Quantity of IL-11 in PEDV-infected piglets. Three-day-old piglets were inoculated orally with PEDV and sacrificed 60 h after challenge. A The necropsy results exhibit gross lesions of the intestine in piglets after PEDV oral inoculation. B Viral RNA expression in different intestine segments of the diarrheic piglets. C Pathological examination and immunohistochemical staining for the detection of PEDV antigen (N protein) in the jejunum of PEDV-inoculated piglets. The black arrow indicates PEDV antigen-positive cells. Bars, 20 μm. D Immunofluorescence staining of PEDV antigen (N protein) and IL-11 in the jejunum of the PEDV inoculated piglets. Blue, DAPI; green, PEDV; red, IL-11. Bars, 25 μm. Moreover, three piglets from PEDV infected group were euthanized at 12 h, 24 h and 48 h after virus inoculation, and jejunal tissues of piglets were collected. The jejunal tissues from mock infected piglets were also acquired as a negative control. E IL-11 mRNA levels in the jejunum was quantified using qPCR. Medium: jejunal tissues from mock infected piglets. F IL-11 secreted from intestinal wash was detected using ELISA. G Correlation analysis between PEDV mRNA and IL-11 mRNA levels in PEDV-infected Vero E6 cells. H Correlation analysis between PEDV mRNA and IL-11 mRNA levels in PEDV-infected jejunum tissues. Linear growth trend (solid line); correlation coefficient (r); Pearson correlation analysis was used to determine r values; Student t test was used to determine P values. Data are presented as mean results ± SD from three independent experiments. *P < 0.05, **P < 0.01.