BORDETELLA PERTUSSIS SURVIVES AND REPLICATES IN NON ACIDIC COMPARTMENTS IN HUMAN MACROPHAGES

LAMBERTI, YANINA; ALVAREZ HAYES, JIMENA; RODRIGUEZ, MARÍA EUGENIA

Tucumán, Argentina

Congreso; XLV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2009

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Although B. pertussis has been observed to survive insidemacrophages, its ability to resist or evade degradation in phagolysosomes has not. We here investigated the trafficking of B. pertussis upon entry into human macrophages by confocal microscopy. Intracellular bacteria survival was evaluated by Polymyxin B protection assays. 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 maker 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 replicates in compartments with earlyendosomes characteristics, potentially contributing to its extraordinary ability to persist within hosts and populations