The Intracellular Growth of M. tuberculosis Is More Associated with High Glucose Levels Than with Impaired Responses of Monocytes from T2D Patients

Figure 4

Effect of high glucose on cytokine production after TLR-specific stimulation or M. tuberculosis infection and intracellular growth control of the mycobacteria in human monocytes. Monocytes were infected with M. tuberculosis (MOI of 10) for 1 h. Subsequently, cells were transferred to RPMI medium or HG (30 mM) and cultured for 0, 1, and 3 days. After the indicated time, the supernatants were analyzed for IL-1β, IL-6, IL-8, IL-10, and TNF-α cytokines, as determined by the CBA-based assay. The cells were lysed with 1% SDS, and the mycobacteria were serially diluted and plated on 7H10 agar media. After 21 days of incubation, CFU were determined. Cytokine production after (a) P3Cys TLR-2 ligand and (b) LPS TLR-4 ligand stimulation or (c) M. tuberculosis infection in culture supernatants in RPMI medium (open circles) and HG (gray circles) (). The growth control of (d) M. tuberculosis in RPMI medium (open circles) and HG (closed circles) is shown (). Mann-Whitney test, , RPMI medium vs. HG. The median is represented by a horizontal line.

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