PD-1/PD-L1 interaction inhibitors

Programmed cell death protein 1 (PD-1) plays a vital role in inhibiting immune responses and promoting self-tolerance through modulating the activity of T-cells, activating apoptosis of antigen-specific T cells and inhibiting apoptosis of regulatory T cells. Programmed cell death ligand 1 (PD-L1) is a trans-membrane protein co-inhibitory factor of the immune response, which can combine with PD-1 to reduce the proliferation of PD-1 positive cells, inhibit their cytokine secretion and induce apoptosis. PD-L1 plays an important role in malignancies where it can attenuate the host immune response to tumour cells. The PD-1/PD-L1 axis is responsible for cancer immune escape and targeting PD-L1 is associated with a significant clinical response in a wide range of cancer patients.  

Isca Biochemicals now offers three important peptides for PD-1/PD-L1 research.

NP-12 is a branched peptide designed from analysis of the strands and loops of PD-1 found at the interface of the PD-1/PD-L1 interaction. NP-12 binds to PD-L1 and is a functional equipotent antagonist of both PD-L1 and PD-L2 signaling. In preclinical models of melanoma, colon cancer, and kidney cancers, NP-12 shows significant efficacy in inhibiting primary tumour growth and metastasis. NP-12 shows antitumour activity either as a single agent or when in combination with other immunologic cell death agents.   See more about NP-12 >

(D)-PPA 1 binds to PD-L1 with a Kd of 0.51 μM and can inhibit interaction at a concentration of 1 mg/mL in flow cytometry experiments. (D)-PPA 1 is a hydrolysis-resistant D-peptide and can disrupt the PD-1/PD-L1 interaction in vivo, inhibiting tumour growth and prolonging survival time in mouse models.  See more about (D)-PPA >

TPP-1 is a peptide identified through bacterial surface display which binds specifically to PD-L1, and blocks PD-1/PD-L1 interaction. TPP-1 binds to free PD-L1 and also cells that express PD-L1 on their cell membranes, and can reverse PD-L1 mediated inhibition of T-cell activation, and inhibit human tumour growth via a T-cell–dependent mechanism. In xenograft mouse models, tumour growth in TPP-1 treated mice was 56% - 71% lower than that in controls.  See more about TPP-1 >

All three peptides are available from stock, in milligram to gram quantities.  Please contact us with your requirements .