Comparison of the transcriptome response within the porcine tracheobronchial lymph node following viral infection

Authors: Miller, Laura; FLEMING, DAMARIUS - Orise Fellow; Kehrli Jr, Marcus; Lager, Kelly

Submitted to: World Congress of Genetics Applied in Livestock Production
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/26/2018
Publication Date: 5/10/2018
Citation: Miller, L., Fleming, D., Harhay, G., Kehrli, M., Lager, K. 2018. Comparison of the transcriptome response within the porcine tracheobronchial lymph node following viral infection. Proceedings of the World Congress on Genetics Applied to Livestock Production, Volume Biology - Disease Resistance 2: 672.

Interpretive Summary: Porcine reproductive and respiratory syndrome virus (PRRSV) is a major respiratory pathogen of swine that has become extremely costly to the swine industry worldwide causing losses in production and animal life. PRRSV was first discovered in 1991 and despite intensive study of how the virus functions, the changes that occur in pigs following respiratory infection are still poorly understood. Likewise, there is limited understanding of how other swine respiratory viruses actually cause disease at the molecular level. The aim of this study was to acquire a better understanding of PRRSV respiratory disease by comparing gene expression changes that occur in tracheobronchial lymph nodes of pigs infected with either PRRSV, porcine circovirus type 2 (PCV2), or swine influenza A virus (IAV-S) infections. The results showed that PRRSV, IAV-S and PCV-2 viral infections followed a clinical course in the pigs typical of experimental infection of young pigs with these viruses. Gene expression results echoed this course, as well as, uncovered genes related to shared and unique host immune responses to the 3 viruses. By testing and observing the host response to other respiratory viruses, our study has elucidated similarities and differences that can assist in development of vaccines and therapeutics that may shorten or prevent a chronic PRRSV infection.

Technical Abstract: Porcine reproductive and respiratory syndrome virus (PRRSV) is a major respiratory pathogen of swine that has become extremely costly to the swine industry worldwide, often causing losses in production and animal life due to its ease of spread. However, the intracellular changes that occur in pigs following viral respiratory infections are still scantily understood for PRRSV, as well as, other viral respiratory infections. The aim of this study was to acquire a better understanding of PRRS disease by comparing gene expression changes that occur in tracheobronchial lymph nodes (TBLN) of pigs infected with either PRRSV, porcine circovirus type 2 (PCV2), or swine influenza A virus (IAV-S) infections. The study identified and compared gene expression changes in the TBLN of pigs infected with either PRRSV, PCV2, IAV-S, or sham inoculation. Five pigs from each group were euthanized on 1, 3, 6, and 14 DPI. TBLN were collected from each pig and total RNA was pooled for each group at each time-point to make 16 libraries for analysis by Digital Gene Expression Tag Profiling (DGETP). The data underwent standard filtering to generate a list of sequence tag raw counts that were then analyzed using multidimensional and differential expression statistical tests. The results showed that PRRSV, IAV-S and PCV-2 viral infections followed a clinical course in the pigs typical of experimental infection of young pigs with these viruses. Gene expression results echoed this course, as well as, uncovered genes related to shared and unique host immune responses to the 3 viruses. By testing and observing the host response to other respiratory viruses, our study has elucidated similarities and differences that can assist in development of vaccines and therapeutics that shorten or prevent a chronic PRRSV infection.