Deficient NK cell function in IT patients.

<p>(A) Deficient NK cell cytotoxicity from IT patients. NK cell cytotoxicity was assessed in primary NK cells from IT, IA, and IN patients and healthy controls using a ⁵¹Cr-release assay with K562 target cells. (B) Results show the mean ± SEM values in 19 patients and 5 controls. Values for IT patients were less than controls (P = 0.0384). (C) Positive correlation between NK cell cytotoxicity and the percentage of NK cells expressing NKG2D and 2B4. (D) Fresh PBMCs were stimulated with/without IL-12 as described in the <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1002594#s4" target="_blank">Materials and Methods</a>. After 16 h, IFN-γ production was determined using flow cytometry by gating on CD3⁻CD56⁺ NK cells. A representative dot plot displaying intracellular IFNγ staining in NK cells with the subsets indicated is shown. (E) Cumulative data are shown. (F, G) Fresh PBMCs from patients before treatment (black) or after treatment (white) were stimulated with IL-12 for 16 h. IFNγ (F) and CD107a (G) production was determined using flow cytometry by gating on CD3⁻CD56⁺ NK cells. (H) Induction of <i>ex vivo</i> NK cell cytotoxic activity after <i>in vivo</i> administration of antiviral treatment with nucleoside analogues until ALT reached normal levels. NK cytotoxicity was determined <i>ex vivo</i> by measuring the lysis of ⁵¹Cr-labelled target cells before treatment (red) or after treatment (green). Cumulative data are shown.