Conserved mechanisms drive host-lipid access, import, and utilization in Mycobacterium tuberculosis and M. marinum

Abstract

Host-derived lipids are known to be important sources of nutrient for mycobacteria, and particularly for Mycobacterium tuberculosis (M. tuberculosis), the etiological agent of tuberculosis (TB). Although assumed to be required for mycobacterial pathogenesis, the underlying molecular mechanisms by which lipids are accessed, imported and metabolized by mycobacteria are not thoroughly elucidated. On the host side, lipid accumulation is strongly associated with mycobacteria infection, during which macrophages acquire a characteristic foamy phenotype, whose impact on mycobacteria intracellular life remains to be determined. On the bacterial side, mycobacteria possess an extensive arsenal dedicated to lipid acquisition, such as lipid-modifying enzymes and specialized import systems. Understanding the host-lipids/bacteria dynamics and their impact on infection is essential to identify new targets and develop strategies for the improvement of TB treatment. To this end, M. marinum, a close cousin of M. tuberculosis, is a widely used alternative model, as it is easier to manipulate in the laboratory. The objective of this chapter is to discuss the conservation of the processes related to host-derived lipid acquisition between M. tuberculosis and M. marinum, to further facilitate the use of the latter as a model for M. tuberculosis.