Cd56 fitc

For staining of cell surface phenotyping markers, the following conjugated antibodies were used: CD3-PE, CD8-APC-H7, CD56-FITC, and CD107a-PE-Cy7, purchased from BD Biosciences (San Jose, CA, USA). For staining of exhaustion markers, the following conjugated antibodies were used: CD3-BV510, CD8-APC-H7, CD56-FITC, and PD1-BV650, purchased from BD Biosciences, as well as CD4-PE, purchased from Immunostep S.L. (Salamanca, Spain) and TIGIT-AlexaFluor700 purchased from Thermo Fisher (Waltham, MA, USA). Samples were acquired by using BD LSRFortessa X-20 flow cytometer with FACS Diva software v 6.0 (BD Biosciences, Franklin Lakes, NJ, USA) and then analyzed using FlowJo software v10.0.7 (Tree Star Inc., Ashland, OR, USA).

The cultures were collected, washed, incubated for 15 min with mouse mAbs against human CD3-PerCP, CD56-FITC, or PE, CD69-APC, CD16-PE (BD Biosciences, USA), and NKG2D-PE (BioLegend, USA). NK cells were incubated with CD158a-PE and CD158b-PE (BD Pharmingen, USA), CIK cells were incubated with CD4-PE and CD8-APC (BD Biosciences) and γδ T cells were incubated with Vγ9-FITC (BD Pharmingen), CD4-PE, and CD8-APC. Isotype-matched antibodies were used as controls. Perforin and granzyme B detection was performed according to the BD Cytofix/Cytoperm™ Kit manual (BD Biosciences). Briefly, NK, CIK, and γδ T cells were harvested and adjusted to 1 × 10⁶ cells/mL in RPMI-1640 medium containing 10 % fetal calf serum, and incubated 0.1 % GolgiStop (BD Biosciences) for 4 h. After pre-incubation with 10 % normal human serum, cells were stained with mAbs to identify NK (CD3⁻CD56⁺), CIK (CD3⁺CD56⁺), and γδ T cells (CD3⁺Vγ9⁺), followed by intracellular staining for perforin-PE and granzyme B-PE (BD Pharmingen), and the corresponding isotype antibodies to determine intracellular cytokine levels.
Flow cytometry data acquisition was performed on a BD FACS Calibur (BD Biosciences) with Cell Quest Pro software. Analysis was performed with FlowJo software (Tree Star, USA).

NK cell phenotype of melanoma patients enrolled in the trial was examined using fluorochrome-conjugated antibodies against the following cell-surface markers: CD56-FITC, CD3-PC7, CD16-APC, CD69-BV421, NKp30-BV711, CXCR3-BV421, CCR3-BV510 (BD Biosciences; San Diego, CA), NKp44-PerCP eFluor 710 (eBioscience; San Diego, CA), CXCR1-PE (R&D Systems; Minneapolis, MN), CCR7-BV711 (BioLegend; San Diego, CA), and matching IgG isotype controls from the same vendors. The immune checkpoint and NK cell activation receptor panel included the following markers: Zombie NIR Fixable Viability Dye (BioLegend; San Diego, CA), CD3-PE-Vio770 (Miltenyi Biotec; San Diego, CA), ANK-1-PE (Santa Cruz Biotechnology; Dallas, TX), TIGIT-PerCP eFluor 710 (eBioscience), CD45-BUV395, CD56-BV510, CD16-BUV737, NKG2D-APC, NKp46-BV711, CD69-BV421, and PD-1-BV650 (BD Biosciences).