The role of extracellular vesicles in pediatric COVID-19 patients with asthma

Abstract

SARS-CoV-2, the causative agent of coronavirus disease 2019 (COVID-19), has infected millions of people, and asthma was initially considered a risk factor for COVID-19. Although numerous studies on asthma and COVID-19 have been conducted, the role of plasma-derived extracellular vesicles (EVs) in COVID-19 patients with asthma remains unknown. In this study, we assessed the influence of EVs from healthy controls, severe and mild COVID-19 pediatric patients with or without asthma during acute and convalescent periods on healthy naïve CD4+T cells and monocytes. While plasma cytokines and anti-SARS-CoV-2 antibodies were similar between the groups with and without asthma, immune responses varied depending on the severity of COVID-19. In the severe acute group, whereas all cytokines increased, IFNγ, CD4+T cell counts, and monocyte numbers decreased. Stimulating healthy cells with EVs from severe acute patients led to increased PDL1 expression, Th2 and Treg cell proportions, decreased IFNγ secretion, Th1, and Th17 cell ratios. Patient EVs also reduced proinflammatory cytokine secretion from monocytes. Severe acute patient EVs caused a decline in healthy CD4+T cell and monocyte populations. Overall, our results indicate immunological responses and EV-related outcomes depending on the severity of COVID-19 rather than the presence of asthma, immunosuppression seen in severe acute COVID-19 and potential contribution of EVs to this immunosuppressive pattern in severe cases.