IDEHU   05542
INSTITUTO DE ESTUDIOS DE LA INMUNIDAD HUMORAL PROF. RICARDO A. MARGNI
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
The potential role of inflammatory immune response in Brucella dissemination from the lung
Autor/es:
HIELPOS, MS; FERRERO, MC; FOSSATI, CA; BALDI, PC
Lugar:
Buenos Aires
Reunión:
Congreso; First French-Argentine Immunology Congress; 2010
Institución organizadora:
Sociedad Argentina de Inmunología
Resumen:
Brucella is a human pathogen that can be acquired by inhalation. We investigated potential mechanisms by which Brucella may cross the pulmonary epithelial barrier (transcellular or paracellular passage, and transmigration of infected phagocytes or "Trojan horse mechanism"). We used the normal human bronchial epithelial cell line 16HBE14o- which forms a polarized monolayer when grown on filters. B. abortus 2308 invaded and also replicated in 16HBE14o- polarized monolayers (99.5 ± 22, 499.5 ± 47.5, 3093.5 ± 12812.5 CFU/well at 2, 24 and 48 h pi, respectively). However, it failed to make either transcellular passage through the monolayer (no bacteria detected in the lower compartments until 48 h p.i) or paracellular passage (no bacteria detected at 4 h after placing B. abortus in the upper compartment). In these experiments, FITC-albumin, added together with the inoculum, did not cross the epithelial barrier indicating preservation of both membrane integrity and intercellular junctions. Since no direct translocation of the epithelial barrier was observed, we decided to evaluate if Brucella induces an epithelial inflammatory response that could induce transepithelial migration of infected phagocytes. Infection with both the smooth strain B. abortus 2308 or the rough strain B. abortus RB51 induced the production of IL-8, GM-CSF but not MCP-1, IL-1 and TNF-alpha. The specific levels of IL-8 in culture supernatants of infected cells with smooth or rough strains were 3348 ±127.8 pg/ml and 3645.5 ± 74.4 pg/ml, and for GM-CSF were 57.4 ± 15.0 pg/ml and 163.89 ± 20.52 pg/ml respectively at 48 h p.i. Neither Brucella LPS nor heat killed bacteria induced these responses.These results indicate that B. abortus does not translocate the lung epithelial barrier by direct passage but is likely to do so by mechanisms related to the inflammatory response triggered by the infection.