Leukocyte–Blood Vessel Interactions

This chapter summarizes the cell adhesion molecules that function during leukocyte–blood vessel interactions during cellular recruitment in allergic inflammation. P-selectin originally received its name because of its stimulus-dependent expression on platelets, but it is also rapidly and transiently expressed on endothelial cells. Unlike E-selectin, P-selectin exists preformed within Weibel–Palade bodies in the endothelial cell and is expressed within minutes after stimulation with agents such as histamine, thrombin, phorbol esters, peroxides, leukotriene-C4. The role of adhesion molecules in allergic diseases in vivo has been also been studied by correlating endothelial adhesion molecule expression with cell influx at sites of allergic inflammation. The local generation and display of chemokines and other chemoattractants, together with the unique phenotypic pattern of expression of adhesion molecules and chemokine receptors on leukocyte subsets, combine to facilitate the selective emigration and accumulation of eosinophils, basophils, and Th2 lymphocytes at sites of chronic allergic inflammation.