Programmed Death-ligand 1 Expression Research Articles

FOXA1 enhances antitumor immunity via repressing interferon-induced PD-L1 expression in nasopharyngeal carcinoma

BackgroundNasopharyngeal carcinoma (NPC) is a distinct subtype of head and neck cancer which is prevalent in south of China and southeastern of Asia. Consistent activation of interferon (IFN) signaling, and...

Periodontitis promotes tumor growth and immune evasion via PD-1/PD-L1.

Our study investigated the role of experimental periodontitis on tumor growth, local and systemic immunosuppressive status, and programmed death receptor 1 (PD-1) / programmed death ligand 1 (PD-L1) expression in oral squamous cell carcinoma (OSCC) and prostate cancer. Mouse oral or prostate cancer xenograft models were divided into control, periodontitis and periodontitis + anti-PD-1 groups. Tumor volume and weight were recorded and the levels of relevant immune-suppressive cells and T cells were detected by flow cytometry or immunofluorescence. THP-1 cells were stimulated using conditioned media of LPS-stimulated Cal-27 cells and PD-L1 expression was measured by quantitative real-time PCR, western blotting and immunofluorescence. Tumor specimens from OSCC patients with or without periodontitis were also collected for immunofluorescence. Periodontitis significantly promoted tumor volume and weight. Compared to the control, the proportions of tumor-associated macrophages (TAMs), regulatory T cells (Tregs), PD-L1+TAMs and PD-1+CD8+T cells increased, while CD8+T cells decreased in the periodontitis group. Immunofluorescence demonstrated that there was an increase in PD-L1+TAMs and PD-1+CD8+T cells, but a decrease in IFN-γ+CD8+T cells in both xenografts and clinical OSCC samples with periodontitis. In vitro, LPS-stimulated Cal-27 cells had a stronger potential to induce PD-L1 expression in macrophages compared with unstimulated Cal-27 cells. And the promoting effect of periodontitis on tumor growth and immune evasion was significantly attenuated after anti-PD-1 therapy. Periodontitis may facilitate tumor growth and immune escape evidenced by the increased immune-suppressive cells and the decreased functional T cells, via enhancing PD-1/PD-L1 expression in the tumor microenvironment.

Abstract A038: Investigating PD-L1 status in circulating tumor cells isolated from blood samples of lung cancer patients

Abstract Background: This research study aimed to assess the performance of a research use only (RUO) immunofluorescence (IF) assay targeting programmed death-ligand 1 (PD-L1) evolution in epithelial and/or mesenchymal circulating tumor cells (CTCs) isolated from blood using Parsortix® microfluidic technology. Upregulation of PD-L1 enables cancer cells to evade the host immune response. Assessment of PD-L1 status in the tumor, as determined by traditional tissue biopsy, can indicate if immunotherapy has the potential to be an effective treatment. However, PD-L1 expression in tumor biopsies may not reflect metastatic sites in their entirety and can become outdated during tumor evolution, as the process cannot be repeated due its invasive nature. Liquid biopsy offers a minimally invasive option for dynamic testing of PD-L1 in CTCs as patients undergo treatment. Methods: Analytical linearity, and specificity and sensitivity were assessed by spiking HCC1954 and Hs 578T cancer cell lines into the blood samples of 34 healthy volunteers. The assay was then evaluated in samples from 47 metastatic lung cancer patients, among which 32 had a known PD-L1 tissue status (19 positive, 13 negative). Up to six successive draws were taken for each patient, collected into Streck Cell-Free DNA blood collection tubes. ANGLE’s Parsortix® instruments were used to isolate spiked cancer cells or CTCs from blood samples based on their size and deformability. The CTC- enriched harvests were processed onto ANGLE’s CellKeepTM slides and IF stained with ANGLE’s Portrait® PD-L1 RUO assay for PD-L1 identification on CTCs. Slides were imaged on a BioView automated imaging system. Results: Analytical specificity of PD-L1 was 98% and analytical sensitivity was 81%. Analytical linearity (R2=0.91) was shown over a 0–500 cells range. In metastatic lung cancer patients, ≥1 CTC was identified in at least one draw for 91% of donors, with 55% of those donors exhibiting ≥1 PD-L1 positive CTC. A majority (81%) of donors exhibited a positive correlation between PD-L1 tissue status and CTC expression. However, the remaining 19% of donors exhibited discordance with a PD-L1 negative tissue status but PD-L1 positivity identified in ≥1 CTC. Of the PD-L1 positive CTCs identified, 98% expressed mesenchymal markers. Dynamic change was shown in all but one donor, with PD-L1 status of the CTCs changing over time. Conclusions: This study demonstrated the ability to determine PD-L1 status in CTCs from the blood of metastatic lung cancer patients and, subject to further study, the future potential to develop dynamic PD-L1 testing for advancement of more personalized cancer treatments. Patients with a PD-L1 negative tissue status exhibited PD-L1 positive CTCs, demonstrating the feasibility of a more repeatable and accurate assessment of PD-L1 status than can be achieved through a traditional tissue biopsy. Citation Format: Morgan Spode, Chloe Goodwin, Aarabhi Varatharajah, Aaron Cottingham, Elisha Duhig, Laura Kaja, David Greaves, Mariacristina Ciccioli, Anne-Sophie Pailhes-Jimenez. Investigating PD-L1 status in circulating tumor cells isolated from blood samples of lung cancer patients [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A038.

