Levels of peripheral blood polymorphonuclear myeloid-derived suppressor cells and selected cytokines are potentially prognostic of disease progression for patients with non-small cell lung cancer

Atypical memory B cells increase in the peripheral blood of patients with breast cancer regardless of lymph node involvement

BACKGROUND

Breast cancer is the most common cancer in females. The immune system has a crucial role in the fight against cancer. B and T cells, the two main components of the adaptive immunity, are critical players that specifically target tumor cells. However, B cells, in contrast to T cells, and their role in cancer inhibition or progression is less investigated. Accordingly, in this study, we assessed and compared the frequency of naïve and different subsets of memory B cells in the peripheral blood of patients with breast cancer and healthy women.

RESULTS

We found no significant differences in the frequencies of peripheral CD19+ B cells between the patients and controls. However, there was a significant decrease in the frequency of CD19+IgM+ B cells in patients compared to the control group (P=0.030). Moreover, the patients exhibited higher percentages of atypical memory B cells (CD19+CD27‒IgM‒, P=0.006) and a non-significant increasing trend in switched memory B cells (CD19+CD27+IgM‒, P=0.074). Further analysis revealed a higher frequency of atypical memory B cells (aMBCs) in the peripheral blood of patients without lymph node involvement as well as those with a tumor size greater than 2cm or with estrogen receptor (ER) negative/progesterone receptor (PR) negative tumors, compared with controls (P=0.030, P=0.040, P=0.031 and P=0.054, respectively).

CONCLUSION

Atypical memory B cells (CD19+CD27‒IgM‒) showed a significant increase in the peripheral blood of patients with breast cancer compared to the control group. This increase seems to be associated with tumor characteristics. Nevertheless, additional research is necessary to determine the precise role of these cells during breast cancer progression.

Deciphering the molecular mechanistic paths describing the chemotherapeutic potential and epigenetic regulation of curcumin in lung cancer: a mini review

In an uncontrolled inflammatory environment, the complex process of lung carcinogenesis occurs. Lung cancer remains the leading cause of cancer-related mortality worldwide. The average 5-year survival rate is still low despite significant advancements in our knowledge of lung carcinogenesis and the development of innovative therapies in recent decades. Research on adjuvant treatment, lung carcinogenesis pathways, and possible prognostic indicators has to be refocused using an innovative approach. The majority of lung cancers are discovered at an advanced stage when there is little chance of recovery. It has grown in popularity in recent years to supplement already available chemotherapeutic therapies with adjuvant herbal medications, which may lessen toxicity and adverse effects without sacrificing therapeutic efficiency. One such prospective contender is curcumin. In-depth research has been done on curcumin as a multi-target anti-tumor and anti-inflammatory molecule. A pharmacologically active polyphenol produced from turmeric is called curcumin. Over the past few decades, curcumin's therapeutic potential has been thoroughly studied, and data indicate that curcumin may play a part in a variety of biological processes, most notably its potent anticancer activity. Being a pleiotropic chemical, curcumin regulates a variety of molecules that are key players in many cell signaling pathways. It has been shown to stifle transformation, restrain proliferation, and trigger apoptosis. Curcumin can reduce the development of non-small cell LC by downregulating Circular RNA hsa_circ_0007580, which in turn controls the expression of integrin subunit beta 1 by adsorbing miR-384. Nevertheless, despite all these advantages, curcumin's effectiveness is still restricted because of its weak bioavailability, poor absorption within the systemic circulation, and quick removal from the body. In an effort to overcome these constraints, scientists from all around the world are working to develop a synthetic and improved curcuminoid by appropriately altering the parent skeleton structurally. These curcuminoids will simultaneously improve the physicochemical properties and efficacy. This review presents evidence from the most recent clinical trials coupled with the molecular mechanisms of curcumin in LC.

MCL1 inhibition targets Myeloid Derived Suppressors Cells, promotes antitumor immunity and enhances the efficacy of immune checkpoint blockade

Immune checkpoint inhibitors (ICIs) are now the first-line treatment for patients with advanced melanoma. Despite promising clinical results, many patients fail to respond to these therapies. BH3 mimetics, a novel class of small molecule inhibitors that bind and inhibit anti-apoptotic members of the BCL2 family proteins such as BCL2 or MCL1, have been very successful in treating hematologic malignancies. However, there are limited studies on the immunomodulatory role of the BH3 mimetics. Several factors contribute to ICI resistance including myeloid-derived suppressor cells (MDSCs) that exert immunosuppressive effects through direct and indirect inhibition of antitumor immunity. Thus, targeting MDSCs to enhance antitumor immunity has the potential to enhance the efficacy of ICIs. In this study, we show that the MCL1 inhibitor S64315 reduces melanoma tumor growth in an immune cell-dependent manner in mice. Specifically, S64315 enhances antitumor immunity by reducing MDSC frequency and by promoting the activity of CD8+T cells. Additionally, human MDSCs are 10 times more sensitive to S64315 than cutaneous melanoma lines. Further, we found that a higher expression of MCL1 is associated with poor survival for patients treated with anti-PD-1. Finally, combining S64315 and anti-PD-1 significantly slowed tumor growth compared to either agent alone. Together, this proof-of-concept study demonstrates the potential of combining an MCL1 inhibitor with anti-PD-1 in the treatment of melanoma. It justifies the further development of next generation MCL1 inhibitors to improve efficacy of ICIs in treating malignant melanoma.

Impact of immunosenescence and inflammaging on the effects of immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) are employed in immunotherapeutic applications for patients with weakened immune systems and can improve the ability of T cells to kill cancer cells. Although ICIs can potentially treat different types of cancers in various groups of patients, their effectiveness may differ among older individuals. The reason ICIs are less effective in older adults is not yet clearly understood, but age-related changes in the immune system, such as immunosenescence and inflammation, may play a role. Therefore, this review focuses on recent advances in understanding the effects of immunosenescence and inflammation on the efficacy of ICIs.

