Platelet/endothelial cell adhesion molecule-1 (PECAM-1, CD31) is a glycoprotein expressed on the surfaces of monocytes, neutrophils, platelets, a subpopulation of T cells, and, as described in this work, on NK cells. It is also concentrated at the junctions between endothelial cells (EC) in culture, and is expressed on continuous endothelia in all tissues. PECAM has been shown to be involved in monocyte and neutrophil transendothelial migration in vitro and in vivo. The function of PECAM in NK cell interaction with EC has never been studied. In this work, we demonstrate that ligation of PECAM on the surface of NK cells activates their β2 integrins. Anti-PECAM Abs added to NK cells caused a 2.5- to 4-fold increase in the binding of these cells to monolayers of EC or 3T3 cells transfected with ICAM-1, and this was inhibited by a mAb against CD18. PECAM also plays a role in NK cell transendothelial migration. Anti-PECAM Abs inhibited 50% of NK cell transmigration through resting EC in an in vitro system. The transmigration of CD56(dim) and CD56(bright) cells was inhibited equally. IFN-γ increased NK cell transmigration; the transmigration of CD56(bright) cells was increased to a much greater extent than CD56(dim) transmigration (4-fold vs 1.5-fold). Anti-PECAM inhibited the transmigration of CD56(dim) cells by 30%, while that of CD56(bright) cells was not blocked. These studies demonstrate that PECAM-1 could play an important role in the extravasation of NK cells into tissues for constitutive surveillance and into sites of inflammation.
|Original language||English (US)|
|Number of pages||10|
|Journal||Journal of Immunology|
|State||Published - Feb 15 1996|
ASJC Scopus subject areas
- Immunology and Allergy