Fig 1: Regulation of cytokine release and immunophenotype in monocytes treated with D614G in the presence of J08 nAbsCD14+ monocytes, purified from peripheral blood mononuclear cells (PBMC) of healthy volunteers (n = 4), were left untreated (not stimulated, ns) or stimulated with D614G virus at a multiplicity of infection of 0.04 alone or upon opsonization with the neutralizing dose of the anti-SARS-CoV-2 Spike neutralizing IgG1 antibody J08 in the wild-type (WT), Fc mutated (MUT) and Fc truncated (Fab) versions. Cells were harvested at 24 and 72 h post-infection (hpi).(A‒C) Production of the inflammatory cytokines interleukin (IL)-6 (A), tumor necrosis factor (TNF)-α (B) as well as of the chemokine IL-8 (C) were measured in culture supernatants.(D‒F) Monocytes were studied by flow cytometry for cell subset differentiation. In particular, classical [CD14hiCD16neg] monocytes are indicated in blue, inflammatory [CD14+CD16int] monocytes in aqua blue, and atypical [CD14low-negCD16hi] monocytes in red. (D) Representative dot plots at the different experimental conditions displaying different monocyte subsets derived from 1 experiment, out of 4 independently performed, are shown. (E) Results shown in the pie charts are mean values of the percentage (%) of the different monocyte subsets analyzed in the parental single-live CD14+-gated cells in the 4 experiments independently performed. (F) Surface expression of the costimulatory marker CD86 as well as of the Fc receptors CD16, CD32, and CD64 was determined as mean fluorescence intensity (MFI) by cytofluorimetric analysis in single-live CD14+ monocytes. Results were shown as median values ± Interquartile range of 4 independent experiments. p-values were calculated by two-way ANOVA and assigned as follows: ∗ ≤0.05.