An alternative pathway of enteric PEDV dissemination from nasal cavity to intestinal mucosa in swine

Abstract

Porcine epidemic diarrhea virus (PEDV) has catastrophic impacts on the global pig industry. Although the fecal–oral route is generally accepted, an increased number of reports indicate that airborne transmission may contribute to PEDV outbreak. Here, we show that PEDV could cause typical diarrhea in piglets through a nasal spray. Firstly, PEDV can develop a transient nasal epithelium infection. Subsequently, PEDV-carrying dendritic cells (DCs) allow the virus to be transferred to CD3+ T cells via the virological synapse. Finally, virus-loaded CD3+ T cells reach the intestine through the blood circulation, leading to intestinal infection via cell-to-cell contact. Our study provides evidence for airborne transmission of a gastrointestinal infected coronavirus and illustrates the mechanism of its transport from the entry site to the pathogenic site.

Emerging and re-emerging coronaviruses in pigs

“…Airborne transmission was reported for both PEDV and PDCoV, probably via ingestion of aerosolized virus particles [71]. Recently, Li et al [73] investigated the potential mechanisms of airborne transmission of PEDV. They concluded that the virions can replicate in the nasal epithelial cells, then are carried by dendritic cells (DCs) and passed to CD3+ T cells that transport PEDV to the gut to infect intestinal cells.…”

Host Factors Affecting Generation of Immunity Against Porcine Epidemic Diarrhea Virus in Pregnant and Lactating Swine and Passive Protection of Neonates

“…Due to its highly contagious nature, PEDV spreads rapidly through the fecal-oral route after direct or indirect exposure to infected animals or their feces [23]. PEDV may also spread through aerosolized particles [24,25]. Genetically the US PEDV strains resembled the highly virulent strains that emerged in China (China AH2012 and CH/ZMZDY/11) [5,26,27].…”

“…However, there is contrasting evidence regarding the ability of PEDV to productively infect DCs [67,71]. A recent study by Li et al demonstrated that PEDV can replicate in the nasal cavity and suggested that PEDV enters submucosal DCs near infected nasal epithelial cells [24]. From there, the authors purport that PEDV accessed migrating T cells, which when in peripheral blood traffic to the intestinal epithelium leading to PEDV infection of the gut [24].…”

“…A recent study by Li et al demonstrated that PEDV can replicate in the nasal cavity and suggested that PEDV enters submucosal DCs near infected nasal epithelial cells [24]. From there, the authors purport that PEDV accessed migrating T cells, which when in peripheral blood traffic to the intestinal epithelium leading to PEDV infection of the gut [24]. However, it is possible that these pigs were inoculated via both intranasal (IN) and oral routes.…”

Quantitative Proteomic Analysis Reveals Antiviral and Anti-inflammatory Effects of Puerarin in Piglets Infected With Porcine Epidemic Diarrhea Virus

“…Since December 2010, massive outbreaks of PED have occurred in China, with 80-100% morbidity and 50-90% mortality in suckling piglets (2,3). The recent research provides evidence for airborne transmission of PED virus (PEDV) (4), which has greater transmission potential than other seasonal diarrhea viruses (5,6). The small intestine, especially the jejunum and ileum, is the target tissue of PEDV infection (7).…”