Intracellular trafficking of Bordetella pertussis in human macrophages

LAMBERTI, Y; ALVAREZ HAYES, J; PEREZ VIDACOVIKS, ML; HARVILL, E.; RODRIGUEZ, ME

INFECTION AND IMMUNITY

AMER SOC MICROBIOLOGY

Año: 2009

0019-9567

            Although B. pertussis has been observed to survive inside macrophages, its ability to resist or evade degradation in phagolysosomes has not been defined. We here investigated the trafficking of B. pertussis upon entry into human macrophages. During the first hours following phagocytosis a high percentage of bacteria were destroyed within acidic compartments positive for the lysosome-associated membrane proteins (LAMP). However, roughly 1/4 of the uptaken bacteria evade this initial killing event, remaining in non acidic compartments. Forty eight hours after infection the number of intracellular bacteria per cell increased, suggesting that B. pertussis is capable of replicating in this type of compartment. Viable bacteria accumulated within phagosomal compartments positive for the early endosomal marker Rab5 but not the late endosomal marker LAMP. Moreover, B. pertussis-containing phagosomes acquired exogenously added transferrin, indicating that intracellular bacteria have access to extracellular components and essential nutrients via the host cell recycling pathway. Overall these results suggest that B. pertussis survives and eventually replicates in compartments with characteristics of early-endosomes, potentially contributing to its extraordinary ability to persist within hosts and populations.