The role of interleukin-10 receptor alpha (IL10Ra) in Mycobacterium avium subsp. paratuberculosis infection of a mammary epithelial cell line
Background: Johne's disease is a chronic wasting disease caused by the bacterium Mycobacterium avium subspecies paratuberculosis (MAP). Johne's disease is highly contagious and MAP infection in dairy cattle can eventually lead to death. With no available treatment for Johne's disease, genetic selection and improvements in management practices could help reduce its prevalence. In a previous study, the gene coding interleukin-10 receptor subunit alpha (IL10Ra) was associated with Johne's disease in dairy cattle. Our objective was to determine how IL10Ra affects the pathogenesis of MAP by examining the effect of a live MAP challenge on a mammary epithelial cell line (MAC-T) that had IL10Ra knocked out using CRISPR/cas9. The wild type and the IL10Ra knockout MAC-T cell lines were exposed to live MAP bacteria for 48 hours. Thereafter, mRNA was extracted from infected and uninfected cells. Differentially expressed genes were compared between the wild type and the IL10Ra knockout cell lines. Gene ontology was performed based on the differentially expressed genes to determine which biological pathways were involved. Results: Immune system processes pathways were targeted to determine the effect of IL10Ra on the response to MAP infection. There was a difference in immune response between the wild type and IL10Ra knockout MAC-T cell lines, and little difference in immune response between infected and not infected IL10Ra knockout MAC-T cells, indicating IL10Ra plays an important role in the progression of MAP infection. Additionally, these comparisons allowed us to identify other genes involved in inflammation-mediated chemokine and cytokine signalling, interleukin signalling and toll-like receptor pathways. Conclusions: Identifying differentially expressed genes in wild type and ILR10a knockout MAC-T cells infected with live MAP bacteria provided further evidence that IL10Ra contributes to mounting an immune response to MAP infection and allowed us to identify additional potential candidate genes involved in this process. We found there was a complex immune response during MAP infection that is controlled by many genes. Overall design: This study includes RNA-Sequencing paired-end (2 x 150 bp) reads for four treatment groups: unedited bovine mammary epithelial (MAC-T) cells, unedited MAC-T cells infected with Mycobacterium avium subspecies paratuberculosis (MAP) bacteria, IL10Ra knockout cells, and IL10Ra knockout cells infected with MAP bacteria.