Positive and negative controls of TLR7/8 inhibition in peripheral blood mononuclear cells (PBMC) and plasmacytoid dendritic cells (pDC).

(A) PBMC were left untreated (not stimulated, ns) or stimulated for 24 hours with the TLR7 ligand Imiquimod (Imq, at 1 and 5μM), the TLR7/8 agonist Resiquimod (R848, at 1 and 5μM), the TLR9 ligand type C CpG (CpG-C, 3μg/ml), SARS-CoV-2 (CoV2) at a multiplicity of infection (MOI) of 0.04 (1 cell, 0.04 TCID50 of virus) and UV-inactivated influenza A (UV-I-Flu-A, 0.1 MOI) in presence or absence of a 30 minute pre-treatment with either a specific TLR7/8 inhibitor ODN-2087 (I-TLR7/8, 1μM) or an unrelated ODN control (ODN-ctrl, 1μM). Production of IFN-αs and IL-6 was tested in collected culture supernatants. (B) pDC were left untreated (ns) or stimulated for 24 hours with R848 (1 and 5μM), CpG-C (3μg/ml), CoV2 (0.1 MOI) and UV-Flu-A (0.1 MOI) in presence or absence of a 30 minute pre-treatment with either I-TLR7/8 (1μM) or with an unrelated ODN-ctrl (1μM). Production of IFN-αs, IL-6 and TNF-α was tested in collected culture supernatants. Shown results were mean relative values ± SEM of 3 independent experiments.

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