Editorial: Mammarenaviruses: pathogenesis, transmission and treatment

Ricardo Martin Gomez^1*Ron Diskin²Slobodan Paessler³

• ¹Laboratorio de Patogénesis Viral, Instituto de Biotecnología y Biología Molecular, CONICET-UNLP, La Plata, Argentina, La Plata, Buenos Aires, Argentina
• ²Department of Chemical and Structural Biology, Faculty of Chemistry, Weizmann Institute of Science, Rehovot, Jerusalem, Israel
• ³Department of Pathology, John Sealy School of Medicine, University of Texas Medical Branch at Galveston, Galveston, Texas, United States

Arenaviruses are single-stranded ambisense RNA viruses with some differences between the genera. Mammarenaviruses and reptarenaviruses have a bisegmented RNA with an ambisense coding strategy for four proteins: GPC and NP are coded in the S-segment and L and Z in the Lsegment. Hartmaniviruses have a bisegmented RNA with an ambisense S segment coding for the GPC and NP proteins and a negative-sense RNA L segment coding for the L protein, but they have no homolog for the Z protein of mammarenavirus and reptarenavirus. Antennaviruses have genomes consisting of three genomic segments, a negative-sense S segment encoding NP, an ambisense segment encoding GPC and an unknown protein, and a negative-sense L segment that encodes the L protein but also has no homologous Z protein. Finally, Innmovirus has three negative-sense RNA segments, the S segment that codes for NP, the ambisense segment that codes for GPC and an unknown protein, and the L segment that codes for the L protein.As far as the members of the Arenaviridae are concerned, it is very likely that more extensive and sensitive analyses and procedures will also lead to a rapid expansion of the family. The mammarenaviruses, in particular, pose a significant threat as emerging pathogens. Human activities such as deforestation and urbanization are leading to increased contact with wild rodents in new environments. This increased interaction increases the risk of future outbreaks and the discovery of new mammarenavirus isolates. As with other members of the genus, it is very likely that the family will expand rapidly with more extensive and sensitive analysis and methods.In this research topics on recent advances in mammarenaviruses: pathogenesis, transmission and treatment, we have compiled a total of four articles. The only licensed vaccine against an arenavirus is the Candid#1 vaccine, which is used in Argentina to protect against AHF caused by JUNV. It is, therefore, understandable that we are making great efforts to improve our knowledge and develop drugs to help prevent or treat infections with mammarenaviruses. In this special issue, Iyer et al. provide an overview of the current state of knowledge on entry inhibitors as antiviral agents against arenaviruses. Homologous recombination (HR) is a fundamental genetic force that drives biological evolution. However, as it is a negative-stranded RNA virus, HR has hardly been studied in mammarenaviruses. Here, He et al. performed a bioinformatic analysis to determine whether HR occurs between LASVs and what influence it has on the occurrence of LF. The genetic code consists of 64 codons, 61 of which code for amino acids and 3 for stop signals in protein synthesis. Since there are only 20 common amino acids, the genetic code is degenerate, i.e., several codons are translated into the same amino acids, with the exception of methionine and tryptophan. However, not all synonymous codons are used with the same frequency. This unequal use of codons is called codon usage bias (CUB). Codon usage bias is an important measure of genome evolution. We hope that this research topic on mammarenaviruses will stimulate interest and the development of new studies on this genus, to which new members have been regularly added since its discovery.