Src kinase-mediated signaling in leukocytes

A concert of antigens, antibodies, cytokines, adhesion molecules, lipid fac tors, and their different receptors mediate leukocyte development and infla mmatory responses. Regardless of the stimulus and receptor type, members of the Src family of protein tyrosine kinases (PTKs) play a critical role in initiating the numerous intracellular signaling pathways. Recruited and act ivated by the receptor, these Src PTKs amplify and diversify the signal. Mu ltiple pathways arise, which affect cell migration, adhesion, phagocytosis, cell cycle, and cell survival. Essential nonredundant properties of Src PT Ks have been identified through the use of gene targeting in mice or in the somatic cell line DT40. Because of their role in mediating leukocyte proli feration and activation, Src PTKs serve as excellent drug targets. Inhibito rs of Src family members and dependent pathways may be useful in the treatm ent of human diseases similar to drugs known to inhibit other signal transd uction pathways.