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Results for “programmed cell death 1 (PD-1)”

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PubMed2026

Genetically proxied circulating PD-1/PD-L1 levels and broadly defined myocarditis: A bidirectional Mendelian randomization study with exploratory lipidomic analyses.

Myocarditis is an inflammatory myocardial disease with potentially severe outcomes. Programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1) regulate immune tolerance, but the association between lifelong genetically proxied circulating PD-1/PD-L1 levels and broadly defined myocarditis remains uncertain. We investigated these associations and explored related plasma lipid species. We conducted bidirectional 2-sample Mendelian randomization using proteomic genome-wide association data from the UK Biobank Pharma Proteomics Project and INTERVAL. FinnGen Release 10 was the primary broadly defined myocarditis outcome, and an independent myocarditis genome-wide association study (GCST90018882) provided outcome-level validation. Complementary estimators, heterogeneity and pleiotropy diagnostics, influence analyses, MR-RAPS, and supportive meta-analyses were performed. Associations with 179 plasma lipid species were examined in exploratory analyses. Higher genetically proxied circulating PD-L1 was inversely associated with broadly defined myocarditis in UKB-PPP (odds ratio [OR] 0.834, 95% confidence interval [CI] 0.698-0.995; P = .0441), and the independent INTERVAL analysis yielded a concordant inverse estimate (OR 0.619, 95% CI: 0.434-0.883; P = .0083); no clear association was observed for PD-1. The MR-RAPS estimate retained the inverse direction; estimates against the independent broadly defined myocarditis dataset were also inverse, and supportive meta-analyses across protein and outcome sources yielded inverse pooled estimates. Reverse MR did not support effects of broadly defined myocarditis liability on circulating PD-1 or PD-L1. Exploratory lipid analyses identified nominal associations requiring confirmation. Higher genetically proxied circulating PD-L1 may be associated with a lower risk of broadly defined myocarditis, supporting further investigation of PD-L1-related immune regulation. These findings do not directly estimate the effects of pharmacologic PD-1/PD-L1 blockade. The lipid findings are hypothesis-generating.

Myocarditis↗

PubMed2026

Programmed cell death-1: from a T-cell immune checkpoint to a regulator of Natural Killer cell biology.

Programmed cell death protein 1 (PD-1, CD279) is a pivotal inhibitory immune checkpoint receptor that plays a central role in maintaining immune homeostasis and peripheral tolerance. Originally characterized as a negative regulator of T-cell activation, PD-1 limits excessive immune responses and prevents autoimmunity, while its sustained expression under conditions of chronic antigen stimulation contributes to T-cell dysfunction and exhaustion. The discovery that blockade of the PD-1 pathway can restore anti-tumor immunity has revolutionized cancer therapy and established immune checkpoint inhibition as a cornerstone of modern oncology. Although PD-1 has traditionally been viewed as a key regulator of adaptive immunity, accumulating evidence indicates that its biological functions extend beyond T cells. In recent years, PD-1 expression has been identified in several innate immune cell populations, particularly Natural Killer (NK) cells, where it has emerged as an important modulator of effector functions, cytokine production, metabolic fitness, and antitumor activity. These findings have challenged the classical view of PD-1 biology and revealed unexpected similarities between NK-cell dysfunction and the exhausted phenotype described in chronically stimulated T cells. In the tumor microenvironment, PD-1 expression on NK cells has been associated with impaired cytotoxicity and reduced immune surveillance, suggesting that NK cells may also represent relevant targets of PD-1-mediated immunosuppression. At the same time, the mechanisms regulating PD-1 expression and signaling in NK cells appear to differ, at least in part, from those operating in T lymphocytes, highlighting the complexity of this pathway across distinct immune cell subsets. In this review, we summarize the current knowledge of PD-1 biology, from its established role in T-cell regulation to its emerging functions in NK cells. We discuss the molecular mechanisms governing PD-1 expression and signaling, its contribution to immune dysfunction in cancer and chronic diseases, and the potential implications of targeting the PD-1 axis to enhance both adaptive and innate antitumor immunity.

Natural Killer (NK) cells↗

PubMed2025

PD-1 transcriptomic landscape across cancers and implications for immune checkpoint blockade outcome.

