Mode of antiviral action of the galactose-specific lectin, AJLec, on the Junin virus propagation.

Junin virus (JUNV), a member of Arenaviridae, is the causative agent of Argentine hemorrhagic fever (AHF). Available AHF treatments are limited; therefore, development of effective and safe treatments is required. Thus, in this study, novel lectins were examined for anti-JUNV activity. To evaluate JUNV propagation, a recombinant Junin virus vaccine strain (r3Candid #1/ZsGreen) containing the ZsGreen gene as a marker in the viral genome was used. The anti-JUNV effects of four types of marine organism-derived lectins collected in Japan, including the Nagasaki Prefecture, were examined. AJLec, which was extracted from the Sea Anemone Anthopleura japonica, reduced the number of infected cells and viral production. Infection and infection-surrogate assays revealed that incubation of AJLec with viruses and cells before infection, and maintaining it during infection, was required to exhibit full antiviral activity. Moreover, the anti-JUNV activity of AJLec was suppressed by the addition of lactose; hence, the anti-JUNV activity of AJLec was a result of its galactose recognition. This indicates the importance of galactose on the surface of the Junin virion and the cell membrane for entry into cells. Overall, these results provide new insights into the anti-JUNV activity of AJLec. Particularly, the potential of lectins as new antiviral agents that inhibit pathogenic arenavirus replication and propagation is promising.