MDSC subtypes and CD39 expression on CD8+ T cells predict the efficacy of anti-PD-1 immunotherapy in patients with advanced NSCLC

Decoding the complex web: cellular and molecular interactions in the lung tumour microenvironment

The lung tumour microenvironment (TME) or stroma is a dynamic space of numerous cells and their released molecules. This complicated web regulates tumour progression and resistance to different modalities. Lung cancer cells in conjunction with their stroma liberate a wide range of factors that dampen antitumor attacks by innate immunity cells like natural killer (NK) cells and also adaptive responses by effector T cells. These factors include numerous growth factors, exosomes and epigenetic regulators, and also anti-inflammatory cytokines. Understanding the intricate interactions between tumour cells and various elements within the lung TME, such as immune and stromal cells can help provide novel strategies for better management and treatment of lung malignancies. The current article discusses the complex network of cells and signalling molecules, which mediate communications in lung TME. By elucidating these multifaceted interactions, we aim to provide insights into potential therapeutic targets and strategies for lung cancer treatment.

CD8+ T Cell Subsets as Biomarkers for Predicting Checkpoint Therapy Outcomes in Cancer Immunotherapy

The advent of immune checkpoint blockade (ICB) has transformed cancer immunotherapy, enabling remarkable long-term outcomes and improved survival, particularly with ICB combination treatments. However, clinical benefits remain confined to a subset of patients, and life-threatening immune-related adverse effects pose a significant challenge. This limited efficacy is attributed to cancer heterogeneity, which is mediated by ligand-receptor interactions, exosomes, secreted factors, and key transcription factors. Oncogenic regulators like E2F1 and MYC drive metastatic tumor environments and intertwine with immunoregulatory pathways, impairing T cell function and reducing immunotherapy effectiveness. To address these challenges, FDA-approved biomarkers, such as tumor mutational burden (TMB) and programmed cell death-ligand 1 (PD-L1) expression, help to identify patients most likely to benefit from ICB. Yet, current biomarkers have limitations, making treatment decisions difficult. Recently, T cells-the primary target of ICB-have emerged as promising biomarkers. This review explores the relationship between cancer drivers and immune response, and emphasizes the role of CD8+ T cells in predicting and monitoring ICB efficacy. Tumor-infiltrating CD8+ T cells correlate with positive clinical outcomes in many cancers, yet obtaining tumor tissue remains complex, limiting its practical use. Conversely, circulating T cell subsets are more accessible and have shown promise as predictive biomarkers. Specifically, memory and progenitor exhausted T cells are associated with favorable immunotherapy responses, while terminally exhausted T cells negatively correlate with ICB efficacy. Ultimately, combining biomarkers enhances predictive accuracy, as demonstrated by integrating TMB/PD-L1 expression with CD8+ T cell frequency. Computational models incorporating cancer and immune signatures could further refine patient stratification, advancing personalized immunotherapy.

Utilizing Nanoparticles to Overcome Anti-PD-1/PD-L1 Immunotherapy Resistance in Non-Small Cell Lung cancer: A Potential Strategy

Lung cancer is the leading cause of cancer-related mortality globally, with non-small cell lung cancer (NSCLC) constituting 85% of cases. Immune checkpoint inhibitors (ICIs) represented by anti-programmed cell death protein 1 (PD-1)/ programmed cell death ligand 1 (PD-L1) have emerged as a promising frontier in cancer treatment, effectively extending the survival of patients with NSCLC. However, the efficacy of ICIs exhibits significant variability across diverse patient populations, with a substantial proportion showing poor responsiveness and acquired resistance in those initially responsive to ICIs treatments. With the advancement of nanotechnology, nanoparticles offer unique advantages in tumor immunotherapy, including high permeability and prolonged retention(EPR) effects, enhanced drug delivery and stability, and modulation of the inflammatory tumor microenvironment(TME). This review summarizes the mechanisms of resistance to ICIs in NSCLC, focusing on tumor antigens loss and defective antigen processing and presentation, failure T cell priming, impaired T cell migration and infiltration, immunosuppressive TME, and genetic mutations. Furthermore, we discuss how nanoparticles, through their intrinsic properties such as the EPR effect, active targeting effect, shielding effect, self-regulatory effect, and synergistic effect, can potentiate the efficacy of ICIs and reverse resistance. In conclusion, nanoparticles serve as a robust platform for ICIs-based NSCLC therapy, aiding in overcoming resistance challenges.

Denosumab combined with immunotherapy, radiotherapy, and granulocyte-macrophage colony-stimulating factor for the treatment of metastatic nasopharyngeal carcinoma: A case report

BACKGROUND

Bone is a major site of metastasis in nasopharyngeal carcinoma (NPC). Recently, nuclear factor kappa-beta ligand (RANKL) inhibitors have garnered attention for their ability to inhibit osteoclast formation and bone resorption, as well as their potential to modulate immune functions and thereby enhance the efficacy of programmed cell death protein 1 (PD-1) inhibitor therapy.

CASE SUMMARY

We present a case of a patient with NPC who developed sternal stalk metastasis and multiple bone metastases with soft tissue invasion following radical chemoradiotherapy and targeted therapy. Prior to chemotherapy, the patient experienced severe bone marrow suppression and opted out of further chemotherapy sessions. However, the patient received combination therapy, including RANKL inhibitors (denosumab) alongside PD-1, radiotherapy, and granulocyte-macrophage colony-stimulating factor (PRaG) therapy (NCT05435768), and achieved 16 months of progression-free survival and more than 35 months of overall survival, without encountering any grade 2 or higher treatment-related adverse events.

CONCLUSION

Denosumab combined with PRaG therapy could be a new therapeutic approach for the second-line treatment in patients with bone metastases.

Monocyte-related markers as predictors of immune checkpoint inhibitor efficacy and immune-related adverse events: a systematic review and meta-analysis

The efficacy and off-target effects of immune checkpoint inhibitors (ICI) in cancer treatment vary among patients. Monocytes likely contribute to this heterogeneous response due to their crucial role in immune homeostasis. We conducted a systematic review and meta-analysis to evaluate the impact of monocytes on ICI efficacy and immune-related adverse events (irAEs) in patients with cancer. We systematically searched PubMed, Web of Science, and Embase for clinical studies from January 2000 to December 2023. Articles were included if they mentioned cancer, ICI, monocytes, or any monocyte-related terminology. Animal studies and studies where ICIs were combined with other biologics were excluded, except for studies where two ICIs were used. This systematic review was registered with PROSPERO (CRD42023396297) prior to data extraction and analysis. Monocyte-related markers, such as absolute monocyte count (AMC), monocyte/lymphocyte ratio (MLR), specific monocyte subpopulations, and m-MDSCs were assessed in relation to ICI efficacy and safety. Bayesian meta-analysis was conducted for AMC and MLR. The risk of bias assessment was done using the Cochrane-ROBINS-I tool. Out of 5787 studies identified in our search, 155 eligible studies report peripheral blood monocyte-related markers as predictors of response to ICI, and 32 of these studies describe irAEs. Overall, based on 63 studies, a high MLR was a prognostic biomarker for short progression-free survival (PFS) and overall survival (OS) hazard ratio (HR): 1.5 (95% CI: 1.21-1.88) and 1.52 (95% CI:1.13-2.08), respectively. The increased percentage of classical monocytes was an unfavorable predictor of survival, while low baseline rates of monocytic myeloid-derived suppressor cells (m-MDSCs) were favorable. Elevated intermediate monocyte frequencies were associated but not significantly correlated with the development of irAEs. Baseline monocyte phenotyping may serve as a composite biomarker of response to ICI; however, more data is needed regarding irAEs. Monocyte-related variables may aid in risk assessment and treatment decision strategies for patients receiving ICI in terms of both efficacy and safety.

Resistance mechanisms to immune checkpoint inhibitors: updated insights

The last decade has witnessed unprecedented succusses with the use of immune checkpoint inhibitors in treating cancer. Nevertheless, the proportion of patients who respond favorably to the treatment remained rather modest, partially due to treatment resistance. This has fueled a wave of research into potential mechanisms of resistance to immune checkpoint inhibitors which can be classified into primary resistance or acquired resistance after an initial response. In the current review, we summarize what is known so far about the mechanisms of resistance in terms of being tumor-intrinsic or tumor-extrinsic taking into account the multimodal crosstalk between the tumor, immune system compartment and other host-related factors.

