Journal Article

Lassa Virus Vaccine Candidate ML29 Generates Truncated Viral RNAs Which Contribute to Interfering Activity and Attenuation

de la Torre, Juan Carlos, Lukashevich, Igor S., Cubitt, Beatrice, Johnson, Dylan M., Pfeffer, Tia L.

2021

Overview

Defective interfering particles (DIPs) are naturally occurring products during virus replication in infected cells. DIPs contain defective viral genomes (DVGs) and interfere with replication and propagation of their corresponding standard viral genomes by competing for viral and cellular resources, as well as promoting innate immune antiviral responses. Consequently, for many different viruses, including mammarenaviruses, DIPs play key roles in the outcome of infection. Due to their ability to broadly interfere with viral replication, DIPs are attractive tools for the development of a new generation of biologics to target genetically diverse and rapidly evolving viruses. Here, we provide evidence that in cells infected with the Lassa fever (LF) vaccine candidate ML29, a reassortant that carries the nucleoprotein (NP) and glycoprotein (GP) dominant antigens of the pathogenic Lassa virus (LASV) together with the L polymerase and Z matrix protein of the non-pathogenic genetically related Mopeia virus (MOPV), L-derived truncated RNA species are readily detected following infection at low multiplicity of infection (MOI) or in persistently-infected cells originally infected at high MOI. In the present study, we show that expression of green fluorescent protein (GFP) driven by a tri-segmented form of the mammarenavirus lymphocytic choriomeningitis virus (r3LCMV-GFP/GFP) was strongly inhibited in ML29-persistently infected cells, and that the magnitude of GFP suppression was dependent on the passage history of the ML29-persistently infected cells. In addition, we found that DIP-enriched ML29 was highly attenuated in immunocompetent CBA/J mice and in Hartley guinea pigs. Likewise, STAT-1-/- mice, a validated small animal model for human LF associated hearing loss sequelae, infected with DIP-enriched ML29 did not exhibit any hearing abnormalities throughout the observation period (62 days).

• Publisher: MDPI AG,MDPI
• Subject: Animal models / Animals / Antigens / Antiviral drugs / Biological products / Complications / complications (disease) / defective interfering particles / Fatalities / Female / Genome, Viral / Genomes / glycoproteins / Green fluorescent protein / Guinea Pigs / Hearing loss / homologous and heterologous interference / Humans / Infections / Lassa fever / Lassa Fever - genetics / Lassa Fever - immunology / Lassa Fever - prevention & control / Lassa Fever - virology / Lassa mammarenavirus / Lassa virus (LASV) / Lassa virus - genetics / Lassa virus - immunology / Lassa virus - physiology / Lassa virus fever / LASV vaccine development / Lymphocytic choriomeningitis mammarenavirus / Matrix protein / Measles / Mice / Mice, Inbred CBA / molecular virology of mammalian arenaviruses / Multiplicity of infection / nucleoproteins / Proteins / Replication / Ribonucleic acid / RNA / RNA viruses / RNA, Viral - genetics / RNA, Viral - immunology / safety in small animal models / Stat1 protein / Vaccines / viral genome / Viral infections / Viral Vaccines - administration & dosage / Viral Vaccines - genetics / Viral Vaccines - immunology / Virus Replication / Viruses