title: Peripheral blood mononuclear cells in early pregnancy promote invasion of human choriocarcinoma cell line, BeWo cells.
abstract: BACKGROUND
  During the establishment of the maternal blood circulation around the implanting human embryo, maternal peripheral blood mononuclear cells (PBMC) directly contact trophoblasts. To determine the physiological significance of this interaction, the effects of PBMC obtained from pregnant women on the proliferative and invasive properties of a human choriocarcinoma cell line, BeWo cells, were examined.
  
  
  RESULTS
  PBMC were obtained from women in early pregnancy and from women in the secretory phase of the menstrual cycle. PBMC from pregnant women significantly increased the number of invading BeWo cells in an invasion assay without affecting the proliferation of BeWo cells (P +/- 0.05). No significant changes were observed in the co-cultures with PBMC from non-pregnant women. The addition of conditioned medium, which was prepared by 2 days of incubation with PBMC from pregnant women, also enhanced BeWo cell invasion in a dose-dependent manner. Moreover, when PBMC obtained from non-pregnant women were incubated with recombinant HCG (0-10 IU/ml) for 2 days, significant augmentation of the effect on BeWo cell invasion was observed in the conditioned medium from HCG-treated PBMC (P +/- 0.05).
  
  
  CONCLUSIONS
  This study indicated that soluble factor(s) secreted from PBMC promote BeWo cell invasion. It also showed the possible involvement of HCG in the regulation of BeWo cell invasion by PBMC. These findings suggest crosstalk between maternal PBMC and trophoblasts via soluble factor(s), which may play an important role in early embryo implantation.
authors.affiliation: Department of Gynaecology and Obstetrics, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors.forename: Haruto
authors.initials: H
authors.lastname: Egawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hirano
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nakayama
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Higuchi
authors.forename: Keiji
authors.initials: K
authors.lastname: Tatsumi
authors.forename: Takahide
authors.initials: T
authors.lastname: Mori
authors.forename: Shingo
authors.initials: S
authors.lastname: Fujii
mesh_terms: D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002448:Cell Adhesion / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002822:Choriocarcinoma / Q000378:metabolism / Q000473:pathology*; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D018920:Coculture Techniques; D017077:Culture Media, Conditioned / Q000494:pharmacology; D005260:Female; D006801:Humans; D019012:Integrin beta1 / Q000276:immunology / Q000378:metabolism; D009000:Monocytes / Q000187:drug effects / Q000502:physiology*; D009361:Neoplasm Invasiveness / Q000503:physiopathology*; D011247:Pregnancy / Q000097:blood*; D011261:Pregnancy Trimester, First; D011994:Recombinant Proteins / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D006063:Chorionic Gonadotropin; D017077:Culture Media, Conditioned; D019012:Integrin beta1; D011994:Recombinant Proteins