In tuberculosis, some macrophages in granulomas assume an epitheloid appearance. Using the Mycobacterium marinum-zebrafish model, Cronan et al. (2016) now show that granuloma macrophages undergo reprograming events involving E-cadherin-dependent formation of epithelial-like cell-cell junctions. Interference with the function of E-cadherin in macrophages disorganized the granulomas and protected the fish, introducing new ideas and questions about macrophage function and granulomatous diseases.
