Animals

Eighty-four SPF male Mongolian gerbils (Meriones unguiculatus, body weight: 50–60 g; age: 8–10 weeks), were purchased from the Department of Experimental Animal Sciences of Capital Medical University (Beijing, China). To avoid extensive stress to the animals, all experiments were performed following an acclimation period of 3 days after their-arrival to our facility. All animals used in this study were confirmed to be negative for HEV antibodies by ELISA and there were no HEV antigens detected in their sera or fecal samples, according to the nested-PCR analyses, as previously described (Yang et al., 2015). All animals were housed in the SPF facilities.