Myeloid Growth Factors Promote Resistance to Mycobacterial Infection by Curtailing Granuloma Necrosis through Macrophage Replenishment.

The mycobacterial ESX-1 virulence locus accelerates macrophage recruitment to the forming tuberculous granuloma. Newly recruited macrophages phagocytose previously infected apoptotic macrophages to become new bacterial growth niches. Granuloma macrophages can then necrose, releasing mycobacteria into the extracellular milieu, which potentiates their growth even further.

Zebrafish and frog models of Mycobacterium marinum infection.

Mycobacterium marinum infection of poikilothermic animals, such as fish and frogs, results in chronic granulomatous diseases that bear many similarities to mycobacterioses in mammals, including tuberculosis. This unit describes three animal models of M. marinum infection that can be used to study basic aspects of Mycobacterium-host interactions and granuloma development, as well as trafficking of immune cells in host tissues.

Mycobacterium marinum infection of adult zebrafish causes caseating granulomatous tuberculosis and is moderated by adaptive immunity.

The zebrafish, a genetically tractable model vertebrate, is naturally susceptible to tuberculosis caused by Mycobacterium marinum, a close genetic relative of the causative agent of human tuberculosis, Mycobacterium tuberculosis. We previously developed a zebrafish embryo-M. marinum infection model to study host-pathogen interactions in the context of innate immunity.