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 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.

Immunoprofiling bronchoalveolar lavage cells reveals multifaceted smoking-associated immune dysfunction

Background

Bronchoalveolar lavage (BAL) is an underutilised tool in the search for pulmonary disease biomarkers. While leukocytes with effector and suppressor function play important roles in airway immunity and tumours, it remains unclear if frequencies and phenotypes of BAL leukocytes can be useful parameters in lung cancer studies and clinical trials. We therefore explored the utility of BAL leukocytes as a source of biomarkers interrogating the impact of smoking, a major lung cancer risk determinant, on pulmonary immunity.

Methods

In this "test case" observational study, BAL samples from 119 donors undergoing lung cancer screening and biopsy procedures were evaluated by conventional and spectral flow cytometry to exemplify the comprehensive immune analyses possible with this biospecimen. Proportions of major leukocyte populations and phenotypic markers levels were found. Multivariate linear rank sum analysis considering age, sex, cancer diagnosis and smoking status was performed.

Results

Significantly increased frequencies of myeloid-derived suppressor cells and PD-L1-expressing macrophages were found in current and former smokers compared to never-smokers. While cytotoxic CD8 T-cells and conventional CD4 helper T-cell frequencies were significantly reduced in current and former smokers, expression of immune checkpoints PD-1 and LAG-3 as well as Tregs proportions were increased. Lastly, the cellularity, viability and stability of several immune readouts under cryostorage suggested BAL samples are useful for correlative end-points in clinical trials.

Conclusions

Smoking is associated with heightened markers of immune dysfunction, readily assayable in BAL, that may reflect a permissive environment for cancer development and progression in the airway.

LncRNAs has been identified as regulators of Myeloid-derived suppressor cells in lung cancer

Lung tumours are widespread pathological conditions that attract much attention due to their high incidence of death. The immune system contributes to the progression of these diseases, especially non-small cell lung cancer, resulting in the fast evolution of immune-targeted therapy. Myeloid-derived suppressor cells (MDSCs) have been suggested to promote the progression of cancer in the lungs by suppressing the immune response through various mechanisms. Herein, we summarized the clinical studies on lung cancer related to MDSCs. However, it is noteworthy to mention the discovery of long non-coding RNAs (lncRNAs) that had different phenotypes and could regulate MDSCs in lung cancer. Therefore, by reviewing the different phenotypes of lncRNAs and their regulation on MDSCs, we summarized the lncRNAs' impact on the progression of lung tumours. Data highlight LncRNAs as anti-cancer agents. Hence, we aim to discuss their possibilities to inhibit tumour growth and trigger the development of immunosuppressive factors such as MDSCs in lung cancer through the regulation of lncRNAs. The ultimate purpose is to propose novel and efficient therapy methods for curing patients with lung tumours.

Fibrotic Lung Disease Alters Neutrophil Trafficking and Promotes Neutrophil Elastase and Extracellular Trap Release

Idiopathic pulmonary fibrosis (IPF) is a progressive, irreversible disease characterized by collagen deposition within the interstitium of the lung. This impairs gas exchange and results in eventual respiratory failure. Clinical studies show a correlation between elevated neutrophil numbers and IPF disease progression; however, the mechanistic roles neutrophils play in this disease are not well described. In the present study, we describe alterations to the trafficking and function of neutrophils after the development of fibrosis. We observed increased numbers of total and aged neutrophils in peripheral tissues of fibrotic mice. This appeared to be driven by an upregulation of neutrophil chemokine Cxcl2 by lung cells. In addition, neutrophil recruitment back to the bone marrow for clearance appeared to be impaired, because we saw decreased aged neutrophils in the bone marrow of fibrotic mice. Neutrophils in fibrosis were activated, because ex vivo assays showed increased elastase and extracellular trap release by neutrophils from fibrotic mice. This likely mediated disease exacerbation, because mice exhibiting a progressive disease phenotype with greater weight loss and mortality had more activated neutrophils and increased levels of extracellular DNA present in their lungs than did mice with a nonprogressive disease phenotype. These findings further our understanding of the dynamics of neutrophil populations and their trafficking in progressive fibrotic lung disease and may help inform treatments targeting neutrophil function for patients with IPF experiencing disease exacerbation in the future.

Selective depletion of polymorphonuclear myeloid derived suppressor cells in tumor beds with near infrared photoimmunotherapy enhances host immune response

The immune system is recognized as an important factor in regulating the development, progression, and metastasis of cancer. Myeloid-derived suppressor cells (MDSCs) are a major immune-suppressive cell type by interfering with T cell activation, promoting effector T cell apoptosis, and inducing regulatory T cell expansion. Consequently, reducing or eliminating MDSCs has become a goal of some systemic immunotherapies. However, by systemically reducing MDSCs, unwanted side effects can occur. Near-infrared photoimmunotherapy (NIR-PIT) is a newly developed treatment that selectively kills targeted cells without damaging adjacent normal cells. The aim of this study is to evaluate the antitumor efficacy of MDSC-directed NIR-PIT utilizing anti-Ly6G antibodies to specifically destroy polymorphonuclear (PMN)-MDSCs in the tumor microenvironment (TME) in syngeneic mouse models. PMN-MDSCs were selectively eliminated within tumors by Ly6G-targeted NIR-PIT. There was significant tumor growth suppression and prolonged survival in three treated tumor models. In the early phase after NIR-PIT, dendritic cell maturation/activation and CD8⁺ T cell activation were enhanced in both intratumoral tissues and tumor-draining lymph nodes, and NK cells demonstrated increased expression of cytotoxic molecules. Host immunity remained activated in the TME for at least one week after NIR-PIT. Abscopal effects in bilateral tumor models were observed. Furthermore, the combination of NIR-PIT targeting cancer cells and PMN-MDSCs yielded synergistic effects and demonstrated highly activated host tumor immunity. In conclusion, we demonstrated that selective local PMN-MDSCs depletion by NIR-PIT could be a promising new cancer immunotherapy.