Intrinsic PD-L1 Degradation Induced by a Novel Self-Assembling Hexapeptide for Enhanced Cancer Immunotherapy.

Programmed death-ligand 1 (PD-L1) is a critical immune checkpoint protein that facilitates tumor immune evasion. While antibody-based PD-1/PD-L1 inhibitors have shown promise, their limitations necessitate the development of alternative therapeutic strategies. This work addresses these challenges by developing a hexapeptide, KFM (Lys-Phe-Met-Phe-Met-Lys), capable of both directly downregulating PD-L1 and self-assembling into a ROS-responsive supramolecular hydrogel. This dual functionality allows Gel KFM to function as a localized drug delivery system and a PD-L1 inhibitor. Loading the hydrogel with mitoxantrone (MTX) and metformin (MET) further enhances the therapeutic effect by combining chemotherapy with PD-L1 downregulation. In vitro and in vivo studies demonstrate significant tumor growth inhibition, increased CD8+ T cell infiltration, and reduced intratumoral PD-L1 expression following peritumoral administration. Mechanistically, KFM promotes PD-L1 degradation via a ubiquitin-dependent pathway. This "carrier-free" delivery system expands the role of supramolecular hydrogels beyond passive carriers to active immunotherapeutic agents, offering a promising new strategy for cancer therapy.

MCRANet: MTSL-based connectivity region attention network for PD-L1 status segmentation in H&E stained images

The quantitative analysis of Programmed death-ligand 1 (PD-L1) via Immunohistochemical (IHC) plays a crucial role in guiding immunotherapy. However, IHC faces challenges, including high costs, time consumption and result variability. Conversely, Hematoxylin-Eosin (H&E) staining offers cost-effectiveness, speed, and stable results. Nonetheless, H&E staining, which solely visualizes cellular morphological features, lacks clinical applicability in detecting biomarker expressions like PD-L1. Substituting H&E staining for IHC in determining PD-L1 status is a clinically significant and challenging task. Motivated by above observations, we propose a Multi-Task supervised learning (MTSL)-based connectivity region attention network (MCRANet) for PD-L1 status segmentation in H&E stained images. To reduce interference from non-tumor areas, the MTSL-based region attention is proposed to enhances the network's capability to distinguish between tumor and non-tumor regions. Consequently, this augmentation further improves the network's segmentation efficacy for PD-L1 positive and negative regions. Furthermore, the PD-L1 expression regions demonstrate interconnection throughout the tissue section. Leveraging this topological prior knowledge, we integrate a connectivity modeling module (CM module) within the MTSL-based region attention module (MRA module) to enhance the precision of MTSL-based region attention localization. This integration further improves the structural similarity between the segmentation results and the ground truth. Extensive visual and quantitative results demonstrate that our supervised-learning-guided MRA module produces more interpretable attention and the introduced CM module provides accurate positional attention to the MRA module. Compared to other state-of-the-art networks, MCRANet exhibits superior segmentation performance with a dice similarity coefficient (DSC) of 79.6 % on the lung squamous cell carcinoma (LUSC) PD-L1 status dataset.

