✍🏼 Fangming Wang, Liyuan Wu, Le Yin, Hui Shi, Yuchun Gu, Nianzeng Xing

🏠 Chinese Academy of Medical Sciences and Peking Union Medical College, China

📑 Clinical and Translation Medicine (2022)

Abstract
The chimeric antigen receptor NK-92 (CAR NK-92) cell targeting the prostate-specific membrane antigen (PSMA) has shown antitumour effects in castration-resistant prostate cancer (CRPC). However, the expression changes of programmed death ligand 1 (PD-L1) and its mechanisms on CAR NK-92 and CRPC cells and the effect of the anti-PD-L1 monoclonal antibody (mAb) on PD-L1 expressed on CAR NK-92 cells remain unknown.

How the WOLF was used in this study
In this study, the WOLF Cell Sorter was used to isolate highly viable immune cell populations for downstream molecular and functional analyses. Following coculture experiments between CAR-engineered NK-92 cells and PSMA-expressing C4-2 prostate cancer cells, fluorescence-activated cell sorting was performed using the WOLF to collect propidium iodide (PI)–negative viable cells, thereby excluding dead or dying cells from analysis. The sorter was also used to purify viable cell populations prior to RNA sequencing and protein studies, with at least 3 × 10⁶ live cells collected per sample. By enabling gentle, low-pressure sorting based on viability staining, the WOLF ensured high-quality cell preparations for transcriptomic profiling and mechanistic studies investigating how CAR NK-92 cells regulate PD-L1 expression and immune signaling pathways in prostate cancer models.