Parent cells for trophoblast hybridization I: Isolation of extravillous trophoblast cells from human term chorion laeve

Abstract

Summary Extravillous trophoblast cells of human placenta produce matrix-type fibrinoid, an oncofetally modified extracellular matrix. Matrix-type fibrinoid is linked to differentiation of extravillous trophoblast cells. It is involved in anchoring of the placenta to the uterine wall, at the same time enabling the trophoblast cells to migrate and to invade maternal tissues. Biochemical isolation of matrix-type fibrinoid is impossible. In vitro production is hampered by the lack of proliferation of differentiated extravillous trophoblast cells. Therefore, we want to immortalize the capability for production of matrix-type fibrinoid. In order to avoid any introduction of non human regulative genes into the trophoblastic genome, we have chosen the hybridoma technique for immortalization. Negatively selectable choriocarcinoma cell lines are available as trophoblast-related malignant parent line for fusion. Here we describe a rapid isolation protocol for differentiated term extravillous trophoblast cells. With chorion laeve as source we avoid any accidental admixture of trophoblast cells of villous origin. Immunomagnetic isolation of extravillous trophoblast cells was performed using placental alkaline phosphatase as highly trophoblast specific positive marker molecule. The relatively simple method yields preparations of differentiated extravillous trophoblast cells of high purity, which are used as second parental cell population for generation of hybridomas.