Inflammation-Triggering Engineered Macrophages (MacTriggers) Enhance Reactivity of Immune Checkpoint Inhibitor Only in Tumor Tissues

Background: We have previously reported engineered macrophages (MacTriggers) that can accelerate the release of tumor necrosis factor-α in response to M2 polarization. MacTriggers are characterized by two original characteristics of macrophages: (1) migration to tumors; and (2) polarization to the M2 phenotype in tumors. Intravenously administered MacTriggers efficiently accumulated in the tumors and induced tumor-specific inflammation. This study reports a novel methodology for enhancing the anti-tumor effects of immune checkpoint inhibitors (ICIs). Results: In this study, we newly found that the intravenously administered MacTriggers in BALB/c mouse models upregulated the expression levels of immune checkpoint proteins, such as programmed cell death (PD)-1 in CD8+ T cells and PD-ligand 1 (PD-L1) in cancer cells and macrophages. Consequently, in two ICI-resistant tumor-inoculated mouse models, the combined administration of MacTrigger and anti-PD-1 antibody (aPD-1) synergistically inhibited tumor growth, whereas monotherapy with aPD-1 did not exhibit anti-tumor effects. This synergistic effect was mainly from aPD-1 enhancing the tumor-attacking ability of CD8+ T cells, which could infiltrate into the tumors following MacTrigger treatment. Importantly, no side effects were observed in normal tissues, particularly in the liver and spleen, indicating that the MacTriggers did not enhance the aPD-1 reactivity in normal tissues. This specificity was from the MacTriggers not polarizing to the M2 phenotype in normal tissues, thereby avoiding inflammation and increased PD-1/PD-L1 expression. MacTriggers could enhance aPD-1 reactivity only in tumors following tumor-specific inflammation induction. Conclusions: Our findings suggest that the MacTrigger and aPD-1 combination therapy is a novel approach for potentially overcoming the current low ICI response rates while avoiding side effects.

The unexpected PD-L1 suppression function of celery-derived extracellular vesicles improves lung cancer chemotherapy efficacy

Aim: The article explores celery-derived extracellular vesicles (CDEVs), characterized by high cellular uptake, low immunogenicity, and high stability, as a therapeutic strategy for antitumor nanomedicines. Methods: The methods employed in this study include in vitro cell experiments such as co-culture, Western Blot, and flow cytometry. In vivo experiments were conducted in C57BL/6 tumor-bearing mice subcutaneously injected with Lewis lung carcinoma (LLC) cells. The experiments encompassed parameters such as survival rate, body weight, tumor size, flow cytometry, immunohistochemistry, and spectral live imaging system. Results: Our study revealed that CDEVs could be used as drugs to effectively downregulate the phosphorylated signal transducer and activator of transcription 3(p-STAT3)/programmed cell death ligand 1 (PD-L1) axis in lung cancer cells. In co-culture experiments, CDEVs were observed to impede the expression of PD-L1, thereby interfering with the interaction between PD-L1 and programmed death 1 (PD-1) and subsequently preventing the suppression of T cells. In in vivo distribution experiments, CDEVs loaded with paclitaxel (PTX) demonstrated better tumor targeting capabilities. Remarkably, following CDEVs-PTX treatment, CD8+ T cell levels in mice were increased, presumably leading to improved antitumor effects. Conclusion: CDEVs not only serve as drug carriers but also function as drugs themselves; as such, through a single administration of CDEVs, it is possible to combine immunotherapy and chemotherapy to achieve better effects between the two, providing a more comprehensive and effective cancer treatment strategy that promises to improve treatment outcomes and reduce the adverse effects of therapy.

Fluorescence Lifetime Imaging Enables In vivo Quantification of PD-L1 Expression and Inter-tumoral Heterogeneity.

Patient selection for cancer immunotherapy requires precise, quantitative readouts of biomarker expression in intact tumors that can be reliably compared across multiple subjects over time. The current clinical standard biomarker for assessing immunotherapy response is programmed death-ligand-1 (PD-L1) expression, typically quantified using immunohistochemistry. This method, however, only provides snapshots of PD-L1 expression status in microscopic regions of ex vivo specimens. While various targeted probes have been investigated for in vivo imaging of PD-L1, non-specific probe accumulation within the tumor microenvironment (TME) has hindered accurate quantification, limiting the utility for preclinical and clinical studies. Here, we demonstrated that in vivo time-domain (TD) fluorescence imaging of an anti-PD-L1 antibody tagged with the near-infrared fluorophore IRDye 800CW (αPDL1-800) can yield quantitative estimates of baseline tumor PD-L1 heterogeneity across untreated mice, as well as variations in PD-L1 expression in mice undergoing clinically relevant anti-PD1 treatment. The fluorescence lifetime (FLT) of PD-L1 bound αPDL1-800 was significantly longer than the FLT of nonspecifically accumulated αPDL1-800 in the TME. This FLT contrast allowed quantification of PD-L1 expression across mice both in superficial breast tumors using planar FLT imaging and in deep-seated liver tumors (>5 mm depth) using the asymptotic TD algorithm for fluorescence tomography. These findings suggest that fluorescence lifetime imaging can accelerate the preclinical investigation and clinical translation of new immunotherapy treatments by enabling robust quantification of receptor expression across subjects.

