Table 2.

Capacity of selected compounds to inhibit perforin delivered by KHYG-1 NK cells

Number	Jurkat IC50a (μM)	KHYG-1 inhibitionb (% at 20 μM)	KHYG-1 viabilityc (%)	Plasma stabilityd (% at 24 h)
Mouse	Human
23	0.18	63	90	75	46
48	0.67	20	92	75	49
59	0.90	13	79	87	73
63	1.09	No activity	—	80	70
67	0.92	80	82	66	39

^aData given for five most potent compounds as determined by the Jurkat assay.

^bInhibition by compound (20 μM) of the perforin-induced lysis of K562 target cells when co-incubated with KHYG-1 human NK cells (see Supplementary data). Percent inhibition calculated compared to untreated control.

^cViability of KHYG-1 NK cells after 24 h by Trypan blue exclusion assay (see Supplementary data).

^dData given as % parent measured at 24 h in mouse and human plasma (see Supplementary data for further details).