INVESTIGADORES
MAYORGA Luis Segundo
artículos
Título:
Intracellular trafficking of Brucella-Abortus in J774 macrophages
Autor/es:
ARENAS, GRACIELA NORA; STASKEVICH, ANA SANDRA; ABALLAY, ALEJANDRO; MAYORGA, LUIS S; LUIS SEGUNDO MAYORGA
Revista:
Infection and Immunity
Editorial:
no lo se
Referencias:
Año: 2000 vol. 68 p. 4255 - 4263
Resumen:
Brucella abortus is a facultative intracellular bacterium capable of surviving inside professional and nonprofessional
phagocytes. The microorganism remains in membrane-bound compartments that in several cell
types resemble modified endoplasmic reticulum structures. To monitor the intracellular transport of B. abortus
in macrophages, the kinetics of fusion of phagosomes with preformed lysosomes labeled with colloidal gold
particles was observed by electron microscopy. The results indicated that phagosomes containing live B. abortus
were reluctant to fuse with lysosomes. Furthermore, newly endocytosed material was not incorporated into
these phagosomes. These observations indicate that the bacteria strongly affect the normal maturation process
of macrophage phagosomes. However, after overnight incubation, a significant percentage of the microorganisms
were found in large phagosomes containing gold particles, resembling phagolysosomes. Most of the Brucella
bacteria present in phagolysosomes were not morphologically altered, suggesting that they can also resist
the harsh conditions prevalent in this compartment. About 50% colocalization of B. abortus with LysoSensor,
a weak base that accumulates in acidic compartments, was observed, indicating that the B. abortus bacteria do
not prevent phagosome acidification. In contrast to what has been described for HeLa cells, only a minor percentage
of the microorganisms were found in compartments labeled with monodansylcadaverine, a marker for
autophagosomes, and with DiOC6 (3,3*-dihexyloxacarbocyanine iodide), a marker for the endoplasmic reticulum.
These results indicate that B. abortus bacteria alter phagosome maturation in macrophages. However,