Interleukin-1 alpha released from epithelial cells after adenovirus type 37 infection activates intercellular adhesion molecule 1 expression on humanvascular endothelial cells

A key event in virus-induced inflammation (leukocyte extravasation through the endothelium) is the local activation of endothelial cells, as indicated by the expression of adhesion molecules such as intercellular adhesion mol ecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selecti n. In order to identify triggers of inflammation in adenovirus infection, w e inoculated respiratory and ocular epithelial cells with adenovirus type 3 7 (Ad37), a human pathogen associated with keratoconjunctivitis as well as urogenital and respiratory infections. Fluids from virus-infected epithelia l cells activated ICAM-1 (and to a lesser extent, VCAM-1) expression on cul tured human umbilical vein endothelial cells. Blocking studies with anticyt okine antibodies implicated interleukin-1 alpha (IL-1 alpha) as the epithel ial cell-derived factor which activated endothelial cell ICAM-1 expression. The results thus identify epithelial cell-derived IL-1 alpha as a potentia lly important activator of endothelial cells in Ad37-induced inflammation.