FIGURE 2.

GITR inhibited NK proliferation. Stimulation index of NK cells was used to evaluate NK proliferation responses to IL-15 and GITR stimulation. An agonist monoclonal antibody of GITR was used to stimulate GITR. 10 ng/ml IL-15 or 0.5 and 5 μg/ml soluble GITR antibody were added into medium when cells were plated. After 3 days (A) and 5 days (B) of incubation, [³H]thymidine assay was performed, and the stimulation index was calculated and represented as mean ± S.E. (*, p < 0.05; **, p < 0.01).