iTRAQ-based quantitative proteomic analysis of peripheral blood serum in piglets infected with Actinobacillus pleuropneumoniae

Abstract

Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae (APP) is a swine respiratory disease with an important impact around the world either as a single infection or part of the porcine respiratory disease complex. The data of interaction between hosts and pathogens has becoming more crucial for exploration of the mechanism. However, up to now, comparatively little information is available on the systemic and dynamic changes that occur in pig serum in response to APP infection. This study used iTRAQ to identify differentially expressed proteins (DEPs) in pig serum in response to APP infection. Compared with the APP un-infected group (S0),there were 137 up-regulated and 68 down-regulated proteins at 24 h (S24), and 81 up-regulated and 107 down-regulated proteins at 120 h (S120). At 24 h, the immune response was not significantly enriched, but cell adhesion, cytosol, Golgi apparatus, GTP and ATP binding and regulation of cell cycle were extremely active, implying host preparation of immune response starting. Subsequently, innate immune response, negative regulation of apoptotic process, immunological synapse, adaptive immune response, the regulation of inflammatory response, positive regulation of T cell proliferation were more enhanced at 120 h then that of 24 h, representing innate immunity transferring to the adaptive, while endocytosis, cell adhesion and platelet aggregation showed obvious decline. The pathways of T cell receptor signaling pathway, cytokine-cytokine receptor interaction, complement and coagulation cascades, leukocyte transendothelial migration were active remarkably during all infection period, and more pathways could connect to form innate immune defense networks. Surprisingly, the pathways like amoebiasis, rheumatoid arthritis and malaria had been found upregulated. As a conclusion, APP could delay host inflammatory response to the infection at early stage, and induced innate immunity to convert from adhesion, interaction into complement activation, proteasome digestion, bacterial invasion at later stage. This would increase our understanding of the porcine distinct response to APP infection.

Dynamic immune response characteristics of piglets infected with Actinobacillus pleuropneumoniae through omic

“…Samples of peripheral blood (collected from the anterior vena cava), PBMCs, BALF, and serum used in this study were collected from the APP-infected piglets as described previously (Jiang et al 2018 ; Zhu et al 2020 ; Baltes et al 2001 ). Total RNA from PBMCs at each time point of APP infection (0 h/24 h/120 h) was harvested for RNA sequencing using the Illumina HiSeq TM 4000 platform (QL Bio., Beijing, China).…”

“…In previous studies, we investigated the transcriptome of porcine PBMCs and the proteomics of porcine serum after infection with APP (Jiang et al 2018 ; Zhu et al 2020 ). In order to further assess host response to APP and identify novel important target molecules, we have determined the transcriptome of PBMCs at different stages of APP infection in combination with proteomics of serum and BALF.…”