MODULATION OF GAMMA/DELTA T CELL ACTIVATION BY NEUTROPHIL ELASTASE

TOWSTYKA N; SABBIONE F; KEITELMAN I; GEFFNER JR; TREVANI AS; JANCIC C

Congreso; Reunión anual Sociedad Argentina de Inmunoogía; 2016

Gamma/delta T cells play a critical role in the recruitment and activation of neutrophils at the sites of infection. In addition, neutrophils can regulate gamma/delta T cell activity. We have previously reported that elastase secreted by neutrophils enhances gamma/delta T cell activation triggered by anti-CD3 antibodies. Now, we aim to investigate the mechanism by which elastase modulates gamma/delta T cell activation. Gamma/delta T cells were purified from human peripheral blood mononuclear cells, by using an anti-TCR gamma/delta MicroBead isolation kit. Neutrophils were isolated by dextran sedimentation. After purification, gamma/delta T cells were stimulated with anti-CD3 antibodies (250 ng/ml), and cultured with or without neutrophils. After 24 h, we analyzed in gamma/delta T cells, the CD69 expression by flow cytometry; and the IFN-gamma and TNF-alpha production by ELISA. We evaluated cell conjugates formation and elastase expression by confocal microscopy. Finally, we analyzed the expression of the proteases activated receptor 1 (PAR1) by flow cytometry and the functionality of PAR1 by using the agonist thrombin (10 U/ml), and the antagonist RWJ56110 (10 uM). Gamma/delta T cells and neutrophils formed cell conjugates, 69±1% of these conjugates recruited elastase at the cell-to-cell contact (p