Abstract P207: Mitochondrial Dysfunction And Natural Killer Cell Activation Stimulated By Il-17 Signaling From Th17 Cells In Response To Placental Ischemia During Pregnancy; Sarah Fitzgerald, Evangeline Deer, Owen Herrock, Tarek Ibrahim, Lorena Amaral, Denise Cornelius And Babbette Lamarca; 1 Department Of Pharmacology, University Of Mississippi Medical Center.

Abstract

Preeclampsia (PE) is a multisystem disorder characterized by new onset hypertension associated with placental ischemia (PI), mitochondrial (mt) dysfunction, and an imbalance in T helper (TH) and Natural Killer (NK) cells during pregnancy. The reduced uterine perfusion pressure (RUPP) model is an established model for PE. We have previously shown an important role for IL-17 in hypertension and activation of NK cells in the RUPP rat. We don’t know the role for IL-17 or TH17 cells in contributing to NK cell mediated mt dysfunction and ROS associated with PI. Therefore, we hypothesize that hypertension in response to PI stimulated TH17 cells causes mt ROS mediated through IL-17 signaling to NK cells. On gestation day 12 (GD12) RUPP-induced TH17s (splenic CD4+/CD25- cells) were adoptively transferred (Ad-T) into normal pregnant (NP) rats. Recombinant mouse IL-17 receptor C (IL-17RC) (100 pg/day) was administered from GD14-19 via osmotic mini-pump. On GD19, samples were collected and mean arterial pressure (MAP) was measured. Mt respiration and mt ROS data was measured in isolated mt from renal and placental tissues using the Oxygraph 2K and fluorescent microplate reader, respectively. A one-way ANOVA with Bonferroni post hoc test was used for statistical analysis. MAP was increased in Ad-T rats (112 ± 0.72mmHg, n=14) compared to NP (92 ± 3.03mmHg, n=14) (p<0.05), and was lowered with IL-17RC (97.2± 2.14 mmHg, n=13). Circulating activated NK cells were significantly increased with Ad-T (3.326± 0.76 %gated, n=9) (p<0.0001) compared to NP (0.05± 0.05 %, n=11), and were attenuated with IL-17RC (0.42± 0.4 %, n=5) (p<0.01). Placental activated NK cells were significantly increased with Ad-T (2.5± 1.01 %, n=4) (p<0.05) compared to NP (0.03± 0.03 %, n=8) and were attenuated with IL-17RC (0.21± 0.12 %, n=4) (p<0.05). Renal mtROS increased in Ad-T (312.4 ± 44.7%, n=9) compared to NP (191.9 ± 20.5%, n=5). Placental mtROS significantly increased in Ad-T (312.5 ± 23.6%, n=9) (P<0.0005) compared to NP controls (134 ± 9.6%, n=5) (p<0.0001), and was decreased by administration of IL-17RC (174.5± 42.5 %, n=5) (p<0.0001). These data demonstrate that IL-17 signaling plays an important role in NK cell activation and tissue mt function in response to TH17 cells stimulated during PE.