Pulmonary alveolar macrophages (PAMs) of Tongcheng piglets response to HP-PRRSV infection in vivo

Porcine reproductive and respiratory syndrome (PRRS), caused by PRRS virus (PRRSV), is the most economically important disease in pig populations. Lung damage is one major pathological condition following PRRSV infection, often leading to animal death. In vivo, PRRSV productive infection occurs predominately in alveolar macrophages of the lung. Here, transcriptome profiling of pulmonary alveolar macrophages (PAMs) from Tongcheng piglets pre- and post- infection of highly pathogenic PRRSV has been performed using porcine Affymetrix GeneChip. All animal procedures were performed according to protocols approved by the Biological Studies Animal Care and Use Committee of Hubei Province, China. Piglets used in this study were free from PRRSV, pseudorabies virus (PRV) and porcine circovirus type 2 (PCV2) determined by ELISA test for serum antibodies. Twelve of 5-week-old boars were obtained from three litters (four piglets per litter), and raised in pathogen-free facilities. In order to perform a paired experiment, every four full-sib individuals were divided equally into two groups: one infected group and one control group with 6 piglets in each group. The infected groups were challenged with PRRSV-Wuh2 (3 ml/15 kg, 10-5 TCID50/ml) by intramuscular inoculation. Slaughters were carried out at 0 days post-infection (dpi) for uninfected (control) groups, and at 5 or 7 dpi for infected groups. The PAMs for microarray analysis were collected by bronchoalveolar lavage from three uninfected pigs and three infected pigs at 5 dpi. Total of 6 microarrays have been hybridized in this experiment.