Prognostic Significance of PD-L1 Expression on Circulating Myeloid-Derived Suppressor Cells in NSCLC Patients Treated with Anti-PD-1/PD-L1 Checkpoint Inhibitors

Even though anti-PD-1/PD-L1 immune checkpoint inhibitors (ICIs) in non-small cell lung cancer (NSCLC) have improved survival, a high percentage of patients still do not respond to ICIs. Myeloid-derived suppressor cells (MDSCs) are circulating cells that express PD-L1 and can infiltrate and proliferate in the tumor microenvironment, inducing immunosuppression. By evaluating changes in PD-L1 expression of live peripheral blood MDSCs, we are able to define a new PD-L1 index, useful in predicting ICI escape in NSCLC patients before initiating anti-PD-1/PD-L1 immunotherapy. In this study, a cohort of 37 NSCLC patients was prospectively analyzed, obtaining independent PD-L1 indexes. In patients with a PD-L1 index > 5.88, progressive disease occurred in 58.33% of patients [median progression-free survival (PFS) = 5.73 months; 95%CI = 2.67-20.53], showing significant differences when compared with patients with a PD-L1 index ≤ 5.88, in whom 7.69% progressed and median PFS was not reached (NR); p-value = 0.0042. Overall survival (OS) was significantly worse in patients with a high vs. low PD-L1 index (41.67% vs. 76.92%; median OS = 18.03 months, 95%CI = 6.77-25.23 vs. NR, 95%CI = 1.87-NR; p-value = 0.035). The PD-L1 index can be applied to stratify NSCLC patients according to their probability of response to ICIs at baseline. In addition to quantifying tumoral expression, this index could be used to compare nonresponse to treatment.

New insights into non-small cell lung cancer bone metastasis: mechanisms and therapies

Bone metastasis is a common cause of death in patients with non-small cell lung cancer (NSCLC), with approximately 30-40% of NSCLC patients eventually developing bone metastases. Bone metastasis, especially the occurrence of skeletal-related events (SREs), significantly reduces overall survival (OS) and quality of life (QoL) in patients. Although bone-targeting agents (BTAs) have been shown to reduce SREs and improve QoL in NSCLC patients with bone metastases, the prognosis for these patients remains poor. Understanding the underlying molecular pathways of bone metastasis is crucial for the development of novel therapeutic approaches. Bone metastasis is a complex, multistep process that involves interactions between tumor cells and the bone microenvironment. The bone microenvironment provides a fertile soil for tumor cells, and crosstalk among various signaling pathways and secreted factors also plays a role in regulating the occurrence and progression of bone metastasis in NSCLC. In this article, we provide a comprehensive review of the process, regulatory mechanisms, and clinical treatment in NSCLC bone metastasis, with the hope of assisting with clinical treatment.

Impact of senescence cell signature in patients with non-small cell carcinoma and melanoma receiving PD-L1/PD-1 inhibitors

Tumor cell senescence plays a crucial role in tumor immunity. We investigated whether the senescent cell signature (SCS) could predict prognosis in non-small cell carcinoma (NSCLC) and melanoma datasets treated with PD-L1/PD-1 inhibitors. Patients with high SCS expression exhibited elevated levels of interferon-gamma and T cell-inflamed signatures in three lung adenocarcinomas (LUAD), two squamous cell carcinoma (LUSC) and three melanoma datasets. The high SCS group was associated with PD-L1-related pathways such as IL6/JAK/STAT3 and TNF-alpha signaling via NF-kB in LUAD, LUSC, and melanoma datasets. A positive correlation was observed between several immune checkpoint markers and the SCS, indicating an immunosuppressive state in LUAD, LUSC and melanoma datasets. In patients treated with PD-1/PD-L1 inhibitors, a higher SCS was associated with a better prognosis, and a positive correlation between SCS and PD-L1 was observed in six independent NSCLC and three independent melanoma datasets. We used the LASSO Cox regression model to build a risk model focusing on the SCS genes that particularly predict prognosis. We confirmed that the model accurately predicts prognosis. However, the senescent immunohistochemical markers p16 and p21 could predict the response to PD-1/PD-L1 inhibitors in patients with LUSC and melanoma but not in patients with LUAD. SCS could serve as a valuable biomarker to complement PD-L1 expression in patients receiving PD-L1/PD-1 inhibitors.

CD8+ T cell exhaustion and its regulatory mechanisms in the tumor microenvironment: key to the success of immunotherapy

A steady dysfunctional state caused by chronic antigen stimulation in the tumor microenvironment (TME) is known as CD8+ T cell exhaustion. Exhausted-like CD8+ T cells (CD8+ Tex) displayed decreased effector and proliferative capabilities, elevated co-inhibitory receptor generation, decreased cytotoxicity, and changes in metabolism and transcription. TME induces T cell exhaustion through long-term antigen stimulation, upregulation of immune checkpoints, recruitment of immunosuppressive cells, and secretion of immunosuppressive cytokines. CD8+ Tex may be both the reflection of cancer progression and the reason for poor cancer control. The successful outcome of the current cancer immunotherapies, which include immune checkpoint blockade and adoptive cell treatment, depends on CD8+ Tex. In this review, we are interested in the intercellular signaling network of immune cells interacting with CD8+ Tex. These findings provide a unique and detailed perspective, which is helpful in changing this completely unpopular state of hypofunction and intensifying the effect of immunotherapy.

Impact of Microparticle Transarterial Chemoembolization (mTACE) on myeloid-derived suppressor cell subtypes in hepatocellular carcinoma: Clinical correlations and therapeutic implications

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) play a pivotal role in immunosuppression and tumor progression in hepatocellular carcinoma (HCC). While various treatments like surgical resection, ablation, and radiotherapy have been studied for their effects on circulating MDSC frequencies in HCC patients, the findings remain inconclusive. Transarterial Chemoembolization (TACE) stands as the standard care for unresectable HCC, with Microparticle TACE (mTACE) gaining prominence for its capacity to induce significant tumor necrosis. However, the immunological ramifications of such pathological outcomes are scarcely reported.

METHODS AND RESULTS

This study aims to elucidate the alterations in MDSC subtypes, specifically monocytic MDSCs (mMDSCs) and early-stage MDSCs (eMDSCs), post-mTACE and to investigate their clinical correlations in HCC patients. A cohort comprising 75 HCC patients, 16 liver cirrhosis patients, and 20 healthy controls (HC) was studied. Peripheral blood samples were collected and analyzed for MDSC subtypes. The study also explored the associations between MDSC frequencies and various clinical parameters in HCC patients. The frequency of mMDSCs was significantly elevated in the HCC group compared to liver cirrhosis and HC. Importantly, mMDSC levels were strongly correlated with aggressive clinical features of HCC, including tumor size, vascular invasion, and distant metastasis. Post-mTACE, a marked reduction in mMDSC frequencies was observed, while eMDSC levels remained stable.

CONCLUSIONS

Our findings underscore the critical role of mMDSCs in HCC pathogenesis and their potential as a therapeutic target. The study also highlights the efficacy of mTACE in modulating the immunosuppressive tumor microenvironment, thereby opening new avenues for combinatorial immunotherapeutic strategies in HCC management.

Peripheral immune biomarkers for immune checkpoint inhibition of solid tumours

BACKGROUND

With the rapid adoption of immunotherapy for the treatment of cancer comes the pressing need for readily accessible biomarkers to guide immunotherapeutic strategies and offer insights into outcomes with specific treatments. Regular sampling of solid tumour tissues outside of melanoma for immune monitoring is not often feasible; conversely, routine, frequent interrogation of circulating immune biomarkers is entirely possible. As immunotherapies and immune checkpoint inhibitors, in particular, are more widely used in first-line, neoadjuvant, and metastatic settings, the discovery and validation of peripheral immune biomarkers are urgently needed across solid tumour types for improved prediction and prognostication of clinical outcomes in response to immunotherapy, as well as elucidation of mechanistic underpinnings of the intervention. Careful experimental design, encompassing both retrospective and prospective studies, is required in such biomarker identification studies, and concerted efforts are essential for their advancement into clinical settings.

CONCLUSION

In this review, we summarize shared immune features between the tumour microenvironment and systemic circulation, evaluate exploratory peripheral immune biomarker studies, and discuss associations between candidate biomarkers with clinical outcomes. We also consider integration of multiple peripheral immune parameters for better prediction and prognostication and discuss considerations in study design to further evaluate the clinical utility of candidate peripheral immune biomarkers for immunotherapy of solid tumours.

HIGHLIGHTS

Peripheral immune biomarkers are critical for improved prediction and prognostication of clinical outcomes for patients with solid tumours treated with immune checkpoint inhibition. Candidate peripheral biomarkers, such as cytokines, soluble factors, and immune cells, have potential as biomarkers to guide immunotherapy of solid tumours. Multiple peripheral immune parameters may be integrated to improve prediction and prognostication. The potential of peripheral immune biomarkers to guide immunotherapy of solid tumours requires critical work in biomarker discovery, validation, and standardization.

What's new about the tumor microenvironment of urothelial carcinoma?

