Pegylated IL-10 induces cancer immunity: the surprising role of IL-10 as a potent inducer of IFN-γ-mediated CD8(+) T cell cytotoxicity

Potential anti-tumor effects of regulatory T cells in the tumor microenvironment: a review

Regulatory T cells (Tregs) expressing the transcription factor FoxP3 are essential for maintaining immunological balance and are a significant component of the immunosuppressive tumor microenvironment (TME). Single-cell RNA sequencing (ScRNA-seq) technology has shown that Tregs exhibit significant plasticity and functional diversity in various tumors within the TME. This results in Tregs playing a dual role in the TME, which is not always centered around supporting tumor progression as typically believed. Abundant data confirms the anti-tumor activities of Tregs and their correlation with enhanced patient prognosis in specific types of malignancies. In this review, we summarize the potential anti-tumor actions of Tregs, including suppressing tumor-promoting inflammatory responses and boosting anti-tumor immunity. In addition, this study outlines the spatial and temporal variations in Tregs function to emphasize that their predictive significance in malignancies may change. It is essential to comprehend the functional diversity and potential anti-tumor effects of Tregs to improve tumor therapy strategies.

Pharmacogenomic and epigenomic approaches to untangle the enigma of IL-10 blockade in oncology

The host immune system status remains an unresolved mystery among several malignancies. An immune-compromised state or smart immune-surveillance tactics orchestrated by cancer cells are the primary cause of cancer invasion and metastasis. Taking a closer look at the tumour-immune microenvironment, a complex network and crosstalk between infiltrating immune cells and cancer cells mediated by cytokines, chemokines, exosomal mediators and shed ligands are present. Cytokines such as interleukins can influence all components of the tumour microenvironment (TME), consequently promoting or suppressing tumour invasion based on their secreting source. Interleukin-10 (IL-10) is an interlocked cytokine that has been associated with several types of malignancies and proved to have paradoxical effects. IL-10 has multiple functions on cellular and non-cellular components within the TME. In this review, the authors shed the light on the regulatory role of IL-10 in the TME of several malignant contexts. Moreover, detailed epigenomic and pharmacogenomic approaches for the regulation of IL-10 were presented and discussed.

Petiveria alliacea Reduces Tumor Burden and Metastasis and Regulates the Peripheral Immune Response in a Murine Myeloid Leukemia Model

The poor response, adverse effects and drug resistance to treatment of acute myeloid leukemia (AML) have led to searching for safer and more effective therapeutic alternatives. We previously demonstrated that the alcoholic extract of Petiveria alliacea (Esperanza) has a significant in vitro antitumor effect on other tumor cells and also the ability to regulate energy metabolism. We evaluated the effect of the Esperanza extract in vitro and in vivo in a murine model of AML with DA-3/ER-GM cells. First, a chemical characterization of the extract was conducted through liquid and gas chromatography coupled with mass spectrometry. In vitro findings showed that the extract modulates tumor metabolism by decreasing glucose uptake and increasing reactive oxygen species, which leads to a reduction in cell proliferation. Then, to evaluate the effect of the extract in vivo, we standardized the mouse model by injecting DA-3/ER-GM cells intravenously. The animals treated with the extract showed a lower percentage of circulating blasts, higher values of hemoglobin, hematocrit, and platelets, less infiltration of blasts in the spleen, and greater production of cytokines compared to the control group. These results suggest that the antitumor activity of this extract on DA-3/ER-GM cells can be attributed to the decrease in glycolytic metabolism, its activity as a mitocan, and the possible immunomodulatory effect by reducing tumor proliferation and metastasis.

A systematic framework for predictive biomarkers in immune effector cell-associated neurotoxicity syndrome

Chimeric antigen receptor (CAR)-T cell therapy has revolutionized the management of several life-threatening malignancies, often achieving durable sustained responses. The number of patients treated with this new class of cell-based therapy, along with the number of Food and Drug Association (FDA) approved indications, are growing significantly. Unfortunately Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS) can often occur after treatment with CAR-T cells, and severe ICANS can be associated with significant morbidity and mortality. Current standard treatments are mainly steroids and supportive care, highlighting the need for early identification. In the last several years, a range of predictive biomarkers have been proposed to distinguish patients at increased risk for developing ICANS. In this review, we discuss a systematic framework to organize potential predictive biomarkers that builds on our current understanding of ICANS.

PEGylated IL-10: Clinical Development in Cancer Immunotherapy, Where to Go?

PURPOSEOF REVIEW

The purpose of this review is to discuss the current understanding of the pegilodecakin (PEGylated interleukin 10) and its role in the inhibition of tumour growth and metastasis. This review also focuses on clinical data published to date that have evaluated the efficacy and safety of pegilodecakin.

