Identification and characterization of host factors involved in mammarenavirus replication, transcription, and translation towards the treatment of viral hemorrhagic fever disease

PROJECT SUMMARY: Mammarenaviruses are zoonotic pathogens capable of spilling over from rodent reservoirs into humans, Human infection can lead to development of hemorrhagic fever diseases associated with high morbidity and case fatality rates. Lassa virus (LASV) is a mammarenavirus endemic to Western Africa and the causative agent of Lassa fever (LF). Despite its significant public health burden and growing concern for global outbreaks, there are currently no FDA-approved vaccines or antiviral therapies for LF. Current treatment of LF cases relies on the off-label use of the nucleoside analogue ribavirin, which has limited efficacy, severe side effects, and a narrow therapeutic window. Therefore, the development of safer and more effective LASV-targeted therapies remains a pressing and unmet global health need. This proposal aims to generate a comprehensive landscape of host-virus interactions that support LASV replication, transcription, and translation. This new knowledge will uncover novel druggable targets to support the future development of host-directed antivirals for LF. In Aim 1, we will conduct a genome-wide CRISPR/Cas9 screen in a stable HEK293T cell line expressing a functional LASV ribonucleoprotein (vRNP) complex to identify host factors contributing to vRNP-mediated activities in replication and transcription of the viral genome. These findings will be integrated with existing mammarenavirus L and NP interactomes to prioritize candidates for validation and mechanistic follow-up studies. In Aim 2, we will investigate how mammarenaviruses engage and modulate the host translation machinery to promote viral gene expression. The Chanda lab's expertise in host- pathogen systems biology and multi-omics approaches complements the de la Torre lab's pioneering work in mammarenavirus reverse genetics, creating an ideal collaborative environment for executing this interdisciplinary research. Together, the proposed studies leverage interdisciplinary tools and cutting-edge screening technologies to illuminate underexplored aspects of LASV biology. By bridging virology, systems biology, and functional genomics, the proposed studies exhibit strong potential for facilitating advancements in mammarenavirus biology and antiviral development, addressing a critical gap in global healthcare.