Programmed cell death protein 1 (PD-1) is a critical immune checkpoint receptor and a target for cancer immune checkpoint inhibitors (ICI). We investigated PD-1 transcript expression across cancer types and its correlations to clinical outcomes. Using a reference population, PD-1 expression was calculated as percentiles in 489 of 514 patients (31 cancer types) with advanced/metastatic disease. PD-1 RNA expression varied across and within cancer types; pancreatic and liver/bile duct malignancies displayed the highest rates of high PD-1 (21.82% and 21.05%, respectively). Elevated CTLA-4, LAG-3, and TIGIT RNA expression were independently correlated with high PD-1. Although high PD-1 was not associated with outcome in immunotherapy-naïve patients (n = 272), in patients who received ICIs (n = 217), high PD-1 transcript expression was independently correlated with prolonged survival (hazard ratio 0.40; 95%CI, 0.18-0.92). This study identifies PD-1 as an important biomarker in predicting ICI outcomes, and advocates for comprehensive immunogenomic profiling in cancer management.

Journal Article↗

PubMed2016

Immunodominant Dengue Virus-Specific CD8+ T Cell Responses Are Associated with a Memory PD-1+ Phenotype.

UNLABELLED: Dengue disease is a large public health problem that mainly afflicts tropical and subtropical regions. Understanding of the correlates of protection against dengue virus (DENV) is poor and hinders the development of a successful human vaccine. The present study aims to define DENV-specific CD8(+)T cell responses in general and those of HLA alleles associated with dominant responses in particular. In human blood donors in Nicaragua, we observed a striking dominance of HLA B-restricted responses in general and of the allele B*35:01 in particular. Comparing these patterns to those in the general population of Sri Lanka, we found a strong correlation between restriction of the HLA allele and the breadth and magnitude of CD8(+)T cell responses, suggesting that HLA genes profoundly influence the nature of responses. The majority of gamma interferon (IFN-γ) responses were associated with effector memory phenotypes, which were also detected in non-B*35:01-expressing T cells. However, only the B*35:01 DENV-specific T cells were associated with marked expression of the programmed death 1 protein (PD-1). These cells did not coexpress other inhibitory receptors and were able to proliferate in response to DENV-specific stimulation. Thus, the expression of particular HLA class I alleles is a defining characteristic influencing the magnitude and breadth of CD8 responses, and a distinct, highly differentiated phenotype is specifically associated with dominant CD8(+)T cells. These results are of relevance for both vaccine design and the identification of robust correlates of protection in natural immunity. IMPORTANCE: Dengue is an increasingly significant public health problem as its mosquito vectors spread over greater areas; no vaccines against the virus have yet been approved. An important step toward vaccine development is defining protective immune responses; toward that end, we here characterize the phenotype of the immunodominant T cell responses. These DENV-reactive T cells express high levels of the receptor programmed death 1 protein (PD-1), while those from disease-susceptible alleles do not. Not only does this represent a possible correlate of immunodominance, but it raises the hypothesis that PD-1 might be a regulator that prevents excessive damage while preserving antiviral function. Further, as this study employs distinct populations (Nicaraguan and Sri Lankan donors), we also confirmed that this pattern holds despite geographic and ethnic differences. This finding indicates that HLA type is the major determinant in shaping T cell responses.

Alleles↗

PubMed2026

Pharmacologic inhibition of SOX9-CDK4 by CYD-4-61 impairs gastric adenocarcinoma growth and amplifies anti-PD-1 response.

Gastric adenocarcinoma (GAC) remains a leading cause of cancer-related mortality, particularly in patients with peritoneal carcinomatosis, for whom effective therapies are limited. We investigated the therapeutic efficacy and molecular mechanism of CYD-4-61, a BAX activator, using human GAC cell lines, patient-derived xenograft models, genetically engineered mouse models, and a syngeneic mouse model. CYD-4-61 potently inhibited tumor cell proliferation, induced apoptosis, and suppressed cancer stem cell-like properties, with enhanced activity in radiation-resistant GAC cells. Mechanistically, CYD-4-61 activated the BAX-caspase pathway, leading to SOX9 protein reduction. Integrated bulk and single-cell transcriptomic analyses identified SOX9-dependent transcriptional programs as major targets of CYD-4-61. Functional rescue experiments together with chromatin immunoprecipitation and CUT&RUN analyses supported CDK4 as a SOX9-regulated gene and demonstrated suppression of the SOX9-CDK4 regulatory axis following CYD-4-61 treatment. In multiple preclinical models, CYD-4-61 significantly inhibited tumor growth and improved the therapeutic response to anti-programmed cell death protein 1 (PD-1) therapy while modulating the tumor immune microenvironment. Clinically, co-expression of SOX9 and CDK4 was associated with diffuse-type GAC and poor patient outcomes. These findings identify the BAX-SOX9-CDK4 axis as an important mechanism contributing to the antitumor activity of CYD-4-61 and provide a strong preclinical rationale for its further development as a therapeutic strategy for aggressive GAC.