Urothelial carcinoma is a significant global health concern that accounts for a substantial part of cancer diagnoses and deaths worldwide. The tumor microenvironment is a complex ecosystem composed of stromal cells, soluble factors, and altered extracellular matrix, that mutually interact in a highly immunomodulated environment, with a prominent role in tumor development, progression, and treatment resistance. This article reviews the current state of knowledge of the different cell populations that compose the tumor microenvironment of urothelial carcinoma, its main functions, and distinct interactions with other cellular and non-cellular components, molecular alterations and aberrant signaling pathways already identified. It also focuses on the clinical implications of these findings, and its potential to translate into improved quality of life and overall survival. Determining new targets or defining prognostic signatures for urothelial carcinoma is an ongoing challenge that could be accelerated through a deeper understanding of the tumor microenvironment.

Myeloid-derived suppressor cells in peripheral blood as predictive biomarkers in patients with solid tumors undergoing immune checkpoint therapy: systematic review and meta-analysis

Background

Immunotherapeutic approaches, including immune checkpoint inhibitor (ICI) therapy, are increasingly recognized for their potential. Despite notable successes, patient responses to these treatments vary significantly. The absence of reliable predictive and prognostic biomarkers hampers the ability to foresee outcomes. This meta-analysis aims to evaluate the predictive significance of circulating myeloid-derived suppressor cells (MDSC) in patients with solid tumors undergoing ICI therapy, focusing on progression-free survival (PFS) and overall survival (OS).

Methods

A comprehensive literature search was performed across PubMed and EMBASE from January 2007 to November 2023, utilizing keywords related to MDSC and ICI. We extracted hazard ratios (HRs) and 95% confidence intervals (CIs) directly from the publications or calculated them based on the reported data. A hazard ratio greater than 1 indicated a beneficial effect of low MDSC levels. We assessed heterogeneity and effect size through subgroup analyses.

Results

Our search yielded 4,023 articles, of which 17 studies involving 1,035 patients were included. The analysis revealed that patients with lower levels of circulating MDSC experienced significantly improved OS (HR=2.13 [95% CI 1.51-2.99]) and PFS (HR=1.87 [95% CI 1.29-2.72]) in response to ICI therapy. Notably, heterogeneity across these outcomes was primarily attributed to differences in polymorphonuclear MDSC (PMN-MDSC) subpopulations and varying cutoff methodologies used in the studies. The monocytic MDSC (M-MDSC) subpopulation emerged as a consistent and significant prognostic marker across various subgroup analyses, including ethnicity, tumor type, ICI target, sample size, and cutoff methodology.

Conclusions

Our findings suggest that standardized assessment of MDSC, particularly M-MDSC, should be integral to ICI therapy strategies. These cells hold the promise of identifying patients at risk of poor response to ICI therapy, enabling tailored treatment approaches. Further research focusing on the standardization of markers and validation of cutoff methods is crucial for integrating MDSC into clinical practice.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023420095, identifier CRD42023420095.

Regulatory role of CD39 and CD73 in tumor immunity

CD39 is the rate-limiting enzyme for the molecular signal cascade leading to the generation of ADP and adenosine monophosphate (AMP). In conjunction with CD73, CD39 converts adenosine triphosphate (ATP) to ADP and AMP, which leads to the accumulation of immunosuppressive adenosine in the tumor microenvironment. This review focuses on the role of CD39 and CD73 in immune response and malignant progression, including the expression of CD39 within the tumor microenvironment and its relationship to immune effector cells, and its role in antigen presentation. The role of CD39- and CD73-targeting therapeutics and cancer-directed clinical trials investigating CD39 modulation are also explored.

CD137+ and regulatory T cells as independent prognostic factors of survival in advanced non-oncogene addicted NSCLC patients treated with immunotherapy as first-line

BACKGROUND

Immune checkpoint inhibitors (ICIs), administered alone or combined with chemotherapy, are the standard of care in advanced non-oncogene addicted Non-Small Cell Lung Cancer (NSCLC). Despite these treatments' success, most long-term survival benefit is restricted to approximately 20% of patients, highlighting the need to identify novel biomarkers to optimize treatment strategies. In several solid tumors, immune soluble factors, the activatory CD137+ Tcells, and the immunosuppressive cell subsets Tregs and MDSCs (PMN(Lox1+)-MDSC and M-MDSCs) correlated with responses to ICIs and clinical outcomes thus becoming appealing predictive and prognostic factors. This study investigated the role of distinct CD137+ Tcell subsets, Tregs, MDSCs, and immune-soluble factors in NSCLC patients as possible biomarkers.

METHODS

The levels of T cells, MDSCs and soluble factors were evaluated in 89 metastatic NSCLC patients who underwent ICIs as first- or second-line treatment. T cell analysis was performed by cytoflurimetry evaluating Tregs and different CD137+ Tcell subsets also combined with CD3+, CD8+, PD1+, and Ki67+ markers. Circulating cytokines and immune checkpoints were also evaluated by Luminex analysis. All these parameters were correlated with several clinical factors (age, sex, smoking status, PS and TPS), response to therapy, PFS , and OS . The analyses were conducted in the overall population and in patients treated with ICIs as first-line (naïve patients).

RESULTS

In both groups of patients, high levels of circulating CD137+ and CD137+PD1+ T cells (total, CD4 and CD8) and the soluble factor LAG3 positively correlated with response to therapy. In naïve patients, PMN(Lox1+)-MDSCs negatively correlated with clinical response, and a high percentage of Tregs was associated with favorable survival. Moreover, the balance between Treg/CD137+ Tcells or PMN(Lox1+)-MDSC/CD137+ Tcells was higher in non-responding patients and was associated with poor survival. CD137+ Tcells and Tregs resulted as two positive independent prognostic factors.

CONCLUSION

High levels of CD137+, CD137+PD1+ Tcells and sLAG3 could predict the response to ICIs in NSCLC patients independently by previous therapy. Combining the evaluation of CD137+ Tcells and Tregs also as Treg/CD137+ T cells ratio it is possible to identify naive patients with longer survival.

Landscape of adenosine pathway and immune checkpoint dual blockade in NSCLC: progress in basic research and clinical application

Lung cancer poses a global threat to human health, while common cancer treatments (chemotherapy and targeted therapies) have limited efficacy. Immunotherapy offers hope of sustained remission for many patients with lung cancer, but a significant proportion of patients fail to respond to treatment owing to immune resistance. There is extensive evidence to suggest the immunosuppressive microenvironment as the cause of this treatment failure. Numerous studies have suggested that the adenosine (ADO) pathway plays an important role in the formation of an immunosuppressive microenvironment and may be a key factor in the development of immune resistance in EGFR-mutant cell lung cancer. Inhibition of this pathway may therefore be a potential target to achieve effective reversal of ADO pathway-mediated immune resistance. Recently, an increasing number of clinical trials have begun to address the broad prospects of using the ADO pathway as an immunotherapeutic strategy. However, few researchers have summarized the theoretical basis and clinical rationale of the ADO pathway and immune checkpoint dual blockade in a systematic and detailed manner, particularly in lung cancer. As such, a timely review of the potential value of the ADO pathway in combination with immunotherapy strategies for lung cancer is warranted. This comprehensive review first describes the role of ADO in the formation of a lung tumor-induced immunosuppressive microenvironment, discusses the key mechanisms of ADO inhibitors in reversing lung immunosuppression, and highlights recent evidence from preclinical and clinical studies of ADO inhibitors combined with immune checkpoint blockers to improve the lung cancer immunosuppressive microenvironment.

Functional Flow Cytometry to Predict PD-L1 Conformational Changes

The programmed cell death protein 1/programmed cell death protein ligand 1 (PD-1/PD-L1) axis is one of the most widely recognized targets for cancer immunotherapy. Importantly, PD-L1 conformational changes can hinder target binding when living cells are used. Antibody affinity, equilibrium binding, association and dissociation rates, and other affinity-related constants are fundamental to ensure target saturation. Here, PD-L1 changes in conformation and their potential impact on PD-L1 function and mutation are explored. Specifically, we present detailed flow cytometry procedures to analyze PD-L1 reactivity in myeloid-derived suppressor cells (MDSCs). This approach can also be used to study the contribution of protein conformational changes in living cells. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Sample preparation for PD-L1+ myeloid-derived suppressor cells detection by flow cytometry Basic Protocol 2: Protocol preparation, sample acquisition, and gating strategy for flow cytometric screening of PD-L1+ myeloid-derived suppressor cells in patients with lung cancer Support Protocol 1: Bioinformatic tools for the analysis of flow cytometric data.

