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

Paslahepevirus balayani and Rocahepevirus ratti are genetically diverse species of hepatitis E virus [HEV]. Previously, only members of the Paslahepevirus genus were known to infect humans but recently some Rocahepevirus members have been found to be infectious to both immunocompromised and immunocompetent humans. Paslahepevirus balayani genotypes (gt) 1, 2, and 4 are known for their detrimental effects during pregnancy, causing pregnancy-related disorders. Recent findings have demonstrated the ability of Paslahepevirus balayani gt3 to replicate within placental cell lines, suggesting a direct effect on the placenta and fetus. To study whether zoonotic rat HEV strains possess a similar human-host placental tropism, we utilized JEG-3 cells to understand the replicative ability of an infectious clone of a recently reported strain of Rocahepevirus ratti, the LCK-3110 strain. Infectious cDNA clones of Pasla-, Avi-, and Rocahepevirus were transcribed and then, transduced into JEG-3 cells. Cells were harvested, and cell lysates were used for testing infectivity. Five days post-transfection or after inoculation onto naive HepG2/C3A cells, the cells were analyzed for infection. Replication in transduced JEG-3 cells and the infection potential in HepG2/C3A cells were assessed via an indirect immunofluorescence assay and a flow-cytometry assay. We found that the Rocahepevirus ratti LCK-3110 strain did not have efficient replication in JEG-3 cell cultures.