Identification of Immune Responsive Genes in Bovine Airway Using Suppression Subtractive Hybridization

Abstract

To identify the host factors that are potentially involved in the bovine airway defense and resistance to M. haemolytica, we employed suppression subtractive hybridization (SSH) to isolate bovine lung-specific genes as well as the genes that are induced in two bovine airway cell lines, namely Embryonic Bovine Tracheal (EBTr) and Bovine Turbinate (BT) cells, following infection with M. haemolytica. Among a total of 224 genes sequenced from three subtracted cDNA libraries, 177 are non-redundant, including 66 novel genes. The expression levels of 16 genes have been further selected for confirmation by semi-quantitative and quantitative real-time RT-PCR. Six have been confirmed to be truly up-regulated in response to M. haemolytica infection. The expression patterns and functions of additional genes will be investigated in the future. Importantly, such a collection of differentially expressed airway genes can be potentially developed as a microarray tool for comprehensive transcriptional profiling of bovine host responses to respiratory infections to facilitate the understanding of airway defense mechanisms as well as the development of more effective therapeutic strategies against the BRD pathogens.