Fig. 1
Immune checkpoint blockade enhances tumour cell killing mediated by primary human lymphocytes. a Surface expression of HLA-ABC and PD-L1 on human breast cancer line MDA-MB-231 is determined by FACS. b Primary human lymphocytes from 11 donors are co-cultured with MDA-MB-231 cells ± αPD-L1 mAb. The resulted activation of CD8 + T cells, CD4 + T cells and NK cells is measured by FACS, and the levels of soluble IFNγ are measured by ELISA on day 6. c Correlations between activation of CD8 + T cells and CD4 + T cells or CD8 + T cells and NK cells are analysed with or without αPD-L1 mAb. d GFP-transfected MDA-MB-231 cells are cultured alone or co-cultured with increasing numbers of primary human lymphocytes, and growth inhibition is quantified in real time by IncuCyte. e MDA-MB-231 and primary human lymphocytes are cultured alone or in TICS with the addition of isotype control antibody, αPD-L1 or αPD-1 mAb, and the resulted cell death is quantified in real time using a caspase 3/7 green dye in the IncuCyte. Data are presented as mean ± SD based on 3 technical replicates. Statistical differences are analysed using paired T tests