Peritumoural neutrophils negatively regulate adaptive immunity via the PD-L1/PD-1 signalling pathway in hepatocellular carcinoma

Two-Faced Roles of Tumor-Associated Neutrophils in Cancer Development and Progression

Neutrophils are the most abundant circulating leukocytes in humans. Neutrophil infiltration into tumor tissues has long been observed but its roles have been ignored due to the presumed short life cycle and metabolic incompetence of neutrophils. Recent advances in neutrophil biology research have revealed that neutrophils have a longer life cycle with a potential to express various bioactive molecules. Clinical studies have simultaneously unraveled an increase in the neutrophil-lymphocyte ratio (NLR), a ratio of absolute neutrophil to absolute lymphocyte numbers in cancer patient peripheral blood and an association of higher NLR with more advanced or aggressive disease. As a consequence, tumor-associated neutrophils (TANs) have emerged as important players in tumor microenvironment. The elucidation of the roles of TANs, however, has been hampered by their multitude of plasticity in terms of phenotypes and functionality. Difficulties are further enhanced by the presence of a related cell population-polymorphonuclear leukocyte (PMN)-myeloid-derived suppressor cells (MDSCs)-and various dissimilar aspects of neutrophil biology between humans and mice. Here, we discuss TAN biology in various tumorigenesis processes, and particularly focus on the context-dependent functional heterogeneity of TANs.

Extracellular Vesicles From Gastric Cancer Cells Induce PD-L1 Expression on Neutrophils to Suppress T-Cell Immunity

Neutrophils are prominent components of solid tumors and exhibit distinct phenotypes in different tumor milieu. We have previously shown that tumor extracellular vesicles (EVs) could induce pro-tumor activation of neutrophils; however, the role of tumor EV-elicited neutrophils in tumor immunity remains unclear. Herein, we reported that gastric cancer cell-derived EVs (GC-EVs) induced the expression of programmed death-ligand 1 (PD-L1) on neutrophils. GC-EVs transported high-mobility group box-1 (HMGB1) to activate signal transducer and activator of transcription 3 (STAT3) and upregulate PD-L1 gene expression in neutrophils. Blocking STAT3 pathway and silencing HMGB1 reversed GC-EV-induced PD-L1 expression on neutrophils. GC-EV-elicited neutrophils suppressed T cell proliferation, activation, and function in vitro, which could be antagonized by a specific PD-L1 antibody. Furthermore, GC tissue-derived EVs also showed similar effects. Taken together, our results indicate that EVs from the GC microenvironment induce PD-L1 expression on neutrophils to suppress T-cell immunity, which provides a new insight into the pro-tumor roles of neutrophils in GC and sheds light on the multifaceted roles of EVs in orchestrating an immunosuppressive microenvironment.

Current advances in PD-1/PD-L1 axis-related tumour-infiltrating immune cells and therapeutic regimens in glioblastoma

Glioblastoma (GBM) is the most common malignant tumour in the brain, and current treatments are not curative and cannot control recurrence. This limitation indirectly places immunotherapy at the focus of translational GBM research. Many studies on the PD-1/PD-L1 axis in GBM are ongoing, and the immunosuppressive mechanism of PD-1/PD-L1 in GBM is different from that in other solid tumours. This review focuses on the effect of the PD-1/PD-L1 axis on infiltrating immune cells in the suppressive GBM immune microenvironment and summarizes the recent progress in PD-1/PD-L1 axis-related therapies reported in preclinical and clinical GBM studies, providing a reference for the systematic study of PD-1/PD-L1 axis-related anti-GBM immunity.

Circulating Neutrophils Predict Poor Survival for HCC and Promote HCC Progression Through p53 and STAT3 Signaling Pathway

Background: Tumor-associated neutrophils (TANs) contribute to tumor progression, invasion, and angiogenesis. However, most studies focus on tumor infiltration neutrophils while the roles of circulating neutrophils in tumor progression remain unclear. This study was aimed to verify the pro-tumor effects of circulating neutrophils and its' mechanism in HCC.

Methods: We collected clinical data of 127 HCC patients underwent TACE. The prognostic factors for overall survival (OS) were analyzed by Kaplan-Meier curve and Cox models. Circulating neutrophils of HCC patients were sorted and co-cultured with human HCC cell lines MHCC-97H and SMMC-7721. Then we detected tumor cells' proliferation, migration, and invasion. Phosphokinase array was used to determine the kinase profile on MHCC-97H and SMMC-7721 cultured with or without circulating neutrophils.

Results: The result of multivariate analyses of 127 patients showed that increased circulating neutrophils was an independent poor prognostic factor for OS of HCC patients underwent TACE. Circulating neutrophils promoted migration and invasion of HCC cell lines but had no impact on proliferation. The kinase profile on HCC cell lines showed that p-p53^S46 and p-STAT3^Y705 were up-regulated after co-cultured with circulating neutrophils. Repeated scratch tests and transwell tests showed a reversed impact on migration and invasion of circulating neutrophils after we treated HCC cell lines with inhibitors of p53 or STAT3.

Conclusion: Circulating neutrophils was an independent poor prognostic factor for OS of HCC patients underwent TACE. It had pro-tumor effect on HCC through p53 and STAT3 signaling pathway.

The complexity of neutrophils in health and disease: Focus on cancer

Neutrophils are essential soldiers of the immune response and their role have long been restricted to their activities in defence against microbial infections and during the acute phase of the inflammatory response. However, increasing number of investigations showed that neutrophils are endowed with plasticity and can participate in the orchestration of both innate and adaptive immune responses. Neutrophils have an impact on a broad range of disorders, including infections, chronic inflammations, and cancer. Neutrophils are present in the tumour microenvironment and have been reported to mediate both pro-tumour and anti-tumour responses. Neutrophils can contribute to genetic instability, tumour cell proliferation, angiogenesis and suppression of the anti-tumour immune response. In contrast, neutrophils are reported to mediate anti-tumour resistance by direct killing of tumour cells or by engaging cooperative interactions with other immune cells. Here we discuss the current understandings of neutrophils biology and functions in health and diseases, with a specific focus on their role in cancer biology and their prognostic significance in human cancer.

Development of an immune-related prognostic index associated with hepatocellular carcinoma

Liver hepatocellular carcinoma (LIHC), an inflammation-associated cancer induced by a variety of etiological factors, is still one of the most prevalent and lethal cancers in human population. In this study, the expression profiles of immune-related genes (IRGs) were integrated with the overall survival (OS) of 378 LIHC patients based on the Cancer Genome Atlas (TCGA) dataset. Moreover, the differentially expressed and survival related IRGs among LIHC patients were predicted through the computational difference algorithm and COX regression analysis. As a result, 7 genes, including HSPA4, S100A10, FABP6, CACYBP, HDAC1, FCGR2B and SHC1, were retrieved to construct a predictive model associated with the overall survival (OS) of LIHC patients. Typically, the as-constructed model performed moderately in predicting prognosis, which was also correlated with tumor grade. Functional enrichment analysis revealed that the genes of high-risk group were actively involved in mRNA binding and the spliceosome pathway. Intriguingly, the prognostic index established based on IRGs reflected infiltration by multiple types of immunocytes. Our findings screen several IRGs with clinical significance, reveal the drivers of immune repertoire, and illustrate the importance of a personalized, IRG-based immune signature in LIHC recognition, surveillance, and prognosis prediction.

