TUMOR-EXPERIENCED T CELLS PROMOTE NK CELL ACTIVITY THROUGH TROGOCYTOSIS OF NKG2D AND NKp46 LIGANDS

CAROLINA DOMAICA; MERCEDES FUERTES; LUCAS ROSSI; DAMIÁN AVILA; GABRIEL A. RABINOVICH; NORBERTO W. ZWIRNER

EMBO REPORTS

Nature Publishing Group

Lugar: Heidelberg; Año: 2009 vol. 10 p. 908 - 915

1469 221X

Natural killer (NK) cells trigger cytotoxicity and interferon (IFN)- secretion on engagement of the natural-killer group (NKG)2D receptor or members of the natural cytotoxicity receptor (NCR) family, such as NKp46, by ligands expressed on tumour cells. However, it remains unknown whether T cells can regulate NK cell-mediated anti-tumour responses. Here, we investigated the early events occurring during T cell–tumour cell interactions, and their impact on NK cell functions. We observed that on co-culture with some melanomas, activated CD4+ T cells promoted degranulation, and NKG2D- and NKp46-dependent IFN- secretion by NK cells, probably owing to the capture of NKG2D and NKp46 ligands from the tumour-cell surface (trogocytosis). This effect was observed in CD4+, CD8+ and resting T cells, which showed substantial amounts of cell surface major histocompatibility complex class I chain-related protein A on co-culture with tumour cells. Our findings identify a new, so far, unrecognized mechanism by which effector T cells support NK cell function through the capture of specific tumour ligands with profound implications at the crossroad of innate and adaptive immunity.