Genetic response to lung infection: on the quest for distinctive expression signatures
BACKGROUND
Respiratory diseases of pigs present a serious problem for farmers worldwide affecting both animal welfare and production economy. Multiple pathogens are involved in respiratory disorders of the pig including well characterized infectious agents such as porcine reproductive and respiratory syndrome virus (PRRS), swine influenza virus (SIV), and bacterial agents, e.g. Actinobacillus pleuropneumoniae (Ap), Mycoplasma hyopneumoniae (Mhp), and Pasteurella multocida (Pm). During the last decades modern pig production has intensified considerably leading to an increased demand for monitoring and control of infectious diseases. Current control of respiratory diseases in pigs is associated with heavy use of antibiotics, leading to significant increases in the occurrence of health threatening antibiotic resistant bacteria. Fast diagnosis is of crucial importance in disease control programs as sick animals have to be isolated to prevent spread of the pathogen and treatment has to be started as soon as possible to prevent further losses. We wish to characterize the porcine innate immune response after single and combined (viral-bacterial) infections by analyzing gene expression and microRNA in pigs using microarrays and quantitative real time reverse transcripted PCR (qRT-PCR).
OVERALL OBJECTIVES AND PERSPECTIVES
To study and identify subsets of host (porcine) gene expression changes that will provide gene expression signatures unique for different lung pathogens of the pig. These analyses will create new prospects for discovery of diagnostic biomarkers and for identification of genes or genetic pathways linked to paghogenesis.
Main hypotheses
- Expression profiles of immune related genes will change according to the infection status of the host, due to specialized host infection response patterns at the molecular level.
- Stock of frozen and formalin fixed paraffin embedded (FFPE) lung tissue at the National Veterinary Institute (VET-DTU) will provide good starting material for gene expression analysis of different well documented lung infections of pigs to provide proof concept.
CURRENT STATUS OF PROJECT
PAPERS
Shila Mortensen, Kerstin Skovgaard, Jakob Hedegaard, Christian Bendixen and Peter M.H. Heegaard. 2009. Transcriptional profiling at different sites in lungs of pigs during acute bacterial respiratory infection. Innate Immun. 2009 Nov 6. [Epub ahead of print].
Kerstin Skovgaard, Shila Mortensen, Mette Boye, Jakob Hedegaard, Peter M. H. Heegaard. 2009. Hepatic gene expression changes in pigs experimentally infected with the lung pathogen Actinobacillus pleuropneumoniae as analysed with an innate immunity focused microarray. Innate Immun. 2009 Aug 26. [Epub ahead of print]. Joint first authors.
K. Skovgaard, S. Mortensen, M. Boye, K.T. Poulsen, F.M. Campbell, P.D. Eckersall, P.M.H. Heegaard, 2009. Rapid and widely disseminated acute phase protein response after experimental bacterial infection of pigs. Veterinary Research 40(3):23. Epub 2009 Feb 24.
POSTERS
Skovgaard, K., Wendt, K. T., Schou, K. K., Trebbien, R. Larsen, L. E., Heegaard, P. M. H. 2009. MicroRNA expression in formalin fixed paraffin embedded lung tissue isolated from pigs suffering from viral or bacterial pneumonia. Graduate School of Immunology 4th Annual Meeting. Ystad, Sweden. PDF.
Shila Mortensen, Kerstin Skovgaard, Jakob Hedegaard & Peter M. H. Heegaard. 2009. Gene expression profiling of the early response in lungs of pigs experimentally infected with Actinobacillus pleuropneumoniae. Graduate School of Immunology 4th Annual Meeting. Ystad, Sweden. PDF.
Kerstin Skovgaard, Shila Mortensen, Karin T. Wendt, Klara T. Lauritsen, Peter M. H. Heegaard. 2009. Stability of microRNA in partly degraded RNA extracted from porcine lung tissue. qPCR 2009, Munich, Germany. PDF.
Kerstin Skovgaard, Shila Mortensen, Mette Boye, Karin T. Poulsen, Fiona M. Campbell, P. David Eckersall, Peter M. H. Heegaard. 2009. Rapid and widely disseminated acute phase response after experimental bacterial infection of pigs. Epizone, Antalya, Turkey. PDF.
PROJECT PARTICIPANTS
National Veterinary Institute-Technical University of Denmark:
Kerstin Skovgaard, Ph.D, senior scientist, project manager
Peter M. H. Heegaard, M.Sc, Ph.D, professor (m.s.o)
Mette Boye, cand.polyt, Ph.D, professor
Lars E. Larsen, Ph.D, senior Scientist
Anders Stockmarr, M.Sc, Ph.D, senior Scientist