Pathway analysis of differentially expressed genes in Mycobacterium bovis challenged bovine macrophages

The immune signalling genes during the challenge of bovine macrophages with bacterial products derived from tuberculosis causing bacteria in cattle were investigated in the present study. An in-vitro cell culture model of bovine monocyte-derived macrophages were challenged to Mycobacterium bovis. Macrophages from healthy and already infected animals can both be fully activated during M. bovis infection. Analysis of mRNA abundance in peripheral blood mononuclear cells from M. bovis infected and non-infected cattle were performed as a controls. Cells of treatment were challenged after six days for six hours incubation at 37 °C, with 5% CO₂, to total RNA was extracted then cDNA labelling, hybridization and scanning for microarray methods have been developed for microarray based immune related gene expression analysis. The differential expressions twenty genes (IL1, CCL3, CXCR4, TNF, TLR2, IL12, CSF3, CCR5, CCR3, MAPT, NFKB1, CCL4, IL6, IL2, IL23A, CCL20, IL8, CXCL8, TRIP10, CXCL2 and IL1B) implicated in M. bovis response were examined Agilent Bovine_GXP_8 × 60 K microarray platform. Cells of treatment were challenged after six days for six hours incubation then pathways analysis of Toll like receptor and Chemokine signalling pathway study of responsible genes in bovine tuberculosis. The PBMC from M. bovis infected cattle exhibit different transcriptional profiles compared with PBMC from healthy control animals in response to M. bovis antigen stimulation, providing evidence of a novel genes expression program due to M. bovis exposure. It will guide future studies, regarding the complex macrophage specific signalling pathways stimulated upon phagocytosis of M. bovis and role of signalling pathways in creating the host immune response to cattle tuberculosis.