Transcriptional profiles of PBMCs from pigs infected with three genetically diverse PRRSV strains

Porcine reproductive and respiratory syndrome virus (PRRSV) is a causative agent of an important infectious disease causing serious economic losses to swine industry called PRRS (porcine reproductive and respiratory syndrome). The clinical signs of this syndrome indcude respiratory disorders, abortions and variable mortality in piglets. To compare the virulence of highly diverse East European strains belonging to subtype 2 (Russian strain ILI and Belarusian strain BOR) and Danish strain from classical subtype 1 (DAN) the experimental study enrolling infection of piglets was performed. Gene expression profiles of peripheral blood mononuclear cells (PBMC) of piglets infected with three PRRSV strains vs control piglets were analysed by microarray analysis to gain insight into transcriptome changes after PRRSV infection. Three groups of 8 weeks old pigs were infected with a PRRSV Type 1 strains including subtype 1 strain 18794 (DAN), Russian isolate ILI6 (ILI) and Belarusian isolate BOR59 (BOR). Pigs were inoculated intranasally with 2 ml of respective virus inoculum. Negative control group was sham-inoculated with 2 ml of Eagle’s medium.Blood samples were collected from 5 randomly selected pigs per each group at 7 days post infection (dpi) and submitted for peripheral blood mononuclear cells (PBMC) isolation. RNA was extracted from PBMSs of each animal using RNeasy Kit (Qiagen). RNA of 5 animals from each group were pooled in 4 groups: DAN, ILI BOR and control, for microarray experiment. Each pool was processed in 4 repeats using Two-Color Microarray-Based Gene Expression Analysis.