Understanding Haemophilus parasuis infection in porcine spleen through a transcriptomics approach.
BACKGROUND
Haemophilus parasuis (HPS) is an important swine pathogen that causes Glässer's disease, which is characterized by fibrinous polyserositis, meningitis and arthritis. The molecular mechanisms that underlie the pathogenesis of the disease remain poorly understood, particularly the resistance of porcine immune system to HPS invasion. In this study, we investigated the global changes in gene expression in the spleen following HPS infection using the Affymetrix Porcine Genechip.


RESULTS
A total of 931 differentially expressed (DE) transcripts were identified in the porcine spleen 7 days after HPS infection; of these, 92 unique genes showed differential expression patterns based on analysis using BLASTX and Gene Ontology. The DE genes involved in the immune response included genes for inflammasomes (RETN, S100A8, S100A9, S100A12), adhesion molecules (CLDN3, CSPG2, CD44, LGALS8), transcription factors (ZBTB16, SLC39A14, CEBPD, CEBPB), acute-phase proteins and complement (SAA1, LTF, HP, C3), differentiation genes for epithelial cells and keratinocytes (TGM1, MS4A8B, CSTA), and genes related to antigen processing and presentation (HLA-B, HLA-DRB1). Further immunostimulation analyses indicated that mRNA levels of S100A8, S100A9, and S100A12 in porcine PK-15 cells increased within 48 h and were sustained after administration of lipopolysaccharide (LPS) and Poly(I:C) respectively. In addition, mapping of DE genes to porcine health traits QTL regions showed that 70 genes were distributed in 7 different known porcine QTL regions. Finally, 10 DE genes were validated by quantitative PCR.


CONCLUSIONS
Our findings demonstrate previously unrecognized changes in gene transcription that are associated with HPS infection in vivo, and many potential cascades identified in the study clearly merit further investigation. Our data provide new clues to the nature of the immune response in mammals, and we have identified candidate genes that are related to resistance to HPS.
Chen
Hongbo
H
Key Lab of Agricultural Animal Genetics, Breeding, and Reproduction, Ministry of Education, Huazhong Agricultural University, Wuhan, PR China. rose060417@yahoo.com.cn
Li
Changchun
C
Fang
Mingdi
M
Zhu
Mengjin
M
Li
Xinyun
X
Zhou
Rui
R
Li
Kui
K
Zhao
Shuhong
S
D000818:Animals; D002874:Chromosome Mapping; D015870:Gene Expression; D020869:Gene Expression Profiling; D006192:Haemophilus Infections / Q000235:genetics / Q000276:immunology / Q000662:veterinary*; D044137:Haemophilus parasuis / Q000472:pathogenicity*; D020411:Oligonucleotide Array Sequence Analysis; D040641:Quantitative Trait Loci; D012313:RNA / Q000378:metabolism; D013154:Spleen / Q000378:metabolism* / Q000382:microbiology; D013552:Swine / Q000235:genetics* / Q000382:microbiology; D013553:Swine Diseases / Q000235:genetics* / Q000276:immunology; D014158:Transcription, Genetic
D012313:RNA