scholarly journals Bent to Bind: Exploiting the Programmed Cell Death-1 (PD-1) Receptor Plasticity to Design Pembrolizumab H3 Loop Mimics

Author(s):  
Mehdi Zaghouani ◽  
Guangkuan zhao ◽  
Alexis Richaud ◽  
Medhi Wangpaichitr ◽  
Niramol Savaraj ◽  
...  

Checkpoint blockade of the Programmed cell Death-1 (PD-1) immunoreceptor with its ligand 1 (PD-L1) by the monoclonal antibody pembrolizumab provided compelling clinical results among various cancer types, yet the molecular mechanism by which this drug blocks the PD-1:PD-L1 binding interface and reactivates exhausted T cells remains unclear. To address this question, we examined the conformational motion of PD-1 associated with the binding of pembrolizumab. The largely overlooked innate plasticity of both PD-1 C’D and FG loops appears crucial to closing in the receptor edges on the drug. Herein, we describe how PD-1 bends to initiate the formation of a deep binding groove (371 Å<sup>3</sup>) across several epitopes while engaging pembrolizumab. Our analysis ultimately provided a rational design for mimicking the pembrolizumab H3 loop [RDYRFDMGFD] as a PD-1 inhibitor. A series of H3 loop mimics were synthesized and their folding characterized by CD and NMR spectroscopy. As a result, a first-in-class <i>b</i>-hairpin peptide inhibitor of the PD-1/PD-L1 interface was identified (IC<sub>50</sub> of 0.6 ± 0.2 μM). Overall, this study demonstrates that the dynamic groove formed between the C’D and FG loops of PD-1 is an attractive target for the development of peptide-based PD-1 inhibitors.

2021 ◽  
Author(s):  
Mehdi Zaghouani ◽  
Guangkuan zhao ◽  
Alexis Richaud ◽  
Medhi Wangpaichitr ◽  
Niramol Savaraj ◽  
...  

Checkpoint blockade of the Programmed cell Death-1 (PD-1) immunoreceptor with its ligand 1 (PD-L1) by the monoclonal antibody pembrolizumab provided compelling clinical results among various cancer types, yet the molecular mechanism by which this drug blocks the PD-1:PD-L1 binding interface and reactivates exhausted T cells remains unclear. To address this question, we examined the conformational motion of PD-1 associated with the binding of pembrolizumab. The largely overlooked innate plasticity of both PD-1 C’D and FG loops appears crucial to closing in the receptor edges on the drug. Herein, we describe how PD-1 bends to initiate the formation of a deep binding groove (371 Å<sup>3</sup>) across several epitopes while engaging pembrolizumab. Our analysis ultimately provided a rational design for mimicking the pembrolizumab H3 loop [RDYRFDMGFD] as a PD-1 inhibitor. A series of H3 loop mimics were synthesized and their folding characterized by CD and NMR spectroscopy. As a result, a first-in-class <i>b</i>-hairpin peptide inhibitor of the PD-1/PD-L1 interface was identified (IC<sub>50</sub> of 0.6 ± 0.2 μM). Overall, this study demonstrates that the dynamic groove formed between the C’D and FG loops of PD-1 is an attractive target for the development of peptide-based PD-1 inhibitors.


Author(s):  
Lifang Zhang ◽  
Yu Zhao ◽  
Quanmei Tu ◽  
Xiangyang Xue ◽  
Xueqiong Zhu ◽  
...  

Background: Cervical cancer induced by infection with human papillomavirus (HPV) remains a leading cause of mortality for women worldwide although preventive vaccines and early diagnosis have reduced morbidity and mortality. Advanced cervical cancer can only be treated with either chemotherapy or radiotherapy but outcomes are poor. The median survival for advanced cervical cancer patients is only 16.8 months. Methods: We undertook a structural search of peer-reviewed published studies based on 1). Characteristics of programmed cell death ligand-1/programmed cell death-1(PD-L1/PD-1) expression in cervical cancer and upstream regulatory signals of PD-L1/PD-1 expression, 2). The role of the PD-L1/PD-1 axis in cervical carcinogenesis induced by HPV infection and 3). Whether the PD-L1/PD-1 axis has emerged as a potential target for cervical cancer therapies. Results: One hundred and twenty-six published papers were included in the review, demonstrating that expression of PD-L1/PD-1 is associated with HPV-caused cancer, especially with HPV 16 and 18 which account for approximately 70% of cervical cancer cases. HPV E5/E6/E7 oncogenes activate multiple signaling pathways including PI3K/AKT, MAPK, hypoxia-inducible factor 1α, STAT3/NF-kB and MicroRNAs, which regulate PD-L1/PD-1 axis to promote HPV-induced cervical carcinogenesis. The PD-L1/PD-1 axis plays a crucial role in immune escape of cervical cancer through inhibition of host immune response. creating an "immune-privileged" site for initial viral infection and subsequent adaptive immune resistance, which provides a rationale for therapeutic blockade of this axis in HPV-positive cancers. Currently, Phase I/II clinical trials evaluating the effects of PD-L1/PD-1 targeted therapies are in progress for cervical carcinoma, which provide an important opportunity for the application of anti-PD-L1/anti-PD-1 antibodies in cervical cancer treatment. Conclusion: Recent research developments have led to an entirely new class of drugs using antibodies against the PD-L1/PD-1 thus promoting the body’s immune system to fight the cancer. The expression and roles of the PD-L1/ PD-1 axis in the progression of cervical cancer provide great potential for using PD-L1/PD-1 antibodies as a targeted cancer therapy.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nghiem Xuan Hoan ◽  
Pham Thi Minh Huyen ◽  
Mai Thanh Binh ◽  
Ngo Tat Trung ◽  
Dao Phuong Giang ◽  
...  

AbstractThe inhibitory effects of programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) modulates T-cell depletion. T-cell depletion is one of the key mechanisms of hepatitis B virus (HBV) persistence, in particular liver disease progression and the development of hepatocellular carcinoma (HCC). This case–control study aimed to understand the significance of PD-1 polymorphisms (PD-1.5 and PD-1.9) association with HBV infection risk and HBV-induced liver disease progression. Genotyping of PD-1.5 and PD-1.9 variants was performed by direct Sanger sequencing in 682 HBV-infected patients including chronic hepatitis (CHB, n = 193), liver cirrhosis (LC, n = 183), hepatocellular carcinoma (HCC, n = 306) and 283 healthy controls (HC). To analyze the association of PD-1 variants with liver disease progression, a binary logistic regression, adjusted for age and gender, was performed using different genetic models. The PD-1.9 T allele and PD-1.9 TT genotype are significantly associated with increased risk of LC, HCC, and LC + HCC. The frequencies of PD-1.5 TT genotype and PD-1.5 T allele are significantly higher in HCC compared to LC patients. The haplotype CT (PD-1.5 C and PD-1.9 T) was significantly associated with increased risk of LC, HCC, and LC + HCC. In addition, the TC (PD-1.5 T and PD-1.9 C) haplotype was associated with the risk of HCC compared to non-HCC. The PD-1.5 CC, PD-1.9 TT, genotype, and the CC (PD-1.5 C and PD-1.9) haplotype are associated with unfavorable laboratory parameters in chronic hepatitis B patients. PD-1.5 and PD1.9 are useful prognostic predictors for HBV infection risk and liver disease progression.


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