RECENT FINDINGS

Pegilodecakin has shown significant promise in preclinical models, notable for decreased tumour burden and fewer sites of metastatic disease across various malignancies. It has been most widely assessed in a phase I/Ib clinical trial against several solid tumours, leading to the phase II and III clinical trials containing pegilodecakin and its combination with other current treatments. However, the updated data have not shown higher efficacy in renal cell carcinoma, metastatic non-small cell lung cancer or pancreatic cancer, with respect to the controls, yet the adverse events presented more mixed results. Further investigation into combination therapies including pegilodecakin is ongoing. Pegilodecakin showed promise in preclinical and phase I clinical trials on its efficacy in several solid tumours, with expected regulation of IL-10 signalling pathway observed. However, the phase II and III trials did not justify its application as potential immunotherapy in selected cancers. Further evaluation of pegilodecakin's efficacy in other cancers, either as monotherapy or in combination with the current treatments, is worth investigating clinically, which warrants to better understand its potential clinical utility.

IL-10 in cancer: an essential thermostatic regulator between homeostatic immunity and inflammation - a comprehensive review

Cytokines are soluble proteins that mediate intercellular signaling regulating immune and inflammatory responses. Cytokine modulation represents a promising cancer immunotherapy approach for immune-mediated tumor regression. However, redundancy in cytokine signaling and cytokines' pleiotropy, narrow therapeutic window, systemic toxicity, short half-life and limited efficacy represent outstanding challenges for cytokine-based cancer immunotherapies. Recently, there has been interest in the paradoxical role of IL-10 in cancer, its controversial prognostic utility and novel strategies to enhance its therapeutic profile. Here, the authors review the literature surrounding the role of IL-10 within the tumor microenvironment, its prognostic correlates to cancer patient outcomes and its pro- and antitumor effects, and they assess the legitimacy of potential therapeutic strategies harnessing IL-10 by outlining the notable preclinical and clinical evidence to date.

Interleukin-10: A double-edged sword in breast cancer

Breast cancer (BC) is a frequently diagnosed cancer among women worldwide. Currently, BC can be divided into different subgroups according to the presence of the following hormone receptors: estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. Each of these subgroups has different treatment strategies. However, the presence of new metastatic lesions and patient deterioration suggest resistance to a given treatment. Various lines of evidence had shown that cytokines are one of the important mediators of tumor growth, invasion, metastasis, and treatment resistance. Interleukin-10 (IL-10) is an immunoregulatory cytokine, and acts as a poor prognostic marker in many cancers. The anti-inflammatory IL-10 blocks certain effects of inflammatory cytokines. It also antagonizes the co-stimulatory molecules on the antigen-presenting cells. Here, we review the current knowledge on the function and molecular mechanism of IL-10, and recent findings on how IL-10 contributes to the progression of BC.

Impact of IL-10 Promoter Polymorphisms and IL-10 Serum Levels on Advanced Laryngeal Squamous Cell Carcinoma and Survival Rate

BACKGROUND/AIM

Prognosis of advanced stages of laryngeal squamous cell carcinoma (LSCC) remains poor. To clarify therapeutic targets and improve survival rate, identification of new specific and prognostic biomarkers of LSCC is required. The study aimed to evaluate the impact of IL-10:rs1800871, rs1800872, rs1800896 single nucleotide polymorphisms (SNPs), and IL-10 serum levels on LSCC development and determine associations of selected SNPs with patient survival rate.

PATIENTS AND METHODS

A total of 300 LSCC patients and 533 controls were included in the study. Genotyping was carried out using RT-PCR; IL-10 serum levels were analyzed by ELISA.

RESULTS

Significant associations were identified between IL-10 rs1800871 variants and advanced stage of LSCC patient group in the codominant, recessive and additive models (OR=0.473, p=0.027; OR=0.510, p=0.040; and OR=0.733; p=0.037). Significant variants of IL-10 rs1800872 were determined in the codominant, recessive and additive models (OR=0.473, p=0.027; OR=0.510, p=0.040; and OR=0.733, p=0.037). The distribution of IL-10 SNPs genotypes did not impact LSCC patient survival rate (respectively, p=0.952; p=0.952; p=0.991).

CONCLUSION

IL-10:rs1800871 and rs1800872 SNPs are associated with advanced stage of LSCC. The genotypic distribution of IL-10 SNPs does not influence the survival rate of LSCC patients.

Follicular cytotoxic CD8 T cells present high cytokine expression, and are more susceptible to Breg-mediated suppression in non-small cell lung cancer

Tumor-infiltrating CD8 T cells are instrumental to antitumor immunity. In this study, we found that a subset of CXCR5-expressing CD8 T cells, termed follicular cytotoxic T (Tfc) cells, potently infiltrated the untreated tumors from non-small cell lung cancer (NSCLC) patients. On average, Tfc cells represented 14% of total tumor-infiltrating CD8 T cells and 6.6% of total tumor-infiltrating lymphocytes. Upon antigenic stimulation, Tfc cells presented significantly higher degranulation and stronger release of proinflammatory cytokines, including IFNg, IL2, and TNF, and the pleiotropic cytokine IL10 than non-Tfc cells. However, the expression of granzyme B and perforin was significantly lower in Tfc cells than in non-Tfc CD8 T cells. B regulatory (Breg) cells could significantly suppress proinflammatory cytokine production in both Tfc cells and non-Tfc CD8 T cells, but in Tfc cells, a lower concentration was required. Moreover, Breg cells could significantly elevate IL10 expression by Tfc cells but could not affect IL-10 expression by non-Tfc CD8 T cells. The neutralization of IL10 significantly reduced the extent of Breg-mediated regulation. Together, this study demonstrated that Tfc cells represented a significant proportion of tumor-infiltrating CD8 T cells in lung carcinoma. These Tfc cells were different from non-Tfc CD8 T cells in terms of cytokine expression and granzyme and perforin release and were more susceptible to Breg-mediated suppression in an IL-10-dependent manner.

