Pathogenic Yersinia Promotes Its Survival by Creating an Acidic Fluid-Accessible Compartment on the Macrophage Surface.
Microbial pathogens and host immune cells each initiate events following their interaction in an attempt to drive the outcome to their respective advantage. Here we show that the bacterial pathogen Yersinia pseudotuberculosis sustains itself on the surface of a macrophage by forming acidic fluid-accessible compartments that are partially bounded by the host cell plasma membrane. These Yersinia-containing acidic compartments (YACs) are bereft of the early endosomal marker EEA1 and the lysosomal antigen LAMP1 and readily form on primary macrophages as well as macrophage-like cell lines. YAC formation requires the presence of the Yersinia virulence plasmid which encodes a type III secretion system. Unexpectedly, we found that the initial formation of YACs did not require translocation of the type III effectors into the host cell cytosol; however, the duration of YACs was markedly greater in infections using translocation-competent Y. pseudotuberculosis strains as well as strains expressing the effector YopJ. Furthermore, it was in this translocation- and YopJ-dependent phase of infection that the acidic environment was critical for Y. pseudotuberculosis survival during its interaction with macrophages. Our findings indicate that during its extracellular phase of infection Y. pseudotuberculosis initiates and then, by a separate mechanism, stabilizes the formation of a highly intricate structure on the surface of the macrophage that is disengaged from the endocytic pathway.
Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Wael
W
Bahnan
Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Douglas R
DR
Boettner
Department of Molecular Biology, Umeå University, Umeå, Sweden.
Linda
L
Westermark
Department of Molecular Biology, Umeå University, Umeå, Sweden.
Maria
M
Fällman
Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, Florida, United States of America.
Kurt
K
Schesser
D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D008264:Macrophages / Q000378:metabolism* / Q000382:microbiology*; D051379:Mice; D015011:Yersinia pseudotuberculosis / Q000502:physiology*; D015012:Yersinia pseudotuberculosis Infections / Q000378:metabolism