Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) causes coronavirus disease 2019 (COVID-19), which has ignited the most significant health crisis of the 21st century. Acute COVID-19 infection has lethal outcomes and post-acute sequelae of COVID-19 (PASC) infections, commonly called 'long-haul' COVID-19. PASC individuals experience prolonged neurologic symptoms including dysregulated taste or smell, altered consciousness, and chronic fatigue, for months following acute COVID-19 infection. The mechanism of COVID-19's effect on brain function is unknown, and there are no effective treatments for those suffering from PASC.

Exosomes are small, extracellular vesicles that bud off from host cells, travel throughout the body, and share their contents with target cells. Exosomes from virally infected cells can modify distant cell functions via the transfer of viral contents. Due to their size and membrane composition, exosomes are suspected to be capable of entering the brain. We suspect exosomes contribute to the development of chronic neurological symptoms experienced during long-haul COVID-19. 

We hypothesize that exosomes isolated from individuals with and without neurological symptoms differ during COVID-19. 

Exosomes were purified from nasal swabs using ultra-centrifugation and separated from viral particles using density gradient. Size and protein analysis was done to confirm the presence of exosomes in the purified samples. Exosome RNA was isolated and quantified in preparation for future aims, where they will be analyzed using RNA sequencing. Differentially expressed cellular or viral RNA could regulate neurological outcomes during COVID-19. We hope to gain an understanding of the role exosomes play in long-haul COVID-19.

Funding: This work was supported by US4 MD006882 from the National Institute on Minority Health and Health Disparities