Cytokines in CAR T Cell-Associated Neurotoxicity

Chimeric antigen receptor (CAR) T cells provide new therapeutic options for patients with relapsed/refractory hematologic malignancies. However, neurotoxicity is a frequent, and potentially fatal, complication. The spectrum of manifestations ranges from delirium and language dysfunction to seizures, coma, and fatal cerebral edema. This novel syndrome has been designated immune effector cell-associated neurotoxicity syndrome (ICANS). In this review, we draw an arc from our current understanding of how systemic and potentially local cytokine release act on the CNS, toward possible preventive and therapeutic approaches. We systematically review reported correlations of secreted inflammatory mediators in the serum/plasma and cerebrospinal fluid with the risk of ICANS in patients receiving CAR T cell therapy. Possible pathophysiologic impacts on the CNS are covered in detail for the most promising candidate cytokines, including IL-1, IL-6, IL-15, and GM-CSF. To provide insight into possible final common pathways of CNS inflammation, we place ICANS into the context of other systemic inflammatory conditions that are associated with neurologic dysfunction, including sepsis-associated encephalopathy, cerebral malaria, thrombotic microangiopathy, CNS infections, and hepatic encephalopathy. We then review in detail what is known about systemic cytokine interaction with components of the neurovascular unit, including endothelial cells, pericytes, and astrocytes, and how microglia and neurons respond to systemic inflammatory challenges. Current therapeutic approaches, including corticosteroids and blockade of IL-1 and IL-6 signaling, are reviewed in the context of what is known about the role of cytokines in ICANS. Throughout, we point out gaps in knowledge and possible new approaches for the investigation of the mechanism, prevention, and treatment of ICANS.

Luteolin alters MUC1 extracellular domain, sT antigen, ADAM-17, IL-8, IL-10 and NF-κB expression in Helicobacter pylori-infected gastric cancer CRL-1739 cells: A preliminary study

Luteolin is a natural flavonoid possessing certain beneficial pharmacological properties, including anti-oxidant, anti-inflammatory, anti-microbial and anti-cancer properties. The majority of types of gastric cancer with chronic gastritis are caused by infection with Helicobacter pylori (H. pylori). The present study evaluated the effect of luteolin on a number of selected factors that are potentially involved in gastric cancer development. The study was performed using gastric cancer CRL-1739 cells treated with 30 µM luteolin and H. pylori alone or combined. ELISA and reverse transcription PCR were used to assess the expression levels of MUC1, GalNAcα-R (Tn antigen) and NeuAcα2-3Galβ1-3GalNAc-R (sT antigen), ADAM-17, IL-8, IL-10 and NF-κB. H. pylori and luteolin independently and in combination significantly reduced the expression levels of the extracellular domain of MUC1 in gastric cancer cells compared with the untreated control cells. ADAM-17 expression was reduced by treatment with the pathogen and luteolin. Additionally, both factors reduced sT antigen expression. Treatment with 30 ≤M luteolin significantly induced IL-8 expression at the mRNA and protein level, and the mRNA expression levels of IL-10 and NF-κB compared with the control. Both H. pylori and luteolin induced IL-8 protein expression. The present preliminary results suggest that luteolin may be used to treat patients with gastric cancer.

Tumor Response to Irinotecan is Associated with IL-10 Expression Level in Metastatic Colorectal Cancer-Results from mCRC Biomarker Study

Purpose

Metastatic colorectal cancer (mCRC) is a leading cause of cancer-related death. Resistance to chemotherapy is the main reason for the failure of the treatment of mCRC. IL-10 has been reported to decrease after surgery and increase after mCRC reoccurrence. The role of IL-10 in chemotherapy drug resistance of mCRC is not well elucidated.

Patients and Methods

The retrospective study recruited 264 mCRC patients between January 2012 and December 2016 (NCT03532711). All the enrolled patients received an oxaliplatin-containing or irinotecan-containing regimen. The expression level of IL-10 in 232 patients’ plasma and 68 patients’ tumor tissue was examined. The relationships between IL-10 and clinicopathological characteristics were analyzed. Kaplan–Meier method and Cox regression were used to evaluate the prognostic impact of IL-10.