Beta cell extracellular vesicle PD-L1 as a novel regulator of CD8+ T cell activity and biomarker during the evolution of type 1 diabetes.

Surviving beta cells in type 1 diabetes respond to inflammation by upregulating programmed death-ligand 1 (PD-L1) to engage immune cell programmed death protein 1 (PD-1) and limit destruction by self-reactive immune cells. Extracellular vesicles (EVs) and their cargo can serve as biomarkers of beta cell health and contribute to islet intercellular communication. We hypothesised that the inflammatory milieu of type 1 diabetes increases PD-L1 in beta cell EV cargo and that EV PD-L1 may protect beta cells against immune-mediated cell death. Beta cell lines and human islets were treated with proinflammatory cytokines to model the proinflammatory type 1 diabetes microenvironment. EVs were isolated using ultracentrifugation or size exclusion chromatography and analysed via immunoblot, flow cytometry and ELISA. EV PD-L1 binding to PD-1 was assessed using a competitive binding assay and in vitro functional assays testing the ability of EV PD-L1 to inhibit NOD CD8+ T cells. Plasma EV and soluble PD-L1 were assayed in the plasma of islet autoantibody-positive (Ab+) individuals or individuals with recent-onset type 1 diabetes and compared with levels in non-diabetic control individuals. PD-L1 protein co-localised with tetraspanin-associated proteins intracellularly and was detected on the surface of beta cell EVs. Treatment with IFN-α or IFN-γ for 24 h induced a twofold increase in EV PD-L1 cargo without a corresponding increase in the number of EVs. IFN exposure predominantly increased PD-L1 expression on the surface of beta cell EVs and beta cell EV PD-L1 showed a dose-dependent capacity to bind PD-1. Functional experiments demonstrated specific effects of beta cell EV PD-L1 to suppress proliferation and cytotoxicity of murine CD8+ T cells. Plasma EV PD-L1 levels were increased in Ab+individuals, particularly in those positive for a single autoantibody. Additionally, in Ab+ individuals or those who had type 1 diabetes, but not in control individuals, plasma EV PD-L1 positively correlated with circulating C-peptide, suggesting that higher EV PD-L1 could be protective for residual beta cell function. IFN exposure increases PD-L1 on the beta cell EV surface. Beta cell EV PD-L1 binds PD1 and inhibits CD8+ T cell proliferation and cytotoxicity. Circulating EV PD-L1 is higher in Ab+ individuals than in control individuals. Circulating EV PD-L1 levels correlate with residual C-peptide at different stages in type 1 diabetes progression. These findings suggest that EV PD-L1 could contribute to heterogeneity in type 1 diabetes progression and residual beta cell function and raise the possibility that EV PD-L1 could be exploited as a means to inhibit immune-mediated beta cell death.

Mechanism of the KIAA1429/KLF1/PD-L1 Axis in Regulating Immune Escape in Non-small Cell Lung Cancer.

Non-small cell lung cancer (NSCLC), accounting for approximately 80% of lung cancer cases, remains the leading cause of cancer-related mortality. Immune evasion is a critical challenge in NSCLC, contributing to poor treatment outcomes. This study investigates the role of KIAA1429 in immune evasion, aiming to identify novel therapeutic targets and provide a theoretical basis for NSCLC treatment. NSCLC cell lines were cultured to assess the expression of KIAA1429, KLF transcription factor (KLF1), and programmed cell death ligand 1 (PD-L1). Co-culture experiments were conducted with peripheral blood mononuclear cells (PBMCs) to evaluate cytotoxicity, CD8+T cell proportions, and levels of interferon-gamma (IFN-γ)/interleukin (IL)-10/IL-2. Additionally, N6-methyladenosine (m6A) modification in NSCLC cells, m6A enrichment on KLF1, and KLF1 mRNA stability were analyzed. Results showed increased expression of KIAA1429 and KLF1 in NSCLC cells. Knockdown of KIAA1429 inhibited NSCLC cell proliferation, enhanced PBMC cytotoxicity and CD8+T cell activation, increased IFN-γ and IL-2 levels, and decreased IL-10 levels. Mechanistically, KIAA1429 stabilized KLF1 mRNA level through m6A modification, promoting both KLF1 and PD-L1 expression. Overexpression of KLF1 or PD-L1 reversed the immune-modulating effects of KIAA1429 knockdown. In conclusion, KIAA1429 facilitates immune evasion in NSCLC by stabilizing KLF1 mRNA and upregulating PD-L1 expression.