Differential expression of Tim-3, PD-1, and CCR5 on peripheral T and B lymphocytes in hepatitis C virus-related hepatocellular carcinoma and their impact on treatment outcomes

BACKGROUND AND OBJECTIVE

Activation of the immune checkpoints and expression of chemokines and chemokine receptors have been reported to promote HCC progression. This study aimed to assess the differential expression of Tim-3, PD-1, and CCR5 on peripheral blood lymphocytes from patients with HCV-related HCC and correlate their expression with the treatment outcomes.

PATIENTS AND METHODS

The study incorporated 40 patients with chronic HCV-related HCC and 40 healthy controls. Patients were radiologically assessed for hepatic focal lesions and portal vein thrombosis. Response to HCC treatment and overall survival (OS) outcomes were determined. The expression of Tim-3, PD-1, and CCR5 among CD19⁺, CD4⁺, and CD8⁺ lymphocytes was assessed by flow cytometry.

RESULTS

Higher frequencies of CD4⁺ and CD8⁺ cells expressing each of Tim-3 and PD-1 and PD-1⁺CD19⁺ cells were observed in the HCV-related HCC patients in comparison with controls. The highest expression of Tim-3 and PD-1 was by the CD8⁺ cells. Strong relations were detected among PD-1⁺CD19⁺, PD-1⁺CD4⁺ and PD-1⁺CD8⁺ cells. Elevated levels of PD-1⁺ lymphocytes were significantly associated with poor treatment response and shorter OS.

CONCLUSION

Modulation of the expression of immune checkpoints as Tim-3 and PD-1, and of CCR5 on T cells is somehow related to HCC. CD8⁺ T cells expressing PD-1 were the most relevant to HCC prognosis (OS and treatment response) and could represent a promising target for immune therapy against HCC. Future studies need to focus on exploring PD-1⁺ B cells and Tim-3⁺CD4⁺ cells, which seem to play a significant role in the pathogenesis of HCC.

Neutrophils Deficient in Innate Suppressor IRAK-M Enhances Anti-tumor Immune Responses

Tumor-associated immune-suppressive neutrophils are prevalent in various cancers, including colorectal cancer. However, mechanisms of immune-suppressive neutrophils are not well understood. We report that a key innate suppressor, IRAK-M (interleukin-1 receptor-associated kinase M), is critically involved in the establishment of immune-suppressive neutrophils. In contrast to the wild-type (WT) neutrophils exhibiting immune-suppressive signatures of CD11bhighPD-L1highCD80low, IRAK-M-deficient neutrophils are rewired with reduced levels of inhibitory molecules PD-L1 and CD11b, as well as enhanced expression of stimulatory molecules CD80 and CD40. The reprogramming of IRAK-M-deficient neutrophils is mediated by reduced activation of STAT1/3 and enhanced activation of STAT5. As a consequence, IRAK-M-deficient neutrophils demonstrate enhanced capability to promote, instead of suppress, the proliferation and activation of effector T cells both in vitro and in vivo. Functionally, we observed that the transfusion of IRAK-M-/- neutrophils can potently render an enhanced anti-tumor immune response in the murine inflammation-induced colorectal cancer model. Collectively, our study defines IRAK-M as an innate suppressor for neutrophil function and reveals IRAK-M as a promising target for rewiring neutrophils in anti-cancer immunotherapy.

A model combining clinical and genomic factors to predict response to PD-1/PD-L1 blockade in advanced urothelial carcinoma

Background

In metastatic urothelial carcinoma (mUC), predictive biomarkers that correlate with response to immune checkpoint inhibitors (ICIs) are lacking. Here, we interrogated genomic and clinical features associated with response to ICIs in mUC.

Methods

Sixty two mUC patients treated with ICI who had targeted tumour sequencing were studied. We examined associations between candidate biomarkers and clinical benefit (CB, any objective reduction in tumour size) versus no clinical benefit (NCB, no change or objective increase in tumour size). Both univariable and multivariable analyses for associations were conducted. A comparator cohort of 39 mUC patients treated with taxanes was analysed by using the same methodology.

Results

Nine clinical and seven genomic factors correlated with clinical outcomes in univariable analysis in the ICI cohort. Among the 16 factors, neutrophil-to-lymphocyte ratio (NLR) ≥5 (OR = 0.12, 95% CI, 0.01–1.15), visceral metastasis (OR = 0.05, 95% CI, 0.01–0.43) and single-nucleotide variant (SNV) count < 10 (OR = 0.04, 95% CI, 0.006–0.27) were identified as independent predictors of NCB to ICI in multivariable analysis (c-statistic = 0.90). None of the 16 variables were associated with clinical benefit in the taxane cohort.

Conclusions

This three-factor model includes genomic (SNV count >9) and clinical (NLR <5, lack of visceral metastasis) variables predictive for benefit to ICI but not taxane therapy for mUC. External validation of these hypothesis-generating results is warranted to enable use in routine clinical care.

Tumor Associated Neutrophils. Their Role in Tumorigenesis, Metastasis, Prognosis and Therapy

Tumor Associated Neutrophils (TANs) are engaged into the tumor microenvironment by cytokines and chemokines, can be distinguished according to their activation and cytokine status and effects on tumor cell growing in N1 and N2 TANs. N1 TANs exert an antitumor activity, by direct or indirect cytotoxicity. N2 TANs stimulate immunosuppression, tumor growth, angiogenesis and metastasis by DNA instability, or by cytokines and chemokines release. In tumor patients, either a high number of TANs and Neutrophil-to-Lymphocyte Ratio (NLR) do correlate with poor prognosis, and, so far, TAN counts and NLR can be regarded as biomarkers. Owing to the pivotal role of TANs in stimulating tumor progression, therapeutic strategies to target TANs have been suggested, and two major approaches have been proposed: (a) targeting the CXCL-8/CXCR-1/CXCR-2 axis, thereby blocking TANs or (b) targeting substances produced by polymorpho-nuclear cells that promote tumor growth. Many studies have been accomplished either in vitro and in animal models, whereas clinical studies are restrained, presently, due to the risk of inducing immunosuppression. In this review, we deeply discuss the anti-tumorigenic or pro-tumorigenic activity of TANs. In particular, TANs relevance in tumor prognosis and in vitro therapeutic strategies are widely described. On-going clinical trials, aimed to inhibit neutrophil recruitment into the tumor are also accurately debated.

Surgical Stress Increases Circulating Low-Density Neutrophils Which May Promote Tumor Recurrence

BACKGROUND

Low-density neutrophils (LDN) have been shown to be increased in peripheral blood in patients with various diseases and closely related to immune-mediated pathology. However, the frequency and function of LDN in circulating blood of the patients following abdominal surgery have not been well understood.

