Transcriptional Profiling of Host Cell Responses to Virulent Haemophilus parasuis: New Insights into Pathogenesis.

Shulin Fu,Ruizhi Li,Zhongyuan Wu,Ling Guo,Chun Ye,Jing Guo,Yinsheng Qiu,Chien-An Hu,Yu Liu,Yongqing Hou

doi:10.3390/ijms19051320

Abstract

Haemophilus parasuis is the causative agent of Glässer’s disease in pigs. H. parasuis can cause vascular damage, although the mechanism remains unclear. In this study, we investigated the host cell responses involved in the molecular pathway interactions in porcine aortic vascular endothelial cells (PAVECs) induced by H. parasuis using RNA-Seq. The transcriptome results showed that when PAVECs were infected with H. parasuis for 24 h, 281 differentially expressed genes (DEGs) were identified; of which, 236 were upregulated and 45 downregulated. The 281 DEGs were involved in 136 KEGG signaling pathways that were organismal systems, environmental information processing, metabolism, cellular processes, and genetic information processing. The main pathways were the Rap1, FoxO, and PI3K/Akt signaling pathways, and the overexpressed genes were determined and verified by quantitative reverse transcription polymerase chain reaction. In addition, 252 genes were clustered into biological processes, molecular processes, and cellular components. Our study provides new insights for understanding the interaction between bacterial and host cells, and analyzed, in detail, the possible mechanisms that lead to vascular damage induced by H. parasuis. This may lead to development of novel therapeutic targets to control H. parasuis infection.

Highlights

Haemophilus parasuis is a small, Gram-negative nicotinamide adenine dinucleotide (NAD)dependent bacterium that is a member of the family Pasteurellaceae
We investigated the transcriptome of porcine aortic vascular endothelial cells (PAVECs) infected with a highly virulent isolate of H. parasuis, to analyze the host cell responses during infection
To evaluate the global picture of host cell transcriptomic response to H. parasuis infection and to understand which host factors were involved in the infection and inflammatory immune response, we used RNA sequencing (RNA-seq) on the Illumina platform with cDNA libraries of PAVECs infected or mock-infected with H. parasuis

Summary

Introduction

Haemophilus parasuis is a small, Gram-negative nicotinamide adenine dinucleotide (NAD)dependent bacterium that is a member of the family Pasteurellaceae. It is the causative agent of Glässer’s disease in pigs, and can cause huge economic losses in pig production [1]. 15 serovars of H. parasuis have been identified, but >20% of isolates have not been isolated yet [3,4]. The serovar is thought to be an important virulence marker in H. parasuis [5]. Serovar 5 of H. parasuis is considered to be highly virulent and serovar 4 moderately virulent [6]. As one of the most important bacterial respiratory pathogens in pigs, controlling infection caused by H. parasuis is crucial

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