Accumulation of CD16+ cells with secretion of Ksp37 in decidua at the end of pregnancy.
OBJECTIVE
Maternal cellular immunity is thought to be in a state of tolerance during pregnancy, but the precise mechanism of immunomodulation is not yet known. We investigated a novel serum protein, killer-specific secretory protein of 37 kDa (Ksp37), produced by cytotoxic lymphocytes, during pregnancy.


METHODS
The level of Ksp37 was determined by enzyme linked immunosorbent assay (ELISA) in the sera of healthy pregnant women. Intracellular Ksp37 expression in mononuclear cells, isolated from peripheral blood and decidua at parturition, was examined with a flow cytometer.


RESULTS
Serum Ksp37 levels significantly increased at late pregnancy, compared with non-pregnant controls and the first trimester of pregnancy. The flow cytometric analysis exhibited that Ksp37 was mainly expressed in CD16+ natural killer (NK) cells in decidua of term placenta.


CONCLUSIONS
Serum Ksp37 level was elevated at late gestational period. CD16+ NK cells in decidua seem to be a main maternal source of Ksp37. Innate immunity, with CD16+ NK cells, may play important roles near parturition.
D000328:Adult; D001798:Blood Proteins / Q000276:immunology / Q000378:metabolism*; D003656:Decidua / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D005260:Female; D006801:Humans; D007113:Immunity, Innate; D007694:Killer Cells, Natural / Q000276:immunology*; D011247:Pregnancy / Q000097:blood / Q000276:immunology*; D011263:Pregnancy Trimester, Third; D017452:Receptors, IgG / Q000276:immunology*
D001798:Blood Proteins; C431908:FGFBP2 protein, human; D017452:Receptors, IgG