FIGURE 4.

Siglec‐1 is not involved in Mtb capture and clearance. a. Relative Siglec‐1 expression on blood‐derived monocytes transfected with a silencing siRNA control (siControl) or with a Siglec‐1‐targeting siRNA (siSiglec‐1). Siglec‐1 geometric mean fluorescence intensity (MFI) was assessed by flow cytometry and values were normalized to control monocytes (set at 100%). Numbers indicate mean values and standard error of the means (SEM) obtained from five donors tested in triplicates. Statistical differences were assessed with a one sample t‐test. b. Kinetic analysis of Mtb replication (CFU/ml) in monocyte‐derived macrophages silenced with a siRNA control (siControl) or with a Siglec‐1‐targeting siRNA (siSiglec‐1). Results are presented as Log₁₀ medians of bacterial CFUs and range. Statistical differences were analyzed using linear models of mixed effects. No significant differences were observed between the values of siControl and siSiglec‐1 either looking at different time points or focusing on the slope of growth. c. Thin‐layer chromatography of GM3 standard (lane 1); Sialyllactose standard (lane 2); Sialic acid standard (lane 3); aqueous extracts of Mtb H37Rv (lane 4) and chloroform extracts of Mtb H37Rv (lane 5). Plate was revealed with resorcinol spray that is specific for sialic acid and detected by brown‐violet or blue‐violet colours. D. Thin‐layer chromatography of sialic acid standard (lane 1); hydrolyzed sialic acid standard (lane 2); aqueous extracts of hydrolyzed Mtb H37Rv (lane 4) and chloroform extracts of hydrolyzed Mtb H37Rv (lane 5). Plate was revealed with resorcinol spray that detects sialic acid by brown‐violet or blue‐violet colours