Damage to intestinal barrier integrity in piglets caused by porcine reproductive and respiratory syndrome virus infection

Abstract

Porcine reproductive and respiratory syndrome (PRRS) induces respiratory disease and reproductive failure accompanied by gastroenteritis-like symptoms. The mechanism of intestinal barrier injury caused by PRRSV infection in piglets has yet to be investigated. An in vivo PRRSV-induced model was established in 30-day-old piglets by the intramuscular injection of 2 mL of 104 TCID50/mL PRRSV for 15 days. Observations of PRRSV replication and histology were conducted in the lungs and intestine, and goblet cell counts, relative MUC2 mRNA expression, and tight junction protein, proinflammatory cytokine, TLR4, MyD88, IκB and p-IκB expression were measured. PRRSV replicated in the lungs and small intestine, as demonstrated by absolute RT-qPCR quantification, and the PRRSV N protein was detected in the lung interstitium and jejunal mucosa. PRRSV infection induced both lung and gut injury, markedly decreased villus height and the villus to crypt ratio in the small intestine, and obviously increased the number of goblet cells and the relative expression of MUC2 mRNA in the jejunum. PRRSV infection aggravated the morphological depletion of tight junction proteins and increased IL-1β, IL-6, IL-8 and TNF-α expression by activating the NF-κB signalling pathway in the jejunum. PRRSV infection impaired intestinal integrity by damaging physical and immune barriers in the intestine by inducing inflammation, which may be related to the regulation of the gut-lung axis. This study also provides a new hypothesis regarding the pathogenesis of PRRSV-induced diarrhoea.

Recombinant Muscovy Duck Parvovirus Led to Ileac Damage in Muscovy Ducklings

“…Occludin and Claudin-1 are crucial to TJs [ 62 , 63 ]. The changes in gene expression of ZO-1 , Occludin, and Claudin-1 in this study suggest the destruction of ileal TJs after XMX infection, which can be observed in other reports about viral infection [ 64 , 65 , 66 , 67 , 68 , 69 ]. The destruction of ileum villi after infection indicates that the intestinal absorption of nutrients is reduced, which may cause Muscovy duck dwarfism.…”

“…Occludin and Claudin-1 are crucial to TJs [62,63]. The changes in gene expression of ZO-1, Occludin, and Claudin-1 in this study suggest the destruction of ileal TJs after XMX infection, which can be observed in other reports about viral infection [64][65][66][67][68][69]. The destruction of ileum villi after infection All WPF sequences were divided into three groups to verify the above-mentioned result, namely, GPV, MDPV and rMDPV, based on the three branches of the complete genome phylogenetic tree (Figure 1A).…”

Differences in Humoral Immune Response against the Type 2 Porcine Reproductive and Respiratory Syndrome Virus via Different Immune Pathways

“…(2) PRRSV evades host cell-mediated immunity and causes the delayed onset of the Th1 immune response [ 28 , 29 ]. (3) PRRSV damages immune barriers [ 30 ]. In addition, PRRSV replicates in PAMs causes dysfunction or even cell death by necrosis and apoptosis [ 31 ], impairing their antigen-presenting function.…”

Isolation and immortalization of macrophages derived from fetal porcine small intestine and their susceptibility to porcine viral pathogen infections

“…Since IPIM were also shown to be susceptible to infection by a PRRSV field strain and exhibited a high infection titer (10 7 TCID 50 /mL), this cell line is expected to be useful for isolating PRRSV from field samples and developing new LAV strains. Furthermore, it is reported that PRRSV infection impairs intestinal integrity by damaging physical and immune barriers in the intestine by inducing inflammation, which may be related to the regulation of the gut-lung axis ( 44 ). Thus, it is conceivable that IPIM or PIM are valuable tools for investigating the mechanisms by which PRRSV affects intestinal mucosal inflammation and the pathogenesis of PRRSV-induced diarrhea.…”