METHODS

LDN were determined by CD66b(+) cells, which were copurified with mononuclear cells by density gradient preparations of peripheral blood of surgical patients. The effects of the purified LDN on T cell proliferation and tumor cell lysis were examined in vitro. Neutrophil extracellular traps (NETs) production was examined by extracellular nuclear staining.

RESULTS

The number of LDN with an immature phenotype is markedly increased in peripheral blood samples in patients after abdominal surgery. The frequency of LDN correlated positively with operative time and intraoperative blood loss. The purified LDN significantly suppressed the proliferation of autologous T cells stimulated with anti-CD3 mAb coated on plate and partially inhibited the cytotoxicity of lymphocytes activated with recombinant interleukin-2 against a human gastric cancer cell, OCUM-1. The LDN also produced NETs after short-term culture in vitro, which efficiently trap many OCUM-1. These results suggest that surgical stress recruits immunosuppressive LDN in the circulation in the early postoperative period.

CONCLUSIONS

The LDN may support the lodging of circulating tumor cells via NETs formation and inhibit T cell-mediated antitumor response in target organs, which may promote postoperative cancer metastases. Functional blockade of LDN might be an effective strategy to reduce tumor recurrence after abdominal surgery.

Long non-coding RNA HOTTIP enhances IL-6 expression to potentiate immune escape of ovarian cancer cells by upregulating the expression of PD-L1 in neutrophils

Background

Long non-coding RNA (lncRNA) HOXA transcript at the distal tip (HOTTIP), has been demonstrated to be a vital biomarker when evaluating the prognosis of multiple cancers. Nevertheless, the potential function of HOTTIP in ovarian cancer (OC), a prevalent cancer among women worldwide, remains elusive. Hence, the current study aimed to elucidate the functional relevance of HOTTIP in the development of OC.

Methods

Positive expression of PD-L1 and IL-6 was determined using immunohistochemical staining in the collected OC and normal tissues. The correlation of IL-6 and PD-L1 was analyzed using flow cytometry, Western blot analysis as well as Pearson’s correlation coefficient. The interaction among HOTTIP, c-jun and IL-6 was investigated with the use of RIP, ChIP and dual luciferase reporter gene assays. Finally, the effects of HOTTIP on T cell proliferation and infiltration were identified through gain- and loss-of-function studies in vitro and in vivo.

Results

HOTTIP, IL-6 and PD-L1 were all highly expressed in OC tissues. A positive correlation was observed between IL-6 and PD-L1 and that between HOTTIP and IL-6 in OC tissues. HOTTIP was noted to promote the expression of IL-6 by binding to c-jun, which resulted in a promoted PD-L1 expression in neutrophils and immune escape while inhibiting T cell proliferation as well as tumor immunotherapy.

Conclusion

Taken together, our study unveiled that HOTTIP could promote the secretion of IL-6, and consequently up-regulate the expression of PD-L1 in neutrophils, thus inhibiting the activity of T cells and ultimately accelerating immune escape of OC cells. Our study provides a potential therapeutic strategy by targeting HOTTIP in OC.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1394-6) contains supplementary material, which is available to authorized users.

Context Drives Diversification of Monocytes and Neutrophils in Orchestrating the Tumor Microenvironment

Recent preclinical/clinical studies have underscored the significant impact of tumor microenvironment (TME) on tumor progression in diverse scenarios. Highly heterogeneous and complex, the tumor microenvironment is composed of malignant cancer cells and non-malignant cells including endothelial cells, fibroblasts, and diverse immune cells. Since immune compartments play pivotal roles in regulating tumor progression via various mechanisms, understanding of their multifaceted functions is crucial to developing effective cancer therapies. While roles of lymphoid cells in tumors have been systematically studied for a long time, the complex functions of myeloid cells have been relatively underexplored. However, constant findings on tumor-associated myeloid cells are drawing attention, highlighting the primary effects of innate immune cells such as monocytes and neutrophils in disease progression. This review focuses on hitherto identified contextual developments and functions of monocytes and neutrophils with a special interest in solid tumors. Moreover, ongoing clinical applications are discussed at the end of the review.

Dose-Dependent Sorafenib-Induced Immunosuppression Is Associated with Aberrant NFAT Activation and Expression of PD-1 in T Cells

The multikinase inhibitor sorafenib is the only standard first-line therapy for hepatocellular carcinoma (HCC). Here, we report the dose-dependent effects of sorafenib on the immune response, which is related to nuclear factor of activated T cells 1 (NFAT1) activity. In vitro and in vivo experiments were performed with low and high doses of sorafenib using human T cells and spontaneous developed woodchuck HCC models. In vitro studies demonstrated that following exposure to a high dose of sorafenib the baseline activity of NFAT1 in T cells was significantly increased. In a parallel event, high dose sorafenib resulted in a significant decrease in T cell proliferation and increased the proportion of PD-1 expressing CD8+ T cells with NFAT1 activation. In the in vivo model, smaller tumors were detected in the low-dose sorafenib treated group compared to the placebo and high-dose treated groups. The low-dose sorafenib group showed a significant tumor growth delay with significantly more CD3+ cells in tumor. This study demonstrates that sorafenib has immunomodulatory effects in a dose- and time-dependent manner. Higher dose of sorafenib treatment was associated with immunosuppressive action. This observed effect of sorafenib should be taken into consideration in the selection of optimum starting dose for future trials.

Neutrophil trafficking to lymphoid tissues: physiological and pathological implications

Recent advances have provided evidence for the involvement of neutrophils in both innate and adaptive immunity, robustly challenging the old dogma that neutrophils are short-lived prototypical innate immune cells solely involved in acute responses to microbes and exerting collateral tissue damage. There is now ample evidence showing that neutrophils can migrate into different compartments of the lymphoid system where they contribute to the orchestration of the activation and/or suppression of lymphocyte effector functions in homeostasis and during chronic inflammation, such as autoimmune disorders and cancer. In support of this notion, neutrophils can generate a wide range of cytokines and other mediators capable of regulating the survival, proliferation and functions of both T and B cells. In addition, neutrophils can directly engage with lymphocytes and promote antigen presentation. Furthermore, there is emerging evidence of the existence of distinct and diverse neutrophil phenotypes with immunomodulatory functions that characterise different pathological conditions, including chronic and autoimmune inflammatory conditions. The aim of this review is to discuss the mechanisms implicated in neutrophil trafficking into the lymphoid system and to provide an overview of the immuno-regulatory functions of neutrophils in health and disease in the context of adaptive immunity. Copyright © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

3D models in the new era of immune oncology: focus on T cells, CAF and ECM

Immune checkpoint inhibitor therapy has changed clinical practice for patients with different cancers, since these agents have demonstrated a significant improvement of overall survival and are effective in many patients. However, an intrinsic or acquired resistance frequently occur and biomarkers predictive of responsiveness should help in patient selection and in defining the adequate treatment options. A deep analysis of the complexity of the tumor microenvironment is likely to further advance the field and hopefully identify more effective combined immunotherapeutic strategies. Here we review the current knowledge on tumor microenvironment, focusing on T cells, cancer associated fibroblasts and extracellular matrix. The use of 3D cell culture models to resemble tumor microenvironment landscape and to screen immunomodulatory drugs is also reviewed.

