NK cells mediate TRAIL-dependent cytotoxicity towards activated CD4⁺ T cells.

Abstract

<p>Autologous NK cells and CD4⁺ T cells were isolated and activated for 4 days as described. Resting NK and CD4⁺ T cells were unstimulated in media for 4 days. (A) Representative histograms for flow cytometric analysis of surface expression of TRAIL-R1 (DR4) and TRAIL-R2 (DR5) on activated CD4⁺ T cells (thick black line) and resting CD4⁺ T cells (thin black line). Isotype-matched control Ig are represented by dashed line (activated CD4⁺ T) and filled histogram (resting CD4⁺). (B) Histograms are representative of TRAIL surface expression on activated NK cells (thick black line) and resting NK cells (thin black line). Isotype-matched control Ig are represented by dashed line (activated NK) and filled histogram (resting NK). (C) Sorted IL-2-activated CD56^dim and CD56^bright NK cells were co-cultured with ⁵¹Cr-labeled activated CD4⁺ T cells in a ⁵¹Cr-release assay with isotype-matched control Ig (•) or anti-TRAIL mAb (○). Experiment shown is representative of n = 3.</p