A novel CD47-blocking peptide fused to pro-apoptotic KLA repeat inhibits lung cancer growth in mice

CD47 is highly expressed in many tumor tissues and induces immune evasion by interaction with SIRP-alpha (signal regulatory protein-alpha) expressed on tumor-associated macrophages. In this study, we identified a novel CD47-blocking peptide VK17 by phage display technique. A pro-apoptotic VK30 peptide was obtained after VK17 was fused to KLA amino acid repeat at C-termini. The VK30 was specifically bound to CD47 on lung cancer cells, and subsequently inducing lung cancer cell apoptosis. Meanwhile, the expression of Bax was increased, whereas the expression of Bcl-2 and Ki-67 were reduced in the VK30-treated lung cancer cells. In addition, VK30 effectively improved the phagocytic activity of macrophages against VK30-pretreated lung cancer cells. Combinational treatment of lung cancer cells with blocking antibody anti-CD47 and VK30 additively enhanced VK30 binding to CD47, subsequently increasing lung cancer cell apoptosis and macrophage phagocytosis. Intraperitoneal administration of 2 mg/kg VK30 induced effective trafficking of VK30 into tumor tissues, and suppressing lung cancer cell growth in mice, associated with increased tumor cell apoptosis, macrophage activation and phagocytosis in vivo. The expression of CD47 was reduced in the VK30-treated tumor tissues and the expression level was positively correlated to tumor size. In addition, VK30 reduced the infiltration of CD11b+Ly6G+ neutrophils and CD11b+Ly6C+Ly6G+ granulocytic myeloid-derived suppressor cells (Gr-MDSCs) in tumor tissues, associated with suppressed expression of tumorigenic IL-6 and TNF-alpha from these cell types. Thereby, VK30 exerted anti-tumor effects in mice through inducing tumor cell apoptosis and macrophage phagocytosis. VK30 would be a novel therapeutic peptide in lung cancer immunotherapy.

Circulating low density neutrophils are associated with resistance to anti-PD1 immunotherapy in squamous head and neck cancer

BACKGROUND

Identification of predictive biomarkers to Immune checkpoint inhibitors (ICIs) in head and neck cancer (HNSCC) is an unmet need.

METHODS

This was a prospective observational study including 25 patients with HNSCC treated with immunotherapy or chemotherapy after a prior platinum-based regimen. Low density neutrophils (LDNs) and serum markers were analyzed.

RESULTS

In the immunotherapy cohort, patients with high LDN levels had a shorter progression free survival (PFS) (1.8 months vs. 10.9 months; *p = 0.034). Also, progressors showed higher percentage of LDNs compared to non-progressors although significance was not reached (mean 20.68% vs. 4.095%, p = 0.0875). These findings were not replicated in patients treated with chemotherapy. High levels of interleukin-7 (IL7) were correlated with a significantly longer overall survival (OS) (13.47 months 3.51 vs. months, *p = 0.013).

CONCLUSIONS

High baseline circulating LDNs and low IL7 could identify a subset of patients intrinsically refractory to ICIs as monotherapy in HNSCC.

Immunotherapy-related biomarkers: Confirmations and uncertainties

Immunotherapy profoundly changed oncology treatment, becoming one of the main therapeutical strategies. Remarkable improvement has been achieved in survival outcomes, but the percentage of patients who benefit from immunotherapy is still limited. Only one-third of patients receiving immune checkpoint inhibitors (ICIs) achieve long-term response. Several patients are not responsive to treatment or relapse after an initial response. To date, programmed death-ligand 1, microsatellite instability, and tumor mutational burden are the three biomarkers validated to predict the ICIs response, but a single variable seems still insufficient in the patient's selection. Considering the substantial and increasing use of these drugs, the identification of new predictive biomarkers of ICI response is of paramount importance. We summarize the state of the art and the clinical use of immune biomarkers in oncology, highlighting the strength and weaknesses of currently approved biomarkers, describing the emerging tissues and circulating biomarkers, and outlining future perspectives.

Plasmacytoid Dendritic Cell, Slan+-Monocyte and Natural Killer Cell Counts Function as Blood Cell-Based Biomarkers for Predicting Responses to Immune Checkpoint Inhibitor Monotherapy in Non-Small Cell Lung Cancer Patients

The advent of immune checkpoint inhibitors (ICIs), for instance, programmed cell death 1 (PD-1)/PD-1 ligand 1 (PD-L1) blockers, has greatly improved the outcome of patients affected by non-small cell lung cancer (NSCLC). However, most NSCLC patients either do not respond to ICI monotherapy or develop resistance to it after an initial response. Therefore, the identification of biomarkers for predicting the response of patients to ICI monotherapy represents an urgent issue. Great efforts are currently dedicated toward identifying blood-based biomarkers to predict responses to ICI monotherapy. In this study, more commonly utilized blood-based biomarkers, such as the neutrophil-to-lymphocyte ratio (NLR) and the lung immune prognostic index (LIPI) score, as well as the frequency/number and activation status of various types of circulating innate immune cell populations, were evaluated in NSCLC patients at baseline before therapy initiation. The data indicated that, among all the parameters tested, low plasmacytoid dendritic cell (pDC), slan+-monocyte and natural killer cell counts, as well as a high LIPI score and elevated PD-L1 expression levels on type 1 conventional DCs (cDC1s), were independently correlated with a negative response to ICI therapy in NSCLC patients. The results from this study suggest that the evaluation of innate immune cell numbers and phenotypes may provide novel and promising predictive biomarkers for ICI monotherapy in NSCLC patients.

Regulation of T cells by myeloid-derived suppressor cells: emerging immunosuppressor in lung cancer

Myeloid-derived suppressor cells (MDSCs), major components maintaining the immune suppressive microenvironment in lung cancer, are relevant to the invasion, metastasis, and poor prognosis of lung cancer, through the regulation of epithelial-mesenchymal transition, remodeling of the immune microenvironment, and regulation of angiogenesis. MDSCs regulate T-cell immune functions by maintaining a strong immunosuppressive microenvironment and promoting tumor invasion. This raises the question of whether reversing the immunosuppressive effect of MDSCs on T cells can improve lung cancer treatment. To understand this further, this review explores the interactions and specific mechanisms of different MDSCs subsets, including regulatory T cells, T helper cells, CD8 + T cells, natural killer T cells, and exhausted T cells, as part of the lung cancer immune microenvironment. Second, it focuses on the guiding significance confirmed via clinical liquid biopsy and tissue biopsy that different MDSC subsets improve the prognosis of lung cancer. Finally, we conclude that targeting MDSCs through action targets or signaling pathways can help regulate T-cell immune functions and suppress T-cell exhaustion. In addition, immune checkpoint inhibitors targeting MDSCs may serve as a new approach for enhancing the efficiency of immunotherapy and targeted therapy for lung cancer in the future, providing better comprehensive options for lung cancer treatment.

The Tian-Men-Dong decoction suppresses the tumour-infiltrating G-MDSCs via IL-1β-mediated signalling in lung cancer

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese medicine (TCM) Tian-Men-Dong decoction (TD) has been able to effectively treat lung cancer in China for thousands of years. TD improves the quality of life in lung cancer patients by promoting nourishment of yin and reducing dryness, clearing the lung and removing toxins. Pharmacological studies show that TD contains active antitumour ingredients, but its underlying mechanism remains unknown.

AIM OF THE STUDY

This study aims at exploring potential mechanisms of TD in the treatment of lung cancer by regulating granulocytic-myeloid-derived suppressor cells (G-MDSCs).

MATERIALS AND METHODS

An orthotopic lung cancer mouse model was generated by intrapulmonary injection with LLC-luciferase cells in immunocompetent C57BL/6 mice or immunodeficient nude mice. TD/saline was orally administered once to the model mice daily for 4 weeks. Live imaging was conducted to monitor tumour growth. Immune profiles were detected by flow cytometry. H&E and ELISA were applied to test the cytotoxicity of the TD treatment. RT-qPCR and western blotting were performed to detect apoptosis-related proteins in G-MDSCs. A neutralizing antibody (anti-Ly6G) was utilized to exhaust the G-MDSCs via intraperitoneal injection. G-MDSCs were adoptively transferred from wild-type tumour-bearing mice. Immunofluorescence, TUNEL and Annexin V/PI staining were conducted to analyse apoptosis-related markers. A coculture assay of purified MDSCs and T cells labelled with CFSE was performed to test the immunosuppressive activity of MDSCs. The presence of TD/IL-1β/TD + IL-1β in purified G-MDSCs cocultured with the LLC system was used for ex vivo experiments to detect IL-1β-mediated apoptosis of G-MDSCs.

RESULTS

TD prolonged the survival of immune competent C57BL/6 mice in an orthotopic lung cancer model, but did not have the same effect in immunodeficient nude mice, indicating that its antitumour properties of TD are exerted by regulating immunity. TD induced G-MDSC apoptosis via the IL-1β-mediated NF-κB signalling cascade leading to effectively weaken the immunosuppressive activity of G-MDSCs and promote CD8⁺ T-cell infiltration, which was supported by both the depletion and adoptive transfer of G-MDSCs assays. In addition, TD also showed minimal cytotoxicity both in vivo and in vitro.