Animals↗

PubMed2026

Safety, Pharmacokinetics, and Pharmacodynamics of Single-Dose Programmed Cell Death Protein 1 Inhibitor, Budigalimab, in People With HIV-1 With Antiretroviral Therapy-Suppressed Viral Load.

BACKGROUND: Blockade of inhibitory immune checkpoint receptor programmed cell death protein 1 (PD-1) on target immune cells is associated with improved HIV-specific immune function and activation of latent HIV. This randomized, placebo-controlled, Phase 1b study assessed low doses of investigational anti-PD-1 monoclonal antibody, budigalimab, for safety, tolerability, pharmacokinetics, and pharmacodynamics in people with HIV (PWH) on antiretroviral therapy. METHODS: Participants received single doses of budigalimab 10 mg subcutaneous (SC), 20 mg SC, 10 mg intravenous (IV), or placebo (n = 8 per arm) and were followed for 24 weeks. RESULTS: Of 32 randomized participants, 22 reported adverse event(s) (AE); most (n = 19) were grade ≤2 and no grade ≥4 AE or treatment-related serious AE. Two participants reported a non-treatment-related grade 3 AE (placebo, n = 1 pneumonia; 10 mg IV, n = 1 elevated aspartate aminotransferase). One reversible immune-related AE (grade 2 lichenoid keratosis) was reported (20 mg SC). Geometric mean maximum serum concentrations were 0.37, 1.57, and 3.2 µg/mL with 10 mg SC, 20 mg SC, and 10 mg IV, respectively. Drug exposure with 20 versus 10 mg SC dosing was more than dose proportional and less variable. Subcutaneous bioavailability was approximately 53%-62%. The PD-1 receptor saturation was ≥95% in most participants (median duration: 20 mg SC, 42 days; 10 mg SC, 14 days; 10 mg IV, 35 days). CONCLUSIONS: Findings suggest an acceptable safety profile for single-dose budigalimab in PWH, with a favorable pharmacokinetic profile for 20 mg SC and 10 mg IV. Further evaluation as a potential component of an HIV treatment is underway.

Humans↗

PubMed2026

HIF1A+CSF3R+ neutrophils-dominated hypoxic niche induced metabolic reprogramming for neoadjuvant therapy resistance in NSCLC.

BACKGROUND: Non-small cell lung cancer (NSCLC) is one of the frequently occurring cancers characterized by molecular heterogeneity and multiple immune cell infiltration patterns, which are associated with treatment sensitivity and resistance. However, the specific microenvironmental cells and their mechanisms that lead to treatment resistance in patients need to be explored in greater depth. METHODS: On the basis of patients receiving neoadjuvant therapy in our center, a multicenter, multicohort NSCLC spatial transcriptome, single-cell transcriptome, T-cell receptor repertoire sequencing, bulk RNA transcriptome, phosphorylated proteome, genome mutation, and clinical data were included for a comprehensive assessment of the therapeutic and prognostic impact of HIF1A+ CSF3R+ neutrophils in NSCLC. In vitro experiments validated the functional phenotype of HIF1A+ CSF3R+ neutrophils and co-localization interactions with other cellular subpopulations. Gradient boosting machine (GBM) constructed region of interest (ROI) models for evaluation. Computer-aided drug design (CADD) was used to predict targeted small molecule drugs, and in vivo mouse models were constructed to assess the effectiveness of the combination treatment regimen. RESULTS: Centered on HIF1A+ CSF3R+ neutrophils, recruited exhausted T cells and stromal cells form a hypoxic niche within the tumor region, which was enriched in non-response patients. ROI composed of these specific cellular subpopulations, associated with senescence and glycolysis, accurately predicting NSCLC progression, prognosis, and microenvironment composition. CADD analysis identified that platycodin-D2 specifically targeted CSF3R, reducing HIF1A expression and inhibiting neutrophil activity. Combining navitoclax, platycodin-D2 with anti-programmed cell death protein 1 (PD-1) significantly suppressed tumor proliferation and improved the immunosuppressive microenvironment. CONCLUSION: Our study emphasized the role of HIF1A+ CSF3R+ neutrophils in immunotherapeutic resistance of NSCLC, constructed a microenvironmental immune dysregulation network in a hypoxic ecological niche with HIF1A+ CSF3R+ neutrophils as the center. Platycodin-D2 specifically targeted HIF1A+ CSF3R+ neutrophils, enhancing the efficacy of anti-PD-1 therapy in NSCLC.

