Brucella abortus activates Human Neutrophils

ASTRID ZWERDLING; M. V. DELPINO; K A PASQUEVICH; P BARRIONUEVO; JULIANA CASSATARO; CLARA GARCÍA SAMARTINO; G H GIAMBARTOLOMEI

MICROBES AND INFECTION

ELSEVIER SCIENCE BV

Lugar: New York; Año: 2009 vol. 11 p. 689 - 697

1286-4579

Human brucellosis is caused by infection with certain species of the genus Brucella and is characterized by bacterial persistence and inflammation of many host tissues. Neutrophils are one of the predominant cell types present in the infiltrate of these inflamed tissue, and due to their potential effect on the inflammatory response and tissue damage, direct activation of neutrophils by B. abortus might contribute to the pathology associated with human brucellosis. B. abortus expresses outer surface lipoproteins (Omp) with inflammatory properties on a variety of cell types. This study examines the effect of B. abortus and its lipoproteins on neutrophil functions. B. abortus induced an increment in CD35 and CD11b expression and a decline in CD62L accompanied by IL-8 secretion, a response compatible with neutrophil activation. B. abortus lipoprotein Omp19 (L-Omp19), but not its unlipidated form, mimicked the phenotypic and functional changes associated with neutrophil activation induced by B. abortus. Like the whole bacterium, L-Omp19 primed neutrophils for oxidative burst as well as promoted neutrophil migration and prolonged neutrophil survival. Thus, Brucella lipoproteins possesses pro-inflammatory properties that could contribute to the localize tissue injury and inflammation by direct activation of neutrophils. Data presented here, together with our previous results implicate Brucella lipoproteins in the pathogenesis of human brucellosis.