title: Immune gene expression profiles in swine inguinal lymph nodes with different viral loads of porcine circovirus type 2.
abstract: Porcine circovirus type 2 (PCV2) infection has been suggested as an acquired immunodeficiency disorder. However, the immunopathogenesis of PCV2 infection is still not fully clarified. In the present study, 35 inguinal lymph nodes (LNs) with different levels of PCV2 load obtained from postwaening multisystemic wasting syndrome (PMWS)-affected pigs and 7 from healthy subclinically PCV2-infected pigs were selected. The LNs were subsequently ranked by their PCV2 loads to mimic the progression of PCV2 infection-associated lesion development. The expressions of 96 selected immune genes in these LNs were assessed by the integration of several reverse transcription quantitative real-time polymerase chain reaction experiments. Hierarchical cluster analysis of the gene expression profiles resulted in 5 major clusters (A, B, C, D, and E). Different clusters of immune gene expression profiles were compatible with the divergent functions of various immune cell subpopulations. 61 out of 96 selected genes belonged to cluster C and were mainly involved in the activation of dendritic cells and B and T lymphocytes. The expression levels of these genes were generally up-regulated in the LNs obtained from PMWS-affected pigs with relatively lower PCV2 loads. However, the up-regulated level tended to reduce or turned into down-regulation as the PCV2 load increased. Genes belonging to cluster B, involved in T cell receptor signaling, became silenced as the PCV2 load increased. The expression profiles of macrophage-associated genes were either independent from or positively correlated with the PCV2 load, such as those in clusters A and E and in cluster D, respectively. In addition, the principle component analysis of the expression of the 96 selected genes in the 42 inguinal LNs revealed that 53.10% and 72.29% of the total data variants could be explained by the top-3 and top-7 principle components, respectively, suggesting that the disease development of PCV2 infection may be associated with a few major and some minor factors. In conclusion, assessment of immune gene expression profiles in LNs supports a close interaction between immune activation and suppression during the progression of PMWS development.
authors.affiliation: Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei 106, Taiwan, ROC.
authors.forename: Chun-Ming
authors.initials: CM
authors.lastname: Lin
authors.affiliation: Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei 106, Taiwan, ROC; Graduate Institute of Molecular and Comparative Pathobiology, School of Veterinary Medicine, National Taiwan University, Taipei 106, Taiwan, ROC.
authors.forename: Chian-Ren
authors.initials: CR
authors.lastname: Jeng
authors.affiliation: Consulting Center for Statistics and Bioinformatics, College of Bio-Resources and Agriculture, National Taiwan University, Taipei 106, Taiwan, ROC.
authors.forename: Jen-Pei
authors.initials: JP
authors.lastname: Liu
authors.affiliation: Consulting Center for Statistics and Bioinformatics, College of Bio-Resources and Agriculture, National Taiwan University, Taipei 106, Taiwan, ROC.
authors.forename: En-Chung
authors.initials: EC
authors.lastname: Lin
authors.affiliation: Department of Veterinary Medicine, National Chia Yi University, Chia Yi 600, Taiwan, ROC.
authors.forename: Chih-Cheng
authors.initials: CC
authors.lastname: Chang
authors.affiliation: Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei 106, Taiwan, ROC; Animal Health Research Institute, Council of Agriculture, Executive Yuan, Tansui 251, Taiwan, ROC.
authors.forename: Yu-Liang
authors.initials: YL
authors.lastname: Huang
authors.affiliation: Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei 106, Taiwan, ROC.
authors.forename: Yi-Chieh
authors.initials: YC
authors.lastname: Tsai
authors.affiliation: Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei 106, Taiwan, ROC.
authors.forename: Mi-Yuan
authors.initials: MY
authors.lastname: Chia
authors.affiliation: Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei 106, Taiwan, ROC; Graduate Institute of Molecular and Comparative Pathobiology, School of Veterinary Medicine, National Taiwan University, Taipei 106, Taiwan, ROC. Electronic address: chwan@ntu.edu.tw.
authors.forename: Cho-Hua
authors.initials: CH
authors.lastname: Wan
authors.affiliation: Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei 106, Taiwan, ROC; Graduate Institute of Molecular and Comparative Pathobiology, School of Veterinary Medicine, National Taiwan University, Taipei 106, Taiwan, ROC. Electronic address: pang@ntu.edu.tw.
authors.forename: Victor Fei
authors.initials: VF
authors.lastname: Pang
mesh_terms: D000818:Animals; D018173:Circoviridae Infections / Q000235:genetics / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D017925:Circovirus / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D015536:Down-Regulation; D005260:Female; D020869:Gene Expression Profiling / Q000662:veterinary; D008198:Lymph Nodes / Q000503:physiopathology* / Q000821:virology*; D008297:Male; D060888:Real-Time Polymerase Chain Reaction; D034421:Sus scrofa; D013552:Swine; D013553:Swine Diseases / Q000235:genetics* / Q000276:immunology / Q000821:virology*; D059467:Transcriptome; D019562:Viral Load; D019282:Wasting Syndrome / Q000235:genetics / Q000662:veterinary* / Q000821:virology