Development of immunotherapy for high-grade gliomas: Overcoming the immunosuppressive tumor microenvironment

The preclinical and clinical development of novel immunotherapies for the treatment of central nervous system (CNS) tumors is advancing at a rapid pace. High-grade gliomas (HGG) are aggressive tumors with poor prognoses in both adult and pediatric patients, and innovative and effective therapies are greatly needed. The use of cytotoxic chemotherapies has marginally improved survival in some HGG patient populations. Although several challenges exist for the successful development of immunotherapies for CNS tumors, recent insights into the genetic alterations that define the pathogenesis of HGG and their direct effects on the tumor microenvironment (TME) may allow for a more refined and targeted therapeutic approach. This review will focus on the TME in HGG, the genetic drivers frequently found in these tumors and their effect on the TME, the development of immunotherapy for HGG, and the practical challenges in clinical trials employing immunotherapy for HGG. Herein, we will discuss broadly the TME and immunotherapy development in HGG, with a specific focus on glioblastoma multiforme (GBM) as well as additional discussion in the context of the pediatric HGG diagnoses of diffuse midline glioma (DMG) and diffuse hemispheric glioma (DHG).

Circulating myeloid-derived suppressors cells correlate with clinicopathological characteristics and outcomes undergoing neoadjuvant chemoimmunotherapy in non-small cell lung cancer

PURPOSE

Myeloid-derived suppressors cells (MDSCs) are heterogeneous immunosuppressive cells, closely related to the development, efficacy and prognosis in various tumors. The relationship between clinicopathological characteristics, efficacy of neoadjuvant chemoimmunotherapy (NCIO) and circulating MDSCs in patients with non-small cell lung cancer (NSCLC) was investigated in this study.

METHODS

This study analyzed the clinical data of patients diagnosed at Department of Thoracic Surgery, Beijing Chest Hospital from November 2020 to August 2021. MDSCs and T cells subgroups were measured in fresh peripheral blood mononuclear cells(PBMCs) at baseline. Flow cytometry was used to detect MDSCs and T cells subgroups.

RESULTS

A total of 78 patients with NSCLC and 20 patients with benign nodule underwent direct surgery. 23 patients with NSCLC scheduled to accept NCIO before surgery. NSCLC had elevated levels of total MDSCs, PMN-MDSCs and M-MDSCs compared to patients with benign nodule. MDSCs subgroups were correlated to the pTNM stage in NSCLC patients. The frequency of total MDSCs were moderately positively correlated with regulatory T cells (Tregs)(r = 0.3597, P < 0.01) and negatively correlated with CD4 + T cells(r = 0.2714, P < 0.05). The baseline levels of total MDSCs, PMN-MDSCs and Tregs in pCR patients were significantly decreased than those of non-pCR patients (P < 0.05).

CONCLUSION

Circulating MDSCs were increased in NSCLC patients. MDSC subgroups were related to pTNM stage in NSCLC patients. Total MDSCs were positively correlated with Tregs levels and negatively correlated with CD4 + T cells in peripheral blood. The level of MDSCs and Tregs in peripheral blood may have potential value in predicting pathological response in NSCLC.

G-CSF/GM-CSF-induced hematopoietic dysregulation in the progression of solid tumors

There are two types of abnormal hematopoiesis in solid tumor occurrence and treatment: pathological hematopoiesis, and myelosuppression induced by radiotherapy and chemotherapy. In this review, we primarily focus on the abnormal pathological hematopoietic differentiation in cancer induced by tumor-released granulocyte colony stimulating factor (G-CSF) and granulocyte-macrophage colony stimulating factor (GM-CSF). As key factors in hematopoietic development, G-CSF/GM-CSF are well-known facilitators of myelopoiesis and mobilization of hematopoietic stem cells (HSCs). In addition, these two cytokines can also promote or inhibit tumors, dependent on tumor type. In multiple cancer types, hematopoiesis is greatly enhanced and abnormal lineage differentiation is induced by these two cytokines. Here, dysregulated hematopoiesis induced by G-CSF/GM-CSF in solid tumors and its mechanism are summarized, and the prognostic value of G-CSF/GM-CSF-associated dysregulated hematopoiesis for tumor metastasis is also briefly highlighted.

Clinical and pathological characteristics associated with the presence of the IS6110 Mycobacterim tuberculosis transposon in neoplastic cells from non-small cell lung cancer patients

Lung cancer (LC) and pulmonary tuberculosis (TB) are the deadliest neoplastic and bacterial infectious diseases worldwide, respectively. Clinicians and pathologists have long discussed the co-existence of LC and TB, and several epidemiologic studies have presented evidence indicating that TB could be associated with the development of LC, particularly adenocarcinoma. Nonetheless, this data remains controversial, and the mechanism which could underlie the association remains largely unexplored. Some bioinformatic studies have shown that human cancer biopsies have a very high frequency of bacterial DNA integration; since Mycobacterium Tuberculosis (MTb) is an intracellular pathogen, it could play an active role in the cellular transformation. Our group performed an exploratory study in a cohort of 88 LC patients treated at the Instituto Nacional de Cancelorogía (INCan) of Mexico City to evaluate the presence of MTb DNA in LC tissue specimens. For the first time, our results show the presence of the MTb IS6110 transposon in 40.9% (n = 36/88) of patients with lung adenocarcinomas. Additionally, through in-situ PCR we identified the presence of IS6110 in the nuclei of tumor cells. Furthermore, shotgun sequencing from two samples identified traces of MTb genomes present in tumor tissue, suggesting that similar Mtb strains could be infecting both patients.

