The Human Programmed Cell Death Protein-1 / CD279 is a recombinant protein consisting of a single, glycosylated polypeptide chain with 383 amino acids (21-170aa).

Programmed cell death-1 (PD-1, PDCD-1, PDCD1, CD279) is a trans- membrane receptor found on various immune cells, including activated T cells, Tregs, B cells, NK cells, and myeloid cells. Its ligands, PD-L1 and PD-L2, are expressed on various cells, including hematopoietic and non-hematopoietic cells. They play a crucial role in immune regulation by promoting cell death upon binding to PD-1. Blocking the PD-1/PD-L1 interaction has shown enhanced anti-tumor responses in various cancers, such as pancreatic carcinoma, melanoma, and colon carcinoma. Combining PD-1 blockade with CTLA-4 antibody treatments has led to significant tumor regression in many patients. PD-1's critical function in modulating immune responses, particularly within the tumor microenvironment, highlights its potential as a target for cancer immunotherapy, with the expectation of greater efficacy and fewer side effects compared to CTLA-4 blockade.

Abbreviations:

PD-1, PDCD1, Programmed cell death protein 1, CD279, hPD-1, SLEB2, hPD-I, hSLE1