PSX-41 Effect of Polyinosinic-polycytidylic acid on gene expression in goat blood

Abstract

Abstract The objective of this study was to investigate the effect of Polyinosinic-polycytidylic [poly(I:C)] acid on gene activation in goat blood. Polyinosinic-polycytidylic acid is a synthetic dsRNA analogue that binds to Toll-like receptor (TLR) 3. Synthetic TLR agonists are promising immune modulators. Blood samples were collected from the jugular vein of BoerXSpanish goats (n = 3) into tubes containing an anticoagulant. Whole blood was treated with the 12.5 µg/ml of poly I:C or 200µl of PBS which served as control. Cells were incubated at 37°C with 5% CO2 and 85% humidity for 30 minutes. Total RNA was isolated from the pellet using Trizol and then converted to cDNA using RETROscript kit (Qiagen). The expression of 84 genes in the human TLR signaling pathway RT2 PCR Array was evaluated using real-time PCR. Fold change in gene expression was calculated using the 2−ΔΔCt method. The housekeeping gene GAPDH, ACTB, HPRT1, TBP, and YWHAZ was used to normalize the data. Fold change was set at a cutoff of 2. Following treatment with poly I:C, 24 genes were up-regulated, 15 genes were down-regulated. The gene MAPK8 was induced by poly I:C treatment. Only 74 genes were expressed in the control. Thirty-nine genes were expressed in both the control group and poly I:C treatment group. Treatment with poly I:C also down-regulated some of the genes tested. Our results show that treatment poly I:C modulated the expression of genes in the TLR signaling pathway and provides insights into how goats respond to viral pathogens for the design of adjuvants to enhance the immune response.