Integrin signalling in neutrophils and macrophages

Integrins have been characterized extensively as adhesion receptors capable of transducing signals inside the cell. In myelomonocytic cells, integrin- mediated adhesive interactions regulate different selective cell responses, such as transmigration into the inflammatory site, cytokine secretion, pro duction or reactive oxygen intermediates, degranulation and phagocytosis. I n the last few years, great progress has been made in elucidating mechanism s of signal transduction by integrins in neutrophils and macrophages. This review summarises the current information on the role of integrins in regul ating myelomonocytic cell functions and highlights the signalling pathways activated by integrin engagement in these cells. Also, exploiting the curre nt knowledge of mechanisms of integrin signal transduction in other cell ty pes, we propose a model to explain how integrins transduce signals inside n eutrophils and macrophages, and how signaling pathways leading to regulatio n of selective cell functions may be coordinated. (C) 1999 Elsevier Science Inc.