Production of Interleukin-4 and Other Cytokines following Stimulation of Mast Cell Lines and in vivo Mast Cells/Basophils

Interleukin-3 (IL-3)-dependent mast cell lines, upon stimulation by calcium ionophores or by FcεRI cross-linking, express mRNA for, and secrete, a distinct pattern of cytokines, similar to those secreted by cloned mouse T cells of the T_H2 type. The mast-cell-derived cytokines include IL-3, IL-4, IL-5 and IL-6. Not only in vitro mast cell lines, but also in vivo derived peritoneal mast cells secrete cytokines. An in vivo derived cell, in mouse spleen and bone marrow, secretes IL-4 and other cytokines upon stimulation with calcium ionophores or by FcεRI cross-linking or FcγRII cross-linking. The IL-4-producing cells are highly enriched in the FcεR⁺ subset of spleen and bone marrow cells. These FcεR⁺ cells produce large amounts of IL-4, and they have characteristics similar to those of immature mast cells and/or basophils. It is possible that cytokines produced by mast cells and/or basophils participate in allergic inflammatory diseases.