Depletion of Neutrophils Exacerbates the Early Inflammatory Immune Response in Lungs of Mice Infected with Paracoccidioides brasiliensis

• Main Authors: Paula Andrea Pino-Tamayo, Juan David Puerta-Arias, Damaris Lopera, Martha Eugenia Urán-Jiménez, Ángel González
• Format: Article
• Language: English
• Published: Hindawi Limited 2016-01-01
• Series: Mediators of Inflammation
• Online Access: http://dx.doi.org/10.1155/2016/3183285

Neutrophils predominate during the acute phase of the Paracoccidioides brasiliensis infection. Herein, we determined the role of the neutrophil during the early stages of experimental pulmonary paracoccidioidomycosis using a monoclonal antibody (mAb) specific for neutrophils. Male BALB/c mice were inoculated intranasally with 1.5×106 or 2×106 P. brasiliensis yeast cells. The mAb was administered 24 h before infection, followed by doses every 48 h until mice were sacrificed. Survival time was evaluated and mice were sacrificed at 48 h and 96 h after inoculation to assess cellularity, fungal load, cytokine/chemokine levels, and histopathological analysis. Neutrophils from mAb-treated mice were efficiently depleted (99.04%). Eighty percent of the mice treated with the mAb and infected with 1.5×106 yeast cells died during the first two weeks after infection. When mice were treated and infected with 2×106 yeast cells, 100% of them succumbed by the first week after infection. During the acute inflammatory response significant increases in numbers of eosinophils, fungal load and levels of proinflammatory cytokines/chemokines were observed in the mAb-treated mice. We also confirmed that neutrophils are an important source of IFN-γ and IL-17. These results indicate that neutrophils are essential for protection as well as being important for regulating the early inflammatory immune response in experimental pulmonary paracoccidioidomycosis.