Figure 2.

MDSCs alter the structure and bacterial containment of in vitro granuloma like structures (IVGLSs) induced by Mtb infection. Images captured using Arrayscan at day 7 of cultures after staining with Giemsa (A–C) or with the nuclear dye DAPI (D–F). Images from uninfected wells (A,D) treated similarly to the Mtb-induced IVGLS wells (B,C,E,F). Images represent IVGLS wells co-cultured for 48 h with MDSCs (B,E) or with MDMs (C,F). (G,H) Bright field images of day 7 IVGLSs acquired with a confocal microscope. Z-stacked image of 30 focal planes (H). Number and size of IVGLSs (I,J) and bacterial colony forming units (CFUs) (K) in IVGLSs at day 7 post generation and after co-culturing for the last 48 h with indicated cell subsets at distinct ratios. Added cells were at two ratios; 1:2 and 1:4 (added cells:number of PBMCs seeded for generation of IVGLSs). Each symbol corresponds to a single donor, shown are median±IQR. Data are from 5 independent experiments (n = 11–14 individuals) (representative for A–H and pooled for I,J) and from 3 independent experiments (pooled, n = 8 individuals) (K); paired Student's t-test if not otherwise mentioned in figure, ^*p ≤ 0.05, ^**p ≤ 0.01, ^***p ≤ 0.001, ^****p ≤ 0.0001.