Poly I:C treatment stimulates CXCL10 chemokine production in human NK cells. (A-B) NK92 (A) or NKL (B) cell lines were stimulated with poly I:C for the indicated times, in the presence or absence of cycloheximide (CHX, 10 μg/mL); RT-PCR with specific primers for CXCL10 and for β-actin (as control) was then performed on total RNA. Positive control (C+) is represented by an RNA sample of poly I:C–stimulated NK92 cells processed in the same experiment. (C) CXCL10 secretion in culture supernatants of poly I:C–stimulated highly purified polyclonal NK cells (3 out of 4 donors) and NK92 cells was quantitated by specific ELISA. These data are representative of 1 out of at least 3 independent experiments.