Multiple receptors and ligands are involved in NK cell-mediated lysis of activated CD4⁺ T cells.

Abstract

<p>Role of (A) activating and (B) inhibitory NK receptors in NK cell degranulation. Left column: representative histograms (of n≥3) for surface expression of ligands on activated (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⁺ T). Middle- and right column: NK and CD4⁺ T cells were activated for 4 days <i>in vitro</i> as described, and co-cultured for 4 hours with 10 ug/mL mAb (or relevant isotype-matched control Ig). Degranulation is shown for CD56^dim (middle column) and CD56^bright (right column) NK cells. Representative histograms of surface expression of receptors on activated (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). * <i>P</i><0.05, ** <i>P</i><0.005, *** <i>P</i><0.001. (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 human IgG4 isotype control (•) or anti-NKG2A mAb (○). Data represents n = 3 experiments.</p