CONICET | Buscador de Institutos y Recursos Humanos

Arenaviruses contain bisegmented single-stranded RNA and express five proteins. One of them, the Z protein, presents a conserved RING finger motif that binds Zn and makes this protein an attractive target for antiviral therapy. In previous studies it was reported the effective inhibitory action against the arenaviruses Junin (JUNV) and Tacaribe (TCRV) of two types of antiretroviral Zn finger compounds provided by the National Cancer Institute (USA), the intermolecular aromatic disulfide NSC20625 and the dithianes NSC624151 and 624152. These compounds were able to inactivate virions by direct contact as well as to reduce virus yields from infected Vero cells. In this report, we demonstrate that treatment with these compounds rendered non-infectious virus particles but preserving the conformational integrity of the virion envelope glycoproteins GP1 and GP2. This conclusion is supported by the following results: 1) binding of inactivated virions to cellular receptor was performed with the same efficacy as native virions; 2) internalization via the fusion between viral and endosome membranes was not affected in inactivated virions; 3) after inoculation of adult mice with 104 PFU of either control or NSC20625 treated JUNV or TCRV, comparable levels of antibodies were induced indicating that the immunogenicity of viral glycoproteins was preserved; 4) no alterations in viral glycoproteins of purified virions were detected by SDS-PAGE. To further understand the antiviral mechanism, the ability of inactivated JUNV virions to perform genome transcription and replication on Vero cells was studied. No amplification products were detected by RT-PCR with specific primers corresponding to genomic and antigenomic NP (nucleocapsid protein) and GPC (glycoprotein precursor) sequences. Thus, inactivation of arenaviruses with these compounds lead to a blockade in viral transcription, probably due to an interaction with the RING finger motif of the viral Z protein.

enviar mensaje