Fig. 3

CD13 mediated the binding and entry of live M. tuberculosis onto human DCs. a The course of M. tuberculosis binding to the CD13 and entering into dendritic cells was shown by a series of representative cells. Confocal microscopy showing CD13 on dendritic cells surface stained with anti-CD13 antibody (red); M. tuberculosis stained with Auramin-Rhodamin T (green); cell nucleus stained with DAPI (blue); colocalization of M. tuberculosis with membrane-bound CD13 on dendritic cells (yellow). The profile quantification tool provided by the Leica confocal software was used to obtain graphs with the profiles of intensities of CD13 and M. tuberculosis along lineal regions of interest (ROI). b At 60 min of incubation, most M. tuberculosis was found inside the DCs. Scale bar, 25 μm