Targeting interleukin-1β and inflammation in lung cancer

Inflammation is a process that protects organs against various potentially harmful stimuli and enables repair. Dysregulated inflammation, however, damages tissues and leads to disease, including cancer. Cancer-related inflammation is characterized by cytokine production, leukocyte infiltration, angiogenesis, and tissue remodeling—all critical processes in modulating the tumor microenvironment (TME). The TME is known to play a key role in tumor progression, and targeting its immune component to achieve a better anti-tumor response is the basis of immunotherapy. Despite the critical role cytokines play in the TME and tumor progression, there is currently only one therapy approved by the FDA that directly involves cytokine signaling: human recombinant interleukin-2 protein, aldesleukin. The recent Canakinumab Anti-inflammatory Thrombosis Outcomes Study (CANTOS) trial evaluated the use of anti-interleukin-1β therapy in atherosclerotic disease; however, it also revealed interleukin-1β (IL-1β) blockade with canakinumab led to a significantly lower incidence of lung cancer. This has opened a promising new avenue for lung cancer therapy, and strategies using anti-IL-1β therapy alone or in combination with chemotherapy and/or immune checkpoint blockade are currently being evaluated in several clinical trials.

Polymorphonuclear myeloid-derived suppressor cells link inflammation and damage response after trauma

Elimination of the posttraumatic inflammatory response and recovery of homeostasis are crucial for the positive prognosis of trauma patients. Myeloid-derived suppressor cells (MDSCs) are known to play a regulatory role in the posttraumatic immune response in mice, but their induction source and involved potential mechanism are poorly understood. Here, we report that polymorphonuclear MDSCs (PMN-MDSCs) are activated after trauma and are closely associated with the progression of the posttraumatic inflammatory response. In humans, lectin-type oxidized LDL receptor 1 (LOX1) was used to specifically characterize LOX1⁺ PMN-MDSCs. Trauma patients showed high intracellular reactive oxygen species (ROS) production, as well as activation of LOX1⁺ PMN-MDSCs. These MDSCs contribute to the anti-inflammatory immune response by regulating the Treg/Th17 and Th2/Th1 balances after trauma, increasing the levels of anti-inflammatory factors, and decreasing the levels of proinflammatory factors. The number of LOX1⁺ PMN-MDSCs was positively correlated with the positive clinical prognosis of trauma patients with infection. Activation of LOX1⁺ PMN-MDSCs is mediated by NF-κB signal, and TGF-β1 may be as an important inducer for LOX1⁺ PMN-MDSCs in the posttraumatic cytokine environment. In a pseudofracture trauma mouse model, we also observed the activation of PMN-MDSCs, accompanying high levels of intracellular ROS production, NF-κB phosphorylation, and changes in the inflammatory environment, in particularly by regulating the Treg/Th17 and Th2/Th1 balance. And more significantly, posttraumatic inflammation was alleviated in mice after transferring trauma-derived PMN-MDSCs, but aggravated after injecting with Gr1 agonistic antibody. These findings provide evidence for the specific role of PMN-MDSCs in the regulation of posttraumatic inflammation.

Elevations of monocyte and neutrophils, and higher levels of granulocyte colony-stimulating factor in peripheral blood in lung cancer patients

Introduction

Immune cells and molecules are considered as clinical biomarkers and potential targets for immunotherapy. Analyses of the composition of peripheral blood cells hold promise for providing a basis for diagnosing and prognosis lung cancer. In this study, we assessed correlations between immune cell subset profiles in peripheral blood and disease prognosis in patients with lung cancer.

Methods

One hundred and thirteen patients with lung cancer and 99 age‐matched healthy people were enrolled in this study. The percentage and cell count of monocytes, neutrophils, T cells, B cells, natural killer (NK), and NKT cells in peripheral blood were analyzed by flow cytometry or peripheral blood analyzer. Serum cytokines and colony‐stimulating factors were detected by enzyme‐linked immunosorbent assay (ELISA).

Results

A reduction in antitumor NK cells (p < 0.0001) and an increase in the protumor MDSCs (p < 0.0001) were observed in the lung cancer patients compared with the controls. Monocyte counts were significantly higher in lung cancer patients with histories of smoking (p < 0.05) or drinking (p < 0.01) than in patients with no relevant history or healthy controls. The number of neutrophils and the neutrophil‐to‐lymphocyte ratio (NLR) were particularly higher in patients with liver metastasis (p < 0.01) compared with no metastasis patients or healthy controls. Levels of the monocyte‐derived cytokine interleukin‐6 (p < 0.05), granulocyte colony‐stimulating factor (G‐CSF) (p < 0.0001), and granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) (p < 0.0001) were higher in patients than in controls. G‐CSF levels decreased during the remission phase (p < 0.05), and positively correlated with carbohydrate antigen 19–9 (p < 0.05) and gene mutation (p < 0.05).

Conclusion

Monocyte and neutrophil counts were higher in peripheral blood in lung cancer patients than in controls, especially when patients had histories of smoking, drinking, and liver metastasis. Serum levels of G‐CSF and GM‐CSF were higher in lung cancer patients, and G‐CSF levels positively correlated with disease severity.