Humans↗

PubMed2026

Ascites reprograms innate lymphoid immune cells in ovarian cancer by promoting ILC2 enrichment and dysfunctional NK-cell states.

BACKGROUND: High-grade serous ovarian cancer (HGSOC) is commonly accompanied by malignant ascites, a clinically relevant tumor niche that promotes immune evasion, metastasis, and treatment resistance. Although natural killer (NK)-cell dysfunction has been described in ovarian cancer, the broader innate lymphoid landscape of ascites and the mechanisms linking ascites-derived signals to innate immune suppression remain insufficiently resolved. METHODS: We performed single-cell RNA sequencing of NK/innate lymphoid cells from ovarian cancer ascites to define cellular heterogeneity and differentiation states. Functional assays assessed NK-cell cytotoxicity, degranulation, and receptor expression following exposure to patient-derived ascites, with or without transforming growth factor-β (TGF-β) receptor inhibition. Proteomic profiling was used to characterize the soluble ascites milieu, and clinical associations were examined for innate lymphoid subsets. RESULTS: Single-cell analysis identified eight transcriptionally distinct NK/innate lymphoid states, including cytotoxic, precursor, early-like, tolerant/immunoregulatory, regulatory, proinflammatory, and innate lymphoid populations. Ovarian cancer ascites was characterized by depletion of cytotoxic and precursor NK-cell states together with enrichment of early-like, tolerant, regulatory, pro-inflammatory, and innate lymphoid cell (ILC) populations. Trajectory analysis indicated impaired maturation toward terminally differentiated cytotoxic NK cells. Notably, ascites contained an expanded population of programmed cell death protein 1 (PD-1)+ ILC2s, which were more abundant in patients with shorter progression-free survival. In functional assays, short-term exposure of healthy donor NK cells to ascites suppressed degranulation and tumor-cell killing, reduced expression of activating receptors including NKp30 and DNAM-1, increased inhibitory receptor expression, and shifted NK cells toward a CD56highCD16low phenotype. Proteomic profiling supported a soluble milieu consistent with type 2 immune skewing and NK-cell suppression. Importantly, TGF-β receptor inhibition partially restored NK-cell activation and function in the presence of ascites. CONCLUSIONS: HGSOC ascites establishes a type 2-skewed immunoregulatory niche that coordinately drives NK cell dysfunction and PD-1+ ILC2 accumulation. The findings identify TGF-β-linked suppression and ascites-associated immune regulators as candidate immunotherapeutic vulnerabilities for restoring antitumor immunity in ovarian cancer.

Humans↗

PubMed2026

Multiomic study of cutaneous T-cell lymphoma reveals single-cell clonal evolution in progression and therapy resistance.

Cutaneous T-cell lymphoma (CTCL) remains a challenging disease due to its significant heterogeneity, therapy resistance, and relentless progression. Multiomics technologies offer the potential to provide uniquely precise views of disease progression and response to therapy. Here, we present a comprehensive multiomics view of CTCL clonal evolution, incorporating exome, whole-genome, epigenome, bulk, single-cell T-cell receptor, and single-cell RNA sequencing of 99 clinically annotated serial skin, peripheral blood, and lymph node samples from 34 patients with CTCL. We leveraged this extensive data set to define the molecular underpinnings of CTCL progression in individual patients at single-cell resolution with the goal of identifying clinically useful biomarkers and therapeutic targets. Our studies identified recurrent progression-associated clonal genomic alterations; we highlight mutation of CCR4, phosphoinositide 3-kinase inhibitor signaling, and programmed cell death protein 1 (PD-1) checkpoint pathways as evasion tactics deployed by malignant T cells. We identified a gain-of-function mutation in STAT3 (D661Y) and demonstrated, using cleavage under targets and release using nuclease (CUT&RUN) and RNA sequencing, that it enhances binding to and transcription of genes in Rho GTPase pathways. With our previous work implicating this pathway in histone deacetylase inhibitor-resistant CTCL, these data provide further support for a previously unrecognized role for Rho GTPase pathway dysregulation in CTCL progression. Recurrent progression-associated mutations were common in the epigenetic modifier EZH2, suggesting that EZH2 inhibition may benefit patients with CTCL. Our findings support an approach in which genomic analysis is widely used for improved disease monitoring, biomarker-informed clinical trial design, and genome-guided therapeutic decision-making. Moreover, these molecular changes present new opportunities for therapeutic targeting in this challenging and incurable cancer.

