Global Gene Networks in 3D4/31 Porcine Alveolar Macrophages Treated with Antigenic Epitopes of Actinobacillus pleuropneumoniae ApxIA, IIA, and IVA

Suji Kim,Han Sang Yoo,Myung Whan Oh,Woo Bin Park

doi:10.1038/s41598-019-41748-3

Suji Kim, Han Sang Yoo + Show 2 more

Open Access

https://doi.org/10.1038/s41598-019-41748-3

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Journal: Scientific Reports	Publication Date: Mar 27, 2019
Citations: 5	License type: open-access

Affiliation: Seoul National University

Abstract

Actinobacillus pleuropneumoniae (App) is the causative agent of porcine pleuropneumonia. Although App produces several virulence factors, Apx toxins, the primary App virulence factors, have been the focus of numerous studies. However, the host response against the Apx toxins has not been elucidated at the transcriptomic level. Therefore, in this study, we examined the response of an immortalized porcine alveolar macrophage cell line (IPAM 3D4/31) to four antigenic epitopes of the App exotoxins, ApxIA, IIA and IVA. The antigenic epitopes of the Apx toxins (ApxIA Ct, ApxIIA Nt, ApxIVA C1 and ApxIV C2) were determined by an in-silico antigenicity prediction analysis. Gene expression in IPAMs was analyzed by RNA-Seq after treatment with the four proteins for 24 h. A total of 15,269 DEGs were observed to be associated with cellular and metabolic processes in the GO category Biological Process and nuclear receptors and apoptosis signaling in IPA analyses. These DEGs were also related to M2 macrophage polarization and apoptosis in IPAMs. These host transcriptional analyses present novel global gene networks of the host response to treatment with Apx toxins.

Highlights

The two primary types of polarized macrophages are M1 and M2 macrophages
The sequences encoding antigenic epitopes of the Apx toxins were cloned into pET vectors, and their expression was induced in E. coli with IPTG
The results indicated that glucocorticoid receptor signaling, GM-CSF signaling, IL-10 signaling, IL-6 signaling, LXR/RXR activation, NF-κB activation by viruses, NF-κB signaling, PI3K signaling in B lymphocytes, PI3K/AKT signaling and Peroxisome proliferator-activated receptors (PPARs) signaling were commonly expressed and showed consistent activation states in cells treated with ApxIA Ct, ApxIIA Nt, ApxIVA C1 and ApxIVA C2

Summary

Introduction

The two primary types of polarized macrophages are M1 and M2 macrophages. A classical phenotype of M1 macrophages is the production of pro-inflammatory cytokines, whereas that of M2 macrophages is the production of anti-inflammatory factors[22,23,24]. One PPAR isoform, PPARγ, exerts anti-inflammatory activity in macrophages to regulates the immune inflammatory response[25,26]. Www.nature.com/scientificreports studies have reported that the absence of PPARγ expression leads to compromised M2-type responses[27] and can negatively control the cell cycle in relation to lung pathogenesis[29]. Many studies have been conducted to identify the changes in gene expression in the host and App. a transcriptomic analysis of Apx toxin-treated host cells has not yet been performed. In this study, the transcriptional responses of an immortalized porcine alveolar macrophage cell line (IPAM 3D4/31) treated with antigenic epitopes of ApxIA, ApxIIA, and ApxIVA were analyzed to identify the mechanism by which Apx toxins affect host cells. The results of this study will be foundational to our understanding of the host response to Apx toxins and aid in the development of control measures against App infection

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