CONCLUSION

This study reveals for the first time that TD, a classic TCM prescription, is able to regulate G-MDSC activity and trigger its apoptosis via the IL-1β-mediated NF-κB signalling pathway, reshaping the tumour microenvironment and demonstrating antitumour effects. These findings provide a scientific foundation the clinical treatment of lung cancer with TD.

The progresses of relevant factors on the efficacy of immune checkpoint inhibitors in the non-small cell lung cancer patients

Lung cancer has the highest mortality rate of all cancers worldwide. Although immune checkpoint inhibitor (ICI)-based therapy can improve the survival of patients with lung cancer, its efficacy is affected by many factors. Therefore, it is necessary to identify factors that affect the efficacy of ICI-based treatment and establish a model for predicting drug response and resistance before and during treatment for individualized and accurate treatment of patients. This review summarizes the clinical and biological factors related to ICI-based treatment of non-small cell lung cancer (NSCLC) and the recent research progress of predictive models for assessing ICI efficacy.

Monocyte subsets associated with the efficacy of anti‑PD‑1 antibody monotherapy

Immune checkpoint inhibitors (ICIs) are among the most notable advances in cancer immunotherapy; however, reliable biomarkers for the efficacy of ICIs are yet to be reported. Programmed death (PD)-ligand 1 (L1)-expressing CD14+ monocytes are associated with shorter overall survival (OS) time in patients with cancer treated with anti-PD-1 antibodies. The present study focused on the classification of monocytes into three subsets: Classical, intermediate and non-classical. A total of 44 patients with different types of cancer treated with anti-PD-1 monotherapy (pembrolizumab or nivolumab) were enrolled in the present study. The percentage of each monocyte subset was investigated, and the percentage of cells expressing PD-L1 or PD-1 within each of the three subsets was further analyzed. Higher pretreatment classical monocyte percentages were correlated with shorter OS (r=-0.32; P=0.032), whereas higher non-classical monocyte percentages were correlated with a favorable OS (r=0.39; P=0.0083). PD-L1-expressing classical monocytes accounted for a higher percentage of the total monocytes than non-classical monocytes with PD-L1 expression. In patients with non-small cell lung cancer (NSCLC), a higher percentage of PD-L1-expressing classical monocytes was correlated with shorter OS (r=-0.60; P=0.012), which is similar to the observation for the whole patient cohort. Comparatively, higher percentages of non-classical monocytes expressing PD-L1 were significantly associated with better OS, especially in patients with NSCLC (r=0.60; P=0.010). Moreover, a higher percentage of non-classical monocytes contributed to prolonged progression-free survival in patients with NSCLC (r=0.50; P=0.042), with similar results for PD-L1-expressing non-classical monocytes. The results suggested that the percentage of monocyte subsets in patients with cancer before anti-PD-1 monotherapy may predict the treatment efficacy and prognosis. Furthermore, more classical monocytes and fewer non-classical monocytes, especially those expressing PD-L1, are involved in shortening OS time, which may indicate the poor efficiency of anti-PD-1 treatment approaches.

The prognostic effects of circulating myeloid-derived suppressor cells in non-small cell lung cancer: systematic review and meta-analysis

Immunotherapy is the main standard treatment for non-small cell lung cancer (NSCLC) patients. Immune suppressive cells in tumor microenvironment can counteract its efficacy. Myeloid-derived suppressor cells (MDSCs) include two major subsets: polymorphonuclear (PMN-MDSCs) and monocytic (M-MDSCs). Many studies explored the prognostic impact of these cell populations in NSCLC patients. The aim of this systematic review is to select studies for a meta-analysis, which compares prognosis between patients with high vs low circulating MDSC levels. We collected hazard ratios (HRs) and relative 95% confidence intervals (CIs) in terms of progression-free survival (PFS) or recurrence-free survival (RFS), and overall survival (OS). Among 139 studies retrieved from literature search, 14 eligible studies (905 NSCLC patients) met inclusion criteria. Low circulating MDSC levels favor a better PFS/RFS (HR = 1.84; 95% CI = 1.28-2.65) and OS (HR = 1.78; 95% CI = 1.29-2.46). The subgroup analysis based on MDSC subtypes (total-, PMN-, and M-MDSCs) obtained a statistical significance only for M-MDSCs, both in terms of PFS/RFS (HR = 2.67; 95% CI = 2.04-3.50) and OS (HR = 2.10; 95% CI = 1.61-2.75). NSCLC patients bearing high M-MDSC levels in peripheral blood experience a worse prognosis than those with low levels, both in terms of PFS/RFS and OS. This finding suggests that detecting and targeting this MDSC subset could help to improve NSCLC treatment efficacy.

Immune Checkpoint Inhibitors in "Special" NSCLC Populations: A Viable Approach?

Over the last decade, the therapeutic scenario for advanced non-small-cell lung cancer (NSCLC) has undergone a major paradigm shift. Immune checkpoint inhibitors (ICIs) have shown a meaningful clinical and survival improvement in different settings of the disease. However, the real benefit of this therapeutic approach remains controversial in selected NSCLC subsets, such as those of the elderly with active brain metastases or oncogene-addicted mutations. This is mainly due to the exclusion or underrepresentation of these patient subpopulations in most pivotal phase III studies; this precludes the generalization of ICI efficacy in this context. Moreover, no predictive biomarkers of ICI response exist that can help with patient selection for this therapeutic approach. Here, we critically summarize the current state of ICI efficacy in the most common "special" NSCLC subpopulations.

Low Pretreatment CD4+:CD8+ T Cell Ratios and CD39+CD73+CD19+ B Cell Proportions Are Associated with Improved Relapse-Free Survival in Head and Neck Squamous Cell Carcinoma

The ectonucleotidases CD39 and CD73 are present on immune cells and play important roles in cancer progression by suppressing antitumour immunity. As such, CD39 and CD73 on peripheral blood mononuclear cells (PBMCs) are emerging as potential biomarkers to predict disease outcomes and treatment responses in cancer patients. This study aimed to examine T and B cells, including CD39 and CD73 expressing subsets, by flow cytometry in PBMCs from 28 patients with head and neck squamous cell carcinoma (HNSCC) and to assess the correlation with the treatment modality, human papillomavirus (HPV) status, and relapse-free survival (RFS). The PBMCs were examined pre-, mid-, and post-radiotherapy with concurrent cisplatin chemotherapy or anti-epidermal growth factor receptor antibody (cetuximab) therapy. Combination radiotherapy caused changes to T and B cell populations, including CD39 and CD73 expressing subsets, but no such differences were observed between concurrent chemotherapy and cetuximab. Pretreatment PBMCs from HPV+ patients contained increased proportions of CD39-CD73-CD4+ T cells and reduced proportions of CD39-/+CD73+CD4+ T cells compared to the equivalent cells from HPV- patients. Notably, the pretreatment CD4+:CD8+ T cell ratios and CD39+CD73+CD19+ B cell proportions below the respective cohort medians corresponded with an improved RFS. Collectively, this study supports the notion that CD39 and CD73 may contribute to disease outcomes in HNSCC patients and may assist as biomarkers, either alone or as part of immune signatures, in HNSCC. Further studies of CD39 and CD73 on PBMCs from larger cohorts of HNSCC patients are warranted.

Circulating immune cell dynamics as outcome predictors for immunotherapy in non-small cell lung cancer

The use of immune checkpoint inhibitors (ICIs) continues to transform the therapeutic landscape of non-small cell lung cancer (NSCLC), with these drugs now being evaluated at every stage of the disease. In contrast to these advances, little progress has been made with respect to reliable predictive biomarkers that can inform clinicians on therapeutic efficacy. All current biomarkers for outcome prediction, including PD-L1, tumor mutational burden or complex immune gene expression signatures, require access to tumor tissue. Besides the invasive nature of the sampling procedure, other disadvantages of tumor tissue biopsies are the inability to capture the complete spatial heterogeneity of the tumor and the difficulty to perform longitudinal follow-up on treatment. A concept emerges in which systemic immune events developing at a distance from the tumor reflect local response or resistance to immunotherapy. The importance of this cancer 'macroenvironment', which can be deciphered by comprehensive analysis of peripheral blood immune cell subsets, has been demonstrated in several cutting-edge preclinical reports, and is corroborated by intriguing data emerging from ICI-treated patients. In this review, we will provide the biological rationale underlying the potential of blood immune cell-based biomarkers in guiding treatment decision in immunotherapy-eligible NSCLC patients. Finally, we will describe new techniques that will facilitate the discovery of more immune cell subpopulations with potential to become predictive biomarkers, and reflect on ways and the remaining challenges to bring this type of analysis to the routine clinical care in the near future.