Results

The median concentration of IL-10 was 7.60 pg/mL before treatment and 11.08 pg/mL after treatment, which suggested that IL-10 level was significantly increased by treatment with a chemotherapeutic regimen (p = 0.000). By utilizing univariate and multivariate Cox proportional hazard analyses, we found that low IL-10 level in plasma was significantly associated with improved overall survival (OS) of mCRC patients treated with irinotecan-containing regimen-with optimal cutoff value of 5.525pg/mL, respectively (p =0.002). In addition, the low IL-10 expression level in tumor tissue was significantly associated with the improved OS for the irinotecan-containing regimen (p = 0.023).

Conclusion

Our study demonstrated that IL-10 could act as a prognostic biomarker for mCRC patients undergoing irinotecan-containing chemotherapy.

Engineered IL-10 variants elicit potent immunomodulatory effects at low ligand doses

Interleukin-10 (IL-10) is a dimeric cytokine with both immunosuppressive and immunostimulatory activities; however, IL-10-based therapies have shown only marginal clinical benefits. Here, we explored whether the stability of the IL-10 receptor complex contributes to the immunomodulatory potency of IL-10. We generated an IL-10 mutant with enhanced affinity for its IL-10Rβ receptor using yeast surface display. Compared to the wild-type cytokine, the affinity-enhanced IL-10 variants recruited IL-10Rβ more efficiently into active cell surface signaling complexes and triggered greater STAT1 and STAT3 activation in human monocytes and CD8⁺ T cells. These effects, in turn, led to more robust induction of IL-10-mediated gene expression programs at low ligand concentrations in both human cell subsets. IL-10-regulated genes are involved in monocyte energy homeostasis, migration, and trafficking and in CD8⁺ T cell exhaustion. At nonsaturating doses, IL-10 did not induce key components of its gene expression program, which may explain its lack of efficacy in clinical settings. Our engineered IL-10 variant showed a more robust bioactivity profile than that of wild-type IL-10 at low doses in monocytes and CD8⁺ T cells. Moreover, CAR-modified T cells expanded with the engineered IL-10 variant displayed superior cytolytic activity than those expanded with wild-type IL-10. Our study provides insights into how IL-10 receptor complex stability fine-tunes IL-10 biology and opens new opportunities to revitalize failed IL-10 therapies.

Elevated VEGF-A & PLGF concentration in aqueous humor of patients with uveal melanoma following Iodine-125 plaque radiotherapy

AIM

To measure the concentration of vascular endothelial growth factor-A (VEGF-A), and placental growth factor (PLGF) in aqueous humor of uveal melanoma patients before and after Iodine-125 plaque therapy (IPT), determine the postoperative fluctuation and evaluate associated factors in vivo.

METHODS

Participants were 18 Chinese patients with uveal melanoma who were elected to IPT. Undiluted aqueous humor samples were collected at Iodine plaque implant and removal time, then stored immediately at -80°C until assayed. The concentration of VEGF-A, PLGF and other 7 cytokines comprising interleukin-2 (IL-2), IL-8, IL-10, interferon (IFN)-γ, programmed death (PD)-1, transforming growth factor (TGF)-β1 and insulin-like growth factor (IGF)-1 in aqueous humor was measured using Raybiotech immunoassay kit, a high throughput strategy. The VEGF-A and PLGF levels were compared across preoperation and postoperation subgroups, as well as those of other 7 interleukins. Correlation and grouped analyses were conducted to determine the independent effects of clinical parameters and other cytokines on VEGF-A and PLGF concentration or fluctuation. This study set a self-control design.

RESULTS

VEGF-A (P=0.038) and PLGF (P=0.026) were the only two increased cytokines after IPT. Preoperative and postoperative level of VEGF-A and PLGF (r=0.575, P=0.013; r=0.987, P<0.001) correlated with each other significantly. Level of VEGF-A (r=0.626, P=0.005; r=0.588, P=0.01) and PLGF (r=0.616, P=0.007; r=0.588, P=0.01) had positive correlation with tumor thickness consistently. Elevated VEGF-A or PLGF level were strong predictive factors of each other (P=0.007, OR=60.0). The elevated VEGF-A group showed a higher postoperative level of IFN-γ (P=0.005), IL-2 (P<0.001) and IL-10 (P=0.004) in aqueous humor. When the elevated PLGF group got similar results that a higher postoperative level of IFN-γ (P=0.007), IL-2 (P<0.001) and IL-10 (P=0.013) in aqueous humor.

CONCLUSION

This study reveals that VEGF-A and PLGF in aqueous humor significantly increased with tumor thickness and radiation process in uveal melanoma patients. VEGF-A and PLGF may be crucial in uveal melanoma genesis and radiotherapy reactions. Immune mediators comprised IFN-γ, IL-2 and IL-10 could play roles in the link between inflammation and angiogenesis in uveal melanoma when exposed to radiotherapy.

