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Progesterone induced blocking factor (PIBF) mediates progesterone induced suppression of decidual lymphocyte
Gordana Laskarin1, Vlatka S Tokmadzić, Natasa Strbo
1Department of Physiology and Immunology, Medical Faculty, University of Rijeka, Rijeka, Croatia.
Problem:
Progesterone induced blocking factor (PIBF) is a mediator of progesterone that blocks peripheral blood lytic natural killer (NK) activity. Progesterone or PIBF stimulated decidual macrophages block up-regulation of perforin expression in decidual lymphocytes (DL). Therefore, we investigated whether progesterone regulates cytotoxicity of DL. METHOD OD STUDY: Decidual mononuclear cells were cultured with progesterone. PIBF, progesterone and anti-PIBF antibody or in the medium only. Cytolytic activity of non-adherent DL was measured by PKH-26 (red) 2 hr cytolytic assay and flow cytometry. Perforin positive DL were detected by immunofluorescency and PIBF-positive cells by immunohistology.
Results:
Progesterone and PIBF, in a dose-dependent manner decreased cytotoxicity of DL against K-562 targets, and perforin egzocytosys was blocked. Anti-PIBF antibodies reversed the progesterone mediated reduction in cytolytic activity of DL. PIBF positive cells were found in first trimester pregnancy decidua.
Conclusion:
The results indicate possible role for PIBF, as a mediator of progesterone in regulation of DL cytolytic activity at the maternal-foetal (M-F) interface.