The recent progress of myeloid-derived suppressor cell and its targeted therapies in cancers

Myeloid-derived suppressor cells (MDSCs) are an immature group of myeloid-derived cells generated from myeloid cell precursors in the bone marrow. MDSCs appear almost exclusively in pathological conditions, such as tumor progression and various inflammatory diseases. The leading function of MDSCs is their immunosuppressive ability, which plays a crucial role in tumor progression and metastasis through their immunosuppressive effects. Since MDSCs have specific molecular features, and only a tiny amount exists in physiological conditions, MDSC-targeted therapy has become a promising research direction for tumor treatment with minimal side effects. In this review, we briefly introduce the classification, generation and maturation process, and features of MDSCs, and detail their functions under various circumstances. The present review specifically demonstrates the environmental specificity of MDSCs, highlighting the differences between MDSCs from cancer and healthy individuals, as well as tumor-infiltrating MDSCs and circulating MDSCs. Then, we further describe recent advances in MDSC-targeted therapies. The existing and potential targeted drugs are divided into three categories, monoclonal antibodies, small-molecular inhibitors, and peptides. Their targeting mechanisms and characteristics have been summarized respectively. We believe that a comprehensive in-depth understanding of MDSC-targeted therapy could provide more possibilities for the treatment of cancer.

Emerging agents for the treatment of advanced or metastatic NSCLC without actionable genomic alterations with progression on first-line therapy

INTRODUCTION

Lung cancer is the second most common cancer in the world and the leading cause of cancer-related mortality. Immune checkpoint inhibitors (ICIs), as monotherapy or in combination with platinum-based chemotherapy, have emerged as the standard of care first-line treatment option for patients with advanced non-small cell lung cancer (NSCLC) without actionable genomic alterations (AGAs). Despite significant improvements in patient outcomes with these regimens, primary or acquired resistance is common and most patients develop disease progression, resulting in poor survival.

AREAS COVERED

We review the current treatments commonly used for NSCLC without AGAs in the first-line and subsequent settings and describe the unmet needs for these patients in the second-line setting, including a lack of standard definitions for primary and required resistance, and few effective treatment options for patients who develop progression of their disease on first-line therapy. We describe key mechanisms of resistance to ICIs and emerging therapies that are being investigated for patients who develop progression on ICIs and platinum-based chemotherapy.

EXPERT OPINION

Emerging agents in development have a variety of different mechanisms of action and will likely change standard of care for second-line therapy and beyond for patients with NSCLC without AGAs in the future.

Plasma fractalkine contributes to systemic myeloid diversity and PD-L1/PD-1 blockade in lung cancer

Recent studies highlight the importance of baseline functional immunity for immune checkpoint blockade therapies. High-dimensional systemic immune profiling is performed in a cohort of non-small-cell lung cancer patients undergoing PD-L1/PD-1 blockade immunotherapy. Responders show high baseline myeloid phenotypic diversity in peripheral blood. To quantify it, we define a diversity index as a potential biomarker of response. This parameter correlates with elevated activated monocytic cells and decreased granulocytic phenotypes. High-throughput profiling of soluble factors in plasma identifies fractalkine (FKN), a chemokine involved in immune chemotaxis and adhesion, as a biomarker of response to immunotherapy that also correlates with myeloid cell diversity in human patients and murine models. Secreted FKN inhibits lung adenocarcinoma growth in vivo through a prominent contribution of systemic effector NK cells and increased tumor immune infiltration. FKN sensitizes murine lung cancer models refractory to anti-PD-1 treatment to immune checkpoint blockade immunotherapy. Importantly, recombinant FKN and tumor-expressed FKN are efficacious in delaying tumor growth in vivo locally and systemically, indicating a potential therapeutic use of FKN in combination with immunotherapy.

Review immune response of targeting CD39 in cancer

The ATP-adenosine pathway has emerged as a promising target for cancer therapy, but challenges remain in achieving effective tumor control. Early research focused on blocking the adenosine generating enzyme CD73 and the adenosine receptors A2AR or A2BR in cancer. However, recent studies have shown that targeting CD39, the rate-limiting ecto-enzyme of the ATP-adenosine pathway, can provide more profound anti-tumor efficacy by reducing immune-suppressive adenosine accumulation and increasing pro-inflammatory ATP levels. In addition, combining CD39 blocking antibody with PD-1 immune checkpoint therapy may have synergistic anti-tumor effects and improve patient survival. This review will discuss the immune components that respond to CD39 targeting in the tumor microenvironment. Targeting CD39 in cancer has been shown to not only decrease adenosine levels in the tumor microenvironment (TME), but also increase ATP levels. Additionally, targeting CD39 can limit the function of Treg cells, which are known to express high levels of CD39. With phase I clinical trials of CD39 targeting currently underway, further understanding and rational design of this approach for cancer therapy are expected.

Soluble biomarkers to predict clinical outcomes in non-small cell lung cancer treated by immune checkpoints inhibitors

Lung cancer remains the first cause of cancer-related death despite many therapeutic innovations, including immune checkpoint inhibitors (ICI). ICI are now well used in daily practice at late metastatic stages and locally advanced stages after a chemo-radiation. ICI are also emerging in the peri-operative context. However, all patients do not benefit from ICI and even suffer from additional immune side effects. A current challenge remains to identify patients eligible for ICI and benefiting from these drugs. Currently, the prediction of ICI response is only supported by Programmed death-ligand 1 (PD-L1) tumor expression with perfectible results and limitations inherent to tumor-biopsy specimen analysis. Here, we reviewed alternative markers based on liquid biopsy and focused on the most promising biomarkers to modify clinical practice, including non-tumoral blood cell count such as absolute neutrophil counts, platelet to lymphocyte ratio, neutrophil to lymphocyte ratio, and derived neutrophil to lymphocyte ratio. We also discussed soluble-derived immune checkpoint-related products such as sPD-L1, circulating tumor cells (detection, count, and marker expression), and circulating tumor DNA-related products. Finally, we explored perspectives for liquid biopsies in the immune landscape and discussed how they could be implemented into lung cancer management with a potential biological-driven decision.

Association between CD8+ tumor-infiltrating lymphocytes and prognosis of non-small cell lung cancer patients treated with PD-1/PD-L1 inhibitors: a systematic review and meta-analysis

BACKGROUND

A meta-analysis method was used to investigate the prognostic value of CD8+ tumor-infiltrating lymphocytes (TILs) in non-small cell lung cancer (NSCLC) patients treated with PD-1/PD-L1 inhibitors.

METHODS

A database search of PubMed, Embase, Web of Science and Cochrane Library up until February 7th, 2023. A clinical study on the relationship between CD8+ TILs and PD-1/PD-L1 inhibitors in the therapeutics of NSCLC. RevMan 5.3 and StataMP 17.0 software were used for meta-analysis. The outcome indicators incorporated overall survival (OS), progression-free survival (PFS) and objective response rate (ORR).

RESULTS

Nineteen articles with 1488 patients were included. The analysis results showed that high CD8+ TILs were associated with better OS (HR=0.60, 95% CI: 0.46-0.77; P<0.0001), PFS (HR=0.68, 95% CI: 0.53-0.88; P=0.003) and ORR (OR=2.26, 95% CI: 1.52-3.36; P<0.0001) in NSCLC patients treated with PD-1/PD-L1 inhibitors. Subgroup analysis indicated that patients with high CD8+ TILs had good clinical prognostic benefits whether the location of CD8+ TILs was intratumoral or stromal, and compared with East Asian, high CD8+ TILs in Caucasians showed a better prognosis. High CD8+ TILs in peripheral blood did not improve OS (HR=0.83, 95% CI: 0.69-1.01; P=0.06) and PFS (HR=0.93, 95% CI: 0.61-1.14; P=0.76) in NSCLC patients receiving PD-1/PD-L1 inhibitors.

CONCLUSION

In spite of the location of CD8+ TILs, high densities of CD8+ TILs were predictive of treatment outcomes in NSCLC patients treated with PD-1/PD-L1 inhibitors. However, high CD8+ TILs in peripheral blood had no predictive effect.

Strategies to overcome myeloid cell induced immune suppression in the tumor microenvironment

Cancer progression and metastasis due to tumor immune evasion and drug resistance is strongly associated with immune suppressive cellular responses, particularly in the case of metastatic tumors. The myeloid cell component plays a key role within the tumor microenvironment (TME) and disrupts both adaptive and innate immune cell responses leading to loss of tumor control. Therefore, strategies to eliminate or modulate the myeloid cell compartment of the TME are increasingly attractive to non-specifically increase anti-tumoral immunity and enhance existing immunotherapies. This review covers current strategies targeting myeloid suppressor cells in the TME to enhance anti-tumoral immunity, including strategies that target chemokine receptors to deplete selected immune suppressive myeloid cells and relieve the inhibition imposed on the effector arms of adaptive immunity. Remodeling the TME can in turn improve the activity of other immunotherapies such as checkpoint blockade and adoptive T cell therapies in immunologically "cold" tumors. When possible, in this review, we have provided evidence and outcomes from recent or current clinical trials evaluating the effectiveness of the specific strategies used to target myeloid cells in the TME. The review seeks to provide a broad overview of how myeloid cell targeting can become a key foundational approach to an overall strategy for improving tumor responses to immunotherapy.

