IDEHU   05542
INSTITUTO DE ESTUDIOS DE LA INMUNIDAD HUMORAL PROF. RICARDO A. MARGNI
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
PULMONARY INFLAMMATORY RESPONSE SUBVERSION BY BRUCELLA ABORTUS
Autor/es:
HIELPOS, MS; FERRERO MC; MUÑOZ GONZALEZ F; FERNÁNDEZ, AG; FOSSATI CA; COMERCI D; BALDI PC
Lugar:
Buenos Aires
Reunión:
Congreso; I meeting LASID FAIC SAI; 2015
Institución organizadora:
Sociedad Argentina de Inmunología
Resumen:
Abstract Text: Introduction: Whereas Brucella infections can be acquired through inhalation, lung inflammatory signs are mild or absent. We studied in mice the innate immune response in lung after intratracheal (i.t.) infection, and a potential bacterial mechanism to subvert it.Methods: Balb/c mice were infected i.t. with wild type B. abortus (WT) or a double mutant for BtpA and BtpB proteins known to interfere with TLR signaling (btpA/btpB-); a control group received PBS. One day later some animals were stimulated i.t. with LPS or peptidoglycan (PGN) from Escherichia coli. Micewere euthanized at days 1, 2 and 7 to obtain lungs and spleens. Additionally, alveolar macrophages (AM) and pneumocytes from non-infected Balb/c mice were infected in vitro with both Brucella strains to measure cytokine responses.Results: Pulmonary inflammatory signs were mild in WT-infected mice but were more pronounced in animals infected with btpAbtpB-. No significant differences in pulmonary CFU counts were observed between btpA/btpB- and WT infections, but spleen CFU counts were lower for the mutant. Inflammatory signs were markedly reduced in lungs from the WT/LPS or WT/PGN groups as compared with the PBS/LPS or PBS/PGN groups. The btpAbtpB-/LPS and btpAbtpB-/PGN groups showed inflammation levels intermediate between the corresponding WT and PBS groups. In vitro IL 1beta secretion by AM was higher in response to btpBbtpA- than in response to WT, and the same was true for KC secretion by pneumocytes. Conclusions: Our results show that Btp proteins from B. abortus modulate the pulmonary inflammatory response to this bacterium or TLR agonists.