Comparison of the transcriptome response within the tracheobronchial lymph node following infection with Porcine Reproductive and Respiratory Syndrome Virus, Porcine Circovirus 2 or Swine Influenza A Virus.

The aim of this study was to acquire a better understanding of porcine reproductive and respiratory syndrome (PRRS) disease through a deeper knowledge of gene expression changes that occur in pulmonary lymph nodes by comparing PRRS virus (PRRSV), porcine circovirus type 2 (PCV-2), and swine influenza virus (IAV-S) infections. The PRRSV, IAV-S and PCV-2 viral infections followed a clinical course in these domestic pigs typical of experimental infection of young pigs with these viruses. PRRSV isolate SDSU-73 was pathogenic in this study inducing fever, anorexia, listlessness, and dyspnea. Overall design: Differentially expressed tags (with respect to control) at all time points were ascertained. The experimental results were integrated with previous studies to develop a robust model of swine respiratory virus infection. Here we identified and compared gene expression changes in tracheobronchial lymph nodes (TBLN) following viral infection using Digital Gene Expression Tag Profiling (DGETP). Pigs were infected with 1 x 10^5 cell culture infectious dose 50% per pig of PRRSV (strain SDSU73), porcine circovirus type 2 (PCV2; group 2), or swine influenza A virus (IAV-S; A/SW/OH/511445/2007). Pigs were allotted to one of 4 treatment groups: sham inoculated control, PRRSV-challenge, PCV2-challenge, or IAV-S-challenge.