Table 1.

Polyinosinic-polycytidylic acid [poly(I:C)] stimulation does not induce interferon-γ (IFN-γ) production in γδ T cells

	% CD69+γδ T cells	% CD25+γδ T cells	% IFN-γ+γδ T cells
Medium	27	5	0
PMA/ionomycin	100	ND	83
IPP	93	88	41
Pamidronate	79	50	57
poly(I:C)	73	ND	9

Intracellular IFN-γexpression of γδT cells was measured by single-cell analysis after culture of peripheral blood mononuclear cells (PBMC) for 72 hr in medium alone or in the presence of phorbol 12-myristate 13-acetate (PMA) (25 ng/ml)/ionomycin (500 ng/ml), isopentenylpyrophosphate (IPP) (5 µg/ml), pamidronate (10 µg/ml) or poly(I:C) (50 µg/ml), as described in the Materials and methods. In addition, the expression of CD69 and CD25 on γδT cells was determined by standard two-colour fluorescence-activated cell sorter (FACS) analysis.

The data show the mean percentages of positive γδ T cells from one experiment that is representative of three separate experiments. ND, not determined.