OUTER MEMBRANE VESICLES AS VACCINE CANDIDATES AGAINST Brucella suis INFECTION

ALONSO PAIVA, IVÁN MATHIAS; MORENO, GRISELDA; FERRERO, MARIANA CRISTINA; ELIZAGARAY, MAIA LINA; RUMBO, MARTÍN; MUÑOZ GONZALEZ, FLORENCIA; BIALER, MAGALÍ; BALDI, PABLO CÉSAR

San Miguel de Tucumán

Congreso; LXVII Reunión Anual de la Sociedad Argentina de Inmunología; 2019

SAI

Outer membrane vesicles (OMVs) have been used in the development of vaccines against Gram negative bacteria. Here we characterized the immunostimulatory activity of Brucella suis OMVs, and the immune response and protection against B. suis attained in mice by immunization with OMVs.THP1-ASC-GFP reporter cells (derived from the THP-1 human monocytic cell line) which allow the monitoring of ASC-dependent inflammasome formation were stimulated overnight with OMVs (2 and 0.5μg/ml). Cells were analysed by fluorescence microscopy to evaluate ASC-GFP specks and IL-1β levels were measured in supernatants.Female Balb/c mice were immunized intramuscularly (i.m.) with OMVs (20 μg) or saline at 0 and 30 days. One week after last immunization serum, bronchoalveolar lavage, feces and saliva samples were obtained to measure OMV-specific antibodies. One week later mice were challenged with B. suis through the intraperitoneal (i.p.) or intratracheal routes. CFU counts were determined in lungs and/or spleens 20 days after challenge.Stimulation of reporter monocytes with both doses of OMVs induced ASC-GFP specks formation and IL-1β secretion. Immunized mice showed increased serum levels of total anti-OMVs antibodies (p