Targeting interleukin-10 signalling for cancer immunotherapy, a promising and complicated task

Interleukin 10 (IL-10) belongs to IL-10 family cytokines that are critical for maintaining the integrity of epithelial tissues, protecting pathogenic infection, and preventing excessive immune responses to damage self. Temporal IL-10 signaling blockade enhances vaccine-induced tumor regression by CD8 + T cells. IL-10, especially pegylated IL-10, mediates tumor regression by expanding tumor-infiltrating CD8 + T cells. Moreover, targeting IL-10 enhances immune checkpoint inhibitor mediated tumor regression. In the current paper, we will review recent advances in this area and discuss the complexity of IL-10 manipulation for cancer therapy.

Combination of Gas Plasma and Radiotherapy Has Immunostimulatory Potential and Additive Toxicity in Murine Melanoma Cells in Vitro

Despite continuous advances in therapy, malignant melanoma is still among the deadliest types of cancer. At the same time, owing to its high plasticity and immunogenicity, melanoma is regarded as a model tumor entity when testing new treatment approaches. Cold physical plasma is a novel anticancer tool that utilizes a plethora of reactive oxygen species (ROS) being deposited on the target cells and tissues. To test whether plasma treatment would enhance the toxicity of an established antitumor therapy, ionizing radiation, we combined both physical treatment modalities targeting B16F10 murine melanoma cell in vitro. Repeated rather than single radiotherapy, in combination with gas plasma-introduced ROS, induced apoptosis and cell cycle arrest in an additive fashion. In tendency, gas plasma treatment sensitized the cells to subsequent radiotherapy rather than the other way around. This was concomitant with increased levels of TNFα, IL6, and GM-CSF in supernatants. Murine JAWS dendritic cells cultured in these supernatants showed an increased expression of cell surface activation markers, such as MHCII and CD83. For PD-L1 and PD-L2, increased expression was observed. Our results are the first to suggest an additive therapeutic effect of gas plasma and radiotherapy, and translational tumor models are needed to develop this concept further.

Composition and plasticity of triple-negative breast carcinoma-infiltrating regulatory T cells

Low Foxp3⁺ regulatory T-cell (Treg) presence in the tumor-infiltrating lymphocytes (TILs) is considered favorable in breast cancer, and numerous CD25-targeting agents have been applied in the attempt to remove Foxp3⁺ Treg cells, which typically present CD4⁺ CD25^+/hi surface phenotype. However, CD25 is not Treg-exclusive and can be upregulated by effector T cells. Hence, CD25 depletion may cause the elimination of activated T cells that are responding to tumor-specific antigens. In this study, the composition and function of CD4⁺ CD25⁺ cells inside the microenvironment of triple-negative breast carcinoma (TNBC) were investigated. Directly ex vivo, the Foxp3⁺ Treg cells represented a minor subset in total CD4⁺ CD25⁺ TILs. Significant differences were observed in the expression of Treg-associated molecules between CD4⁺ CD25⁺ Foxp3⁺ TILs and CD4⁺ CD25⁺ Foxp3^- TILs. While both the CD4⁺ CD25⁺ Foxp3⁺ and the CD4⁺ CD25⁺ Foxp3^- TILs could express CTLA-4 and LAG-3, the expression levels were significantly higher in CD4⁺ CD25⁺ Foxp3⁺ TILs than in CD4⁺ CD25⁺ Foxp3^- TILs. Upon TCR stimulation, the expression of TGF-beta was significantly higher in CD4⁺ CD25⁺ Foxp3⁺ TILs, while the expression of IL-10 was significantly higher in CD4⁺ CD25⁺ Foxp3^- TILs. These differences were conserved in the blood counterparts of these cells. Interestingly, the level of CD25⁺ Foxp3⁺ cells in circulating CD4⁺ T cells was positively correlated with the level of CD25⁺ Foxp3⁺ cells in CD4⁺ TILs, but the level of CD25⁺ Foxp3^- cells in circulating CD4⁺ T cells was not associated with the level of CD25⁺ Foxp3^- cells in CD4⁺ TILs. Th17-polarizing medium could readily remodel CD4⁺ CD25⁺ Foxp3^- , but not CD4⁺ CD25⁺ Foxp3⁺ , T cells into RORgammat and IL-17-expressing T cells, demonstrating stronger plasticity of the former subset. Together, these data demonstrated that the CD4⁺ CD25⁺ TILs were composed of distinctive Foxp3^- and Foxp3⁺ cells, with the former representing the major subset. The antigen specificity and effector molecule expression of the CD4⁺ CD25⁺ Foxp3^- thus require further analyses.

Title: IL-10-producing T cells and their dual functions

Interleukin (IL)-10 is considered a prototypical anti-inflammatory cytokine, which significantly contributes to the maintenance and reestablishment of immune homeostasis. However, this classical view fails to fully describe the pleiotropic roles of IL-10. Indeed, IL-10 can also promote immune responses, e.g. by supporting B-cell and CD8⁺ T-cell activation. The reasons for these seemingly opposing functions are unclear to a large extent. Recent and previous studies suggest that the cellular source and the microenvironment impact the function of IL-10. However, studies addressing the mechanisms which determine whether IL-10 promotes inflammation or controls it have just begun. This review first summarizes the recent findings on the heterogeneity of IL-10 producing T cells and their impact on the target cells. Finally, we will propose two possible explanations for the dual functions of IL-10.

