Programmed death 1 (PD-1) is a cell surface co-receptor member of the CD28/CTLA-4 family, and functions as a downregulator of the immune system through a dual mechanism of inhibition (1). PD-1 is expressed on the cell surface of activated T- and B-cells. Anti-tumor immunity may be controlled by the PD-1/PD-L1 signaling pathway. PD-L1, one of the ligands associated with PD-1, provides immunity for tumor cells by inducing apoptosis of activated T cells or by inhibiting cytotoxic T cells (1,2). Therapies that target the PD-1 receptor have shown unprecedented results with high levels of clinical response in patients with various cancer types (2,3). The presence of PD-1 positive tumorinfiltrating lymphocytes (TIL) has been associated with poor prognosis in human breast cancers and may be useful in antibody therapy targeting the PD-1/PD-L1 signaling pathway (1). Treatments targeting PD-1 and its ligand, PD-L1, have also shown encouraging results in melanoma, non-small-cell lung cancer, and renal cell carcinoma (3-5). This antibody can also be used in multiplex stains with other antibodies such as CD4, CD8, FOXP3, cytokeratin and melanoma markers (6).
1. Muenst S, et al. The presence of programmed death 1 (PD-1)-positive tumor-infiltrating lymphocytes is associated with poor prognosis inhuman breast cancer. Breast Cancer Res Treat. 2013 Jun; 139(3):667-76.
2. Kim JW, Eder JP. Prospects for Targeting PD-1 and PD-L1 in Various Tumor Types. Oncology. (Williston Park). 2014 Nov; 28(11 Suppl 3).
3. Tumeh PC, et al. PD-1 blockade induces responses by inhibiting adaptive immune resistance. Nature. 2014 Nov 27; 515(7528):568-71.
4. D’Incecco A, et al. PD-1 and PD-L1 expression in molecularly selected non-small cell lung cancer patients. Br J Cancer. 2015 Jan 6; 112(1):95-102.
5. Tykodi SS. PD-1 as an emerging therapeutic target in renal cell carcinoma: current evidence. Onco Targets Ther. 2014 Jul 25; 7:1349-59.
6. Yang G, et al. A multiplex IHC evaluation of multiple immune checkpoint receptors and mismatch repair proteins in colorectal carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1026.
7. Center for Disease Control Manual. Guide: Safety Management, NO. CDC-22, Atlanta, GA. April 30, 1976 “Decontamination of Laboratory Sink Drains to Remove Azide Salts.”
8. Clinical and Laboratory Standards Institute (CLSI). Protection of Laboratory Workers from Occupationally Acquired Infections; Approved Guideline-Fourth Edition CLSI document M29-A4 Wayne, PA 2014.