IHEM   20887
INSTITUTO DE HISTOLOGIA Y EMBRIOLOGIA DE MENDOZA DR. MARIO H. BURGOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
ROCK Downstream effectors participate in the internalization process of Coxiella burnetii
Autor/es:
DISTEL JS; ORTIZ FLORES R.; BERÓN W.
Lugar:
Mar del Plata
Reunión:
Congreso; LI Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2015
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)
Resumen:
Phagocytosis is an important host defense mechanism against pathogens. In this process the actin and actin-interacting proteins play important roles. Coxiella burnetii (Cb) is an intracellular pathogen that enters into host cells by a mechanism poorly characterized. Our goal was to study the role of ROCK downstream effectors ezrin, LIMK 2 and non-muscle myosin II (NM II) in the phagocytosis of Cb. HeLa cells were transfected with siRNA targets to Ezrin, or with pEGFP-Ezrin WT, -Ezrin T567D, pHA-LIMK 2 WT, -LIMK 2 TA or -LIMK 2 TEE and then infected with Cb. After 6h, cells were processed for indirect immunofluorescence and analyzed by confocal microscopy. We observed a decrease in the uptake of Cb when ezrin was depleted by the specific siRNA. Treatment of HeLa cells with the ROCK inhibitor Y27632 before Cb infection, inhibited uptake nevertheless overexpression of the ezrin phosphomimetic (T567D) mutant partially recovered the conditions without the inhibitor. In cells overexpressing LIMK 2 WT or their mutants the entry of Cb was not affected. Finally, we investigate the possible participation of NM II in the internalization of Cb by using a NM II specific inhibitor blebbistatin. This inhibitor diminished the uptake of the bacteria. These results suggest that ROCK and downstream effectors ezrin and NM II participate in Cb internalization into non-phagocytic cells.