BRUCELLA ABORTUS RNA CONTRIBUTES TO THE DOWN-MODULATION OF MHC-II EXPRESSION ON MONOCYTES/MACROPHAGES DIMINISHING CD4+ T CELL RESPONSES

TROTTA, ALDANA; MARINHO, FÁBIO V.; BALBOA, LUCIANA; BARRIONUEVO, PAULA; MILILLO, M. AYELÉN; MARIN FRANCO, JOSÉ LUIS; GENOULA, MELANIE; GIAMBARTOLOMEI, GUILLERMO H.; SERAFINO, AGUSTINA; ALCAIN, JULIETA; COSTA OLIVEIRA, SERGIO

San Miguel de Tucumán

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

Brucella abortus (Ba) displays many resources to evade T cell responses conducive to persist inside the host. We showed that Ba infection of human monocytes down-modulates the IFN-γ-induced MHC-II expression. Ba outer membrane lipoproteins are structural components involved in this phenomenon. Yet, the MHC-II down-regulation exerted by lipoproteins was less marked than the one observed as consequence of infection. We have previously demonstrated that Ba RNA (PAMP related to pathogens? viability) mediates MHC-I down-regulation. So we aimed to investigate if Ba RNA could contribute together with Ba lipoproteins to MHC-II down-modulation. Ba RNA significantly down-regulated the IFN--induced MHC-II surface expression on THP-1 cells (P