Bi-Directional Calcium Signaling Between Adjacent Leukocytes and Trophoblast-Like Cells

Abstract

Citation Elfline M, Clark A, Petty HR, Romero R. Bi-directional calcium signaling between adjacent leukocytes and trophoblast-like cells. Am J Reprod Immunol 2010Trophoblasts 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.Using a highly sensitive microfluorometric ratioing method and Ca 2+ -sensitive dyes, we measured Ca 2+ signals in trophoblast-like cell lines (JEG-3 and JAR) or in leukocytes (neutrophils and monocytes) during intercellular contact.Trophoblast cell lines exhibit Ca 2+ signals during leukocyte contact. In contrast, leukocytes cannot elicit Ca 2+ signals in non-opsonized tumour cells, suggesting that Ca 2+ signaling is not a general feature of cell–cell encounters. Similarly, leukocytes demonstrate Ca 2+ signals during contact with trophoblast cell lines. Ca 2+ signals were confirmed using three dyes and with the Ca 2+ buffer BAPTA.We suggest that leukocyte-to-trophoblast interactions lead to mutual Ca 2+ signaling events in both cell types, which may contribute to immunoregulation at the materno–fetal interface.