The prognostic implications of podoplanin in cancer-associated fibroblasts and PD-L1 expression in high-grade neuroendocrine carcinoma of the lung.

Podoplanin (PDPN) expression in cancer-associated fibroblasts (CAFs) (CAF-PDPN) is considered a poor prognostic factor in nonsmall cell lung cancer, but little is known about its clinical significance in high-grade neuroendocrine carcinoma of the lung (HGNEC). This study examines the association between CAF-PDPN and stromal programmed death-ligand 1 (PD-L1) expression and the prognostic implications of CAF-PDPN and PD-L1 expression status in surgically resected HGNEC patients. Immunohistochemical analyses were performed on 121 resected HGNEC specimens using antibodies against PDPN and PD-L1. Correlations between CAF-PDPN, stromal PD-L1 expression, and clinicopathologic features and their implications for survival were analyzed statistically. There were substantially more large-cell neuroendocrine carcinomas in the stromal PD-L1-positive group and more vascular invasion in the tumoral PD-L1-positive group. PDPN expression in CAF was moderately correlated with stromal PD-L1 expression (ρ = 0.567, p < 0.001). In a survival analysis combining CAF-PDPN and stromal PD-L1 status, the 5-year RFS rates for Group A: CAF-PDPN (+)/stromal PD-L1 (+), Group B: CAF-PDPN (+)/stromal PD-L1 (-), Group C: CAF-PDPN (-)/stromal PD-L1 (+), and Group D: CAF-PDPN (-)/stromal PD-L1 (-) were 62.0%, 46.8%, 17.5%, and 20.2%, respectively, with corresponding 5-year OS rates of 76.6%, 69.2%, 27.0%, and 25.3%. The log-rank test showed statistically significant differences among the groups in RFS (p < 0.001) and OS (p < 0.001). There is a correlation between CAF-PDPN and tumoral/stromal PD-L1 expression, and positive status for either CAF-PDPN or stromal PD-L1 expression could be an independent favorable prognostic factor in surgically resected HGNEC patients.

PD-L1 (22C3) expression and prognostic implications in esophageal squamous cell carcinoma

Programmed cell death-ligand 1 (PD-L1) clone 22C3 is the only Food and Drug Administration-approved companion diagnostic test for pembrolizumab for the treatment of esophageal squamous cell carcinoma (ESCC). However, prior studies conducted in Asia and Europe have used various PD-L1 antibody clones other than 22C3. We aimed to study the expression profile of PD-L1, specifically of clone 22C3, in ESCC and its significance with regards to histological features, clinical parameters, and overall survival in a case series from two large US hospital systems. PD-L1 (22C3) immunohistochemistry was performed on 82 specimens obtained from 75 patients. Electronic medical records were reviewed to obtain the clinical and follow-up data. Of these specimens, 39 % (32/82) were negative for PD-L1 (22C3) expression (combined positive score (CPS) of 0). The remaining 50 specimens were positive, with CPSs ranging from 1 to 100. Treated specimens showed decreased PD-L1 (22C3) expression compared to untreated specimens. In the multivariate Cox proportional hazards regression model, PD-L1 (22C3) expression was shown to be a favorable prognostic factor for overall survival (p = 0.03, hazard ratio 0.16) only when the CPSs were ≥ 25, independent of surgery, definitive chemotherapy and/or radiotherapy, immunotherapy, and initial clinical stages. We performed a comprehensive study to investigate the expression profile of PD-L1 clone 22C3 in the US patients with ESCC. Our analysis showed that PD-L1 (22C3) expression decreased in treated specimens, and a CPS of ≥25 was associated with a favorable prognosis.

Clinical factors associated with high PD-L1 expression in patients with early-stage non-small cell lung cancer.