Targeting MDSC for Immune-Checkpoint Blockade in Cancer Immunotherapy: Current Progress and New Prospects

Immune-checkpoint blockade (ICB) demonstrated inspiring effect and great promise in anti-cancer therapy. However, many obstacles, such as drug resistance and difficulty in patient selection, limited the efficacy of ICB therapy and awaited to be overcome. By timely identification and intervention of the key immune-suppressive promotors in the tumor microenvironment (TME), we may better understand the mechanisms of cancer immune-escape and use novel strategies to enhance the therapeutic effect of ICB. Myeloid-derived suppressor cell (MDSC) is recognized as a major immune suppressor in the TME. In this review, we summarized the roles MDSC played in the cancer context, focusing on its negative biologic functions in ICB therapy, discussed the strategies targeted on MDSC to optimize the diagnosis and therapy process of ICB and improve the efficacy of ICB therapy against malignancies.

Engineered hypoxia-responding Escherichia coli carrying cardiac peptide genes, suppresses tumor growth, angiogenesis and metastasis in vivo

Development of engineered non-pathogenic bacteria, capable of expressing anti-cancer proteins under tumor-specific conditions, is an ideal approach for selectively eradicating proliferating cancer cells. Herein, using an engineered hypoxia responding nirB promoter, we developed an engineered Escherichia coli BW25133 strain capable of expressing cardiac peptides and GFP signaling protein under hypoxic condition for spatiotemporal targeting of mice mammary tumors. Following determination of the in vitro cytotoxicity profile of the engineered bacteria, selective accumulation of bacteria in tumor microenvironment was studied 48 h after tail vein injection of 108 cfu bacteria in animals. For in vivo evaluation of antitumoral activities, mice with establishment mammary tumors received 3 consecutive intravenous injections of transformed bacteria with 4-day intervals and alterations in expression of tumor growth, invasion and angiogenesis specific biomarkers (Ki-67, VEGFR, CD31and MMP9 respectively), as well as fold changes in concentration of proinflammatory cytokines were examined at the end of the 24-day study period. Intravenously injected bacteria could selectively accumulate in tumor site and temporally express GFP and cardiac peptides in response to hypoxia, enhancing survival rate of tumor bearing mice, suppressing tumor growth rate and expression of MMP-9, VEGFR2, CD31 and Ki67 biomarkers. Applied engineered bacteria could also significantly reduce concentrations of IL-1β, IL-6, GC-SF, IL-12 and TNF-α proinflammatory cytokines while increasing those of IL-10, IL-17A and INF-γ. Overall, administration of hypoxia-responding E. coli bacteria, carrying cardiac peptide expression construct could effectively suppress tumor growth, angiogenesis, invasion and metastasis and enhance overall survival of mice bearing mammary tumors.

Circulating CD15+ LOX-1+ PMN-MDSCs are a potential biomarker for the early diagnosis of non-small-cell lung cancer

AIMS

Non-small-cell lung cancer (NSCLC) is the most common clinical lung cancer. Polymorphonuclear-myeloid derived suppressor cells (PMN-MDSCs), which are the major population of MDSCs, are involved in NSCLC progression. Recently, it was found that lectin-type oxidized LDL receptor 1 (LOX-1) could identify human PMN-MDSCs. However, the role of CD15⁺ LOX-1⁺ PMN-MDSCs in NSCLC early diagnosis has not been revealed. Here, we tried to confirm the application of the newly identified CD15⁺ LOX-1⁺ PMN-MDSCs in the early diagnosis of NSCLC.

METHODS

Flow cytometry (FCM) was used to detect the proportion of CD15⁺ LOX-1⁺ PMN-MDSCs in the peripheral blood (PB) of healthy controls (HC) and NSCLC patients. The correlation of CD15⁺ LOX-1⁺ PMN-MDSC frequency with levels of cytokeratin 19-fragments (CYFRA21-1), carcinoembryonic antigen (CEA), and carbohydrate antigen 125 (CA125) was analysed. Receiver operating characteristic (ROC) curve was used to estimate the diagnostic efficacy of CD15⁺ LOX-1⁺ PMN-MDSCs for NSCLC. Additionally, the association of CD15⁺ LOX-1⁺ PMN-MDSC frequency with NSCLC prognosis/recurrence after surgery was explored.

RESULTS

The proportion of CD15⁺ LOX-1⁺ PMN-MDSCs increased in PB of NSCLC patients. CD15⁺ LOX-1⁺ PMN-MDSC proportion was positively correlated with levels of CEA, CA125 and CYFRA21-1. Detection of PMN-MDSC percentage in PB owed high sensitivity and specificity for NSCLC diagnosis. The proportion of CD15⁺ LOX-1⁺ PMN-MDSCs decreased in patients after surgery. The frequency of CD15⁺ LOX-1⁺ PMN-MDSCs was lower in NSCLC patients without recurrence compared to those with recurrence after surgery.

CONCLUSIONS

Circulating CD15⁺ LOX-1⁺ PMN-MDSCs are a potential diagnostic marker for NSCLC, and are associated with NSCLC prognosis and recurrence after surgery.

Tumor promoting capacity of polymorphonuclear myeloid-derived suppressor cells and their neutralization

Myeloid-derived suppressor cells (MDSC) represent a highly immunosuppressive population that expands in tumor bearing hosts and inhibits both T and NK cell antitumor effector functions. Among MDSC subpopulations, the polymorphonuclear (PMN) one is gaining increasing interest since it is a predominant MDSC subset in most cancer entities and inherits unique properties to facilitate metastatic spread. In addition, further improvement in distinguishing PMN-MDSC from neutrophils has contributed to the design of novel therapeutic approaches. In this review, we summarize the current view on the origin of PMN-MDSC and their relation to classical neutrophils. Furthermore, we outline the metastasis promoting features of these cells and promising strategies of their targeting to improve the efficacy of cancer immunotherapy.