Multiomics↗

PubMed2026

Lipid metabolic reprogramming of tumor-associated macrophages drives resistance to immune checkpoint blockade in lung cancer: a narrative review of mechanisms and therapeutic strategies.

BACKGROUND AND OBJECTIVE: Immune checkpoint inhibitors (ICIs), represented by programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1), have shown remarkable efficacy in non-small cell lung cancer (NSCLC); however, many patients still develop resistance to immunotherapy. Although small cell lung cancer (SCLC) is also an important histological type of lung cancer, NSCLC accounts for the majority of lung cancer cases. Current research on ICI development, first-line treatment efficacy, and the mechanisms of lipid metabolism in tumor-associated macrophages (TAMs) is predominantly focused on NSCLC. In patients with advanced NSCLC, objective response rates (ORRs) with PD-1/PD-L1 inhibitor monotherapy remain limited. Only in patients with high PD-L1 expression [tumor proportion score (TPS) ≥50%] and without sensitizing epidermal growth factor receptor (EGFR) mutations or anaplastic lymphoma kinase (ALK) rearrangements does the ORR increase to approximately 40-45%. TAMs are a key component of the immunosuppressive tumor microenvironment (TME). Lipid metabolic reprogramming profoundly influences the functional and transcriptional features of TAMs. This review aims to integrate relevant evidence, elucidate how TAM lipid metabolism promotes immunosuppression and resistance to ICIs, and outline potential therapeutic strategies. METHODS: We searched PubMed/MEDLINE, Web of Science, and Scopus for publications up to June 2026 using terms combining lung cancer, TAMs, lipid metabolism, and immune checkpoint blockade/resistance. Mechanistic, translational, and clinically relevant studies were selected by author consensus. KEY CONTENT AND FINDINGS: Lipid uptake, de novo lipogenesis, fatty acid oxidation (FAO), cholesterol remodeling, and eicosanoid metabolism are not independent processes in TAMs. Lipid metabolic reprogramming in TAMs ultimately suppresses type I interferon (IFN-I) signaling, upregulates PD-L1 expression, and impairs the function of CD8+ T cells with stem-like features, thereby establishing an immunosuppressive TME and leading to resistance to ICIs. In lung cancer, hypoxia, high lactate levels, and tobacco exposure further shape the lipid phenotype of TAMs, such as lipid raft enrichment and lipid-laden macrophage subsets like SPP1+ macrophages. Different driver genomic backgrounds differentially impact tumor cell-intrinsic metabolism and the lipid metabolic programs of myeloid cells. In preclinical models, interventions targeting these metabolic axes, including TAM-directed delivery systems, have demonstrated potential therapeutic benefit when combined with anti-PD-1/PD-L1 therapy. CONCLUSIONS: Targeting TAM lipid metabolism to convert immunologically cold tumors into more inflamed, ICI-responsive tumors is a promising strategy to overcome resistance in NSCLC. Identification of predictive biomarkers of therapeutic response and development of cell-selective drug delivery systems come to be major challenges.

Non-small cell lung cancer (NSCLC)↗

PubMed2026

Proteomic and Metabolomic Analysis of Immune-Related Adverse Events in Patients Treated with PD-1 Inhibitors.

