TY - CONF

T1 - Studies of shifts in natural killer cell subpopulations under influence of trophoblast- derived choriocarcinoma JEG-3 cells and interleukin-15

AU - Andersen, Lærke H.j.

AU - Persson, Gry

AU - Bork, Julie S.

AU - Nielsen, Rikke Nørgaard

AU - Kimmerslev, Laura

AU - Larsen, Tine G.

AU - Nielsen, Henriette Svarre

AU - Hviid, Thomas Vauvert F.

PY - 2023

Y1 - 2023

N2 - Problem: The immune regulation at the fetal-maternal interfaceis crucial for establishing a healthy pregnancy as the mother musttolerate the semi-allogeneic fetus, while simultaneously being alertto protect both the mother and the fetus from pathogens. Animbalance in the immune regulation might have an important rolein unexplained early pregnancy disorders. The decidual natural killer(dNK) cells comprise about 50-90 % of the decidual lymphocytes inthe first trimester. Decidual NK cells secrete cytokines, angiogenicfactors and growth factors, and they may play a key role for thedevelopment of the placenta. The majority of the circulatingperipheral NK cells are cytotoxic with a CD56dimCD16+ phenotype.In contrast, the majority of the dNK cells are CD56brightCD16-, andare less cytotoxic and upon balanced activation seem to secretefactors important for placentation. The cytokine interleukin-15 (IL-15) is also present in the decidualized endometrium of the uterus. Inthe present study, we investigated a possible shift from a peripheralCD56dimCD16+ NK cell phenotype towards the CD56brightCD16-decidual NK cell phenotype induced by trophoblast cells with thechoriocarcinoma cell line JEG-3 as a model, or by IL-15, or by both.Method of Study: Peripheral blood mononuclear cells (PBMCs)were isolated from buffy coats from 15 healthy, non-pregnantwomen n (<40 years). The PBMCs were incubated in co-culturestogether with a monolayer of the human trophoblast-derived chor-iocarcinoma cell line JEG-3 with or without IL-15 for six days.Natural killer cell subpopulations in the PBMCs were analyzed byflow cytometry for the markers CD3, CD14, CD20, CD56, CD16 atday 0 and day 6. Natural killer cells were sub-grouped according tothe expression of CD56 and CD16,and analyzed for surface expres-sion of various receptors at day 0 and day 6. JEG-3 cells wereanalyzed by flow cytometry for the expression of human leukocyteantigens (HLA) (HLA-C, HLA-E, HLA-F and HLA-G).Results: PBMCs co-cultured with IL-15 with or without JEG-3 forsix days resulted in an increase in the CD56brightCD16- NK cellsubpopulation and a reduction in the CD56dimCD16+ NK cellsubpopulation. Interleukin-15 and the JEG-3 cells seemed to somedegree to have an additive effect. Additionally, we observed anincrease in the KIR2DL4 and ILT2 receptors on the CD56brightCD16-NK cell subpopulation after co-culture with IL-15 and JEG-3 cells.Conclusion: Our main findings were an increase in theCD56brightCD16- NK cell subpopulation after co-cultures withPBMCs and the trophoblast-derived choriocarcinoma cell line JEG-3 and addition of IL-15. The effect was primarily driven by IL-15.The results may indicate that the cytokine IL-15 and trophoblast cellsat the fetalmaternal interface induce an increase in theCD56brightCD16- NK cell subpopulation of importance for fetalma-ternal immune interactions and placentation

AB - Problem: The immune regulation at the fetal-maternal interfaceis crucial for establishing a healthy pregnancy as the mother musttolerate the semi-allogeneic fetus, while simultaneously being alertto protect both the mother and the fetus from pathogens. Animbalance in the immune regulation might have an important rolein unexplained early pregnancy disorders. The decidual natural killer(dNK) cells comprise about 50-90 % of the decidual lymphocytes inthe first trimester. Decidual NK cells secrete cytokines, angiogenicfactors and growth factors, and they may play a key role for thedevelopment of the placenta. The majority of the circulatingperipheral NK cells are cytotoxic with a CD56dimCD16+ phenotype.In contrast, the majority of the dNK cells are CD56brightCD16-, andare less cytotoxic and upon balanced activation seem to secretefactors important for placentation. The cytokine interleukin-15 (IL-15) is also present in the decidualized endometrium of the uterus. Inthe present study, we investigated a possible shift from a peripheralCD56dimCD16+ NK cell phenotype towards the CD56brightCD16-decidual NK cell phenotype induced by trophoblast cells with thechoriocarcinoma cell line JEG-3 as a model, or by IL-15, or by both.Method of Study: Peripheral blood mononuclear cells (PBMCs)were isolated from buffy coats from 15 healthy, non-pregnantwomen n (<40 years). The PBMCs were incubated in co-culturestogether with a monolayer of the human trophoblast-derived chor-iocarcinoma cell line JEG-3 with or without IL-15 for six days.Natural killer cell subpopulations in the PBMCs were analyzed byflow cytometry for the markers CD3, CD14, CD20, CD56, CD16 atday 0 and day 6. Natural killer cells were sub-grouped according tothe expression of CD56 and CD16,and analyzed for surface expres-sion of various receptors at day 0 and day 6. JEG-3 cells wereanalyzed by flow cytometry for the expression of human leukocyteantigens (HLA) (HLA-C, HLA-E, HLA-F and HLA-G).Results: PBMCs co-cultured with IL-15 with or without JEG-3 forsix days resulted in an increase in the CD56brightCD16- NK cellsubpopulation and a reduction in the CD56dimCD16+ NK cellsubpopulation. Interleukin-15 and the JEG-3 cells seemed to somedegree to have an additive effect. Additionally, we observed anincrease in the KIR2DL4 and ILT2 receptors on the CD56brightCD16-NK cell subpopulation after co-culture with IL-15 and JEG-3 cells.Conclusion: Our main findings were an increase in theCD56brightCD16- NK cell subpopulation after co-cultures withPBMCs and the trophoblast-derived choriocarcinoma cell line JEG-3 and addition of IL-15. The effect was primarily driven by IL-15.The results may indicate that the cytokine IL-15 and trophoblast cellsat the fetalmaternal interface induce an increase in theCD56brightCD16- NK cell subpopulation of importance for fetalma-ternal immune interactions and placentation

U2 - 10.1016/j.jri.2022.103584

DO - 10.1016/j.jri.2022.103584

M3 - Poster

SP - 34

ER -