Study of the effect of intestinal immunity in neonatal piglets coinfected with porcine deltacoronavirus and porcine epidemic diarrhea virus

Abstract

Porcine deltacoronavirus (PDCoV) and porcine epidemic diarrhea virus (PEDV) have often been detected simultaneously in piglets with coronavirus diarrhea. However, the intestinal immune response to the interaction between circulating PDCoV and PEDV is unknown. Therefore, this study was conducted to investigate the intestinal immunity of neonatal piglets that were exposed first to PDCoV and then to PEDV. The amounts and distribution of CD3 + T lymphocytes, B lymphocytes, and goblet cells (GCs) in the small intestine were analyzed by immunohistochemistry and periodic acid–Schiff staining, respectively. The expression levels of pattern recognition receptors and downstream mediator cytokines were analyzed by qPCR and ELISA. The results showed that the numbers of GCs, CD3 + T lymphocytes, and B lymphocytes in the duodenum and jejunum of the PDCoV + PEDV coinoculated piglets were increased compared with those of piglets inoculated with PEDV alone. The piglets in the PDCoV + PEDV group had significantly upregulated IFN-α and IFN-λ 1 compared with the PEDV single-inoculated piglets. These results suggest that PDCoV + PEDV-coinfected piglets can activate intestinal antiviral immunity more strongly than piglets infected with PEDV alone, which provides new insight into the pathogenesis mechanism of swine enteric coronavirus coinfection that may be used for vaccination in the future.

Transcriptome Analysis of LLC-PK Cells Single or Coinfected with Porcine Epidemic Diarrhea Virus and Porcine Deltacoronavirus

“…The coinfection rate of PEDV and PDCoV was high, reaching 60.4% in diarrheal pigs in Henan Province, China [ 25 ]. Furthermore, compared to a single infection, coinfection with PEDV and PDCoV in piglets could worsen clinical symptoms and have a synergetic effect on the intestinal antiviral immune response and the modulation of inflammatory cytokine expression [ 27 , 28 , 29 ]. In addition, coinfection of PEDV and PDCoV can alter PEDV tropism, which may affect the outcome of viral disease in piglets [ 30 ].…”