Decreased NK cell lytic capacity in patients with active KS.

<p>(A) Comparative analysis of CD107a expression on NK cells from healthy controls (HC, n = 10) and classical KS patients (n = 13, including 3 active and 10 resolved KS). Box and whisker plots show the median and 25–75^th percentiles of CD107a expression, in the absence of stimulation (unst) and after stimulation with SV2G or HHV8-SV2G target cells. Horizontal bars indicate minimum and maximum values. (B) The capacity to degranulate in the presence of K562 target cells is significantly decreased in patients with active KS (n = 6) compared to healthy controls (HC, n = 18) and patients with resolved KS (n = 12). (C) K562-induced NK cell degranulation is inhibited in the presence of anti-NKG2D blocking antibody. Data are mean ± SEM of results in 3 healthy controls, 3 patients with resolved classical KS and 2 patients with active classical KS. (D) Correlation between the expression level of NKG2D and the respective K562-induced degranulation of NK cells in 15 KS patients (active/resolved). Cells were analyzed on a LSRFortessa flow cytometer. Correlation coefficient (r) and P values are indicated. (E) Comparative analysis of K562-induced CD107a degranulation and levels of NKG2D, NKp30 and NKp46 in NK cells from 3 patients with active classical KS analyzed before and one year after successful local treatment.