Evaluation of Intracellular Trafficking in Macrophages

Macrophages are phagocytic cells that constitute the primary barrier against pathogens. After phagocytosis a single-membraned vesicle that contains the pathogen is formed. This phagosome undergoes a maturation process to acquire an increasingly antimicrobial environment. Leptospiral uptake by macrophages induces the formation of a Leptospira-containing phagosome (LCP). The kinetics of lysosomal marker recruitment by the LCP is correlated with virulence. This chapter presents a protocol to study the intracellular trafficking of Leptospira spp. within macrophages by fluorescent labeling bacteria and different markers of the phagocytic pathway. We also describe a method to evaluate the bacterial survival within macrophages.