Characterization of ovine lymphatic endothelial cells and their interactions with lymphocytes.

The interaction of blood-borne lymphocytes with blood vascular endothelial cells is a fundamental component of lymphocyte circulation. The role of lymphatic endothelial cells is less certain. These studies describe the isolation, characterization and lymphocyte binding capacity of efferent lymphatic endothelial cells from ovine mesenteric lymphatic vessels. Lymphatic endothelial cells had anti-thrombin 3, von Willebrand Factor and MHC I on their surface. The cells also actively metabolized acetylated low density lipoprotein. The morphological appearance was indistinguishable from blood vascular endothelium but quite different from cultured smooth muscle cells. Lymphocyte binding to lymphatic endothelial cells was not significantly different from binding to carotid artery or jugular vein endothelial cells. The degree of binding in all cases could be enhanced by incubating endothelial cells in medium containing rh TNF-alpha (recombinant human tumor necrosis factor alpha).