Pancreatic cancer is associated with aberrant monocyte function and successive differentiation into macrophages with inferior anti-tumour characteristics

BACKGROUND/OBJECTIVES

Inflammation is related to the development and progression of pancreatic cancer (PC). Locally, anti-inflammatory macrophages (M2), and systemically, high levels of certain inflammation-modulating cytokines associate with poor prognosis in PC. The detailed effects of systemic inflammation on circulating monocytes and macrophage polarisation remain unknown. We aimed to find out how intracellular signalling of peripheral blood monocytes is affected by the systemic inflammatory state in PC patients and how it affects their differentiation into macrophages.

METHODS

Monocytes were isolated from 50 consenting PC patients and 20 healthy controls (HC). The phosphorylation status of the signalling molecules was assessed by flow cytometry both from unstimulated and appropriately stimulated monocytes. Monocytes derived from HC and PC patients were co-cultured with cancer cells (MIA PaCa-2 and HPAF-II) in media supplemented with autologous serum, and the CD marker expression of the obtained macrophages was assessed by flow cytometry.

RESULTS

Phosphorylation levels of unstimulated STAT2, STAT3 and STAT6 were higher (p < 0.05) and those of stimulated NF-kB (p = 0.004) and STAT5 (p = 0.006) were lower in patients than in controls. The expression of CD86, a proinflammatory (M1) marker, was higher in control- than patient-derived co-cultured macrophages (p = 0.029).

CONCLUSIONS

Circulating monocytes from PC patients showed constitutive phosphorylation and weaker response to stimuli, indicating aberrant activation and immune suppression. When co-culturing the patient-derived monocytes with cancer cells, they differentiated into macrophages with reduced levels of M1 macrophage marker CD86, suggesting compromised anti-tumour features. The results highlight the need for global management of tumour-associated immune aberrations in PC treatment.

Immune Modulation in Lung Cancer: Current Concepts and Future Strategies

Cancer immunotherapy represents the most dynamic field of biomedical research currently, with thoracic immuno-oncology as a forerunner. PD-(L)1 inhibitors are already part of standard first-line treatment for both non-small-cell and small-cell lung cancer, while unprecedented 5-year survival rates of 15-25% have been achieved in pretreated patients with metastatic disease. Evolving strategies are mainly aiming for improvement of T-cell function, increase of immune activation in the tumor microenvironment (TME), and supply of tumor-reactive lymphocytes. Several novel therapeutics have demonstrated preclinical efficacy and are increasingly used in rational combinations within clinical trials. Two overarching trends dominate: extension of immunotherapy to earlier disease stages, mainly as neoadjuvant treatment, and a shift of focus towards multivalent, individualized, mutatome-based antigen-specific modalities, mainly adoptive cell therapies and cancer vaccines. The former ensures ample availability of treated and untreated patient samples, the latter facilitates deeper mechanistic insights, and both in combination build an overwhelming force that is accelerating progress and driving the greatest revolution cancer medicine has seen so far. Today, immune modulation represents the most potent therapeutic modality in oncology, the most important topic in clinical and translational cancer research, and arguably our greatest, meanwhile justified hope for achieving cure of pulmonary neoplasms and other malignancies in the next future.

Circulating Myeloid-derived Suppressor Cells Facilitate Invasion of Thyroid Cancer Cells by Repressing miR-486-3p

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) have become increasingly recognized as facilitators of tumor development. However, the role of MDSCs in papillary thyroid carcinoma (PTC) progression has not been clearly explored.

OBJECTIVE

We aimed to evaluate the levels and function of circulating MDSCs in PTC.

METHODS

The proportion of circulating polymorphonuclear (PMN)-MDSCs and mononuclear-MDSCs from patients with PTC or benign thyroid nodules and healthy controls was measured using flow cytometry. For immunosuppressive activity analysis, sorted circulating MDSCs were cocultured with CD3/CD28-costimulated T lymphocytes and the proliferation of T cells was determined. PTC cell lines (TPC-1 and BC-PAP) were cocultured with PMN-MDSCs, and the effects on cell migration, invasion, proliferation, and apoptosis were evaluated. The differential expressed microribonucleic acids (RNAs) and messenger RNAs and their function were also explored in TPC-1 cells cocultured with or without PMN-MDSCs.

RESULTS

PMN-MDSCs were increased in peripheral blood mononuclear cells of patients with PTC. Circulating PMN-MDSCs displayed strong T cell suppressive activity. PTC cells demonstrated enhanced invasive capabilities in vitro and in vivo when cocultured with sorted PMN-MDSCs. PMN-MDSCs decreased expression of miR-486-3p and activated nuclear factor kappa B2 (NF-κB2), a direct target of miR-486-3p. Rescue of miR-486-3p diminished the cell migration and invasion induced by PMN-MDSCs.

CONCLUSION

Collectively, our work indicates that circulating PMN-MDSCs promote PTC progression. By suppressing miR-486-3p, PMN-MDSCs promote the activity of the NF-κB2 signaling pathway, resulting in accelerated invasion of PTC cells, which may provide new therapeutic strategies for treatment of thyroid cancer.

Pharmacokinetics and Systems Pharmacology of Anti-CD47 Macrophage Immune Checkpoint Inhibitor Hu5F9-G4

Background:

Hu5F9-G4, a human immunoglobulin G4 (IgG4) monoclonal antibody (mAb) has recently been granted fast-track designation by the FDA for the treatment of relapsed or refractory diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma. Hu5F9-G4 has the ability to block CD47-SIRPα signaling along with anti- EGFR and anti-PD-L1 immune checkpoint activity that is involved in a variety of cancers like solid tumors, Non-Hodgkin’s Lymphoma (NHL), colorectal cancer (CRC), breast, ovarian and bladder cancers, and hematological malignancies. Thus, Hu5F9-G4 is an important biologic that has increasing clinical relevance in cancer care.

