Figure 1. Expression of complement receptors on monocytes from DENV-infected patients and healthy controls.

Flow cytometry procedures were performed to determine complement receptor (CR) expression on monocytes from patients compared with those obtained from non-infected (NI) individuals (controls). (A) The analysis of monocytes was performed by establishing a specific scatter gate using the combination of anti-cell surface antigens and laser forward scatter (FSC) to discriminate, and the monocytes were gated as FSC High (300–500) CD14^High+. (B) The expression of CR markers was performed using the percentage determined by histogram distribution applied on events versus FL1/FITC (CR1 [CD35) and CD59), FL2/PE (CR4 [CD11c]), FL5/PECy7 (CR3 [CD11b]) or FL8/APC (CR2 [CD21]). Representative histograms of CR+ on monocytes from a healthy control (black line), DF patient (blue line), severe DF patient (red line) and isotype control (gray line). (C–G) Graphic representations of the frequency of CR1 (CD35), CR2 (CD21), CR3 (CD11b), CR4 (CD11c) and CD59 among CD14+ monocytes population from controls (NI = O) and patients with distinct clinical forms of dengue disease (DF; DF/WS; Severe DF). Each point represents an individual analysed. The horizontal line represents the medians, and the vertical bars represent the interquartile ranges for the various populations. The Mann-Whitney U-test was used in order to analyse differences between control and patient groups. Statistically significant p-values for differences between patients and controls are shown above the pairs. SSC, side scatter.