Stimulation of Mast Cell Chemotaxis

Connective tissue mast cells (CTMC) reside near to blood vessels in connective tissues and are found also in the peritoneal cavity in many species (1) . Once thought to be terminally differentiated cells, CTMC arenowknown to proliferate in response to activated spleen cell-conditioned medium (SCCM) or to a mixture of IL-3 and IL-4 (2, 3) . CTMC, which contain large quantities of heparin and histamine, are distinguished from mucosal mast cells (MMC), which are found in the digestive tract, contain little histamine, and have granules that contain chondroitin sulfate E as opposed to heparin proteoglycan . Athird related cell type, the circulating basophil, shares some properties with mucosal mast cells but is not considered identical to either MMC or CTMC (1) . Although, basophils and basophilic leukemia cells have been shown to migrate toward specific stimuli such as IFN (4), IgE (5), and to undefined factors released from activated lymphocytes (6), little is known concerning the regulation of cell migration in connective tissue mast cells . In the current study, we have tested SCCM as well as purified lymphokines known to stimulate mast cell proliferation for their effects on CTMC migration .