A Ménage à Trois of Cytotoxic Effector Cells: γδ T Cells Suppress NK Cells but Not CTLs.

Three types of cytotoxic effector cells can kill tumor cells: innate natural killer (NK) cells, CD8+ CTL, and γδ T cells. In this issue, Walwyn-Brown and colleagues report new insights into the interplay between these three cell types that are integral to antitumor immunity, finding that γδ T cells can specifically suppress NK cells but not CD8+ CTLs. These results are relevant in view of the so far limited efficacy of γδ T-cell immunotherapy. See related article by Walwyn-Brown et al., p. 558 (3).