Neutrophils on the mast cell menu

A recent article in Cell reported a new peculiar interaction between mast cells (MCs) and neutrophils. Upon IgE/Ag-mediated degranulation, MCs produce leukotriene B4, which attracts migrating neutrophils. Some neutrophils are able to establish close contact with MCs and end up trapped inside the MC, forming a cell-in-cell structure. While the neutrophil eventually dies inside the vacuole, the MC benefits from the remains of its prisoner, using it as a nutrient reserve and reusing its antimicrobial weapons.