Buffy coat preparation is a convenient source of progenitors for culturing mature human mast cells

Mast cells are unique immune cells that release a spectrum of chemical mediators contributing to the inflammatory symptoms of allergic disorders. Mature mast cells have recently been cultured from CD34(+) progenitors isolated from fresh umbilical cord blood and adult peripheral blood. In the current study, we investigated whether buffy coat preparations, which are readily available from blood banks, could be used as a convenient and more abundant source of progenitors for culturing human mast cells. We were able to culture a homogeneous population of human mast cells from progenitor cells isolated from human buffy coat. Morphologically, our cultured mast cells contained abundant cytoplasmic granules which stained positively using antibodies against human mast cell tryptase and, to a lesser extent, with those against human mast cell chymase. Functionally, these cultured mast cells responded to anti-human-IgE by releasing histamine in a dose-dependent manner after sensitization with human IgE. Taken together, buffy coat preparations can be a convenient source for culturing human mast cells which are predominantly tryptase positive only and express functional high-affinity IgE receptors.