Exposure of bovine blood to pathogen associated and non pathogen associated molecular patterns results in transcriptional activation. Joint Annual Meeting (ASAS, ADSA, CSAS), Salt Lake City, Utah. July 19-23, 2016.

The effect of exposure of cow blood to non pathogen associated (probiotics) molecular patterns on the subsequent response to pathogen associated molecular patterns (PAMPS) was evaluated using transcriptional profiling. Probiotic supplements are beneficial for animal health and rumen function and represent non pathogen associated molecular patterns. Lipopolysacharides form gram negative bacteria are associated with inflammatory diseases and represent PAMPS. A global gene expression profile in whole blood collected from probiotics-supplemented cow was investigated in response to stimulation with lipopolysaccharide (LPS) in vitro. The recommended dose of FASTtrak microbial pack (Conklin Company, Kansas City, MO, USA) was administered orally in 50 ml of sterile water to Holstein-Friesian cows (n = 10) in mid lactation, for 60 d. Whole blood was collectedly aseptically and treated with 100 ng/ml of LPS and untreated samples served as control. Total RNA was extracted, and samples (0.5ug, RIN > 7) pooled together, were used for the microarray experiment on a bovine (v2) 4 × 44 arrays with 44,000 gene transcripts. A Real-time quantitative PCR was performed to validate the expression of Wnt signaling pathway and innate and adaptive immune response genes using RT-PCR profilers arrays (Qiagen) with 84 test genes each. Global gene expression analysis identified 13,658 differentially expressed genes (fold change cutoff ≥ 2, P < 0.05), 3816 upregulated genes and 9842 downregulated genes. Treatment with LPS resulted in increased expression of TLR4 (Fold change (FC) = 3.16), TLR2 (FC = 2.4), TLR7 (FC = 2.13), WNT5A (FC = 2.68), and transcription factor NF-Kb (FC = 5.4). Genes downregulated in expression included WNT 11 (FC = -2.60), TLR1 (FC = -2.54), TLR3 (FC = -2.43), TLR10 (FC = -3.88), NOD2 (FC = -2.4), NOD1 (FC = -2.45) and pro-inflammatory cytokine IL1B (FC = -3.27). Thus, probiotic supplementation had an effect on the response to LPS exposure with specific effects on Toll-like receptor transcription. Exposure of bovine blood to pathogen associated (LPS) and non pathogen associated (probiotics) patterns resulted in transcriptional activation. Thus, probiotic supplementation may modulate the response to gram negative bacteria.