Therapy with CD4+CD25+ T regulatory cells - should we be afraid of cancer?

This review focuses on the role of regulatory T cells (Tregs) in the process of carcinogenesis. The controversy of this issue arose due to the increasing therapeutic use of Tregs in humans (inter alia, in the treatment of autoimmune diseases). It is mainly due to potential dangers related to immunosuppressive activity of these cells, especially regarding cancer. The natural function of regulatory T cells (which is the suppression of excessive activity of the immune system) is purportedly linked to an increased risk of cancer initiation. This work brings together and summarizes the most important reports of researchers dealing with this problem and attempts to explain doubts and fears related to Tregs and their uncertain connection with cancer initiation and progression. It is clearly shown that regulatory T cells are associated with acceleration of existing tumors (they are attracted by microenvironments created by cancer cells) but cannot initiate them on their own.

Certain BCG-reactive responses are associated with bladder cancer prognosis

A subset of bladder patients does not respond to BCG treatment effectively and the underlying reason behind this observation is currently unclear. CD4+ T cells are composed of various subsets that each expresses a distinctive set of cytokines and can potently shift the immune response toward various directions. In this study, we examined the CD4+ T-cell cytokine response in bladder cancer patients toward BCG stimulation. We found that bladder cancer patients presented a variety of responses toward BCG, with no uniform characteristics. Those patients with high IFN-γ and IL-21 expression in CD4+ T cells presented significantly better prognosis than patients with low cytokine secretion in CD4+ T cells. Tumor-infiltrating CD4+ T cells were significantly less potent in expressing IFN-γ, IL-4, and IL-17, and more potent in expressing IL-10 than circulating CD4+ T cells. In addition, we found no difference in CD80, CD86, or MHC II expression by macrophages from patients with different IFN-γ and IL-21 levels. However, the secretion of IL-12, a Th1-skewing cytokine, was released at significantly higher level by macrophages from patients with high IFN-γ or high IL-21 secretion. We also identified that modulating monocytes/macrophages by GM-CSF-mediated polarization resulted in significantly elevated expression of IFN-γ and IL-21 from CD4+ T cells. Overall, these results suggested that the specific types of responses mounted by CD4+ T cells were critical to the final outcome of bladder cancer patients and can be influenced by monocyte/macrophage polarization.

Aberrant Peripheral Immune Function in a Good Syndrome Patient

Good's syndrome (GS) is often accompanied by recurrent respiratory infections and chronic diarrhea. The main purpose was to evaluate the peripheral immune status of a GS patient after thymoma resection. Twenty healthy volunteers were recruited as healthy controls (HCs). Flow cytometry was applied to determine the proportions of circuiting CD4⁺ T cells, CD8⁺ T cells, γδT cells, and regulatory T (Treg) cells in our GS patient. We also examined the proliferation capability of ex vivo CD4⁺ T cells and detected the levels of cytokines interferon- (IFN-) γ and interleukin-17A secreted by ex vivo immune cells from this GS patient. Compared with healthy control subjects, this GS patient had fewer B cells, an inverted ratio of CD4⁺/CD8⁺ cells, and more Treg cells in his peripheral blood. Additionally, the patient's Vδ2 T cell levels were significantly decreased despite having a normal percentage of γδT cells. Ex vivo peripheral CD4⁺ T cells from the patient showed insufficient proliferation and division potential as well as excessive expression of PD-1. Moreover, IFN-γ was predominantly derived from CD8⁺ T cells in this GS patient, rather than from CD4⁺ T cells and γδT cells. This GS patient had impaired T and B cell immunological alternations and cytokine disruptions after thymectomy. Detailed research should focus on therapies that can adjust the immune status in such patients for a better outcome.

Interleukin 10 enhanced CD8+ T cell activity and reduced CD8+ T cell apoptosis in patients with diffuse large B cell lymphoma

The pleiotropic cytokine interleukin (IL)-10 is best characterized by its ability to downregulate inflammation and promote peripheral tolerance. On the other hand, IL-10 was also found to maintain the effector response of CD8⁺ T cells and promote the expansion of tumor-resident CD8⁺ T cells. In diffuse large B cell lymphoma (DLBCL), the role of IL-10 has been characterized in tumor cells but not in CD8⁺ T cells. We found that CD8⁺ T cells in DLBCL presented robust interferon (IFN)-γ expression early during TCR-activation but could not maintain this response later on, which was characterized by significantly lower CD8⁺ T cell degranulation and higher apoptosis. These observations were associated with higher PD-1 expression in DLBCL CD8⁺ T cells. Furthermore, the PD-1⁺ cells were strongly enriched in the IFN-γ⁺, but not the IFN-γ^-, fraction. Interestingly, exogenous IL-10 significantly improved the survival of DLBCL CD8⁺ T cells, and resulted in significantly higher IFN-γ, ganzyme A and granzyme B expression in the absence of CD19⁺ tumor cells, and significantly improved CD8⁺ T cell-mediated specific lysis of CD19⁺ tumor cells. IL-10 did not alter the expression of PD-1 in DLBCL CD8⁺ T cells, but curiously, IL-10-treated DLBCL CD8⁺ T cells were less susceptible to PD-L1-mediated apoptosis. We then demonstrated that IL-10 treatment significantly elevated the expression of pro-survival factor Bcl-2. Blocking IL-10 resulted in higher apoptosis, fewer IFN-γ⁺ CD8⁺ T cells, and lower Bcl-2 expression. IL-10 also significantly increased STAT3, but not STAT1, phosphorylation in CD8⁺ T cells. Together, these results suggested that IL-10 could enhance CD8⁺ T cell inflammation in DLBCL patients.

