Expression of functional chemokine receptors of human placental cells

PROBLEM: Chemokine receptors of placental trophoblasts possibly act as co-r eceptors or alternative receptors of maternal-fetal infection by HIV. To cl arify their possible expression and the physiological roles of chemokines o n human placentae, we studied chemokine/chemokine receptor expression and t he effects of exogenous chemokines on choriocarcinoma cell lines. MATERIALS AND METHODS: Placental samples were obtained from 13 placentae of various gestational ages. Villous tissue was mechanically dissected from s amples. Trophoblasts were enriched by anti-human chorionic gonadotropin (hC G)-coated magnetic beads. Human choriocarcinoma cell lines (JAR, BeWo, JEG- 3) were maintained in RPMI 1640 media supplemented with 10% FCS. Expression of chemokine receptors was studied by RT-PCR. The effects of MIP-1 alpha, RANTES, MCP-1 on hCG production were estimated by EIA. Effects of chemokine s on proliferation of choriocarcinoma cell lines were examined by MTT assay . RESULTS: We observed mRNA expression of CCR-1, 2, 3, 4, 5 and CXCIR-1, 2, 4 in 1st trimester placental villi, CCR-1, 2, 4 and CXCR-1, 2, 4 in 2nd trim ester placental villi, CCR-1, 2, 4 and CXCR-4 in 3rd trimester placental vi lli. Using MACS enriched trophoblasts, we observed identical results. A cho riocarcinoma cell line BeWo expressed CCR-1, 3, 4 and CXCR-1, 2, 4 while JE G-3 and JAR expressed CCR-1, 3, 4, 5 and CXCR-1, 2, 4. Expression of the CC R-5 and CXCR-4 protein in choriocarcinoma cell lines and MACS-enriched trop hoblats were confirmed by flow cytometry. Chemokine MCP-3, MIP-1 alpha, RAN TES mRNA were expressed by the 1st, 2nd and 3rd trimester placental samples and the three choriocarcinoma cell lines examined. MCP-1 was expressed by 1st and 2nd trimester placental villi. Administration of chemokines up-regu lated proliferation (10(-1)-10 ng/mL) and hCG production (10(-1)-10(-2)ng/m L) of the three choriocarcinoma cell lines examined. CONCLUSIONS: Our results suggest possible roles of chemokines/chemokine rec eptors on placental physiology and their involvement in HIV transmission as alternative receptors.