Progesterone induced blocking factor (PIBF) mediates progesterone induced suppression of decidual lymphocyte cytotoxicity.
OBJECTIVE
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.


CONCLUSIONS
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.
Laskarin
Gordana
G
Department of Physiology and Immunology, Medical Faculty, University of Rijeka, Rijeka, Croatia.
Tokmadzić
Vlatka S
VS
Strbo
Natasa
N
Bogović
Tatjana
T
Szekeres-Bartho
Julia
J
Randić
Ljiljana
L
Podack
Eckhard R
ER
Rukavina
Daniel
D
D001681:Biological Assay; D003656:Decidua / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007694:Killer Cells, Natural / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism*; D013491:Suppressor Factors, Immunologic
D008562:Membrane Glycoproteins; C110058:PIBF1 protein, human; D052899:Pore Forming Cytotoxic Proteins; D011257:Pregnancy Proteins; D013491:Suppressor Factors, Immunologic; D054353:Perforin; D011374:Progesterone