Regulatory T-cell heterogeneity and the cancer immune response

The frequency of circulating or tumour-infiltrating regulatory T cells (Tregs) has been associated with poor patient survival in many cancers including breast, melanoma and lung. It has been hypothesised that Tregs impact the anti-tumour function of effector T cells, resulting in worse outcomes for patients. However, high infiltrates of Tregs have been associated with a positive outcome of patients in a minority of cancers including colorectal, bladder and oesophageal. In addition, many studies have shown no impact of Tregs in patient outcome. Traditionally, research has identified Tregs as forkhead box P3 (FOXP3+) T cells in order to make such associations. Recently, it has become evident that regulatory populations are very heterogeneous, and this heterogeneity is essential for Treg function. Treg heterogeneity likely affects predictions of patient outcome, and different Treg populations may have different influences on tumours. The study of Tregs in cancer must include a better definition of the cells analysed. This review will focus primarily on colorectal cancer in humans, due to mixed data on the impact of Tregs on patient outcome in this disease.

Interleukin 2 and interleukin 10 function synergistically to promote CD8+ T cell cytotoxicity, which is suppressed by regulatory T cells in breast cancer

The precise role of interleukin (IL)-10 in breast cancer is not clear. Previous studies suggested a tumor-promoting role of IL-10 in breast cancer, whereas recent discoveries that IL-10 activated and expanded tumor-resident CD8+ T cells challenged the traditional view. Here, we investigated the role of IL-10 in HLA-A2-positive breast cancer patients with Grade III, Stage IIA or IIB in-situ and invasive ductal carcinoma, and compared it with that of IL-2, the canonical CD8+ T cell growth factor. We first observed that breast cancer patients presented higher serum levels of IL-2 and IL-10 than healthy controls. Upon prolonged TCR stimulation, peripheral blood CD8+ T cells from breast cancer patients tended to undergo apoptosis, which could be prevented by the addition of IL-2 and/or IL-10. The cytotoxicity of TCR-activated CD8+ T cells was also enhanced by exogenous IL-2 and/or IL-10. Interestingly, IL-2 and IL-10 demonstrated synergistic effects, since the enhancement in CD8+ T cell function when both cytokines were added was greater than the sum of the improvements mediated by each individual cytokine. IL-10 by itself could not promote the proliferation of CD8+ T cells but could significantly enhance IL-2-mediated promotion of CD8+ T cell proliferation. In addition, the cytotoxicity of tumor-infiltrating CD8+ T cells in breast tumor was elevated when both IL-2 and IL-10 were present but not when either one was absent. This synergistic effect was stopped by CD4+CD25+ regulatory T cells (Treg), which depleted IL-2 in a cell number-dependent manner. Together, these results demonstrated that IL-2 and IL-10 could work synergistically to improve the survival, proliferation, and cytotoxicity of activated CD8+ T cells, an effect suppressible by CD4+CD25+ Treg cells.

Inclusion of BLIMP-1+ effector regulatory T cells improves the Immunoscore in a cohort of New Zealand colorectal cancer patients: a pilot study

Analysis of tumour-infiltrating T cells in colorectal cancer can predict disease-free survival. The Immunoscore, obtained by quantifying tumour-infiltrating CD3+ and CD8+ T cells, may improve current staging. Effector regulatory T cells are a potently suppressive subset in mice and, while present in human colorectal cancer, their role in patient outcome is unknown. Immunofluorescence was used to analyse immune cell infiltrates in patients with early (stage II) colorectal cancer with (n = 13) and without (n = 19) recurrent disease. CD3 and CD8 were used for the Immunoscore; FOXP3, BLIMP-1 and CD3 to identify effector regulatory T cells. Patients with high Immunoscores had increased disease-free survival compared to patients with low Immunoscores (Log-rank test p < 0.01). Prediction of outcome was further improved by stratifying patients with a low Immunoscore according to CD3+FOXP3+BLIMP-1+ cell infiltration at the invasive margin. Patients with a low Immunoscore and high infiltrate of CD3+FOXP3+BLIMP-1+ cells tended to have better disease-free survival than patients with low Immunoscore and low infiltrate of CD3+FOXP3+BLIMP-1+ cells. Patients with a high Immunoscore had better disease-free survival than patients with a low Immunoscore and low infiltrate of CD3+ FOXP3+ BLIMP-1+ cells (Log-rank test p < 0.001). These results indicate that tumour infiltration with effector regulatory T cells improves the prognostic value of the Immunoscore and implies that these cells may play a role in colorectal cancer patient outcome.

