Brucella egresses from infected cells exploiting multivesicular bodies

JUAN M. SPERA; CZIBENER, C; GUAIMAS, F; JUAN E. UGALDE

mbio

asm

Lugar: washington; Año: 2023

Host cell egress is a critical step in the life cycle of intracellular pathogens,especially in microbes capable of establishing chronic infections. The Gram-negative bacterium Brucella belongs to such a group of pathogens. Even though much has been doneto understand how Brucella avoids killing and multiplies in its intracellular niche, the mechanism that this bacterium deploys to egress from the cell to complete its cycle has beenpoorly studied. In the manuscript, we quantify the kinetics of bacterial egress and showthat Brucella exploits multivesicular bodies to exit host cells. For the first time, we visualizedthe process of egress in real time by live video microscopy and showed that a populationof intracellular bacteria exit from host cells in vacuoles containing multivesicular body-likefeatures. We observed the colocalization of Brucella with two multivesicular markers, namely,CD63 and LBPA, both during the final stages of the intracellular life cycle and in egressedbacteria. Moreover, drugs that either promote or inhibit multivesicular bodies either increasedor decreased the number of extracellular bacteria, respectively. Our results strongly suggestthat Brucella hijacks multivesicular bodies to exit the host cells to initiate new infectionevents