Myeloid Maturity: ATRA to Enhance Anti-PD-1?

Myeloid-derived suppressor cells (MDSC) are associated with resistance to anti-PD-1 therapies. All-trans retinoic acid (ATRA) may induce maturation of MDSCs and alter their immunosuppressive effects. Adding ATRA to pembrolizumab may target this resistance mechanism to enhance the overall impact of anti-PD-1-based immunotherapy. See related article by Tobin et al., p. 1209.

Reactivation of Anticancer Immunity by Resetting Interorgan Crosstalk in Immune-Suppressive Cells with a Nanoparticulated Anti-Inflammatory Drug

The reactivation of anticancer immunity is a fundamental principle in cancer immunotherapy as evidenced by the use of immune checkpoint inhibitors (ICIs). While treatment with the ICIs is shown to have remarkable and durable therapeutic effects in the responders, the low objective response rate (<40%) continues to be a major problem. Since myeloid-derived suppressor cells (MDSCs), heterogenous cells with strong immunosuppressive activity that originate in the hematopoietic system, suppress the anticancer immunity via parallel immune checkpoint-dependent and independent pathways, these cells are potential targets for improving the efficacy of cancer immunotherapy. In this study, it is demonstrated that MDSCs can be depleted by delivering synthetic glucocorticoid dexamethasone to phagocytic cells in the spleen using a lipid nanoparticle. Since the interaction of nanoparticles with T cells is intrinsically poor, this strategy also enables the "detargeting" from T cells, thus avoiding the nonspecific suppression of cytotoxic immune responses against cancer cells. In addition to the direct anticancer effect of the nanoparticulated dexamethasone, their synergistic anticancer effect with ICIs is also reported.

Mechanisms of drug resistance to immune checkpoint inhibitors in non-small cell lung cancer

Immune checkpoint inhibitors (ICIs) in the form of anti-CTLA-4 and anti-PD-1/PD-L1 have become the frontier of cancer treatment and successfully prolonged the survival of patients with advanced non-small cell lung cancer (NSCLC). But the efficacy varies among different patient population, and many patients succumb to disease progression after an initial response to ICIs. Current research highlights the heterogeneity of resistance mechanisms and the critical role of tumor microenvironment (TME) in ICIs resistance. In this review, we discussed the mechanisms of ICIs resistance in NSCLC, and proposed strategies to overcome resistance.

"Open Sesame" to the complexity of pattern recognition receptors of myeloid-derived suppressor cells in cancer

Pattern recognition receptors are primitive sensors that arouse a preconfigured immune response to broad stimuli, including nonself pathogen-associated and autologous damage-associated molecular pattern molecules. These receptors are mainly expressed by innate myeloid cells, including granulocytes, monocytes, macrophages, and dendritic cells. Recent investigations have revealed new insights into these receptors as key players not only in triggering inflammation processes against pathogen invasion but also in mediating immune suppression in specific pathological states, including cancer. Myeloid-derived suppressor cells are preferentially expanded in many pathological conditions. This heterogeneous cell population includes immunosuppressive myeloid cells that are thought to be associated with poor prognosis and impaired response to immune therapies in various cancers. Identification of pattern recognition receptors and their ligands increases the understanding of immune-activating and immune-suppressive myeloid cell functions and sheds light on myeloid-derived suppressor cell differences from cognate granulocytes and monocytes in healthy conditions. This review summarizes the different expression, ligand recognition, signaling pathways, and cancer relations and identifies Toll-like receptors as potential new targets on myeloid-derived suppressor cells in cancer, which might help us to decipher the instruction codes for reverting suppressive myeloid cells toward an antitumor phenotype.

Interleukin-10 induces expression of CD39 on CD8+T cells to potentiate anti-PD1 efficacy in EGFR-mutated non-small cell lung cancer

BACKGROUND

Anti-PD-1(L1) therapies are less efficacious in patients with EGFR-mutated non-small-cell lung cancer. However, the underlying mechanism is poorly understood.

METHODS

The characteristics of T cells in EGFR-mutated and wild-type tumors were analyzed based on The Cancer Genome Atlas database and clinical samples. Plasma levels of 8 T-cell-related cytokines were evaluated and its association with immunotherapy efficacy were explored. Association between EGFR signaling pathway and IL-10 was examined through tumor cell lines and clinical tumor samples. In vitro restimulation model of human CD8⁺T cells isolated from peripheral blood was used to analyze the impact of IL-10 on T cells. Doxycycline-inducible transgenic EGFR^L858R mouse models were used to investigate the efficacy of combining recombinant mouse IL-10 protein and PD-1 blockade and its underlying mechanism in vivo.

RESULTS

EGFR-mutated tumors showed a lack of CD8⁺T cell infiltration and impaired CD8⁺T cell cytotoxic function. The incompetent CD8⁺T cells in EGFR-mutated tumors were characterized as absence of CD39 expression, which defined hallmarks of cytotoxic and exhausted features and could not be reinvigorated by anti-PD-1(L1) treatment. Instead, CD39 expression defined functional states of CD8⁺T cells and was associated with the therapeutic response of anti-PD-1(L1) therapies. Mechanically, IL-10 upregulated CD39 expression and was limited in EGFR-mutated tumors. IL-10 induced hallmarks of CD8⁺T cells immunity in CD39-dependent manner. Using autochthonous EGFR ^L858R-driven lung cancer mouse models, combining recombinant mouse IL-10 protein and PD-1 blockade optimized antitumor effects in EGFR-mutated lung tumors.

CONCLUSIONS

Our study suggested that owing to low level of IL-10 to induce the expression of CD39 on CD8⁺T cells, fewer phenotypically cytotoxic and exhausted CD39⁺CD8⁺T cells in EGFR-mutated tumors could be potentially reinvigorated by anti-PD-1(L1) treatment. Hence, IL-10 could potentially serve as a cytokine-based strategy to enhance efficacy of anti-PD-1(L1) treatment in EGFR-mutated tumors.

The road of NSCLC stem cells toward bone metastases

Despite advancement in therapeutic options, Non-Small Cell lung cancer (NSCLC) remains a lethal disease mostly due to late diagnosis at metastatic phase and drug resistance. Bone is one of the more frequent sites for NSCLC metastatization. A defined subset of cancer stem cells (CSCs) that possess motile properties, mesenchymal features and tumor initiation potential are defined as metastasis initiating cells (MICs). A better understanding of the mechanisms supporting MIC dissemination and interaction with bone microenvironment is fundamental to design novel rational therapeutic option for long lasting efficient treatment of NSCLC. In this review we will summarize findings about bone metastatic process initiated by NSCLC MICs. We will review how MICs can reach bone and interact with its microenvironment that supports their extravasation, seeding, dormancy/proliferation. The role of different cell types inside the bone metastatic niche, such as endothelial cells, bone cells, hematopoietic stem cells and immune cells will be discussed in regards of their impact in dictating the success of metastasis establishment by MICs. Finally, novel therapeutic options to target NSCLC MIC-induced bone metastases, increasing the survival of patients, will be presented.

Integrative tumour mutation burden with CD39 and PD-L1 for the prediction of response to PD-L1 blockade and adjuvant chemotherapy in muscle-invasive bladder cancer patients

BACKGROUND

CD39, a rate-limiting enzyme to convert extracellular ATP (eATP) to adenosine, has been reported to be a key modulator of immune response, but its correlation with therapeutic sensitivity remains obscure. We conducted this study to determine whether the integration of CD39 and traditional biomarkers could improve the prediction of responsiveness to PD-L1 blockade and platinum-based chemotherapy.

METHODS

We retrospectively enrolled a total of 760 patients from IMvigor210 trial, TCGA database and Zhongshan Hospital in this study. We constructed the CPT scoring system based on CD39, PD-L1 and tumour mutation burden (TMB) and validated its efficacy in predicting therapeutic responsiveness in MIBC patients. Kaplan-Meier survival and Cox regression analyses were applied to assess clinical outcomes of patients.

RESULTS

The CPT scoring system could predict the response to PD-L1 blockade and platinum-based chemotherapy. The CPT score was positively correlated with APOBEC mutational signature and SNV neoantigens enrichment, antigen presentation, and TCR signalling. High CPT score also indicated the inflamed immune phenotype and basal/squamous molecular subtype.

CONCLUSIONS

CD39 expression is closely correlated with the immunogenic contexture of MIBC. Integrating CD39 with PD-L1 and TMB could stratify the sensitivity of patients with MIBC to PD-L1 blockade and platinum-based chemotherapy.

