Cytpkine synthesis in first trimester tissues

Both villous and extravillous trophoblast contact maternal blood. This juxtaposition should result inplacental rejection. However, detrimental anti-placental reactivity is uncommon. First trimesterplacental samples obtained by chorion villous sampling(CVS) were assayed for the presence IL-4 and IL-10. Tissue lysates were prepared and assayed RT-PCR and ELISA and sections were analyzed byhistochemical techniques. By both approaches these cytokines were detected. Reproducible amount of IL-4 or IL-10 were observed by ELISA and RT_PCR showed that specific sequences were associated with pregnancy tissue. RNA isolated from the JEG-3 cell line also contained IL-4 andIL-10. These findings were confirmed by immunohistology and by insitu hybridization. Preliminary evidence suggests that these cytokines are secreted by JEG-3 cells and there production is not inducible but is constitutive in these cells. Isolated tropho blast also produce these cytokines in culture. These data support the hypothesis that maternal-fetal tolerance is maintained at the uteroplacental interface by anti-inflammatory cytokine synthesis by atypical fetal-derived trophoblast.