Genomic expression profiling in lymph nodes with lymphoid depletion from porcine circovirus 2 (PCV2)-infected pigs

Porcine circovirus type 2 (PCV2) is the main causative agent of porcine circovirus- associated disease (PCVAD), such as postweaning multisystemic wasting syndrome (PMWS), which involves lymphocyte depletion. But little is known about the molecular mechanisms of lymphoid depletion. To gain insight into the interaction between the virus and host cells, microarrays were used to analyze changes in genomic expression of lymph nodes following PCV2 infection and negative control in pigs. Total RNA was subjected to microarray analysis with the Affymetrix Porcine Genome Array GeneChip.

Of the 23,256 pig genes arrayed in the chip, 160 genes showed alterations after infection (up-regulation: 64, down-regulation: 96). The altered genomic expression of 18 selected genes was confirmed by quantitative real-time polymerase chain reaction (qPCR). The expression changes of numerous genes involved in innate immune defense (TLR1, CD14, and CD180), immunosuppressed responses (FGL2, and GPNMB), pro-inflammatory signals (Galectin-3) and fasting process (ANGPTL-4) indicated that PCV2 developed intricate mechanism to cause immunosuppression, inflammatory cells infiltration and weight loss in pigs.

The results of this study provide a basis for understanding the molecular pathogenesis of PCV2 infection.