Intratumoral, rather than stromal, CD8+ T cells could be a potential negative prognostic marker in invasive breast cancer patients

BACKGROUND

Tumor infiltrating lymphocytes (TILs) are widely considered a key sign of the immune interaction between host and tumor, and potentially prognostic biomarkers of good or bad outcome in many cancers, included invasive breast cancer (BC). However, results about the association between TIL typology, location and BC prognosis, are controversial. The aim of the study was to evaluated the prognostic significance of TIL subtypes (CD4+, CD8+, FOXP3+ T cells) and their location (stromal "s" and intratumoral "i" CD4+ and CD8+) in BC patients, focusing on the association between these markers and immunocheckpoint molecules such as cytotoxic T lymphocyte antigen 4 (CTLA-4), programmed cell death ligand 1 (PD-L1) and its receptor (PD-1).

METHODS

CD4+, CD8+, FOXP3+, CTLA4+, PD-L1+ and PD-1+ expression was examined by immunohistochemistry on tissue microarrays (TMAs) from 180 BC patients. Univariate and Kaplan-Meier analyses of disease free survival (DFS) were performed to evaluate the prognostic significance of marker expression.

RESULTS

Total CD8+ T cells were not significantly associated with DFS. Differently, patients with iCD8+ and sCD8+ overexpression showed a trend toward respectively a worse (P = .050) and a better 5-years DFS (P = .064). Interestingly, TIL expression of both PD-1+ and PD-L1+, was significantly associated with iCD8+ (P = .0004; P < .0001 respectively), while only TIL expression of PD-1 was associated with sCD8+ (P = .001).

CONCLUSION

Our data show that iCD8+ T cells, but no sCD8+ T cells identify a subgroup of patients with poor DFS and this could be due to the overexpression of PD-L1/PD-1 pathway.

Epigenetic modulation enhances immunotherapy for hepatocellular carcinoma

BACKGROUND

Anti-PDL-1 immunotherapy for Hepatocellular Carcinoma (HCC) demonstrated a mixed response. Polycomb Repressor Complex 2(PRC2) contributes to the initiation and progression of HCC by suppressing tumor antigens and inhibiting an immune response. Two components of epigenetic modulation are Enhancer of Zeste Homolog 2 (EZH2, the catalytic component of PRC2) and DNA Methyltransferase 1 (DNMT1). We aim to investigate the potential role of epigenetic therapy targeting EZH2 and DNMT1 as a novel strategy to modulate immunotherapy response in HCC.

METHODS

HepG2, Hep3B, and Hepa1-6 HCC cell lines were treated with EZH2 inhibitor (DZNep) and DNMT1 inhibitor (5-Azacytidine) with and without anti-PDL-1. Quantitative RT-PCR and immunohistochemistry were performed to evaluate the expression of tumor suppressors, tumor antigens, and Th1 chemokines. In-vivo C57/LJ immunocompetent mice model with subcutaneous tumor inoculation was performed with intraperitoneal drug injections.

RESULTS

There was a significant upregulation of Th1 chemokines in HepG2 (CXCL9 5.5 ± 0.2 relative fold change; CXCL10 1.44 × 103 ± 37 relative fold change) and Hep3B (CXCL 9 6.85 × 103 ± 1.3 × 103 relative fold change; CXCL 10 2.15 × 103 ± 3.1 × 102 relative fold change). Additionally, there was a significant induction of cancer testis antigens NY-ESO-1 (3.6-3.7 ± 0.3 relative fold change) and LAGE (8.3-11.7 ± 1.9 relative fold change). In vivo model demonstrated statistically significant tumor regression in the combination treatment group (0.02 g ± 0.02) compared to epigenetic therapy (0.63 g ± 0.61) or immunotherapy alone (0.15 g ± 0.21) with untreated control (2.4 g ± 0.71). There was significantly increased trafficking of cytotoxic T- lymphocytes and associated apoptosis for the combination treatment group compared to epigenetic or immunotherapy alone.

CONCLUSIONS

This study demonstrates that epigenetic modulation could be a novel potential strategy to augment immunotherapy for HCC by stimulating T cell trafficking into tumor microenvironment via activation of transcriptionally repressed chemokine genes responsible for T-cell trafficking, inducing previously silent neoantigens for immune targets, and allowing tumor regression as a result. A clinical trial of this feasible combination therapy of these clinically available agents is warranted.

Recent advances on the crosstalk between neutrophils and B or T lymphocytes

An increasing body of literature supports a role for neutrophils as players in the orchestration of adaptive immunity. During acute and chronic inflammatory conditions, neutrophils rapidly migrate not only to sites of inflammation, but also to draining lymph nodes and spleen, where they engage bidirectional interactions with B- and T-lymphocyte subsets. Accordingly, a relevant role of neutrophils in modulating B-cell responses under homeostatic conditions has recently emerged. Moreover, specialized immunoregulatory properties towards B or T cells acquired by distinct neutrophil populations, originating under pathological conditions, have been consistently described. In this article, we summarize the most recent data from human studies and murine models on the ability of neutrophils to modulate adaptive immune responses under physiological and pathological conditions and the mechanisms behind these processes.

Immunometabolism: A novel perspective of liver cancer microenvironment and its influence on tumor progression

The initiation and progression of liver cancer, including hepatocellular carcinoma and intrahepatic cholangiocarcinoma, are dependent on its tumor microenvironment. Immune cells are key players in the liver cancer microenvironment and show complicated crosstalk with cancer cells. Emerging evidence has shown that the functions of immune cells are closely related to cell metabolism. However, the effects of metabolic changes of immune cells on liver cancer progression are largely undefined. In this review, we summarize the recent findings of immunometabolism and relate these findings to liver cancer progression. We also explore the translation of the understanding of immunometabolism for clinical use.

Baseline neutrophil-to-lymphocyte ratio (NLR) and derived NLR could predict overall survival in patients with advanced melanoma treated with nivolumab

Background

Previous studies have suggested that elevated neutrophil-to-lymphocyte ratio (NLR) is prognostic for worse outcomes in patients with a variety of solid cancers, including those treated with immune checkpoint inhibitors.

Methods

This was a retrospective analysis of 97 consecutive patients with stage IV melanoma who were treated with nivolumab. Baseline NLR and derived (d) NLR were calculated and, along with other characteristics, correlated with progression-free survival (PFS) and overall survival (OS) in univariate and multivariate analyses. The best cutoff values for NLR and dNLR were derived using Cutoff Finder software based on an R routine which optimized the significance of the split between Kaplan-Meier survival curves.

