Anti cd13

For staining of surface proteins, 1 × 10⁵ cells were seeded for drug treatment and detached on day 3 after seeding (resulting in ∼5 × 10⁵ cells). Cells were resuspended in ice-cold PBS with 3% bovine serum albumin (PBS 3% BSA) containing a primary antibody at the individual working dilution. After 1 h incubation at 4 °C, cells were washed twice and taken up in ice-cold PBS 3% BSA containing a goat-anti-mouse antibody labeled with phycoerythrin (PE) (Santa Cruz, Dallas, USA). After incubation for 1 h at 4 °C in the dark, cells were washed twice, resuspended in ice-cold PBS and analyzed on a BD FACSCalibur (BD biosciences, New Jersey, USA). All washing steps were performed with ice-cold PBS. Data were analyzed using FlowJo Software (Tree Star, USA). Primary antibodies and respective concentrations used during this study were anti-IFN-γR1 (1 μg/ml; R&D systems, Minneapolis, Canada), anti-CD13 (1 μg/ml; abcam), anti-HLA-A^∗02 (1 μg/ml; abcam, Cambridge, UK), anti-β2 microglobulin (1 μg/ml) and anti-HLA-A, B, C (W6/32; 4 μg/ml) (both Biolegend, London, UK). Isotype control antibodies were mouse IgG2bκ (Biolegend) and mouse IgG1 (R&D systems, Wiesbaden, Germany). For each condition data of at least 10,000 cells were collected. Staining for intracellular IFN-γ and surface CD8 was performed as described previously [9] (link).