Extracellular RNA in viral-host interactions: Thinking outside the cell

Area of Science:

• Molecular Biology
• Virology
• Genetics

Background:

• Small RNAs and RNA interference (RNAi) are crucial for gene regulation and host defense across life.
• While plants and fungi possess an ancestral antiviral RNAi pathway, mammals generally do not, though other RNAi mechanisms impact viral infections.
• Small RNAs can be transported between cells via extracellular vesicles, suggesting roles in cell-to-cell communication and disease.

Purpose of the Study:

• To review the current understanding of extracellular RNA functions in viral infections.
• To discuss the technical challenges in studying extracellular RNAs in the context of viral infections.
• To explore how small RNAs, particularly in extracellular vesicles, may influence virus-host interactions in mammals.

Main Methods:

• Literature review of existing research on small RNAs, RNAi, viral infections, and extracellular vesicles.
• Analysis of studies investigating non-cell autonomous functions of small RNAs in mammals.
• Synthesis of data on host- and viral-derived RNAs exported from infected cells.

Main Results:

• Extracellular small RNAs, including those in vesicles, are increasingly implicated in modulating viral infections.
• Exported RNAs from infected cells can influence various aspects of the infection process.
• While not a direct antiviral RNAi pathway, mammalian small RNAs play complex roles in viral pathogenesis and host response.

Conclusions:

• Extracellular RNA export from infected cells is a significant factor in virus-host dynamics.
• Further research and technological advancements are needed to fully elucidate the roles and mechanisms of extracellular RNAs in viral infections.
• Understanding these pathways could reveal novel therapeutic targets for viral diseases.