DUAL MODULATION OF LYMPHOCYTE ACTIVATION BY MICROBIAL RNA

BERTINAT, YASMÍN; BUENO, JORGELINA; SERAFINO, AGUSTINA; BIRNBERG WEISS, FEDERICO; PITTALUGA, JOSÉ R; MILILLO, M AYELÉN; BARRIONUEVO, PAULA

San Luis

Congreso; Reunión Anual de la Sociedad Argentina de Inmunología (SAI) 2023; 2023

SAI

In order to survive inside the host, Brucella abortus (Ba) must trigger different strategies to evade the robust adaptive T cell response it elicits. We have recently demonstrated that Ba RNA (a PAMP related to pathogens’ viability or vita-PAMP) activates lymphocytes at early time points but, later on it could contribute to circumvent this activation. More specifically, Ba RNA increases the expression of the early activation marker CD69 on peripheral blood mononuclear cells (PBMCs) independently of plate-bound anti-CD3 stimulation at 24 h. However, Ba RNA decreases the expression of the senescence marker CD28 only in anti-CD3 pre-stimulated PBMCs at 4 days. The aim of this study was to deepen this dual modulation of lymphocyte activation. For this, we first evaluated the effect of Ba RNA on the secretion of IL-2 and IFN-γ. For this, unstimulated or anti-CD3 pre-stimulated PBMCs were treated with Ba RNA (1, 5 and 10 μg/ml) for 24 h and 4 days. After these times, supernatants were collected and the secretion of IL-2 and IFN-γ was quantified by sandwich ELISA. Ba RNA increased IL-2 and IFN-γ secretion (p