Abstract: Background Extracellular vesicles (EVs) are membrane-derived nanoparticles released from cells that are critical in cell communication by transporting various bioactive components. The interplay between EVs and SARS-CoV-2 has become an appealing research topic during the COVID-19 pandemic. However, most studies on this topic have been conducted in traditional or engineered cell lines such as HEK293, 293T overexpressing ACE2, and Vero-E6. Interestingly, studies conducted in different cell lines have produced contradictory findings regarding the effect of EVs on SARS-CoV-2 infection. Similarly, circulating EVs were demonstrated to be a contributor or a mitigator to disease deterioration in COVID-19 clinical studies. Overall, it remains unclear regarding the role of EV during SARS-CoV-2 infection in human respiratory epithelial cells, the primary target of the virus. We have established the first respiratory organoid culture system that enables us to rebuild and expand the human respiratory epithelium in culture plates with excellent efficiency and stability. With these robust and biologically active respiratory organoids, we aim to investigate the role of EVs in SARS-CoV-2 pathogenesis, identify novel host factors mediated through EVs, and elucidate the mechanism(s) underlying the biological effects in our respiratory organoids model.
Results We conducted an LC-MS proteomics analysis on EVs derived from SARS-CoV-2-infected or mock-infected airway organoids. The proteomics analysis identified several upregulated EV-associated proteins in EVs from SARS-CoV-2 infected airway organoids. Among these upregulated proteins, we have identified some EV-enriched candidate proteins affecting SARS-CoV-2 replication. In conclusion, we investigated the role of EVs and EV-related host factors in SARS-CoV-2 pathogenesis within the human upper respiratory tract using human respiratory organoids.
