Mechanical Isolation of Human Endothelial Cells from Large Vessels for Flow Cytometry Immunophenotyping

Endothelial cells (EC) have important physiological functions, and they may also have a role in pathology. To better understand their role in health and disease, we must know very well their phenotype. Previous studies have identified and characterized EC mainly by immunohistochemistry, but there are also some studies using flow cytometry (FCM) after exposing these cells to enzymatic digestion, either to isolate and/ or to detach them from the vessel wall. However, it is well known that enzymatic treatment can cause deleterious effects on cell surface receptors, then influencing the antibody-antigen reaction. We describe a simple and cheap mechanical method to isolate EC from human vessels, avoiding alterations in the expression of cell surface receptors caused by the use of enzymes, and we tested it using FCM. With this method we were able to obtain fresh EC that were identified by FCM as a well-defined cluster of CD45-CD146+brightCD31+bright cells. This approach can be used in the future to isolate EC for further immunophenotypic characterization and for ex-vivo functional studies, as well as to test the effect of different stimuli, including pharmacological drugs.