I. Athanassakis et al., Interferon-gamma induces differentiation of ectoplacental cone cells to phenotypically distinct trophoblasts, DEV COMP IM, 24(6-7), 2000, pp. 663-672
Maturation of the murine ectoplacental cone results in the development of t
he placental tissue which essentially consists of two trophoblastic zones,
the spongiotrophoblast and labyrinthine trophoblast. In this study we attem
pted to investigate the action of cytokines on ectoplacental cone cell diff
erentiation to mature trophoblast cells. After determining the cellular com
position of the ectoplacental cone cell suspensions based on the expression
of cytokeratin, vimentin, Mac-1, class I and class II MHC antigens, the ce
lls were exposed to the differentiation-inducing cytokines IL-3, GM-CSF, CS
F-1 and IFN-gamma. From the four factors employed, only IFN-gamma increased
the levels of cytokeratin-positive cells without inducing Mac-1 expression
. IL-3 increased the percentages of cytokeratin as well as Mac-1- and vimen
tin-positive cells whereas GM-CSF and CSF-1 preferentially promoted an incr
ease of the Mac-1 and vimentin markers. For further analysis, ectoplacental
cone cells were negatively selected for Mac-1, class I and class II antige
ns to exclude non-trophoblastic contaminants and thereafter treated with th
e same cytokines. We show here that only IFN-gamma leads the sorted ectopla
cental cone cells to a pure trophoblastic population composed of 100% cytok
eratin-positive cells. The specificity of IFN-gamma on this differentiation
pathway is strengthened by the fact that murine maternal serum on the day
of EC formation contains high levels of this cytokine, suggesting that its
natural presence supports - at least phenotypically - the in vivo different
iation of EC cells to trophoblasts. (C) 2000 Elsevier Science Ltd. All righ
ts reserved.