Programmed cell death protein 1
Programmed cell death protein 1 (PD-1), encoded by PDCD1, is an inhibitory immune-checkpoint receptor expressed primarily on activated immune cells, including T cells.
Programmed cell death protein 1 (PD-1), encoded by PDCD1, is an inhibitory immune-checkpoint receptor expressed primarily on activated immune cells, including T cells. Binding of PD-1 to its ligands, programmed death-ligand 1 (PD-L1; encoded by CD274) or PD-L2, attenuates signaling that promotes T-cell activation and effector function. This pathway contributes to immune tolerance and is frequently exploited within the tumor immune microenvironment to limit antitumor immune responses.
In cancer immunotherapy, antibodies that block PD-1 or PD-L1 can restore or enhance antitumor activity, particularly that of CD8-positive T cells. Anti-PD-1 therapy is therefore used alone or in combination with other approaches, including antibody–drug conjugates, antiangiogenic agents, therapeutic vaccines, targeted drugs, and agents intended to modify immunosuppressive tumor niches. Current research also addresses biomarkers of response and resistance, including PD-1/PD-L1 expression, soluble immune-checkpoint molecules, cytokine and chemokine profiles, tumor-cell mechanics, and factors associated with the tumor microenvironment.
- Exploring trop-2-directed ADCs monotherapy and combination therapy in pretreated mTNBC: a real-world study. PMID 42714605
- PRKX-mediated stabilization of PD-L1 characterizes an immunosuppressive gastric cancer subtype. PMID 42716706
- Discovery and Crystallographic Study of Water-Soluble Quaternary Ammonium-Based PD-1/PD-L1 Inhibitors with Anti-Angiogenic Activity. PMID 42720488
Where the papers sit
11 papers study programmed cell death protein 1 directly. The themes below are drawn from those 11. 1 paradigm shift follows.
-
Cancer Immunotherapy Strategies : Cancer immunotherapy is being pursued through oral nanovaccines, cytokine and metabolomic biomarkers, IKZF2/IKZF4 degradation, and TROP-2 ADC combinations. The shared direction is broader, biomarker-informed treatment rather than one dominant mechanism. 5 papers · 45.5%
-
Immunotherapy Resistance in Cancer : Resistance involves impaired cytotoxic lymphocyte lysis, PRKX-stabilized PD-L1, hypoxic HIF1A+CSF3R+ neutrophils, and cancer-cell mechanics. Work is converging on tumor-state and microenvironment markers to predict anti-PD-1 response. 4 papers · 36.4%
-
PD-1/PD-L1 Drug Discovery : Discovery combines water-soluble PD-1/PD-L1 inhibitors with miRNA-based regulation, seeking agents that also limit angiogenesis and migration. The field remains early, spanning glioblastoma and colorectal cancer. 2 papers · 18.2%
Tumor-cell mechanics and cytoskeletal dynamics are active determinants of anti-PD-1 response
The gastric cancer study of LASP1 deficiency and the AFM study of four human solid-tumor cell lines found, independently, that anti-PD-1 efficacy cannot be understood solely as checkpoint-mediated immune activation: loss of LASP1 disrupted actin dynamics at the immunological synapse and conferred resistance to cytotoxic lymphocyte lysis and anti-PD-1 therapy, while anti-PD-1 treatment produced distinct, cell-type-specific trajectories of softening, adhesion loss, and mechanical deterioration during immune attack 42686372Sep 42535479Jul. The result shifts the explanatory focus toward the physical state of tumor cells, making cytoskeletal organization and mechanical integrity determinants of whether checkpoint blockade can produce tumor-cell killing rather than merely downstream consequences of it.
Recent Findings on Programmed cell death protein 1
A study of glioblastoma and colorectal cancer identified a conserved group of microRNAs that were dysregulated in both diseases, correlated with survival, and showed inverse relationships with PD-1, PD-L1, and PD-L2 expression. These findings place miRNA regulation within the PD-1/PD-L1 immune-checkpoint network and extend work on molecular biomarkers across distinct tumor types 42616478Aug.
In gastric cancer, investigators examined a subtype characterized by PRKX-mediated stabilization of PD-L1. The clinical relevance of this tumor feature was evaluated using specimens from patients receiving anti-PD-1 therapy, linking PD-L1 regulation with the clinical study of checkpoint-treatment response 42716706Sep.
