EXPRESSION OF E-SELECTIN AND P-SELECTIN BY VASCULAR ENDOTHELIAL-CELLSIN HUMAN TONSILS

Selectins play an important role in the adhesion between vascular endo thelial cells and leukocytes in immuno-inflammatory events. We investi gated the immunohistochemical localization of E- and P-selectins in th e human palatine tonsils at light and electron microscopic levels. E-s electin was expressed by high endothelial venules (HEV) in a linear pa ttern in heavily inflamed tonsils with focal infection and extensive n eutrophilic infiltration, and much less in hypertrophic tonsils withou t focal infection. P-selectin expression was found on HEV to the same extent in both disease states in a dot pattern in the cytoplasm. Immun oelectron microscopically, E- and P-selectins were localized along the luminal plasma membrane and in the perinuclear space in HEV endotheli al cells. The present study suggests that increased expression of E- a nd P-selectin in vascular endothelial cells is a significant feature o f inflamed tonsils induced by focal infection. E- and P-selectins may participate in different roles in the inflammatory process of the tons ils.