Superior outcomes have been obtained for neoadjuvant treatment with immune checkpoint inhibitors (ICI) plus chemotherapy over neoadjuvant chemotherapy alone, especially in patients with high programmed cell death ligand 1 (PD-L1) expression. However, it is not always possible to obtain sufficient tumor specimens for biomarker testing before surgery. In this study, we explored clinical factors that can predict high PD-L1 expression. We retrospectively enrolled 340 lung cancer patients who received pulmonary resection between 2014 and 2023 and who had PD-L1 expression data. Chi-squared tests and logistic regression analyses were used to identify clinical factors associated with high PD-L1 status. Univariable and multivariable analyses revealed that smoking, high maximum standardized uptake value (SUVmax) of 18F-fluorodeoxyglucose positron emission computed tomography (18F-FDG PET/CT), and high plasma fibrinogen are independent predictors of high PD-L1 expression. A predictive score for high PD-L1 expression (ranging from 0 to 3) was developed based on these parameters. Notably, only 5% of patients with a score of 0 exhibited high PD-L1 expression, whereas this proportion increased to 53% for patients with a score of 3. These results showed that plasma fibrinogen, smoking history, and SUVmax are predictors of high PD-L1 expression, providing a basis for identifying patients expected to benefit from neoadjuvant ICI treatment.

The role of PD-1/PD-L1 pathway in ulcerative colitis and changes following tonsil-derived mesenchymal stem cells treatment

Background/Aims: The programmed death 1 (PD-1)/programmed death-ligand 1 (PD-L1) pathway has not been fully evaluated in inflammatory bowel disease. We evaluated PD-1/PD-L1 levels in patients with ulcerative colitis (UC) and their significance in tonsil-derived mesenchymal stem cells (TMSCs) treatment.Methods: Using acute and chronic murine colitis model, we measured the PD-1 and PD-L1 levels in inflamed colonic tissues pre- and post-treatment with TMSCs. We also measured PD-1 and PD-L1 levels in colonic tissues from UC patients, compared to normal controls.Results: In the analysis using human colonic tissues, a significant increase in the levels of PD-1 and PD-L1 was observed in the colonic mucosa of patients with UC compared with normal controls (&lt;i&gt;p&lt;/i&gt; &lt; 0.001 and &lt;i&gt;p&lt;/i&gt; = 0.005, respectively). When comparing the maximal disease extent, PD-L1 levels were highest in patients with proctitis (38.5 ± 46.7), followed by left-side colitis (17.5 ± 23.1) and extensive colitis (5.2 ± 8.2) (&lt;i&gt;p&lt;/i&gt; &lt; 0.001). In the chronic colitis model, the level of PD-L1 was decreased (&lt;i&gt;p&lt;/i&gt; = 0.040) and the level of PD-1 increased more than in normal controls (&lt;i&gt;p&lt;/i&gt; = 0.047). After treatment with TMSC, significant improvements were observed in body weight, disease activity index, and colon length recovery. Additionally, the levels of PD-1 and PD-L1 were recovered; PD-L1 significantly increased (&lt;i&gt;p&lt;/i&gt; = 0.031), while the level of PD-1 decreased (&lt;i&gt;p&lt;/i&gt; = 0.310).Conclusions: The altered expression of PD-1 and PD-L1 in colonic mucosa may be a possible mechanism of UC, and T-MSC-derived PD-L1 could help suppress colitis.

Invasive Stratified Mucin-producing Carcinoma of the Uterine Cervix: Comparison of Its Clinicopathological Characteristics and Programmed Death-ligand 1 Expression Status With Those of Other Endocervical Adenocarcinomas.

Invasive stratified mucin-producing carcinoma (ISMC) is a rare but aggressive variant of endocervical adenocarcinoma (EAC). The aim of this study was to investigate the differences in clinicopathological features, patient outcomes, and programmed death-ligand 1 (PD-L1) expression among ISMC, usual-type EAC (UEA), and gastric-type EAC (GEA). PD-L1 22C3 immunostaining was performed using 20 ISMCs, 20 UEAs, and 20 GEAs. Combined positive score (CPS) method was used to assess PD-L1 immunoreactivity. ISMC was diagnosed at a younger age and showed a more advanced stage and shorter survival than UEA. The disease-free survival (DFS) and overall survival (OS) rates of ISMC patients were lower than those of UEA but comparable to those of GEA. ISMC type was an independent prognostic factor for predicting short DFS [hazard ratio (HR)=2.790, 95% confidence interval (CI)=1.153-6.756] and OS (HR=6.071, 95%CI=1.257-29.327). All ISMCs showed PD-L1 over-expression with a mean CPS of 44.5 (range=10-100), which was higher than those of UEA (mean CPS=8.2) and GEA (mean CPS=6.5). PD-L1 positivity (CPS≥1) was also an independent prognostic factor for worse OS (HR=2.472, 95%CI=1.097-5.570). Despite PD-L1 over-expression, ISMC patients treated with pembrolizumab showed no clinical response. All examined ISMCs over-expressed PD-L1. ISMC showed higher PD-L1 expression than UEA and GEA and worse survival than UEA. PD-L1 over-expression was found to be a significant predictor for worse DFS and OS in patients with ISMC. Our data suggest that PD-L1 over-expression is associated with poor ISMC prognosis.

