B. abortus RNA activates macrophages towards a pro-inflammatory profile early on during infection.

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

Buenos Aires

Congreso; Reunión Conjunta SAIC-SAI-AAFE-NANOMED.AR; 2021

SAIC-SAI-AAFE-NANOMED.AR

Brucellosis is a zoonotic disease caused by Brucella spp bacteria. These pathogens can survive inside macrophages, persisting inside the host. We previously demonstrated that Brucella abortus (Ba) RNA is a PAMP involved in the immune evasion mediated by Ba. One of the mechanisms displayed by this bacterium is the down-modulation of MHC molecules when Th1 response is being held, i.e., in the presence of IFN-Ɣ. Nevertheless, we acknowledged whether Ba RNA could activate macrophages early on during the infection, 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 (alternative macrophages) markers were assessed by flow cytometry. Regarding M1 markers, CD86 and MHC-II expressions did not change neither at 24 nor 48 h. Surprisingly, CD64 expression was reduced in Ba RNA treated macrophages (p