A real-world study in pretreated metastatic triple-negative breast cancer evaluated Trop-2-directed antibody–drug conjugates as monotherapy and in combination with a PD-1 inhibitor. A third treatment strategy combined the Trop-2 ADC, a PD-1 inhibitor, and an antiangiogenic agent, providing a clinical context for multi-agent cancer immunotherapy 42714605Sep.
The effects of anti-PD-1 treatment on cancer-cell properties were investigated using atomic force microscopy in quantitative imaging mode. Four human solid-tumor cell lines—A-375, HCC-4006, SGC-7901, and MDA-MB-231—were cocultured with CD8-positive T cells either alone or with an anti-PD-1 antibody. The analysis tracked time-dependent changes in Young’s modulus, adhesion, roughness, and cell morphology, examining whether mechanical properties distinguish cellular responses to anti-PD-1 immunotherapy 42535479Jul.
Researchers engineered oral commensal nanovaccines designed to activate mucosal and systemic immune responses against tumors. Combining this strategy with PD-1 blockade enhanced antitumor efficacy by promoting effector-cell mobilization and establishing immune memory against tumor rechallenge 42497859Jul.
BMS-986449, a degrader of the transcription factors IKZF2 (Helios) and IKZF4 (Eos), was investigated as a strategy to target regulatory T cells in solid tumors. Tumor-growth inhibition was more pronounced when BMS-986449 was administered together with anti-PD-1, supporting further investigation of regulatory-T-cell-directed treatments in combination with checkpoint inhibition 42677819Sep.
A medicinal-chemistry study focused on water-soluble quaternary-ammonium-based inhibitors of the PD-1/PD-L1 interaction. The work addressed poor aqueous solubility, a limitation reported for many small-molecule PD-1/PD-L1 inhibitors, and investigated compounds with both checkpoint-inhibitory and antiangiogenic activity 42720488Sep.
In non-small-cell lung cancer, a hypoxic niche dominated by HIF1A-positive, CSF3R-positive neutrophils was associated with metabolic reprogramming and resistance to neoadjuvant therapy. Treatment with navitoclax and platycodin-D2 in combination with anti-PD-1 significantly suppressed tumor proliferation and improved the immunosuppressive tumor immune microenvironment in the reported model 42711068Sep.
A proteomic and metabolomic study examined immune-related adverse events in patients treated with PD-1 inhibitors. The work characterized PD-1 blockade as an immune-checkpoint-inhibitor approach with activity across multiple malignancies and investigated molecular measurements that may help define treatment-associated immune toxicity 42695906Sep.
In head and neck squamous cell carcinoma, plasma concentrations of cytokines, chemokines, and soluble immune-related molecules were measured in 49 patients and 22 healthy donors. The analytes included IL-6, IL-10, IL-16, IL-18, VEGF, CXCL9, CXCL13, soluble PD-1, soluble PD-L1, soluble CTLA-4, and soluble CD163. This study evaluated circulating immune markers as indicators of the immunophenotype of the disease 42684559Sep.
Resistance to cytotoxic lymphocyte-mediated lysis and immunotherapy in gastric cancer was investigated in relation to LIM and SH3 protein 1 deficiency and disrupted cytoskeleton dynamics. Single-cell RNA sequencing was used to identify cytoskeleton-related genes associated with response to anti-PD-1 therapy across four digestive tumors, connecting tumor-cell structural biology with checkpoint-treatment resistance 42686372Sep.
Taken together, these publications extend the major literature themes of cancer immunotherapy strategies and immunotherapy resistance. They also broaden PD-1 research beyond direct receptor blockade by examining PD-L1 stabilization, miRNA regulation, hypoxic immune-cell niches, tumor-cell mechanics, soluble checkpoint markers, and combinations with targeted agents, antibody–drug conjugates, nanovaccines, and regulatory-T-cell-directed therapies. The medicinal-chemistry work additionally advances the development of small-molecule PD-1/PD-L1 inhibitors with improved solubility and antiangiogenic properties 42616478Aug42716706Sep42535479Jul42497859Jul42677819Sep42720488Sep42711068Sep42684559Sep42686372Sep.
Written from 11 PubMed abstracts, each one cited by PMID above. Published: 2026-09-11. Drafted by language models from published abstracts; not medical advice.