Leveraging chemotherapy-induced PD-L1 upregulation to potentiate targeted PD-L1 degradation using nanoparticle-based targeting chimeras

The combination of nab-paclitaxel and the programmed death-ligand 1(PD-L1) antibody atezolizumab showed limited benefits in clinical trials involving PD-L1-positive triple-negative breast cancer patients. This observed lack of success is attributed to the upregulation of PD-L1 on tumor cells induced by paclitaxel, leading to resistance against PD-L1 antibodies. Here, we introduce nanoparticle-based PD-L1 targeting chimeras (NanoTACPD-L1) to induce PD-L1 degradation instead of blockade. NanoTACPD-L1 initiates endocytosis independent of specific lysosome-targeting receptors, and delivers membrane-bound PD-L1 to lysosomes for targeted degradation. Furthermore, the efficiency of degradation is directly correlated with the PD-L1 expression level. NanoTACPD-L1 effectively leverages paclitaxel-induced PD-L1 upregulation to enhance PD-L1 degradation, employing a “Meet-Plot-With-Plot” strategy. In a series of in vivo models, NanoTACPD-L1 demonstrates superior therapeutic efficacy and immune activation, both when administered individually and in combination with paclitaxel, surpassing the effects of anti-PD-L1 antibody treatment. Collectively, our study provides a nanotechnology-based tool that can be enhanced by paclitaxel for PD-L1 degradation and validates its potential application in overcoming chemo-immunotherapy resistance.

Simple Analysis Using Immunohistochemical Staining for Tumor-Infiltrating Lymphocytes in Brain Metastasis of Small Cell Lung Cancer

Background: We investigated the distribution of tumor-infiltrating lymphocytes (TILs) and the expression of programmed cell death-ligand 1 (PD-L1) in patients with brain metastasis (BM) from small cell lung cancer (SCLC). Methods: A retrospective analysis was performed on 12 surgical specimens of BMs from SCLC at our institute for 5 years. The Immunofluorescence-based Tissue Microenvironment Analysis Panel (MAP) was utilized for the detection of TILs, including CD3, CD8, PD-1, and PD-L1, in pathological archival specimens of BMs. The correlation between the overall survival (OS) and the above-mentioned markers was analyzed in the patients.Results: Positive rates of CD3+ TILs in the tumor parenchyma versus tumor stroma were 0.60±0.94% versus 1.76±2.72% (p=0.010), respectively; positive rates of CD8+ TILs in the tumor parenchyma versus tumor stroma were 0.80±0.78% versus 2.46±3.72% (p=0.016), respectively. There was no co-expression of CD8+ and PD-1+ TILs in the tumor parenchyma of 11 cases, and the infiltration density of co-expressed CD3+ and PD-1+ TILs was more than 10/mm2 in only 1 case. There was no co-expression of CD3+ and PD-1+ TIL in the stroma of 10 cases, and the infiltration density of CD8+ and PD-1+ TILs was more than 10/mm2 in 2 cases. Immunohistochemistry was used to detect the expression of PD-L1 in 12 cases of BMs, and 3 cases (25%) were positive. Survival analysis showed that patients with positive CD3+ TILs had significantly longer OS (p=0.040). Conclusions: The distribution of TILs in BM of SCLC is low and mainly distributed in the stroma, with the low expression of PD-L1 in the tumor tissues.

Avelumab reduces STAT3 expression with effects on IL-17RA and CD15.

