CXCL12/CXCR4 expression in trophoblasts takes part in materno-fetal immune tolerance and vascular remodeling.

In this study, we investigated the expression of CXCL12 (SDF-1)/CXCR4 in trophoblasts and the role they play in the gestation. Immunochemistry was used to detect the expression of CXCR4 and CXCL12 in human villi and placenta. Highly purified extra-villous trophoblasts (EVTs) ere detected for CXCR4 and CXCL12 in vitro by immunocytochemistry. The chemotaxis of CXCL12 was tested in transwell and the chemotactic activity was quantitatively examined. It was suggested that both CXCR4 and CXCL12 were expressed in trophoblasts and were decreased with the gestation time P < 0.05). In a certain coverage, CXCL12 exhibited chemotactic activity which was positively correlated with its concentration [(r) = 0.68, P < 0.01], the maximum chemotactic index (CI) was 1.62 +/- 0.12. Our results suggest that interaction between CXCR4 and CXCL12 is involved in materno-fetal immunological tolerance in all three trimesters of gestation and contributes to the invasion of EVTs during pregnancy.