title: Bi-directional calcium signaling between adjacent leukocytes and trophoblast-like cells.
abstract: OBJECTIVE
  Trophoblasts are believed to play an important role in mitigating immunological responses against the fetus. To better understand the nature of trophoblast-leukocyte interactions, we have studied signal transduction during intercellular interactions.
  
  
  METHODS
  Using a highly sensitive microfluorometric ratioing method and Ca²(+) -sensitive dyes, we measured Ca²(+) signals in trophoblast-like cell lines (JEG-3 and JAR) or in leukocytes (neutrophils and monocytes) during intercellular contact.
  
  
  RESULTS
  Trophoblast cell lines exhibit Ca²(+) signals during leukocyte contact. In contrast, leukocytes cannot elicit Ca²(+) signals in non-opsonized tumour cells, suggesting that Ca²(+) signaling is not a general feature of cell-cell encounters. Similarly, leukocytes demonstrate Ca²(+) signals during contact with trophoblast cell lines. Ca²(+) signals were confirmed using three dyes and with the Ca²(+) buffer BAPTA.
  
  
  CONCLUSIONS
  We suggest that leukocyte-to-trophoblast interactions lead to mutual Ca²(+) signaling events in both cell types, which may contribute to immunoregulation at the materno-fetal interface.
authors.affiliation: Department of Ophthalmology and Visual Sciences, The University of Michigan Medical School, Ann Arbor, USA.
authors.forename: Megan
authors.initials: M
authors.lastname: Elfline
authors.forename: Andrea
authors.initials: A
authors.lastname: Clark
authors.forename: Howard R
authors.initials: HR
authors.lastname: Petty
authors.forename: Roberto
authors.initials: R
authors.lastname: Romero
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry; D001572:Benzofurans / Q000737:chemistry; D020013:Calcium Signaling / Q000276:immunology*; D002460:Cell Line; D005260:Female; D005333:Fetus; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007093:Imidazoles / Q000737:chemistry; D007211:Indoles / Q000737:chemistry; D007962:Leukocytes / Q000276:immunology / Q000378:metabolism* / Q000648:ultrastructure; D008857:Microscopy, Interference; D020442:Poloxamer / Q000737:chemistry; D011247:Pregnancy; D014327:Trophoblasts / Q000276:immunology / Q000378:metabolism* / Q000648:ultrastructure; D014966:Xanthenes / Q000737:chemistry
chemical_list: D000814:Aniline Compounds; D001572:Benzofurans; C409648:Fluo 4; D007093:Imidazoles; D007211:Indoles; D014966:Xanthenes; D020442:Poloxamer; C059587:Indo-1 pentaacetoxymethyl ester; C082877:fura red