Results

In univariate analysis, increasing absolute neutrophil count (ANC), NLR, dNLR and lactate dehydrogenase (LDH) (continuous variables) were all significantly associated with OS. Only NLR (hazard ratio [HR] = 2.85; 95% CI 1.60–5.08; p < 0.0001) and LDH (HR = 2.51; 95% CI 1.36–4.64; p < 0.0001) maintained a significant association with OS in multivariate analysis. Patients with baseline NLR ≥5 had significantly worse OS and PFS than patients with NLR < 5, as did patients with baseline dNLR ≥3 versus < 3. Optimal cut-off values were ≥ 4.7 for NLR and ≥ 3.8 for dNLR. Using this ≥4.7 cut-off for NLR, the values for OS and PFS were overlapping to the canonical cut-off for values, and dNLR< 3.8 was also associated with better OS and PFS.

Conclusion

Both Neutrophil-to-lymphocyte ratio (NLR) and derived (d) NLR were associated with improved survival when baseline levels were lower than cut-off values. NLR and dNLR are simple, inexpensive and readily available biomarkers that could be used to help predict response to immunotherapy in patients with advanced melanoma.

Electronic supplementary material

The online version of this article (10.1186/s40425-018-0383-1) contains supplementary material, which is available to authorized users.

The dark side of granulocyte-colony stimulating factor: a supportive therapy with potential to promote tumour progression

Granulocyte-colony stimulating factor (G-CSF) is one of several cytokines that can expand and mobilize haematopoietic precursor cells from bone marrow. In particular, G-CSF mobilizes neutrophils when the host is challenged by infection or tissue damage. Severe neutropenia, or febrile neutropenia is a life-threatening event that can be mitigated by administration of G-CSF. Consequently, G-CSF has been used to support patients undergoing chemotherapy who would otherwise require dose reduction due to neutropenia. Over the past 10-15 years it has become increasingly apparent, in preclinical tumour growth and metastasis models, that G-CSF can support tumour progression by mobilization of tumour-associated neutrophils which consequently promote tumour dissemination and metastasis. With the increasing use of G-CSF in the clinic, it is pertinent to ask if there is any evidence of a similar promotion of tumour progression in patients. Here, we have reviewed the preclinical and clinical data on the potential contribution of G-CSF to tumour progression. We conclude that, whilst the evidence for a promotion of metastasis is strong in preclinical models and that limited data indicate that high serum G-CSF levels in patients are associated with poorer prognosis, no studies published so far have revealed evidence of increased tumour progression associated with supportive G-CSF use during chemotherapy in patients. Analysis of G-CSF receptor positive cohorts within supportive trials, as well as studies of the role of G-CSF blockade in appropriate tumours in the absence of chemotherapy could yield clinically translatable findings.

Cancer-related circulating and tumor-associated neutrophils - subtypes, sources and function

In recent years, the role of neutrophils in cancer biology has been a matter of increasing interest. Many patients with advanced cancer show high levels of neutrophilia, tumor neutrophils are connected to dismal prognosis, and the neutrophil-to-lymphocyte ratio has been introduced as a significant prognostic factor for survival in many types of cancer. Neutrophils constitute an important portion of the infiltrating immune cells in the tumor microenvironment, but controversy has long surrounded the function of these cells in the context of cancer. Multiple evidences have shown that neutrophils recruited to the tumor can acquire either protumor or antitumor function. These findings have led to the identification of multiple and heterogeneous neutrophil subsets in the tumor and circulation. In addition, tumor-associated neutrophils (TANs) were shown to demonstrate functional plasticity, driven by multiple factors present in the tumor microenvironment. In this review, we examine the current knowledge on cancer-related circulating neutrophils, their source and the function of the different subtypes, both mature and immature. We then discuss the pro vs antitumor nature of TANs in cancer, their functional plasticity and the mechanisms that regulate neutrophil recruitment and polarization. Although the vast majority of the knowledge on neutrophils in cancer comes from murine studies, recent work has been done on human cancer-related neutrophils. In the final paragraphs, we expand on the current knowledge regarding the role of neutrophils in human cancer and examine the question whether cancer-related neutrophils (circulating or intratumoral) could be a new possible target for cancer immunotherapy.

Neutrophil-to-lymphocyte ratio as prognostic indicator in gastrointestinal cancers: a systematic review and meta-analysis

An accurate, time efficient, and inexpensive prognostic indicator is needed to reduce cost and assist with clinical decision making for cancer management. The neutrophil-to-lymphocyte ratio (NLR), which is derived from common serum testing, has been explored in a variety of cancers. We sought to determine its prognostic value in gastrointestinal cancers and performed a meta-analysis of published studies using the Meta-analysis Of Observational Studies in Epidemiology guidelines. Included were randomized control trials and observational studies that analyzed humans with gastrointestinal cancers that included NLR and hazard ratios (HR) with overall survival (OS), disease-free survival (DFS), progression-free survival (PFS), and/or cancer-specific survival (CSS).

We analyzed 144 studies comprising 45,905 patients, two-thirds of which were published after 2014. The mean, median, and mode cutoffs for NLR reporting OS from multivariate models were 3.4, 3.0, 5.0 (±IQR 2.5-5.0), respectively. Overall, NLR greater than the cutoff was associated with a HR for OS of 1.63 (95% CI, 1.53-1.73; P < 0.001). This association was observed in all subgroups based on tumor site, stage, and geographic region. HR for elevated NLR for DFS, PFS, and CSS were 1.70 (95% CI, 1.52-1.91, P < 0.001), 1.64 (95% CI, 1.36-1.97, P < 0.001), and 1.83 (95% CI, 1.50-2.23, P < 0.001), respectively.

Available evidence suggests that NLR greater than the cutoff reduces OS, independent of geographic location, gastrointestinal cancer type, or stage of cancer. Furthermore, DFS, PFS, and CSS also have worse outcomes with elevated NLR.

Programmed death ligand 1 expression in esophageal cancer following definitive chemoradiotherapy: Prognostic significance and association with inflammatory biomarkers

Immunotherapy with anti-programmed cell death protein 1 or programmed death ligand 1 (PD-L1) agents has demonstrated promising efficacy for the treatment of various types of malignancies. However, the role of PD-L1 as a tumor prognostic marker remains poorly understood. In the present study, the prognostic value of PD-L1 expression in esophageal carcinoma (EC) following definitive chemoradiotherapy (CRT) was investigated, and its associations with three systemic inflammation biomarkers, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and lymphocyte-to-monocyte ratio (LMR) were further explored. A total of 104 patients with non-metastatic EC, who underwent definitive CRT between January 2009 and December 2012, were retrospectively analyzed. The expression of PD-L1 was examined by immunohistochemistry and the impact of PD-L1 expression level on overall survival (OS) was assessed. Furthermore, pretreatment neutrophil, lymphocyte, platelet and monocyte counts were obtained from routine blood tests to calculate the NLR, PLR and LMR. PD-L1 was overexpressed in EC compared with normal esophageal epithelium, with a positive expression rate of 37.5%. Additionally, patients with positive PD-L1 expression had a lower NLR than those with negative PD-L1 expression (P=0.001). On multivariate analysis, the positive staining of PD-L1 was significantly associated with improved OS (HR, 0.6; 95% CI, 0.372–0.965; P=0.035). Kaplan-Meier survival analysis showed a similar result (P=0.009). Additionally, sex (HR, 0.449; 95% CI, 0.229–0.880; P=0.020), clinical stage III (HR, 2.471; 95% CI, 1.171–5.212; P=0.018), and receipt of concurrent chemoradiation (HR, 0.590; 95% CI, 0.368–0.945; P=0.028) were all independent prognostic factors in EC treated with definitive CRT. The correlation of NLR with PD-L1 expression validated the relevance of immunity and inflammation. In summary, the present study demonstrated that positive PD-L1 expression is associated with improved survival in patients with EC treated with radical CRT, indicating that PD-L1 is a promising prognostic marker.

