engleski

Granulysin expression and distribution in peripheral blood lymphocytes of first trimester pregnancy

Problem: Granulysin is a novel cytolytic molecule localized in cytolytic granules of human natural killer cells and activated cytotoxic T lymphocytes. Granulysin is also expressed in activated CD4 and CD8 positive T lymphocytes and human NKT cells. Granulysin is lytic against a variety of tumor cells and microbes but little is known about its role during pregnancy. The aim of our study was to analyse the granulysin expression and distribution in peripheral blood of pregnant women. Methods of study: Phenotype of granulysin in peripheral blood of pregnant women and freshly isolated first trimester pregnancy decidual mononuclear cells was analysed using cell permeabilisation method, flow cytometry or immunohistochemistry. Intracellular localization of granulysin in comparison with perforin was analysed using confocal microscopy. Results: Approximately 25% of peripheral blood lymphocytes express granulysin. Most of the granulysin positive cells are CD56+CD3- NK cells and CD3+CD56- T lymphocytes, whereas only few percent of granulysin positive cells are NKT cells. Granulysin is stored in cytoplasmatic granules of peripheral blood lymphocytes under the cell membrane. Unlike granulysin, only few freshly isolated PBL of pregnant women express perforin which rarely colocalizes with granulysin. However, after the contact with K562 cells the expression of perforin increases and the colocalization with granulysin is much higher. Conclusion: In comparison to first trimester pregnancy decidua, the percentage of granulysin positive cells in the peripheral blood of pregnant women is significantly lower. Acknowledgement: The experiments are financed by Croatian Ministry of Science, grant No. 0620402-0376 and EMBIC project, European FP6 project No. 512040, NoE, LSHM-CT-2004-512040

granulysin; peripheral blood lymphocytes; pregnancy; K562

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