deficiency, we demonstrated that mast cells did not affect physiological bone turnover.