Rat hepatitis E virus (HEV) cross-species infection and transmission in pigs

Abstract

Rocahepevirus ratti, an emerging hepatitis E virus (HEV), has recently been found to be infectious to humans. Rats are a primary reservoir of the virus; thus, it is referred to as rat HEV. Rats are often found on swine farms in close contact with pigs. Our goal was to determine whether swine may serve as a transmission host for rat HEV by characterizing an infectious cDNA clone of a zoonotic rat HEV, strain LCK-3110, in vitro and in vivo. RNA transcripts of LCK-3110 were constructed and assessed for their replicative capacity in cell culture and in gnotobiotic pigs. Fecal suspension from rat HEV-positive gnotobiotic pigs was inoculated into conventional pigs cohoused with naïve pigs. Our results demonstrated that capped RNA transcripts of LCK-3110 rat HEV replicated in vitro and successfully infected conventional pigs that transmit the virus to cohoused animals. The infectious clone of rat HEV may afford an opportunity to study the genetic mechanisms of rat HEV cross-species infection and tissue tropism.

A Zoonotic Strain of Rocahepevirus ratti Hepatitis E Virus Does Not Replicate Efficiently within Human Placental JEG-3 Cells

“…In addition, we have used the LCK-3110 rat HEV transcripts in other cell lines, such as Huh7 S10-3 liver cells, swine testicular (ST) cells, baby hamster kidney (BHK)-21, and mouse subcutaneous (LMTK) cells. ST and Huh7 S10-3 cells were the two most promising cell lines for replication studies [29]. Intrahepatic inoculation of gnotobiotic pigs with rat HEV RNA transcripts resulted in fecal viral shedding, demonstrating the functionality of the RNA transcripts [29] Thus, the rat HEV transcripts do possess replicative capability (Supplementary Figures S1 and S2) but did not show any replication in JEG-3 cells for unknown reasons.…”

“…ST and Huh7 S10-3 cells were the two most promising cell lines for replication studies [29]. Intrahepatic inoculation of gnotobiotic pigs with rat HEV RNA transcripts resulted in fecal viral shedding, demonstrating the functionality of the RNA transcripts [29] Thus, the rat HEV transcripts do possess replicative capability (Supplementary Figures S1 and S2) but did not show any replication in JEG-3 cells for unknown reasons.…”

“…Like the transfection results, infected HepG2/C3A did not show any positive ORF2 staining, suggesting a lack of infectious virus in the transfected JEG-3 cells. HepG2/C3A cells have been demonstrated to support replication of the zoonotic Rocahepevirus ratti LCK-3110 strain (Supplementary Figure S2) [29] and also the non-zoonotic strain LA-B350 [37] isolated from rats. In addition, we performed long-term experiments for 3 weeks to determine whether rat HEV could adapt to JEG-3 cells.…”

“…For linearization, isolated plasmid DNA-encoding Paslahepevirus balayani gt3 (Kernow-C1 P6), Avihepevirus magniiecur, and Rocahepevirus ratti (LCK-3110) [29] were used. Kernow C-1 P6 was used as a positive control and Avihepevirus was used as a negative control in the study, as Avihepevirus does not replicate in mammalian cells.…”

Isolation and characterization of a novel rodent hepevirus in long-tailed dwarf hamsters (Cricetulus longicaudatus) in China

“…Previously, in vivo experiments were inconclusive and attempts to infect immunocompetent rhesus macaques or domestic pigs with various strains of RHEV have been unsuccessful [24,25]. Recently, however, the zoonotic RHEV strain LCK-3110 was reported to replicate in conventional pigs [26]. RHEV strains can cause transient infection in laboratory rats [24,27].…”