Protective Roles of Folic Acid in the Responses of Bovine Mammary Epithelial Cells to Different Virulent Strains.

Mastitis caused by () infection is one of the most difficult diseases to treat in dairy cattle. Exploring the biological progression of mastitis via the interaction between host, pathogen, and environment is the key to an effective and sustainable improvement of animal health. Here, two strains of and a strain of MRSA (Methicillin-resistant ) isolated from cows with different inflammation phenotypes were used to challenge Mac-T cells and to investigate their effects on the global transcriptome of the cells, then to explore the potential regulatory mechanisms of folic acid on mastitis prevention. Differential gene expression or splicing analysis showed that different strains of led to distinct transcriptional responses from the host immune system. Folic acid could protect host defense against the challenge of and MRSA partially through activating cytoplasmic DNA sensing and tight junction pathway. at the upstream of cytoplasmic DNA sensing pathway was verified and related to anti-pathogen through RNA interference. Further enrichment analysis using these transcriptome data with cattle large-scale genome-wide association study (GWAS) data confirmed that gene is highly associated with bovine somatic cell score (SCS) trait. Our data shed light on the potential effect of FA through regulating key gene and then protect host cells' defense against and MRSA.