Developing a Predictive Model for Clinical Outcomes of Advanced Non-Small Cell Lung Cancer Patients Treated With Nivolumab

INTRODUCTION

Despite significant improvement of clinical outcomes of advanced non-small-cell lung cancer (NSCLC) patients treated with immunotherapy, our knowledge of optimal biomarkers is still limited.

PATIENTS AND METHODS

We retrospectively evaluated 159 advanced NSCLC patients in our institution treated with nivolumab after disease progression during platinum-based chemotherapy. We correlated several variables with progression-free survival (PFS) to develop the immunotherapy, Sex, Eastern Cooperative Oncology Group performance status, Neutrophil-to-lymphocyte ratio (NLR), and Delta NLR (iSEND) model. We categorized patients into iSEND good, intermediate, and poor risk groups and evaluated their clinical outcomes. Performance of iSEND at 3, 6, 9, and 12 months was evaluated according to receiver operating characteristic (ROC) curves and internally validated using bootstrapping. The association of iSEND risk groups with clinical benefit was evaluated using logistic regression.

RESULTS

Median follow-up was 11.5 months (95% confidence interval [CI], 9.4-13.1). There were 50 deaths and 43 with disease progression without death. PFS rates at 3, 6, 9, and 12 months were 78.4%, 63.7%, 55.3%, and 52.2% in iSEND good; 79.4%, 44.3%, 25.9%, and 19.2% in iSEND intermediate; and 65%, 25.9%, 22.8%, and 17.8% in iSEND poor. Time-dependent area under ROC curves of iSEND for PFS at 3, 6, 9, and 12 months were 0.718, 0.74, 0.746, and 0.774. The iSEND poor group was significantly associated with progressive disease at 12 ± 2 weeks (odds ratio, 9.59; 95% CI, 3.8-26.9; P < .0001).

CONCLUSION

The iSEND model is an algorithmic model that can characterize clinical outcomes of advanced NSCLC patients receiving nivolumab into good, intermediate, or poor risk groups and might be useful as a predictive model if validated independently.

Circulating cell-free DNA content as blood based biomarker in endometrial cancer

Background

Altered circulating cell-free DNA (cfDNA) levels are related to cancer development and aggressiveness. Up to now, very few studies have been performed for evaluating cfDNA content in endometrial cancer (EC).

Methods

First, we measured cfDNA release in blood serum of EC cancer patients collected before surgery and before the beginning of any treatment by SYBR Gold assay and correlated it with tumor aggressiveness. We also assessed the relative mitochondrial cell-free DNA (cfmtDNA) content by qRT-PCR. Next, we correlated cfDNA levels with BMI, age, hypertension and inflammation markers.

Results

CfDNA levels are higher in G2 and G3 compared with G1 EC sera. A significant modulation of cfDNA content was detected in sera from patients with BMI>30 compared with those with BMI<30. We observed a further and significant alteration in cfDNA level in hypertensive patients with G2-G3, but not in G1 EC. Analysis of preoperative neutrophil-to-lymphocyte (NLR) and monocyte-to-lymphocyte (MLR) ratios suggests a contribution of the host response in the altered cfDNA levels in EC.

Conclusions

Our data indicate that assessment of total and mitochondrial cfDNA levels in blood sera and the relative NLR and MLR in blood obtained from preoperative patients may help clinical management and prognosis in EC.

Program death-1 immune checkpoint and tumor microenvironment in malignant liver tumors

Hepatic malignancies are one of the leading causes of cancer death globally. Considering the limited efficacy of current standard treatments in management of patients with advanced liver cancers, there has been a growing interest in identifying novel therapies. Despite achieving promising results in initial clinical trials, the therapeutic benefit of immunotherapy is limited due to strong immune-tolerogenic characteristics of liver tumors. Therapeutic regimens that impede tumor immunosuppressive mechanisms or elaborate tumor-specific immunity may improve clinical outcomes of patients with liver malignancies. Programmed cell death 1 (PD-1), an inhibitory checkpoint molecule, and its ligands (PD-L1 and -L2) are the main mediators of immunosuppression within the tumor microenvironment. The expression level of PD-1/PD-L1 may act as a biomarker to predict disease progression, as well as long-term survival. Furthermore, early trials have demonstrated the efficacy and safety of targeting PD-1/PD-L1 as an emerging field in the management of patients with advanced hepatocellular carcinoma. We herein review the role of PD-1/PD-L1 in the pathogenesis of liver malignancies, as well as its potential diagnostic and therapeutic implications.

Role of inflammatory markers as hepatocellular cancer selection tool in the setting of liver transplantation

Since the advent of the Milan criteria in 1996 and its widespread adoption for selection of patients with hepatocellular carcinoma (HCC) who would benefit from transplant, there has been an extensive hunt for the ideal clinical biomarker to predict HCC recurrence. This is because Milan lack does not include tumor biology indices and recurrence rates remain in the 15-20% range worldwide. While a 'silver-bullet' biomarker has not been found, several useful inflammatory markers have been identified and used in scoring systems that supersede Milan in their ability to predict HCC recurrence post liver transplantation (LT). In this review, we aim to summarize the role of inflammatory markers paly in the selection of HCC patients awaiting LT.

Immune checkpoint inhibition: prospects for prevention and therapy of hepatocellular carcinoma

The global prevalence of liver cancer is rapidly rising, mostly as a result of the amplified incidence rates of viral hepatitis, alcohol abuse and obesity in recent decades. Treatment options for liver cancer are remarkably limited with sorafenib being the gold standard for advanced, unresectable hepatocellular carcinoma but offering extremely limited improvement of survival time. The immune system is now recognised as a key regulator of cancer development through its ability to protect against infection and chronic inflammation, which promote cancer development, and eliminate tumour cells when present. However, the tolerogenic nature of the liver means that the immune response to infection, chronic inflammation and tumour cells within the hepatic environment is usually ineffective. Here we review the roles that immune cells and cytokines have in the development of the most common primary liver cancer, hepatocellular carcinoma (HCC). We then examine how the immune system may be subverted throughout the stages of HCC development, particularly with respect to immune inhibitory molecules, also known as immune checkpoints, such as programmed cell death protein-1, programmed cell death 1 ligand 1 and cytotoxic T lymphocyte antigen 4, which have become therapeutic targets. Finally, we assess preclinical and clinical studies where immune checkpoint inhibitors have been used to modify disease during the carcinogenic process. In conclusion, inhibitory molecule-based immunotherapy for HCC is in its infancy and further detailed research in relevant in vivo models is required before its full potential can be realised.

