[The expression of chemokine receptors in CD56(bright) CD16- natural killer cells and the mechanism of their recruitment in decidua].
OBJECTIVE
To investigate the transcriptions of 18 chemokine receptors in human decidual natural killer (NK) cells and explore the possible mechanisms of preferential accumulation of CD56(bright)CD16(-)NK cells in decidua during first-trimester pregnancy.


METHODS
Villi and decidual tissue were collected from normal pregnant women with 5 approximately 10 gestational weeks by artificial abortion. The decidual CD56(bright)CD16(-)NK cells were isolated by immune magnetic beads. The transcription levels of 18 chemokine receptors in the decidual CD56(bright)CD16(-)NK cells were assessed by reverse transcription-polymerase chain reaction (RT-PCR). After the high expression of CXCR4 and CXCR3 mRNA in these cells was found, the expression of stromal cell-derived factor-1 (SDF-1), the specific ligand of CXCR4, in first-trimester human placenta was detected by in situ hybridization and immunohistochemistry. The concentration of SDF-1alpha in the supernatant of culture of isolated trophoblast cells derived from the first-trimester human placentas was measured by ELISA. The chemotaxis of SDF-1 to decidual CD56(bright)CD16(-)NK cells was tested in Transwell, and the chemotactic activity was quantitatively examined.


RESULTS
Among the 18 chemokine receptors, CXCR4 and CXCR3 were found highly transcribed in decidual CD56(bright)CD16(-)NK cells. The concentration of SDF-1alpha in the supernatant was 385 ng/L +/- 91 ng/L after trophoblast cells had been cultured for 60 hours. Both rhSDF-1alpha and supernatants in the culture of trophoblast cells exhibited chemotactic activity on decidual CD56(bright)CD16(-)NK cells. When the concentration of rhSDF-1alpha was 10 micro g/L the number of cells that entered the lower chamber of Transwell accounted for 22.9% +/- 4.3% of the total calls.


CONCLUSIONS
First-trimester human trophoblast cells produce SDF-1, which in turn endows the trophoblast cells with the capacity to attract decidual CD56(bright)CD16(-)NK cells highly expressing CXCR4. This activity contributes to the recruitment of decidual lymphocytes and may be used at a local level to manipulate the microimmune environment at the materno-fetal interface.
Wu
Xia
X
Institute of Obstetrics and Gynecology, Fudan University, Shanghai 200011, China.
Li
Da-jin
DJ
Yuan
Min-min
MM
Zhu
Ying
Y
Wang
Ming-yan
MY
D019002:CD56 Antigen / Q000378:metabolism*; D002824:Chorionic Villi / Q000276:immunology / Q000378:metabolism; D003656:Decidua / Q000276:immunology* / Q000378:metabolism; D005260:Female; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism*; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000378:metabolism; D019707:Receptors, Chemokine / Q000276:immunology / Q000378:metabolism*; D017452:Receptors, IgG / Q000378:metabolism*
D019002:CD56 Antigen; D019707:Receptors, Chemokine; D017452:Receptors, IgG