engleski

Dendritic CD1a+ cells selectively govern NK cell population at the maternal-fetal interface

We have previously shown cytolytic properties of decidual CD1a+ cells such as the expression of cytolytic mediators, cytokines (IFN-gamma and TNF-alpha) and cytotoxic receptors. The aim of this study was to analyze cytotoxic interactions between early human pregnancy decidual CD1a+ and NK cells, as well as the proliferation of NK cells after the contact with cognate CD1a+ cells. Although enriched population of positively selected CD1a+ cells (purity~30%) caused proliferation of cognate NK cells after 48 hours, they were able to kill them from 5-15% or 10-30% (effector:target ratios 6:1 to 25:1) in 2 or 18 hours cytotoxicity assay, respectively. In turn, decidual CD56+ cells kill less efficiently CD1a+ cells in corresponding effector target cell ratio. The NK cell mediated killing of mature CD83+ cells was significantly higher in comparison to CD1a+ cells. Perforin seems to be main cytolytic mediator employed by CD1a+ and CD56+ cells in mutual short term cytolytic reactions ; although it only partially mediates long term cytotoxicity of CD1a+ cells against NK cells. Additional effects of blocking antibodies directed toward Fas ligand, TNF related apoptosis induced ligand or granulysin were observed neither in short nor in long term CD1a+ cells mediated killing of CD56+ cells. NKG2D is expressed on ~10% of CD1a+CD56- cells and MIC A/B on ~10% of decidual CD56+ cells, therefore pre-treatment of CD1a+ with anti-NKG2D or NK cells with anti-MIC A/B antibodies only slightly decreased NK cells killing by CD1a+ cells. Decidual CD1a+ cells by selective and mainly perforin mediated cytotoxicity govern decidual NK cell population. Acknowledgement: The experiments were financed by Croatian Ministry of Science, Education and Sport, Grants No. 0620402-0376 and No. 062-620402-0377.

dendritic cells; cytokines; pregnancy

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