Avelumab is a human antibody that targets the programmed cell death ligand-1 (PD-L1) protein in cancer cells. Novel anticancer therapies for renal cell carcinoma (RCC) consider cluster of differentiation 15 (CD15) and interleukin 17 receptor A (IL-17RA) as potential targets. Notably, the expression of PD-L1, CD15 and IL-17RA is dependent on signal transducer and activator of transcription 3 (STAT3). The aim of the study was to investigate whether targeting PD-L1 with avelumab alters the expression levels of CD15 and IL-17RA, and to assess the STAT3-mediated regulation of CD15 and IL-17RA. We applied immunocytochemistry (ICC) and confocal laser scanning (CLS) microscopy to assess the expression and localization of the immunotherapy targets in 3 renal cancer cell lines and 1 healthy renal cell line. After treatment with 20 ng/mL avelumab, renal cancer cells showed a reduction in STAT3 expression. The expression of CD15 increased in cancer cells that exhibited a high level of IL-17RA, and the membrane signal of CD15 was reduced. In other renal cancer cell lines, the expression of CD15 decreased. Conversely, the level of IL-17RA changed only in healthy renal cells after treatment with avelumab, with no impact on renal cancer cells. Our study suggests that the targeting of PD-L1 with avelumab alters the expression of CD15 and IL-17RA, which play an important prognostic and therapeutic role in novel anticancer therapy.

Non-invasive assessment of programmed cell death ligand-1 expression using 18F-FDG PET-CT imaging in esophageal squamous cell carcinoma

Programmed cell death ligand-1 (PD-L1) is an ideal checkpoint for immunohistochemical detection. The method of obtaining PD-L1 expression through biopsy can impact the accurate assessment of PD-L1 expression due to the spatial and temporal heterogeneity of tumors. Because of the limited sample size, biopsies often give only a localized picture of the tumor. In this retrospective study, a total of 2,386 metabolic tumor volume (MTV) features were extracted from 18F-FDG PET-CT images. A radiomics model was developed to holistically and non-invasively assess PD-L1 expression in patients with esophageal squamous cell carcinoma by identifying seven independent factors through feature screening. The radiomics model shows effective discrimination, with an area under the receiver operating characteristic curve of 0.888 [95% confidence interval (CI): 0.831–0.945] and 0.889 (95% CI: 0.706–1.000) for the training and validation cohorts, respectively. The results of the decision curve analysis demonstrated that utilizing the radiation model to forecast PD-L1 expression levels yielded more net benefits at threshold probabilities below 0.669. The clinical impact curves demonstrate that when the threshold probability is less than 0.501, the loss-to-benefit ratio is less than one in all cases.

PD-L1 Expression Varies in Thyroid Cancer Types and Is Associated with Decreased Progression Free Survival (PFS) in Patients with Anaplastic Thyroid Cancer.

Thyroid cancer (TC) remains a significant clinical challenge worldwide, with a subset of patients facing aggressive disease progression and therapeutic resistance. Immune checkpoint inhibitors targeting programmed death-ligand 1 (PD-L1) have emerged as promising therapeutic approaches for various malignancies, yet their efficacy in TC remains uncertain. The objective of this study was to investigate PD-L1 expression in aggressive TC and its association with histological subtypes, molecular mutation, and progression-free survival. This is a retrospective study of patients with advanced TC seen in two tertiary health care centers. Included in this study were patients with advanced TC with recurrence or progression on therapy for whom tumor molecular profiling and PD-L1 status were available. Kaplan-Meier estimators were utilized to analyze the progression-free survival (PFS) between patients with PD-L1 positive and negative status in Anaplastic TC (ATC) subgroup. A total of 176 patients with advanced thyroid cancer were included (48.9% female). Of the patients, 13 had ATC, 11 Medullary TC (MTC), 81 Papillary TC Classic Variant (PTCCV), 20 Follicular TC (FTC), 8 Oncocytic TC (OTC), 10 Poorly Differentiated TC (PDTC), and 30 had the Papillary TC Follicular Variant (PTCFV). BRAF mutation was present in 41%, TERT in 30%, RAS in 19%, TP53 in 10%, and RET in 8.6% of patients. PD-L1 positivity was significantly different across different TC types and histological subtypes (p < 0.01): Patients with OTC had the highest frequency of PD-L1 positivity (71%), followed by ATC (69%), PTCCV (28.5%), and FTC (11%). Patients with MTC and PTCFV did not exhibit any PD-L1 positivity. TP53 mutation was positively associated with PD-L1 expression (21.6% vs. 7.5%, p = 0.03), and RAS mutation was negatively associated with PD-L1 expression (8.1% vs. 24.2% p = 0.04). Among patients with ATC, positive PD-L1 expression was associated with lower PFS (p = 0.002). PD-L1 expression varies across different TC types and histological subtypes and may be modulated by the mutational landscape. PD-L1 expression in ATC is associated with shorter PFS. Follow up studies are warranted to elucidate the molecular mechanism driving the observed differences in immune pathways, potentially paving the way for the development of more effective and personalized immune therapies for patients with aggressive TC.