Human trophoblast interferon: pattern of response to priming and superinduction of purified term trophoblast and choriocarcinoma cells.

We recently described a beta interferon response of primary cultures of term human trophoblast exposed to poly(I:C). The response pattern has now been studied further with priming and superinduction both of normal placental cell types and JAR, JEG-3 and BeWo choriocarcinoma cells. Pre-treating placental trophoblast cells, fibroblasts and macrophages with human interferon generally led to increased yields of interferon after poly(I:C) induction, whereas choriocarcinoma cells did not respond to priming. All the cells showed the superinduction phenomenon although to varying degrees. The combination of priming and superinduction conditions led to the production of very high yields of interferon in placental fibroblast cultures. The combined procedure also produced more interferon in macrophage cultures than priming or superinduction alone. Combined superinduction and priming of normal trophoblast did not produce higher yields than those obtainable by superinduction alone. These data might help to provide additional insight into the cellular control mechanisms of sensitivity of normal and malignantly transformed cells to interferon. Furthermore, the large quantity of trophoblast interferon produced by superinduction could be used for studies of its anti-viral and immunomodulatory effects.