Zoledronate but not pamidronate effectively induces IFN-γ production in CD56⁺ PBMCs: abrogation of the IFN-γ response after depletion of CD14⁺ DC-like cells but residual IFN-γ production after depletion of CD3⁺ cells (T lymphocytes). (A) CD56⁺ PBMCs or CD56⁺ PBMCs depleted of CD14⁺ DC-like cells (1 × 10⁶/mL) were stimulated with IL-2, bisphosphonate (zol, pam), or bisphosphonate plus IL-2. IFN-γ levels were determined on day 3. (B) CD56⁺ PBMCs (1 × 10⁶/mL) or CD56⁺ PBMCs depleted of CD3⁺ cells (T lymphocytes including γδ T lymphocytes) were stimulated with IL-2, zoledronate (zol), or zoledronate plus IL-2 (dose and time dependence). Results are representative of 5 independent experiments.