Abstract 2555: A cell based bioluminescent reporter assay for rapid measuring function of PD-1 or PD-L1 therapeutic antibodies

Programmed death-1(PD-1) and its ligand (PD-L1) are important immunotherapy targets for cancer. PD-1 serves as a negative costimulatory receptor on various cell types, including T and B cells as well as myeloid-derived cells. Its ligand PD-L1 (B7-H1) is not expressed by normal epithelial tissues, but it is aberrantly expressed on a wide array of human cancers including melanoma, non-small cell lung carcinoma, breast cancer, pancreatic cancer, etc. Engagement of PD-1 by its ligands PD-L1 expressed on tumor cells associated with poorer prognosis by disabling the host antitumor response. The most recent investigational anti-PD-1 immunotherapy drugs such as nivolumab from BMS and lambrolizumab (MK-3475) from Merck have all demonstrated significant overall survival rate in patients with advanced melanoma. Here we developed a cell based bioluminescent reporter assay that can be used for rapid quantifying function of PD-1 or PD-L1 therapeutic antibodies as measured by activation of NFAT signaling pathway. For this, Jurkat T-cell line stably expressing NFAT-luciferase reporter and human PD-1 was generated. Raji stably expressing human PD-L1 was generated as antigen presenting cells (APC). by co-cultivating the two cell lines in the present of CD3 and IgG, Raji cells fully activate Jurkat NFAT pathway via CD28 binding to CD80 (B7-1) and CD86 (B7-2) endogenously expressed on Raji cells. PD-1 signaling in Jurkat cells following engagement of PD-L1 ectopically expressed on Raji cells inhibits T cell function, and results in NFAT pathway inhibition. Blockade of PD-L1 using anti-PD-L1 mAb reversed NFAT pathway activation. Citation Format: Mei Cong, Natasha Karassina, Jey Cheng, Frank Fan. A cell based bioluminescent reporter assay for rapid measuring function of PD-1 or PD-L1 therapeutic antibodies. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2555. doi:10.1158/1538-7445.AM2014-2555