As a class of immune checkpoint inhibitors (ICIs), programmed cell death protein-1 (PD-1) blockade has demonstrated remarkable efficacy in the treatment of various malignancies. However, their clinical application is constrained by the high incidence of immune-related adverse events (irAEs), which arise from nonspecific immune activation and can affect multiple organ systems, with severe cases posing life-threatening risks. This study integrated high-throughput proteomic and metabolomic analyses to systematically characterize the molecular features associated with irAEs in cancer patients receiving PD-1 inhibitor therapy. The results showed that, following the first treatment, patients who developed irAEs exhibited potential involvement of the NF-κB pathway, along with lower baseline levels of SNRPA and higher expression of CD63. Metabolomic analyses further revealed that the kynurenine/tryptophan ratio was significantly elevated in the irAE group both at baseline and post-treatment compared with patients who did not develop irAEs. In addition, significant differences in the abundance of specific lipids were observed between the two groups prior to the administration of immunotherapy. Our findings provide exploratory insights into immune and metabolic alterations associated with PD-1 blockade treatment and may help generate hypotheses for future studies on early irAE risk assessment in cancer patients undergoing PD-1 blockade therapy.

Humans↗

PubMed2026

Intratumoral PD-1+LAG-3+CD8+ T cells are associated with improved prognosis in gastric cancer.

PURPOSE: PD-1 and LAG-3 are frequently used as markers of T cell exhaustion, yet the prognostic relevance and phenotypic characteristics of PD-1+LAG-3+CD8+ T cells in gastric cancer (GC) remain poorly defined. This study aimed to investigate their association with clinical outcomes and characterize their immune characteristics across independent GC cohorts. METHODS: Four independent GC cohorts were analyzed: the Zhongshan Hospital cohort (ZSGC, n = 298), The Cancer Genome Atlas cohort (TCGA, n = 371), an Immune Checkpoint Blockade cohort (ICB, n = 45), and the Yonsei cohort (n = 433). Intratumoral PD-1+LAG-3+CD8+ T cell infiltration was quantified by immunofluorescence staining and transcriptomic gene signature scoring. Survival analysis was performed using Kaplan-Meier estimation and multivariate Cox regression. Functional characterization was performed by flow cytometry on resected GC tissue. The immune microenvironment composition was evaluated using computational analyses. RESULTS: PD-1+LAG-3+CD8+ T cells were enriched within tumors compared to adjacent normal mucosa, and their infiltration correlated with advanced tumor stage, poor differentiation, microsatellite instability, and Epstein-Barr virus (EBV)-positive molecular subtypes. High intratumoral infiltration was significantly associated with improved overall survival in both the ZSGC and TCGA cohorts, whereas single-positive PD-1+CD8+ or LAG-3+CD8+ T cells showed no such association. In the ICB cohort, higher infiltration was associated with a higher response rate to pembrolizumab. Intratumoral PD-1+LAG-3+CD8+ T cells exhibit an activated phenotype characterized by increased expression of CD137, IFN-γ, perforin, and CXCL13, along with elevated TCF7 and lower PD-1 levels, suggesting a tumor-reactive, pre-exhausted state. High infiltration was further associated with an immune-active tumor microenvironment. CONCLUSIONS: High intratumoral infiltration of PD-1+LAG-3+CD8+ T cells is associated with favorable prognosis and an immune-active microenvironment in GC. These cells display phenotypic features consistent with a pre-exhausted state and may serve as independent prognostic biomarkers and candidate predictive biomarkers for immunotherapy stratification.

Humans↗

PubMed2026

Localized PD-1 CAR T therapy reprograms neuroinflammation.

B cell-depleting therapies are effective in multiple sclerosis (MS), yet some patients relapse, underscoring the need for more precise interventions. To identify new therapeutic targets, we generated a single-cell RNA sequencing (scRNA-seq) atlas of cerebrospinal fluid (CSF), brain, and blood from non-inflammatory controls and patients with MS or other neuroinflammatory diseases. We found disease-associated enrichment of class-switched immunoglobulin G+ (IgG+) B cells and plasma cells in MS CSF. Unbiased analysis identified a rare disease-enriched subset of activated, T cell receptor (TCR)-restricted, PD-1+ T follicular helper-like cells with B cell-recruiting features. To target this population, we developed PD-1-directed chimeric antigen receptor (CAR) T cells that selectively depleted pathogenic PD-1+ CD4 T cells and locally released IL-10. This strategy attenuated central nervous system (CNS) inflammation, reprogrammed the local immune milieu, and improved clinical outcomes across murine neuroinflammation models. These findings define a CNS-localized adaptive immune circuit in MS and nominate programmable PD-1 CAR T cells as a strategy to disrupt it.