Methods:

We queried PubMed, Web of Science, Google Scholar, Science Direct and Scopus databases with keywords pertaining to Hu5F9-G4. In addition, we have included the Hu5F9-G4 data presented at the 60th American Society of Hematology (ASH) Annual Meeting, the American Society of Clinical Oncology (ASCO) Annual Meeting and 23rd Congress of the European Hematology Association (EHA).

Results:

We discuss the mechanistic basis and preclinical evidence for the anticancer activity of Hu5F9-G4. Further, we delineate clinical studies, alone and in combination with anti-CD20 mAb rituximab, anti-EGFR mAb cetuximab, PD-L1 checkpoint inhibitors avelumab and atezolizumab, and anti-HER2 mAb trastuzumab. Moreover, the potential adverse effects, pharmacokinetics, and pharmacodynamics of Hu5F9-G4 with emphasis on the role of CD47-SIRPα signaling in phagocytosis are presented.

Conclusions:

Taken together, we review the pharmacokinetics and systems pharmacology of Hu5F9-G4 which appears to hold great promise for the future of cancer care.

Myeloid-derived suppressor cells infiltration in non-small-cell lung cancer tumor and MAGE-A4 and NY-ESO-1 expression

Cancer/testis antigens melanoma-associated antigen 4 (MAGE-A4) and New York esophageal squamous cell carcinoma-1 (NY-ESO-1) are of clinical interest as biomarkers and present valuable targets for immunotherapy; however, they are poor prognostic markers in non-small cell lung cancer (NSCLC). In addition, myeloid derived suppressor cells (MDSCs) are recognized as a key element in tumor escape and progression. The aim of the present study was to investigate the diagnostic and prognostic value of MAGE-A4 and NY-ESO-1, and their association with MDSCs in NSCLC samples. The expression levels of MAGE-A4 and NY-ESO-1, and the infiltration of MDSCs (CD33⁺), were analyzed by immunohistochemistry of 67 tissue samples from patients with NSCLC. Overall, 58.33% of the NSCLC squamous cell carcinoma tissues and 94.7% of adenocarcinoma tissues were positive for MAGE-A4. NY-ESO-1 expression was observed in 52.78% of the squamous cell carcinoma tissues and 80% of the adenocarcinoma tissues. In primary adenocarcinoma tumor tissues, MAGE-A4 and NY-ESO-1 demonstrated a higher intensity of expression compared with the squamous cell carcinoma tissues. A total of 33 (91.7%) squamous cell carcinoma and 19 (95.0%) adenocarcinoma specimens were positive for CD33. The expression of MAGE-A4 and NY-ESO-1 antigens and infiltration of MDSCs was associated with poor prognosis of patients with NSCLC. Further studies investigating the association between these findings and underlying molecular mechanisms are required.

Myeloid derived suppressor cells contribute to the malignant progression of oral squamous cell carcinoma

Purpose

The tumor-related myeloid derived suppressor cells (MDSCs), important immunosuppressive cells in tumor microenvironment, play an important role in the cancer progression. This study is aimed to investigate the crosstalk between MDSCs and oral squamous cell carcinoma (OSCC) cells and their role in the malignant progression of OSCC.

Methods

Immunochemistry (IHC) was used to investigate the expression of CD33 in 200 OSCC, 36 premalignant. CD33⁺ MDSCs were sorted and enriched via magnetic-activated cell sorting (MACS) from OSCC patients or health donor, and their phenotypes were identified by flow cytometry. With a co-culture system of MDSCs and OSCC, the effects of MDSCs on OSCC proliferation, apoptosis, migration invasion, epithelial-mesenchymal transition (EMT), and vasculogenic mimicry formation (VM) formation were assessed, respectively. Besides, peripheral blood mononuclear cells (PBMCs) from health donor were cultured with OSCC supernatant, the level of MDSCs and expressions of Arginase (Arg-1) and inducible nitric oxide synthase (iNOS) were measured.

Results

The number of MDSCs was increased in tumor tissues of OSCC patients, and was positively related to the T stage, pathological grade, lymph node metastasis and poor prognosis. Tumor-related MDSCs of the co-culture system promoted OSCC progression by contributing to cell proliferation, migration and invasion as well as inducing EMT and VM. In turn, OSCC cells had potential to induce MDSCs differentiation from PBMCs and increase the expression of Arg-1 and iNOS.

Conclusion

These indicated that the crosstalk between MDSCs and tumor cells facilitated the malignant progression of OSCC cells and the immune suppressive properties of MDSCs, which may provide new insights into tumor treatment on targeting tumor-associated immunosuppressive cells.

Interleukin-27 is abrogated in gastric cancer, but highly expressed in other Helicobacter pylori-associated gastroduodenal diseases

BACKGROUND

IL-27 has dual roles in the immune response either stimulating Th1 or inhibiting Th17 cells. Because there is a particular link of IL-23/Th17 axis in the development of cancer and IL-27 has been considered a potential treatment for cancer, we evaluated the gastric and serum concentrations of IL-27 in two mutually exclusive Helicobacter pylori-associated diseases, gastric cancer (GC) and duodenal ulcer (DU).

MATERIAL AND METHODS

We prospectively studied 110 H pylori-positive patients and 40 healthy blood donors. Serum and gastric concentrations of IL-27 and cytokines of the Th1/Th17 cells were assessed by ELISA.

RESULTS

IL-27 was not detected in GC patients, but the cytokine concentration was very high in the patients with DU. IL-27 was also detected in the gastritis patients and in the H pylori-positive blood donors. IL27RA mRNA expression in peripheral blood mononuclear cells, evaluated by rt-PCR, was stimulated by H pylori strains. The cytokine concentration positively correlated with the Th1 and negatively with Th17 cell representative cytokine levels. Gastric IL-27 concentrations were positively correlated with increased degree of mononuclear and polymorphonuclear cells on the antral gastric mucosa of DU patients in consonance with the DU gastritis pattern. IL-12p70 and IFN-γ gastric concentrations were significantly higher in DU than in GC. Conversely, gastric concentrations of Th17 cell-associated cytokines (IL-1β, IL-6, IL-17A, IL-23, and TGF-β) were significantly higher in GC than in DU patients.

