Open Access Highly Accessed Research article

Systems infection biology: a compartmentalized immune network of pig spleen challenged with Haemophilus parasuis

Ming Zhao1, Xiang-dong Liu1, Xin-yun Li1, Hong-bo Chen12, Hui Jin3, Rui Zhou3, Meng-jin Zhu1* and Shu-hong Zhao1

Author affiliations

1 Key Lab of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, PR China

2 School of Animal Science and Nutritional Engineering, Wuhan Polytechnic University, Wuhan, Hubei, 430023, PR China

3 Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, PR China

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Citation and License

BMC Genomics 2013, 14:46  doi:10.1186/1471-2164-14-46

Published: 22 January 2013



Network biology (systems biology) approaches are useful tools for elucidating the host infection processes that often accompany complex immune networks. Although many studies have recently focused on Haemophilus parasuis, a model of Gram-negative bacterium, little attention has been paid to the host's immune response to infection. In this article, we use network biology to investigate infection with Haemophilus parasuis in an in vivo pig model.


By targeting the spleen immunogenome, we established an expression signature indicative of H. parasuis infection using a PCA/GSEA combined method. We reconstructed the immune network and estimated the network topology parameters that characterize the immunogene expressions in response to H. parasuis infection. The results showed that the immune network of H. parasuis infection is compartmentalized (not globally linked). Statistical analysis revealed that the reconstructed network is scale-free but not small-world. Based on the quantitative topological prioritization, we inferred that the C1R-centered clique might play a vital role in responding to H. parasuis infection.


Here, we provide the first report of reconstruction of the immune network in H. parasuis-infected porcine spleen. The distinguishing feature of our work is the focus on utilizing the immunogenome for a network biology-oriented analysis. Our findings complement and extend the frontiers of knowledge of host infection biology for H. parasuis and also provide a new clue for systems infection biology of Gram-negative bacilli in mammals.

Pig model; Haemophilus parasuis; Spleen; Immunogenome; Network; Quantitative topology; Scale-free, C1R