Identification and categorization of inducible mast cell genes in a subtraction library.

Mast cells play an important role in allergic inflammation by releasing inducible proinflammatory cytokines. While many inducible genes have been identified, we hypothesized that a significant number remain to be identified. We thus constructed an activation-specific mast cell subtraction library to establish a profile of induced genes in mast cells following allergic stimulation. To date, we have sequenced 150 cDNA clones. Among them, we have isolated 22 known genes whose expression has not been reported in mast cells, and an additional 26 cDNA clones which do not have significant homology to known genes in the Genbank database. We next selected 10 cDNA clones with strong signals by differential plaque hybridization. Of these cDNA clones, five genes were induced in mast cells upon Fc epsilon RI-mediated stimulation. They are cofilin, annexinVI, interferon (IFN)-beta, serglycin, and a novel inducible mast cell (IMC) gene, IMC-415. Characterization and relevant studies of this novel gene and other inducible known genes in mast cells will provide insight into the functions of mast cells in mammalian biology.