Tuberculous Granuloma Induction via Interaction of a Bacterial Secreted Protein with Host Epithelium

In tuberculosis, the tuberculous granuloma has been viewed traditionally as a host-protective structure that serves to “wall off” mycobacteria. However, recent work in the zebrafish embryo showed that mycobacteria convert the nascent granuloma into a vehicle for bacterial expansion and dissemination. Thus, intercepting granuloma formation could provide a strategy for treating tuberculosis, an urgent public health goal in light of the epidemic of extensively drug-resistant tuberculosis. Now Volkman et al. (p. [466][1], published online 10 December; see the Perspective by [Agarwal and Bishai][2] ) present the molecular pathway by which mycobacteria induce granulomas in zebrafish. Inhibition of this pathway attenuates infection by reducing granuloma formation, suggesting a therapeutic target for tuberculosis treatment. [1]: /lookup/doi/10.1126/science.1179663 [2]: /lookup/doi/10.1126/science.1185569