Functional characterization of human mast cells cultured from adult peripheral blood

Mast cells are important effector cells of allergy and techniques for culturing human mast cells have been developed in recent years. In the current investigation, we studied the phenotypic and functional characteristics of mast cells cultured from adult human peripheral blood mononuclear cells. Mature human mast cells were obtained by first culturing mononuclear cells in methylcellulose containing stem cell factor (SCF), IL-3 and IL-6 for six weeks and subsequently in liquid medium containing SCF and IL-6 for another six weeks. These cells expressed numerous basophilic cytoplasmic granules that were predominantly tryptase positive but chymase negative. Following sensitization with human IgE, these cells released histamine and synthesized prostaglandin D2 and cysteinyl-leukotrienes dose-dependently upon activation by anti-IgE and calcium ionophores. Compound 48/80 and substance P were ineffective. When the effects of anti-asthmatic agents on anti-IgE induced mediator release from these cells were compared, only the beta2-adrenoceptor agonists and phosphodiesterase inhibitors produced dose-dependent inhibition but not cromolyn. In total, mast cells cultured from human peripheral blood shared similar morphological, immunocytochemical and functional properties of enzymatically dispersed human lung mast cells. These cultured mast cells can be a convenient substitute for the in vitro studies of human lung mast cell reactions and may be useful for investigating the roles of mast cells in allergic diseases.