Figure 6.

CLU promotes IFN‐γ secretion without affecting NK cytotoxicity. (A) Purified NK cells were incubated with 100 U/ml IL‐2 and/or 5 μg/ml CLU for 5 days. At the end of culture, cells were coincubated with RMA/S target cells in a 1:1 ratio for 6 h in the presence of Golgi stop, and intracellular staining for IFN‐γ was performed (n=3). Cells were gated on CD3^–NK1.1⁺ NK cells. (B) ⁵¹Cr‐labeled RMA/S cells were mixed with NK cells cultured for 5 days with IL‐2 alone or IL‐2 + CLU at indicated E:T ratios (n=6). Radioactivity released into the supernatant after 4 h was counted by using a γ‐counter. Percent of specific lysis was calculated as follows: 100 × (experimental release–spontaneous release)/(maximum release–spontaneous release).