Fig. 5. Human macrophages mobilize MT1-MMP to degrade basement membranes.

a Relative MT1-MMP/MT1-MMP expression in human macrophages left unstimulated, polarized with LPS (1 µg/mL) or recombinant human IL-4 (20 ng/mL) as determined by qPCR (top panel) or western blot (bottom panel). Results expressed as mean ± SEM (n = 3 independent exps) with significance determined by two-tailed t test. b, c Confocal images of endogenous MT1-MMP immunofluorescence (green) in permeabilized (top three panels) or non-permeabilized (bottom 3 panels) human macrophages counterstained with DAPI (blue). In c, cell surface MT1-MMP immunofluorescence is shown from a single experiment of 3 performed where staining intensity in control (n = 11), LPS-stimulated (n = 9) and IL-4-treated (n = 9) cells and quantified as mean ± SEM with significance determined by two-tailed t test. d, e Basement membrane laminin immunofluorescence following culture with macrophages in the presence of LPS (1 µg/mL) without or with 5 µM BB-94, or 75 µg/mL IgG control antibody or 75 µg/mL of MT1-MMP blocking antibody, DX-2400, for 6 days (e). Results representative of three independent experiments performed. f Scanning electron micrograph of mesentery basement membrane after culture with macrophages in the presence of LPS (1 µg/mL) and either 75 µg/mL IgG or 75 µg/mL DX-2400 for 6 days. Images shown in b, d, f are representative of three replicates. Bars: b–e 10 µm. g Quantification of the area of basement membrane degraded and perforation size as analyzed by ImageJ pixel analysis of each condition from d, e. Results are expressed as mean ± SEM (n = 3 and n = 5, respectively, independent exps) with significance determined by two-tailed t test. Source data are provided as a Source data file.