Activation of Rho and Rab GTPases dissociates Brucella abortus internalization from intracellular trafficking

Brucella abortus is an intracellular pathogen that relies on unconventional virulence factors to infect hosts. In non-professional phagocytes, Rho GTPasesactivation by the Escherichia coli cytotoxic necrotiz ing factor (CNF) promoted massive Brucella entrance by membrane ruffling, a mechanism that d...

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Main Authors: Chaves-Olarte, Esteban, Guzman-Verri, Caterina, Méresse, Stephane, Desjardins, Michel, Pizarro-Cerdá, Javier, Badilla, Jenny, Gorvel, Jean-Pierre, Moreno, Edgardo
Format: Artículo
Language: Inglés
Published: Blackwell Science 2020
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Online Access: http://hdl.handle.net/11056/18430
https://doi.org/10.1046/j.1462-5822.2002.00221.x
Summary: Brucella abortus is an intracellular pathogen that relies on unconventional virulence factors to infect hosts. In non-professional phagocytes, Rho GTPasesactivation by the Escherichia coli cytotoxic necrotiz ing factor (CNF) promoted massive Brucella entrance by membrane ruffling, a mechanism that differs from the common mode of entrance used by this bacterium in non-treated cells. Cytotoxic necrotizing factor treatment, however, did not alter the intracellular route followed by the wild type or non-virulent defined mutants. In contrast, expression of a constitutively active Rab5Q79L GTPase did not alter cell-invasion by Brucella but hampered its ability to reach the endoplasmic reticulum. The CNF-induced Brucella superinfection did not reduce the ability of host cells to synthesize DNA and progress through the cell cycle. Furthermore, CNF-treatment increased the isolation of Brucella-containing compartments by a factor of 15. These results demonstrate that in nonprofessional phagocytic cells, Brucella manipulates two different sets of GTPases during its biogenesis, being internalization and intracellular trafficking two consecutive but independent processes. Besides, CNF-induced super-infection demonstrates that Brucella does not interfere with crucial cellular processes and has shown its potential as tool to characterize the intracellular compartments occupied by this bacterium.