Enzymatic isolation of human trophoblast and culture on various substrates: comparison of first trimester with term trophoblast.

A simple method is described for the isolation of trophoblast cells from both first trimester and term placenta. Trophoblast preparations were characterized by light microscopy, scanning and transmission election miscroscopy and immunohistochemistry to distinguish these cells from mesenchyme and endothelium. Trophoblast cells were cultured on various substrates and a comparison made of their ability to attach, proliferate and function. A collagen gel substrate produced by repolymerization of an acid soluble collagen fraction from chorionic villi allowed rapid attachment of trophoblast cells and maintainance of their original morphology. Term trophoblast cells were shown to become fully functional in short term (three day) cultures by virtue of their increased immunocytochemical staining for the presence of beta hCG, hPL and SPI. beta hCG increased significantly by day three thus demonstrating functional activation. Trophoblast cells from first trimester placenta formed proliferating colonies of hormone producing cells while those from term placenta reaggregated into clusters and closely resembled syncytiotrophoblast both morphologically and functionally. This short term culture system for term trophoblast will allow further studies into the biology of trophoblast polypeptide hormone synthesis and secretion.