Animals↗

PubMed2026

Conserved miRNA regulators of PD-1/PD-L1 in glioblastoma and colorectal cancer.

Immune checkpoint inhibitors (ICIs) targeting the PD-1/PD-L1 axis have transformed cancer therapy, but their efficacy remains limited in glioblastoma (GBM) and heterogeneous in colorectal cancer (CRC). MicroRNAs (miRNAs) regulate gene expression at the post-transcriptional level, including immune checkpoint molecules, yet conserved regulatory miRNA networks across distinct cancers remain poorly defined. Five conserved miRNAs (miR-106a-5p, miR-106b-5p, miR-20a-5p, miR-20b-5p, miR-138-5p) fulfilled the selection criteria and were consistently dysregulated in GBM and CRC. MiR-106a-5p and miR-106b-5p were upregulated in both cancers and showed favourable prognostic associations, with higher expression correlating with improved survival. miR-20a-5p and miR-20b-5p were preferentially expressed in microsatellite-stable (MSS) CRC and correlated with favourable outcomes in both cancers, whereas miR-138-5p was downregulated in both tumours compared to normal tissue, but showed opposite survival associations, with higher levels linked to worse prognosis. Correlation analysis revealed significant inverse associations between several miRNAs and checkpoint gene expression, including moderate inverse correlations for CD274-miR-106a-5p in GBM, CD274-miR-20a-5p in CRC and PDCD1LG2-miR-20a-5p in both cancers. Pan-cancer profiling demonstrated broad and heterogeneous dysregulation, with expression absent in ovarian cancer for four of the five miRNAs. Pathway enrichment implicated the TGF-β, Hippo, FoxO, and cell cycle pathways, consistent with their known roles in tumour immune evasion. We identified a conserved set of miRNAs that are dysregulated in both GBM and CRC, correlate with survival, and display inverse relationships with PD-1/PD-L1/PD-L2 expression. These miRNAs represent candidate regulators of the PD-1/PD-L1/PD-L2 axis and potential biomarkers of tumour biology that may influence immune checkpoint signalling.

Humans↗

PubMed2025

High baseline PD-1+ CD8 T Cells and TIGIT+ CD8 T Cells in circulation associated with response to PD-1 blockade in patients with non-small cell lung cancer.

Blockade of PD-1 or its ligand PD-L1 with antibodies revolutionized treatment for stage III and IV non-small cell lung cancer (NSCLC) since FDA approval in 2015. However, resistance to PD-1/PD-L1 blockade remains a challenge, highlighting the need for biomarkers. This study analyzed 36 stage III and IV NSCLC patients, classified as responders or non-responders by iRECIST criteria. Peripheral blood mononuclear cells collected at baseline and post-treatment were examined for surface and intracellular markers via flow cytometry. CITE sequencing of CD8 T cells from three patients and plasma ctDNA analysis from 13 patients was performed using an ultrasensitive barcoding and next-generation sequencing method. Phenotypic analysis of CD8 T cells revealed higher TIGIT and PD-1 expression at baseline in responders compared to non-responders. Long-term responders (> 21 months) exhibited increased TCF-1+PD-1+ CD8 T cell frequencies relative to shorter-term responders (> 15 months) and non-responders. CITE sequencing revealed intrinsic differences in immune regulation pathways between responders and non-responders. Finally, non-responders showed elevated and increasing ctDNA levels post-treatment, correlating with declining TCF-1+PD-1+ CD8 T cells. Our data suggests combining CD8 T cell analysis with ctDNA dynamics could identify promising biomarkers for monitoring clinical response and treatment efficacy to PD-1/PD-L1 blockade in NSCLC.

Humans↗

PubMed2024

The phosphatidylserine targeting antibody bavituximab plus pembrolizumab in unresectable hepatocellular carcinoma: a phase 2 trial.

