Figure 2

Cytokine production of PBMC treated with plasma exosomes. (a) Expression of IL-6, IL-8, and TNF-α in PBMC gated on CD3⁺, CD4⁺, CD8⁺, and CD14⁺. PBMCs were treated with plasma exosomes (4 × 10⁹ ml⁻¹) from COVID-19 patients upon admission (E exo) and later in their hospitalization (L exo, average 19-day of hospitalization, n = 10), or non-COVID-19 donors (C exo, n = 8) in RPMI media at 37 °C for 16 h, followed by staining of cells with respective antibodies for flow cytometry. Exosome-depleted plasma of each donor group (E depl, L depl, and C depl) was used along with plasma exosomes. Isotype antibody controls and blank controls were performed in parallel. Data represent average ± SD, n = 10, one-way ANOVA; *p < 0.05. (b) Gating strategy for CD3⁺ lymphocytes, CD4⁺ T cells, and CD8⁺ T cells. Monocytes were gated for CD14 (Supplementary Fig. S2a).