ALTERNATIVELY ACTIVATED (M2) MACROPHAGES DISPLAY IMMUNOMODULATORY EFFECTS ON CD56bright AND CD56dim NK CELL EFFECTOR FUNCTIONS

SOL YANEL NUÑEZ; NICOLAS IGNACIO TORRES; XIMENA LUCIA RAFFO IRAOLAGOITIA; ANDREA ZIBLAT; ROMINA ELIZABETH ARAYA; JESSICA MARIEL SIERRA; CAROLINA INES DOMAICA; MERCEDES BEATRIZ FUERTES; NORBERTO WALTER ZWIRNER

Congreso; 63a Reunión Anual de la Sociedad Argentina de Inmunología; 2015

Background: Macrophages display a high degree of plasticity. Upon activation, they can become M1 (pro-inflammatory, anti-tumoral) or M2 (anti-inflammatory, pro-tumoral) macrophages. As interaction between M1 and M2 and Natural killer (NK) cells has been poorly explored, the aim of this work was to investigate the consequences of such interaction. Methods: Human monocytes differentiated in vitro to unpolarized macrophages (M0) with M-CSF for 6 days were exposed overnight to LPS and IFN-g or IL-4 to obtain M1 and M2, respectively. NK cells (resting or stimulated with IL-12, IL-15 and IL-18) were co-culture overnight with M1 or M2 and expression of CD69 and CD25, intracellular IFN-g and viability was measured by flow cytometry on CD3-CD56+ cells. Also, degranulation (CD107a expression) was assessed on NK cells after stimulation with K562 cells for 5 h. Results: M1 displayed higher expression of CD86 and CD274 and increased ratio IL-12/IL-10 secretion compared to M0 and M2, while M2 up-regulated CD206 expression. Increased percentages of CD69+ NK cells were observed when resting NK cells were co-cultured with M1 (p