Specific antigen and organelle expression of a long-term rhesus endothelial cell line

A long-term culture of a spontaneously transformed endothelial cell line derived from the choroid-retina of a rhesus macaque fetus is reported. It has been carried in vitro by serial propagation more than 548 passages in 17 yr. Cells were identified as being of endothelial origin by cellular morphology, growth pattern, ultrastructure, immunocytochemistry (immunofluorescence and immunoperoxidase), and immunodiffusion. The transformants are characterized by an infinite life span, a changed expression of Factor VIII-related antigen, and chromosomal aberrations. Throughout long-term serial passages and after repeated freeze-storage, thawing, and reculture the cells retain the specific organelles, Weibel-Palade bodies, and most of the other characteristic morphologic features. For this long-term cultured endothelial cell line, Weibel-Palade bodies seem to be a more reliable marker than Factor VIII-related antigen.