B. ABORTUS RNA ACTIVATES MACROPHAGES TOWARDS A PRO-INFLAMMATORY PROFILE EARLY ON DURING INFECTION

SERAFINO, AGUSTINA; FRANCO MARIN, JOSÉ L.; CASTILLO, LUIS A.; BIRNBERG WEISS, FEDERICO; PITTALUGA, JOSÉ R.; BALBOA, LUCIANA; BARRIONUEVO, PAULA; MILILLO, M. AYELÉN

Congreso; Reunión de Sociedades de Biociencias 2021; 2021

Brucellosis is a zoonotic disease caused by Brucella spp bacteria.These pathogens can survive inside macrophages, persistinginside the host. We previously demonstrated that Brucella abortus(Ba) RNA is a PAMP involved in the immune evasion mediatedby Ba. One of the mechanisms displayed by this bacterium is thedown-modulation of MHC molecules when Th1 response is beingheld, i.e., in the presence of IFN-ϒ. Nevertheless, we acknowledgedwhether Ba RNA could activate macrophages early on during theinfection, before Th1 response is settled. To evaluate this, M0 (undifferentiated)macrophages were stimulated with Ba RNA (10 μg/ml)and at 24 and 48 h M1 (classical macrophages) or M2 (alternativemacrophages) markers were assessed by flow cytometry. RegardingM1 markers, CD86 and MHC-II expressions did not change neitherat 24 nor 48 h. Surprisingly, CD64 expression was reduced inBa RNA treated macrophages (p