ARS | Publication request: Innate immune response to a bovine mastitis pathogen profiled in milk and blood monocytes using a systems biology approach

Submitted to: International Symposium of Animal Functional Genomics
Publication Type: Abstract Only
Publication Acceptance Date: August 19, 2011
Publication Date: N/A

Technical Abstract: Bovine mastitis is an inflammatory condition of the mammary gland which leads to reduced milk yield and increased milk somatic cell counts (SCC) resulting in an estimated annual cost to the dairy industry worldwide of ~ 2 billion euros. Mastitis has a complex etiology, with pathogenic, host and environmental factors influencing pathology. We are using a systems biology approach to profile the host response in blood and milk isolated monocytes to pathogenic Streptococcus uberis (0510J), a major causative agent of bovine mastitis. In a pilot study, one mammary quarter of two Holstein Friesian cows have been infected with 500 CFU of S. uberis via the teat canal and compared with an uninfected cow from the same herd. A dramatic increase in SCC was observed in the infected animal and bacteriology was undertaken to confirm infection. Milk and blood samples were taken from the infected and control animal at 0, 12, 24, 36 and 48 hrs post-infection. CD14+ monocytes have been isolated by cell sorting from both milk and blood samples. Infections in 5 other animals, along with 5 additional controls are currently been carried out. From the cells processed to date, total RNA (RINs > 8) has been extracted using the Ambion mirVana RNA isolation kit and this RNA is being prepared for RNAseq using the Illumina HiSeq machine. To profile miRNA expression, small RNAs have also been extracted using Sigma mirPremier small RNA isolation kit and microRNAseq libraries are also being prepared for sequencing. Bioinformatics analysis of RNAseq and miRNAseq will then be undertaken to simultaneously profile gene and miRNA regulatory network expression in response to S. uberis, providing unprecedented resolution of the local and systemic monocyte transcriptional networks induced in mastitis and providing the first insight into the role of miRNAs have in regulating these responses.