Prognostic value of the neutrophil-to-lymphocyte ratio in the ARQ 197-215 second-line study for advanced hepatocellular carcinoma

The ARQ 197-215 study randomized patients to tivantinib or placebo and pre-specified efficacy analyses indicated the predictive value of MET expression as a marker of benefit from tivantinib in hepatocellular carcinoma (HCC). We aimed to explore the neutrophil-to-lymphocyte ratio (NLR) in 98 ARQ 197-215 patients with available absolute neutrophil count and absolute lymphocyte count at baseline. The cut-off value used to define high versus low NLR was 3.0. In univariate analysis, high NLR was associated with hazard ratio (HR) for overall survival (OS) of 1.58 [95% confidence interval (CI) 1.01; 2.47; P <0.046], corresponding to median OS of 5.1 months versus 7.8 months in patients with low NLR (P = 0.044). In contrast, time to progression was not significantly affected by NLR (P = 0.20). Multivariable model confirmed that both NLR >3 (P = 0.03) and presence of vascular invasion (P = 0.017) were negatively associated with OS. After adjustment for vascular invasion, NLR independently predicted survival in both the placebo and the tivantinib cohort. For OS, no interaction was detected between NLR status and treatment (P_interaction = 0.40). Baseline NLR is an independent prognostic biomarker in patients with HCC and compensated liver function who are candidate for second-line treatments.

HYPE or HOPE: the prognostic value of infiltrating immune cells in cancer

Interactions between immune and malignant cells have been known to have clinical relevance for decades. The potential for immune control is now being therapeutically enhanced with checkpoint inhibitors and other novel agents to improve outcomes in cancer. The importance of the immune infiltrate as a prognostic marker is increasingly relevant. In this minireview, we present an overview of the immune infiltrate and its spatial organisation, and summarise the prognostic value of immune cells in different cancer types. International collaborative efforts are standardising histopathologic reporting of the immune infiltrate, to allow application of these parameters in the clinical and research settings. In general terms, a 'pro-inflammatory' tumour microenvironment and infiltrating CD8-expressing T lymphocytes are associated with improved clinical outcomes in a broad range of tumour types. The inhibitory function of other immune cells, for example, myeloid-derived suppressor cells and regulatory T cells, appear to have a major role in disrupting the capacity for the immune control of cancers.

Advances and Future Directions in the Treatment of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths worldwide. Liver transplant is considered the gold standard for curative therapy for HCC when patients are not candidates for surgical resection or ablation. Because a subset of patients with HCC have a survival rate with liver transplantation that is comparable to that of cirrhotic patients without tumors, the organ allocation system allows for increased priority for transplant in potential recipients within the Milan criteria. With the recent change in the Model for End-Stage Liver Disease exception point allocation, patients with HCC will now need to wait at least 6 months before being awarded extra points. This extension leads to increased time on the transplant waiting list and underscores the importance of locoregional therapy to contain the tumor burden. Fortunately, there has been significant progress in therapy for HCC in the past few decades, namely due to advances in interventional radiology, radiotherapy, and expanded surgical and transplant criteria. Recent advances in immunotherapy also provide promising options for patients who are not candidates for other therapies. This article highlights the major therapeutic options for HCC, including surgical resection, liver transplant, thermal and nonthermal ablation, chemoembolization, radiotherapy, and systemic chemotherapy, as well as discusses the evidence supporting these approaches.

Positive Expression of Programmed Death Ligand 1 in Peritumoral Liver Tissue is Associated with Poor Survival after Curative Resection of Hepatocellular Carcinoma

BACKGROUND: Recurrence or metastasis of hepatocellular carcinoma (HCC) is mainly intrahepatic after curative resection, demonstrating that the peritumoral environment is important but often neglected. Programmed death ligand 1 (PD-L1) in intratumoral liver tissues is a poor prognosis factor whose impact is removed after curative resection. However, PD-L1 expression remains in the peritumoral liver tissues and its distribution and prognostic value are still not clear. METHODS: We assessed the expression of PD-L1 by immunohistochemistry in peritumoral liver tissues from 90 HCC patients who underwent curative hepatectomy. The results were validated in an independent cohort of additional 90 HCC patients. RESULTS: We found PD-L1 positive expression in 31.11% (28/90) of peritumoral tissues. Peritumoral PD-L1 expression was associated with a significantly worse overall survival (OS) (P = .000) and disease-free survival (DFS) (P = .001) compared to the negative expression group. Additionally, peritumoral PD-L1 positivity significantly correlated with vascular invasion and a lower albumin level (≤35 g/L). Univariate and multivariate Cox regression models both revealed peritumoral PD-L1 as an independent prognostic factor for OS (HR = 2.853, P = .002) and DFS (HR = 2.362, P = .003). The prognostic value of PD-L1 positivity was validated in the independent data set. CONCLUSIONS: Our data suggest PD-L1 expression in peritumoral hepatocytes is an independent prognostic factor for OS and DFS. This implies that future anti-cancer therapy should target not only residual tumor cells but also the “soil” for promoting tumor growth. Peritumoral PD-L1 could be a good target for adjuvant therapy after hepatectomy.

Neutrophils as active regulators of the immune system in the tumor microenvironment

In recent years, the role of immune cells in tumor progression has been a matter of increasing interest. Neutrophils constitute an important portion of the immune cells infiltrating the tumor microenvironment. Traditionally viewed as the first line of defense against infections, it is now well accepted that neutrophils also have an important role in multiple aspects of cancer biology. Multiple and heterogeneous neutrophil subsets have been identified in tumors and in circulation. Evidence from many studies now supports the notion that tumor-associated neutrophils (TANs) show functional plasticity driven by multiple factors present in the tumor microenvironment. In this review, we first concisely discuss the pro-tumor vs. anti-tumor nature of neutrophils in cancer, their functional plasticity, and the mechanisms that regulate neutrophil polarization. We then expand on the various crosstalks and mutual effects between TANs and other tumor-infiltrating immune cell types, emphasizing the active role of neutrophils as regulators of the immune system, promoting or inhibiting the establishment of a permissive tumor microenvironment. Finally, the possible modulation of cancer-related neutrophils by therapies directed toward immune checkpoints is discussed briefly.

