Table 1.

Divergent effects of LPS on NK cell cytokine production and cytotoxicity.

	IFN-γ production (pg/ml)			Degranulation (% CD107a+ cells)
	IL-2	IL-2 + LPS	P-value	IL-2	IL-2 + LPS	P-value
Exp. 1	59.0 ± 5.7	130 ± 24	0.027	20.2 ± 0.4	14.2 ± 1.6	0.008
Exp. 2	2.0 ± 3.5	8.8 ± 0.9	0.040	30.9 ± 1.7	21.1 ± 0.5	0.016
Exp. 3	0	398 ± 343	0.028	45.3 ± 0.9	27.6 ± 3.5	<0.001

Natural killer cells were stimulated by IL-2 (500 U) alone or by combined treatment with IL-2 and LPS (5 μg/ml) for 18 h. Cytolytic activity of NK cells was estimated by LAMP-1 degranulation assay. IFN-γ levels in supernatants were measured by ELISA. Data are mean ± SD of triplicate wells in individual experiments.