Fig. 5: Mtb co-localizes with MSC in human pulmonary and extra-pulmonary granulomas.

a CD73 staining of biopsies from granuloma-positive intestinal tuberculosis patient, showing polarization of CD73-positive cells around the submucosal macrogranulomas [×100 (left panel, scale bar = 100 µm), ×200 (Right panel, scale bar = 50 µm)]. b CD73 and Ag85B dual staining performed on lung biopsy tissue from patients with pulmonary tuberculosis showing polarization of CD73⁺ cells (green arrows) toward the granulomas. Ag85B-positive organisms (black arrows) are seen inside the granulomas (×100, scale bar =  100 µm). c Representative of two independent human lung biopsies, Ag85B-positive organisms (brown color) are seen inside the histiocytes (black arrows), CD73⁺ cells are stained with blue chromogen (green arrows) and the cells showing both positivity for CD73⁺ and Ag85B⁺ organisms have been represented by red arrows (×400, scale bar = 20 µm). Insets below show the corresponding magnified CD73⁺ cells showing positivity of Ab85B staining. d Immunofluorescence staining performed on formalin-fixed paraffin-embedded (FFPE) tissue of human lung biopsies from patients with known tuberculosis show green fluorescence for Ag85B⁺ (green arrows), red fluorescence for CD73⁺ cells (red arrows) and colocalization signals are marked with white arrows. The strong colocalization area is shown in the yellow inset and magnified in the panel at the right. In the further right panel, corresponding green and red channel fluorescence is shown. Scale bar is 10 µm. e FFPE tissue processed for dual IF staining show Ag85B⁺ only (green arrows), CD105⁺ MSCs (red arrow) and cells positive for both CD105 and Ag85B (white arrow). The strong colocalization area is shown in the yellow inset and magnified in the panel at the right. In the further right panel, corresponding green and red channel fluorescence is shown. Scale bar is 10 µm. Data shown in this figure are representative of seven independent experiments.