• Monocytes;
  • neutrophils;
  • signal transduction

Citation Elfline M, Clark A, Petty HR, Romero R. Bi-directional calcium signaling between adjacent leukocytes and trophoblast-like cells. Am J Reprod Immunol 2010

Problem  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.

Method of study  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.

Conclusion  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.