Tumour-activated liver stromal cells regulate myeloid-derived suppressor cells accumulation in the liver

Regulating mechanisms underlying hepatic myeloid-derived suppressor cell (MDSC) accumulation remain to be described. Here, we provide evidence for the involvement of tumour-activated liver stromal cells in the process of hepatic MDSCs migration and accumulation. Our data showed an elevated frequency of MDSCs in the liver of tumour-bearing mice. Moreover, tumour-activated liver stromal cells promote MDSC migration into the liver site. Further investigation indicated higher levels of cytokine and chemokine expression in liver stromal cells after exposure to the tumour-conditioned supernatant. Notably, the expression levels of proinflammatory factors, mainly including macrophage colony stimulating factor (M-CSF), transforming growth factor-β (TGF-β), monocyte chemotactic protein-1 (MCP-1) and stromal-derived factor-1 (SDF-1), increased after treatment with tumour-conditioned supernatant, and blockade of MCP-1 or SDF-1 decreased the proportion of tumour infiltrated MDSCs in mice co-transplanted with liver stromal cells and tumour cells, but not in mice with only tumour cells injection. These findings demonstrate that tumour-activated liver stromal cells produce higher levels of chemokines and cytokines, which may contribute to MDSC accumulation into the liver site in patients with liver cancer.

Phenotypic and functional characteristics of HLA-DR+ neutrophils in Brazilians with cutaneous leishmaniasis

The protozoan Leishmania braziliensis causes cutaneous leishmaniasis (CL) in endemic regions. In murine models, neutrophils (PMNs) are recruited to the site of infection soon after parasite inoculation. However, the roles of neutrophils during chronic infection and in human disease remain undefined. We hypothesized that neutrophils help maintain a systemic inflammatory state in subjects with CL. Lesion biopsies from all patients with CL tested contained neutrophils expressing HLA-DR, a molecule thought to be restricted to professional antigen-presenting cells. Although CL is a localized disease, a subset of patients with CL also had circulating neutrophils expressing HLA-DR and the costimulatory molecules CD80, CD86, and CD40. PMNs isolated from a low-density leukocyte blood fraction (LD-PMNs) contained a higher percentage of HLA-DR⁺ PMNs than did normal-density PMNs. In vitro coculture experiments suggested LD-PMNs do not suppress T cell responses, differentiating them from MDSCs. Flow-sorted HLA-DR⁺ PMNs morphologically resembled conventional PMNs, and they exhibited functional properties of PMNs. Compared with conventional PMNs, HLA-DR⁺ PMNs showed increased activation, degranulation, DHR123 oxidation, and phagocytic capacity. A few HLA-DR⁺ PMNs were observed in healthy subjects, and that proportion could be increased by incubation in either inflammatory cytokines or in plasma from a patient with CL. This was accompanied by an increase in PMN hladrb1 mRNA, suggesting a possible connection between neutrophil "priming" and up-regulation of HLA-DR. These data suggest that PMNs that are primed for activation and that also express surface markers of antigen-presenting cells emerge in the circulation and infected tissue lesions of patients with CL.

Immune checkpoint inhibitors for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer deaths worldwide, and advanced HCC generally caries a poor prognosis. The treatment of advanced disease is limited to sorafenib, which provides only a limited improvement in survival, and novel therapies are, thus, sorely needed. Among emerging alternative approaches, immune checkpoint inhibitors are a particularly promising treatment modality. In this review, we summarize current knowledge of the mechanisms for the two primary targets of immune checkpoint inhibitors and discuss the relevance of these pathways to the immunology of HCC. We also review the state of ongoing and forthcoming trials of immune checkpoint blockade in HCC.

S100A8 facilitates the migration of colorectal cancer cells through regulating macrophages in the inflammatory microenvironment

Previous studies have shown that S100 calcium-binding protein A8 (S100A8) contributes to the survival and migration of colorectal cancer (CRC) cells. However, whether S100A8 participates in the progression and metastasis of CRC via the regulation of macrophages in the tumor inflammatory microenvironment remains unknown. In this study, phorbol myristate acetate (PMA) was used to induce the differentiation of THP-1 monocytes to macrophages. MTT assay, western blot analysis, immunofluorescence staining, semi-quantitative RT-PCR (semi-PCR), quantitative real-time PCR (qPCR), Gaussia luciferase activity assay and ELISA were performed to analyze the roles and molecular mechanisms of S100A8 in the modulation of macrophages. MTT assay, flow cytometric analysis, Hoechst staining, wound healing and Transwell migration assay were used to test the effect of S100A8 on the viability and migration of CRC cells co-cultured with macrophages in the inflammatory microenvironment. We found that THP-1 monocytes were induced by PMA and differentiated to macrophages. S100A8 activated the NF-κB pathway in the macrophages and promoted the expression of miR-155 and inflammatory cytokines IL-1β and TNF-α in the inflammatory microenvironment mimicked by lipopolysaccharides (LPS). Furthermore, S100A8 contributed to augment the migration but not the viability of the CRC cells co-cultured with the macrophages in the inflammatory microenvironment. Altogether, our study demonstrated that S100A8 facilitated the migration of CRC cells in the inflammatory microenvironment, and the underlying molecular mechanisms may be partially attributed to the overexpression of miR-155, IL-1β and TNF-α through activation of the NF-κB pathway in macrophages.

Human neutrophils: Their role in cancer and relation to myeloid-derived suppressor cells

Increased frequencies of peripheral blood neutrophils as well as tumor-infiltrating (associated) neutrophils (TAN) have been observed in many tumor entities. Although the most frequent cell type in the peripheral blood, neutrophils are outnumbered by other leukocyte subsets in the tumor microenvironment. Nevertheless, a number of recent meta-analyses identified TAN as well as high neutrophil-lymphocyte ratio in the blood as one of the most powerful immunologic prognostic parameters in human oncology. This clinical impact is based on an intense bidirectional crosstalk of neutrophils and tumor cells resulting in changes in neutrophil as well as tumor cell biology. These changes eventually lead to TAN equipped with various tumor promoting features, which enhance angiogenesis, cancer cell invasion and metastasis. Many of the pro-tumor features of TAN are shared with PMN-MDSC (myeloid-derived suppressor cells). Consequently, the distinction of these two cell populations is a matter of intensive debate and also specifically discussed in this article. The importance of neutrophils in cancer progression has triggered numerous efforts to therapeutically target these cells. Current strategies in this area focus on the inhibition of either TAN recruitment or pro-tumorigenic function.

Chemokine regulation of neutrophil function in tumors

The role of neutrophils in cancer and metastasis is still debated and controversial since they have been shown to be endowed with both pro- and antitumor functions. These contradictory results seem to be now explained by recent discoveries of tumor-associated neutrophils plasticity and multiple neutrophil subsets. Chemokines and chemokine receptors are known to tightly regulate the release of neutrophils from the bone marrow, their passage into circulation and transmigration into the tissues as well as tumor infiltration. It is emerging that chemokine receptors are differentially expressed by neutrophil subsets and they affect not only their recruitment but also their effector functions. Here we are resuming human and murine data suggesting that therapeutic modulation of neutrophil activity through the targeting of specific chemokines or chemokine receptors can improve their anti-tumoral properties.