Figure 6.

Cytokine production and TLRs in response to plasma exosomes. (a) PBMCs were treated with the TLR3 inhibitor (10 µM) for 30 min or remained untreated, followed by stimulation with plasma exosomes (4 × 10⁹ ml⁻¹) for 16 h. Production of cytokines was determined by flow cytometry gated on CD4⁺, CD8⁺, and CD14⁺. COV exo, COVID-19 plasma exosome treatment; inh/cov, TLR3 inhibitor treated and COVID-19 plasma exosomes stimulated; non-COV, treatment with non-COVID plasma exosomes. *p < 0.05; ns, p > 0.05. ANOVA, equal variants. (b) CD4⁺ T cells, CD8⁺ T cells, and CD14⁺ monocytes were isolated from PBMC using MicroBeads, followed by treatment with plasma exosomes from COVID-19 patients upon admission (COV exo, 4 × 10⁹ ml⁻¹), non-COVID donors (non-COV exo, 4 × 10⁹ ml⁻¹), or poly(I:C) (5 µg ml⁻¹) for 16 h at 37 °C. Expression of TLR3, TLR7, TLR8, and TLR9 was determined by flow cytometry gated on live cells. Isotype antibodies and no-antibody blanks were used in each flow cytometry assay. ctrl, medium only control. Error bars, ± SD; *p < 0.05; ns, p > 0.05; one-way ANOVA. Isotype antibody controls and blank controls were performed in parallel in flow cytometry.