Characterization of human decidual mast cells and establishment of a culture system.

BACKGROUND

Although rodent decidual mast cells (MCs) reportedly play an important role in implantation and placenta formation, the characterization of human decidual MCs has been not well clarified. The aims of this study were to investigate the distribution and characteristics of MCs in human decidua and to establish a culture system for decidua-derived MCs.

METHODS

Decidual tissues were obtained from patients who underwent a legal elective abortion (6th week to 9th week of pregnancy), and decidual MCs were enzymatically dispersed. Cultured decidua-derived MCs were generated by culturing decidual cells with stem cell factor. An ultrastructural analysis of primary decidual MCs and cultured decidua-derived MCs was performed using a transmission electron microscope. Receptor and protease expression was analyzed using FACS. Histamine released from MCs was measured using enzyme immune assays.

RESULTS

A larger proportion of tryptase positive MCs in decidua was present on the maternal side. Both enzymatically dispersed decidual MCs and cultured decidua-derived MCs showed an FcεRIαKittryptasechymase phenotype. Their granules contenting particles exhibited variable amounts of electron-lucent space separating electron-dense particles. Both enzymatically dispersed decidual MCs and cultured decidua-derived MCs released comparable amounts of histamine following FcεRI aggregation.

CONCLUSIONS

The isolation method for MCs from decidua during early pregnancy and the culture system for decidua-derived MCs may enable the roles of decidual MC during pregnancy to be explored.