Abstract 272: Reduced Uterine Perfusion Pressure Stimulated T-helper 17 Cells Cause Hypertension during Pregnancy

Abstract

Preeclampsia (PE), new onset hypertension with proteinuria during pregnancy, is associated with chronic inflammation and an imbalance among T-helper cell subtypes. Adoptive transfer of all CD4+ T cells from Reduced Uterine Perfusion Pressure (RUPP) rats into Normal Pregnant (NP) rats caused elevations in blood pressure and Angiotensin II type I receptor autoantibody (AT1-AA) and inflammatory cytokines. We have shown that chronic IL-17 infusion increases blood pressure and AT1-AA during pregnancy. Furthermore, we have shown that blockade of IL-17 decreases blood pressure and AT1-AA in the RUPP rat model of PE. The objective of this study was to determine a role for the elevated autoimmune associated T-helper 17 (T H 17) cells from RUPP rats to cause hypertension and chronic inflammation during pregnancy. CD4 + CD25 - T cells were isolated from RUPP rat spleens using biotinylated antibody. Isolated cells were then stimulated on CD3 and CD28 magnetic beads and cultured in T-helper media to differentiate cells into T H 17 cells. Differentiation of isolated cells into T H 17 cells was verified via flow cytometry. On day 12 of gestation, 1x10 6 T H 17 cells from RUPP rats were adoptively transferred into NP rats. Carotid catheters were inserted on gestation day18, and on day 19 blood pressure (MAP) was recorded, serum and plasma were collected. One-way ANOVA was used for statistical analysis. MAP increased from 99 ±2 mmHg in NP (n=8), to 128±4 mmHg in RUPP (n=9, P<0.0001). Likewise, adoptive transfer of RUPP T H 17 cell into NP (NP + RUPP T H 17) significantly increased MAP to 111±3 mmHg (n=11, P<0.001 compared to NP). AT1-AA significantly increased from 0.1±0.2 beats/min in NP to 15.6±0.7 beats/min in NP + RUPP T H 17 rats (p<0.01). Plasma inflammatory cytokines were assessed via ELISA. IL-6 increased from 27.5±7.3 pg/mL in NP to 60.3±9.5 pg/mL in NP + RUPP T H 17 rats (p<0.05); TNF-α increased from 11.4±9 pg/mL in NP to 19.9±6 pg/mL in NP + RUPP T H 17; IL-17increased from 0.49±0.32 pg/ml in NP to 5.46±5 pg/mL in NP +RUPP T H 17. In conclusion, RUPP T H 17 cells increased blood pressure, AT1-AA, and inflammatory cytokines when transferred to NP rats, indicating a role for autoimmune associated T H 17 cells, to cause much of the pathophysiology associated with PE.