Immune checkpoint inhibitors targeting PD-1/L1 have modest efficacy in hepatocellular carcinoma as single agents. Targeting membranous phosphatidylserine may induce pro-inflammatory and -immune stimulating effects that enhance immunotherapy activity. This hypothesis was tested in a single-arm phase 2 trial evaluating frontline bavituximab, a phosphatidylserine targeting antibody, plus pembrolizumab (anti-PD-1) in patients with unresectable hepatocellular carcinoma (NCT03519997). The primary endpoint was investigator-assessed objective response rate among evaluable patients, and secondary end points included progression-free survival, incidence of adverse events, overall survival, and duration of response. Among 28 evaluable patients, the confirmed response rate was 32.1%, which met the pre-specified endpoint, and the median progression-free survival was 6.3 months (95% CI, 1.3-11.3 months). Treatment related-adverse events of any grade occurred in 45.7% of patients, with grade 3 or greater adverse events in 14.3% of patients. Adverse events of any cause were observed in 33 patients (94.3%), with grade 3 or greater adverse events in 11 patients (31.4%). Prespecified exploratory analyses of baseline tumor specimens showed that a depletion of B cells, and the presence of fibrotic tissue and expression of immune checkpoints in stroma was associated with tumor response. These results suggest that targeting phosphatidylserine may lead to synergistic effects with PD-1 blockade without increasing toxicity rates, and future studies on this therapeutic strategy may be guided by biomarkers characterizing the pre-treatment tumor microenvironment.

Humans↗

PubMed2025

Comprehensive clinical and genetic characterization of hyperprogressive biliary tract cancer during PD-1 blockade monotherapy: case report and literature review.

BACKGROUND: Some genetically characterized patients show the rapid disease progression during immune checkpoint inhibitors (ICIs) monotherapy, a phenomenon known as hyperprogressive disease (HPD). CASE PRESENTATION: Herein we report a relevant case of biliary tract cancer (BTC) that initially responded to gemcitabine plus oxaliplatin (GEMOX) and PD-1 blockade but subsequently developed HPD in the process of PD-1 blockade maintenance therapy, leading to death within two weeks. Genomic analysis revealed mutations in CDKN2A, PIK3CA, KRAS and EPHA2 in both baseline and hyperprogressive plasma and tumor samples. Notably, higher KRAS mutation abundance was observed in plasma and ascites after disease progression. CONCLUSIONS: These findings suggest a potential association between these negative genes especially KRAS mutation and HPD. Therefore, administration of PD-1 blockade monotherapy in this subgroup of patients harboring KRAS mutation should be performed with caution. Further studies are warranted to confirm these results and explore the correlation between genomic mutations and HPD.

Humans↗

PubMed2024

Soluble immune checkpoint factors reflect exhaustion of antitumor immunity and response to PD-1 blockade.

BACKGROUNDPrecise stratification of patients with non-small cell lung cancer (NSCLC) is needed for appropriate application of PD-1/PD-L1 blockade therapy.METHODSWe measured soluble forms of the immune-checkpoint molecules PD-L1, PD-1, and CTLA-4 in plasma of patients with advanced NSCLC before PD-1/PD-L1 blockade. A prospective biomarker-finding trial (cohort A) included 50 previously treated patients who received nivolumab. A retrospective observational study was performed for patients treated with any PD-1/PD-L1 blockade therapy (cohorts B and C), cytotoxic chemotherapy (cohort D), or targeted therapy (cohort E). Plasma samples from all patients were assayed for soluble immune-checkpoint molecules with a highly sensitive chemiluminescence-based assay.RESULTSNonresponsiveness to PD-1/PD-L1 blockade therapy was associated with higher concentrations of these soluble immune factors among patients with immune-reactive (hot) tumors. Such an association was not apparent for patients treated with cytotoxic chemotherapy or targeted therapy. Integrative analysis of tumor size, PD-L1 expression in tumor tissue (tPD-L1), and gene expression in tumor tissue and peripheral CD8+ T cells revealed that high concentrations of the 3 soluble immune factors were associated with hyper or terminal exhaustion of antitumor immunity. The combination of soluble PD-L1 (sPD-L1) and sCTLA-4 efficiently discriminated responsiveness to PD-1/PD-L1 blockade among patients with immune-reactive tumors.CONCLUSIONCombinations of soluble immune factors might be able to identify patients unlikely to respond to PD-1/PD-L1 blockade as a result of terminal exhaustion of antitumor immunity. Our data suggest that such a combination better predicts, along with tPD-L1, for the response of patients with NSCLC.TRIAL REGISTRATIONUMIN000019674.FUNDINGThis study was funded by Ono Pharmaceutical Co. Ltd. and Sysmex Corporation.

Humans↗