Development of a new in vitro inhibition strategy for Zika Virus and Influenza Virus using CRISPR-Cas13 RNA-editing technique as an alternative treatment

Abstract

Several influenza pandemics caused by Influenza Virus have already been described, the last occurring less than ten years ago. The danger of a new pandemic is always present, especially because of the particular rearrangement capacity of this virus. The disease, the Flu, is caused by Influenza Virus, which belongs to the Orthomyxoviridae family. The increased frequency of circulating mutant viruses has caused concern, since one of the neuraminidase surface protein inhibitors (Oseltamivir) is the most prescribed antiviral for Influenza Virus infections control. The emergence of Oseltamivir-resistant strains among Influenza A (H1N1) viruses exposes the need to find new forms of treatment. It is in this context that new forms of viral infection come into play, and one technique has been in the spotlight for at least four years: the CRISPR-Cas genomic editing tool, developed from an acquired immune defense mechanism of prokaryotes. The Cas9 protein, which possesses the genomic DNA as a target, has been extensively studied, and now a new Cas nuclease begins to gain notoriety: the Cas13 protein, which cleaves RNA molecules and not DNA. From this technique, a group has already been able to use it as an in vivo RNA tracer, as a diagnostic method and as a genomic editor. In addition to the Influenza Virus, in a development of a therapeutic alternative for RNA viruses, it is important to test the treatment in both sense-negative (RNA-) viruses and positive-sense (RNA+) viruses. Influenza Virus has an RNA+ genome and the choice for RNA- virus was Zika Virus, mainly because of its impact on Brazilian and world public health, since it has already been declared a "Global Emergency" by the World Health Organization. In addition, ZIKV does not have licensed therapies and reinforces the importance of creating a treatment or even a prevention method to combat the ZIKV infection. Therefore, our goal with this work is to use the new technique as a form of treatment for Influenza and Zika viruses, taking into account particularities of the genomes of these viruses that would be excellent targets for Cas13 protein. In addition, the work will also increase the study of this new nuclease by testing new forms of delivery/transfection, making it possible to aggregate new parts in the study of genomic editors. (AU)