CONCLUSION

Although H pylori infection is able to elicit IL-27 and IL-27Rα secretion, DU and GC have diametrically opposed cytokine patterns.

LOX-1+ PMN-MDSC enhances immune suppression which promotes glioblastoma multiforme progression

Background/aims

Patients with glioblastoma multiforme (GBM) that is the most common brain cancer in adults have a rather poor prognosis. The accumulation of immune suppressive myeloid-derived suppressor cell (MDSC) is negatively associated with clinical outcomes in various cancers. A recent study identified that lectin-type oxidized LDL receptor 1 (LOX-1) may serve as a specific marker of human polymorphonuclear neutrophil (PMN)-MDSC. Thus, herein we focused on exploring the role of LOX-1+ PMN-MDSC in GBM progression.

Methods

LOX-1, IFN-γ, dichlorodihydrofluorescein diacetate (DCFDA), CD15, CD4 and CD8 expression levels were examined by flow cytometry. ARG1 and iNOS expression levels in PMN were examined by quantitative real-time PCR. LOX-1 and CD15 expression levels in tumor tissue were determined by immunofluorescent microscopy. T cell proliferation was determined by 3H-thymidine incorporation.

Results

We identified a protumorigenic subset of PMN, which constitutively expressed LOX-1 and accumulated in the peripheral blood of GBM patients. Compared to LOX-1− PMN, the LOX-1+ PMN exhibited a PMN MDSC profile, with a significant increase in the expression of DCFDA, ARG1 and iNOS, and the capacity of inhibiting the CD3+ T cell proliferation in a dependent-ARG1/iNOS way. Additionally, we found that LOX-1+ PMN negatively correlated with effector immune cells in GBM patients, accumulated in GBM tissues, and was related to early recurrence and disease progression tightly.

Conclusion

Our study revealed that LOX-1+ PMN-MDSC inhibited the T cell proliferation to enhance immune suppression, which may play a key role in driving the GBM progression.

Peri-operative monocyte count is a marker of poor prognosis in gastric cancer: increased monocytes are a characteristic of myeloid-derived suppressor cells

Gastric cancer (GC) is the most common malignant tumor in digestive organs, and the prognosis of GC patients who have undergone surgery remains poor because of frequent recurrence. Therefore, the identification of new markers to predict the outcome of these patients is needed. Monocyte count is a negative prognostic factor associated with inflammation. We investigated the relationship between peripheral monocytes in the peri-operative period and prognosis in GC patients. A high pre-operative monocyte count was identified as a prognostic factor in a retrospective analysis of 278 stage II and III GC patients who underwent curative gastrectomy. In contrast, an increased post-operative monocyte count compared to the pre-operative monocyte count was a marker of poor prognosis, particularly for early relapse. In a prospective analysis of 75 GC patients, a subset of the increased post-operative monocytes was similar to CD14+ HLA-DR- CD11b+ CD33+ cells by flow cytometry, and these monocytes produced IDO and arginase and suppressed T cell functions; therefore, we classified these cells as monocytic myeloid-derived suppressive cells (M-MDSCs). Peri-operative neutrophils and C-reactive protein (CRP), which are also related to inflammation, did not affect the prognosis of GC patients, and a neutrophil immunosuppressive function was not observed. These results suggest that peripheral monocytes in the peri-operative period in GC patients are a useful marker for the prognosis of GC patients, and a subset of increased post-operative monocytes may be characterized as M-MDSCs.

Macrophage-derived CCL22 promotes an immunosuppressive tumor microenvironment via IL-8 in malignant pleural effusion

Immune dysfunction often occurs in malignant pleural effusion (MPE). In our previous study, TGF-β derived predominantly from macrophages plays an important role in impairing T cell cytotoxicity in MPE. Therefore, we aimed to investigate whether other immunoregulatory cells and factors mediated TGF-β secretion from macrophages, involved in the immunosuppressive microenvironment of MPE, and to provide clues for potential immune therapy for MPE as well. We found that CCL22 level in MPE was significantly higher than that in non-malignant pleural effusion. The high level of CCL22 was closely associated with poor survival in MPE patients with lung cancer. CCL22 was dominantly produced by tumor-associated macrophages (TAMs) in MPE. Meanwhile, TAM-derived TGF-β mediated CCL22 expression in TAMs via c-Fos. CCL22 promoted the recruitment of regulatory T cells (Tregs) in MPE. Lastly, Treg-secreted high level of IL-8 further induced TGF-β production from TAMs, and promoted the immunosuppressive tumor microenvironment in MPE. Our results indicate that macrophage-derived CCL22 plays an important role in the immunosuppressive tumor microenvironment via IL-8 in MPE.

Making cold malignant pleural effusions hot: driving novel immunotherapies

Malignant pleural effusions, arising from either primary mesotheliomas or secondary malignancies, heralds advanced disease and poor prognosis. Current treatments, including therapeutic thoracentesis and tube thoracostomy, are largely palliative. The immunosuppressive environment within the pleural cavity includes myeloid derived suppressor cells, T-regulatory cells, and dysfunctional T cells. The advent of effective immunotherapy with checkpoint inhibitors and adoptive cell therapies for lung cancer and other malignancies suggests a renewed examination of local and systemic therapies for this malady. Prior strategies reporting remarkable success, including instillation of the cytokine interleukin-2, perhaps coupled with checkpoint inhibitors, should be further evaluated in the modern era.