Characterization of Novel Human Endothelial Cell Lines

Abstract

Leukocyte-endothelial cell interactions are centra to the normal re-circulation of lymphocytes and to pathological situations such as inflammation. In vitro studies aimed at dissecting molecular processes underlying these interactions would benefit greatly from a stable, reproducible, homogeneous source of human endothelial cells. Here we report the characterization of a novel series of human endothelial cell lines (designated “SGHEC”) regarding the expression and release of adhesion molecules and their binding of lymphocytes. SGHEC expressed significant levels of intercellular adhesion molecule-1 (ICAM-1) which increased after cytokine stimulation. Vascular cell adhesion molecule-1 (VCAM-1) and E-selectin were not detectable on unstimulated SGHEC but substantial levels were expressed after stimulation with either TNFα or IL-1β but not with IFN-γ. The increased expression of ICAM-1 and VCAM-1 was evident after 4h stimulation and was even higher after 24h; E-selectin was maximal after 4h and returned almost to basal levels by 24h. Substantial quantities of immunoreactive ICAM-1 and VCAM-1 also accumulated as soluble material in the supernatants of TNFα-stimulated SGHEC (VCAM-1) was substantially higher than ICAM-1), but E-selectin remained below the limits of detection. The quantities suggested that this release is stimulated by the cytokine and is not merely a loss of a fixed proportion of the cell-surface content, thus providing support for the idea of a physiological function for these soluble molecules.