Therapeutic targets and biomarkers of tumor immunotherapy: response versus non-response

Cancers are highly complex diseases that are characterized by not only the overgrowth of malignant cells but also an altered immune response. The inhibition and reprogramming of the immune system play critical roles in tumor initiation and progression. Immunotherapy aims to reactivate antitumor immune cells and overcome the immune escape mechanisms of tumors. Represented by immune checkpoint blockade and adoptive cell transfer, tumor immunotherapy has seen tremendous success in the clinic, with the capability to induce long-term regression of some tumors that are refractory to all other treatments. Among them, immune checkpoint blocking therapy, represented by PD-1/PD-L1 inhibitors (nivolumab) and CTLA-4 inhibitors (ipilimumab), has shown encouraging therapeutic effects in the treatment of various malignant tumors, such as non-small cell lung cancer (NSCLC) and melanoma. In addition, with the advent of CAR-T, CAR-M and other novel immunotherapy methods, immunotherapy has entered a new era. At present, evidence indicates that the combination of multiple immunotherapy methods may be one way to improve the therapeutic effect. However, the overall clinical response rate of tumor immunotherapy still needs improvement, which warrants the development of novel therapeutic designs as well as the discovery of biomarkers that can guide the prescription of these agents. Learning from the past success and failure of both clinical and basic research is critical for the rational design of studies in the future. In this article, we describe the efforts to manipulate the immune system against cancer and discuss different targets and cell types that can be exploited to promote the antitumor immune response.

Peripheral cytokine levels as novel predictors of survival in cancer patients treated with immune checkpoint inhibitors: A systematic review and meta-analysis

Background

Early identification of patients who will benefit from immune checkpoint inhibitors (ICIs) has recently become a hot issue in cancer immunotherapy. Peripheral cytokines are key regulators in the immune system that can induce the expression of immune checkpoint molecules; however, the association between peripheral cytokines and the efficiency of ICIs remains unclear.

Methods

A systematic review was conducted in several public databases from inception through 3 February 2022 to identify studies investigating the association between peripheral cytokines (i.e., IL-1β, IL-2, IL-2RA, IL-2R, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-15, IL-17, TNF-α, IFN-γ, and TGF-β) and ICI treatment. Survival data, including overall survival (OS) and/or progression-free survival (PFS), were extracted, and meta-analyses were performed.

Results

Twenty-four studies were included in this analysis. The pooled results demonstrated that the pretreatment peripheral levels of IL-6 (univariate analysis: HR = 2.53, 95% CI = 2.21–2.89, p < 0.00001; multivariate analysis: HR = 2.21, 95% CI = 1.67–2.93, p < 0.00001) and IL-8 (univariate analysis: HR = 2.17, 95% CI = 1.98–2.38, p < 0.00001; multivariate analysis: HR = 1.88, 95% CI= 1.70–2.07, p < 0.00001) were significantly associated with worse OS of cancer patients receiving ICI treatment in both univariate and multivariate analysis. However, high heterogeneity was found for IL-6, which might be attributed to region, cancer type, treatment method, sample source, and detection method.

Conclusion

The peripheral level of IL-8 may be used as a prognostic marker to identify patients with inferior response to ICIs. More high-quality prospective studies are warranted to assess the predictive value of peripheral cytokines for ICI treatment.

Circulating Low Density Neutrophils Are Associated with Resistance to First Line Anti-PD1/PDL1 Immunotherapy in Non-Small Cell Lung Cancer

Simple Summary

Immunotherapy has been positioned as frontline therapy for advanced non-small cell lung cancer (NSCLC), alone when PD-L1 tumor expression is high, or combined with chemotherapy otherwise. However, 50% of the patients do not respond to the treatment and the mechanisms of resistance are not well defined. Moreover, it is not clear whether chemo-immunotherapy could be advantageous in high PD-L1 tumor expression. We have found that baseline circulating low-density neutrophils (LDN) identify a subset of patients intrinsically refractory to immunotherapy. Interestingly, responses can be achieved with CT+IT, detecting a progressive depletion of LDN. Besides the potential role as predictive biomarker we observed that resistance was mediated by soluble molecules related with the HGF/c-MET pathway. Our findings establish circulating myeloid cells as one of the main mediators of resistance to immunotherapy in NSCLC, and give a rationale for potential drug combinations that might improve the outcomes.

Abstract

Single-agent immunotherapy has been widely accepted as frontline treatment for advanced non-small cell lung cancer (NSCLC) with high tumor PD-L1 expression, but most patients do not respond and the mechanisms of resistance are not well known. Several works have highlighted the immunosuppressive activities of myeloid subpopulations, including low-density neutrophils (LDNs), although the context in which these cells play their role is not well defined. We prospectively monitored LDNs in peripheral blood from patients with NSCLC treated with anti-PD-1 immune checkpoint inhibitors (ICIs) as frontline therapy, in a cohort of patients treated with anti-PD1 immunotherapy combined with chemotherapy (CT+IT), and correlated values with outcomes. We explored the underlying mechanisms through ex vivo experiments. Elevated baseline LDNs predict primary resistance to ICI monotherapy in patients with NSCLC, and are not associated with response to CT+IT. Circulating LDNs mediate resistance in NSCLC receiving ICI as frontline therapy through humoral immunosuppression. A depletion of this population with CT+IT might overcome resistance, suggesting that patients with high PD-L1 tumor expression and high baseline LDNs might benefit from this combination. The activation of the HGF/c-MET pathway in patients with elevated LDNs revealed by quantitative proteomics supports potential drug combinations targeting this pathway.

Myeloid-derived suppressor cells in hematologic malignancies: two sides of the same coin

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of bone marrow cells originating from immature myeloid cells. They exert potent immunosuppressive activity and are closely associated with the development of various diseases such as malignancies, infections, and inflammation. In malignant tumors, MDSCs, one of the most dominant cellular components comprising the tumor microenvironment, play a crucial role in tumor growth, drug resistance, recurrence, and immune escape. Although the role of MDSCs in solid tumors is currently being extensively studied, little is known about their role in hematologic malignancies. In this review, we comprehensively summarized and reviewed the different roles of MDSCs in hematologic malignancies and hematopoietic stem cell transplantation, and finally discussed current targeted therapeutic strategies.Affiliation: Kindly check and confirm the processed affiliations are correct. Amend if any.correct

Liposomal Co-delivery of PD-L1 siRNA/Anemoside B4 for Enhanced Combinational Immunotherapeutic Effect

Combination therapy has gained a lot of attention thanks to its superior activity against cancer. In the present study, we report a cRGD-targeted liposomal preparation for co-delivery of programmed cell death ligand 1 (PD-L1) small interfering RNA (siRNA) and anemoside B4 (AB4)─AB4/siP-c-L─and evaluate its anticancer efficiency in mouse models of LLC and 4T1 tumors. AB4/siP-c-L showed a particle size of (180.7 ± 7.3) nm and a ζ-potential of (32.8 ± 1.5) mV, with high drug encapsulation, pH-sensitive release properties, and good stability in serum. AB4/siP-c-L demonstrated prolonged blood circulation and increased tumor accumulation. Elevated cellular uptake was dependent on the targeting ligand cRGD. This combination induced significant tumor inhibition in LLC xenograft tumor-bearing mice by downregulating PD-L1 protein expression and modulating the immunosuppressive microenvironment. Liposomes favored the antitumor T-cell response with long-term memory, without obvious toxicity. A similar tumor growth inhibition was also demonstrated in the 4T1 tumor model. In summary, our results indicate that cRGD-modified and AB4- and PD-L1 siRNA-coloaded liposomes have potential as an antitumor preparation, and this approach may lay a foundation for the development of a new targeted drug delivery system.

Tumor-induced erythroid precursor-differentiated myeloid cells mediate immunosuppression and curtail anti-PD-1/PD-L1 treatment efficacy

Despite the unprecedented success of immune checkpoint inhibitors (ICIs) as anti-cancer therapy, it remains a prevailing clinical need to identify additional mechanisms underlying ICI therapeutic efficacy and potential drug resistance. Here, using lineage tracking in cancer patients and tumor-bearing mice, we demonstrate that erythroid progenitor cells lose their developmental potential and switch to the myeloid lineage. Single-cell transcriptome analyses reveal that, notwithstanding quantitative differences in erythroid gene expression, erythroid differentiated myeloid cells (EDMCs) are transcriptionally indistinguishable from their myeloid-originated counterparts. EDMCs possess multifaceted machinery to curtail T cell-mediated anti-tumor responses. Consequently, EDMC content within tumor tissues is negatively associated with T cell inflammation for the majority of solid cancers; moreover, EDMC enrichment, in accordance with anemia manifestation, is predictive of poor prognosis in various cohorts of patients undergoing ICI therapy. Together, our findings reveal a feedforward mechanism by which tumors exploit anemia-triggered erythropoiesis for myeloid transdifferentiation and immunosuppression.