Transcriptome profiling identifies immune response genes against porcine reproductive and respiratory syndrome virus and Haemophilus parasuis co-infection in the lungs of piglets

• Published in: Journal of veterinary science (Suwŏn-si, Korea) Vol. 23; no. 1; pp. 2.1 - 2.18
• Main Authors: Zhang, Jing, Wang, Jing, Zhang, Xiong, Zhao, Chunping, Zhou, Sixuan, Du, Chunlin, Tan, Ya, Zhang, Yu, Shi, Kaizhi
• Format: Journal Article
• Language: Korean
• Published: 2022
• Subjects: RNA sequencing; Porcine reproductive and respiratory syndrome virus; co-infection; immune response; Haemophilus parasuis
• ISSN: 1229-845X; 1976-555X

Background: Co-infections of the porcine reproductive and respiratory syndrome virus (PRRSV) and the Haemophilus parasuis (HPS) are severe in Chinese pigs, but the immune response genes against co-infected with 2 pathogens in the lungs have not been reported. Objectives: To understand the effect of PRRSV and/or HPS infection on the genes expression associated with lung immune function. Methods: The expression of the immune-related genes was analyzed using RNA-sequencing and bioinformatics. Differentially expressed genes (DEGs) were detected and identified by quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemistry (IHC) and western blotting assays. Results: All experimental pigs showed clinical symptoms and lung lesions. RNA-seq analysis showed that 922 DEGs in co-challenged pigs were more than in the HPS group (709 DEGs) and the PRRSV group (676 DEGs). Eleven DEGs validated by qRT-PCR were consistent with the RNA sequencing results. Eleven common Kyoto Encyclopedia of Genes and Genomes pathways related to infection and immune were found in single-infected and co-challenged pigs, including autophagy, cytokine-cytokine receptor interaction, and antigen processing and presentation, involving different DEGs. A model of immune response to infection with PRRSV and HPS was predicted among the DEGs in the co-challenged pigs. Dual oxidase 1 (DUOX1) and interleukin-21 (IL21) were detected by IHC and western blot and showed significant differences between the co-challenged pigs and the controls. Conclusions: These findings elucidated the transcriptome changes in the lungs after PRRSV and/or HPS infections, providing ideas for further study to inhibit ROS production and promote pulmonary fibrosis caused by co-challenging with PRRSV and HPS.