The role of interleukin 10 in human papilloma virus infection and progression to cervical carcinoma

Although Human Papillomavirus (HPV) exerts a vital influence on cervical carcinogenesis, other factors influence the development of a squamous intraepithelial lesion (SIL) that may or not progress to cervical cancer. Among several cytokines, Interleukin 10 (IL-10) stands out as an important anti-inflammatory factor, leading to immune system evasion through an immunosuppressive state. In the cervical microenvironment, during different stages of HPV infection, IL-10 production can be induced and maintained by different cell sources, including infected keratinocytes, some subsets of dendritic cells (DC), tumor associated macrophages (TAM), T regulatory cells (Treg) and tumor cells. Further, a wide range of effects can be exerted by IL-10 on different cell populations, such as inhibiting proinflammatory cytokine production, DCs differentiation, antigen presenting function and T-helper 1 (Th1) polarization. IL-10 is one of several cytokines involved in cancer development and sustenance, although its role in cancer is still controversial and poorly understood. However, cervical IL-10 levels tend to increase in parallel to SIL development and are even higher within cervical tumors. Accumulating data have shown that after HPV infection, IL-10 levels are enhanced as a result of HPV E2, E6 and E7 proteins action over IL-10 gene transcription, while IL-10 stimulates HPV E6 and E7 expression. Therefore, this interplay between HPV and IL-10 creates a vicious cycle that could favor an immunosuppressive microenvironment in the cervix, facilitating the progression of a simple HPV infection to SIL or cervical cancer.

Regulator Versus Effector Paradigm: Interleukin-10 as Indicator of the Switching Response

The interleukin-10 (IL-10) is generally considered as the most important cytokine with anti-inflammatory properties and one of the key cytokines preventing inflammation-mediated tissue damage. In this respect, IL-10 producing cells play a crucial role in the outcome of infections, allergy, autoimmune reactions, tumor development, and transplant tolerance. Based on recent findings with regard to the mentioned clinical conditions, this review attempts to shed some light on the IL-10 functions, considering this cytokine as inherent inducer of the switching immunity. While acute infections and vaccinations are associated by IL-10 enhanced during few weeks, chronic parasitoses, tumor diseases, allergen-specific immunotherapy, transplants, and use of immune-suppressor drugs show an increased IL-10 level along months or years. With regard to autoimmune pathologies, the IL-10 increase is prevalently observed during early stages, whereas the successive stages are characterized by reaching of immune equilibrium independently to disease's activity. Together, these findings indicate that IL-10 is mainly produced during transient immune conditions and the persistent IL-10-related effect is the indication/prediction (and maybe effectuation) of the switching immunity. Actual knowledge emphasizes that any manipulation of the IL-10 response for treatment purposes should be considered very cautiously due to its potential hazards to the immune system. Probably, the IL-10 as potential switcher of immunity response should be used in association with co-stimulatory immune effectors that are necessary to determine the appropriate deviation during treatment of respective pathologies. Hopefully, further findings would open new avenues to study the biology of this "master switch" cytokine and its therapeutic potential.

A unique CD8(+) T lymphocyte signature in pediatric type 1 diabetes

Human type 1 diabetes results from a destructive auto-reactive immune response in which CD8(+) T lymphocytes play a critical role. Given the intense ongoing efforts to develop immune intervention to prevent and/or cure the disease, biomarkers suitable for prediction of disease risk and progress, as well as for monitoring of immunotherapy are required. We undertook separate multi-parameter analyses of single naïve and activated/memory CD8(+) T lymphocytes from pediatric and adult patients, with the objective of identifying cellular profiles associated with onset of type 1 diabetes. We observe global perturbations in gene and protein expression and in the abundance of T cell populations characterizing pediatric but not adult patients, relative to age-matched healthy individuals. Pediatric diabetes is associated with a unique population of CD8(+) T lymphocytes co-expressing effector (perforin, granzyme B) and regulatory (transforming growth factor β, interleukin-10 receptor) molecules. This population persists after metabolic normalization and is especially abundant in children with high titers of auto-antibodies to glutamic acid decarboxylase and with elevated HbA1c values. These findings highlight striking differences between pediatric and adult type 1 diabetes, indicate prolonged large-scale perturbations in the CD8(+) T cell compartment in the former, and suggest that CD8(+)CD45RA(-) T cells co-expressing effector and regulatory factors are of interest as biomarkers in pediatric type 1 diabetes.

Immune cell interplay in colorectal cancer prognosis

The immune response to colorectal cancer has proven to be a reliable measure of patient outcome in several studies. However, the complexity of the immune response in this disease is not well understood, particularly the interactions between tumour-associated cells and cells of the innate and adaptive immune system. This review will discuss the relationship between cancer associated fibroblasts and macrophages, as well as between macrophages and T cells, and demonstrate how each population may support or prevent tumour growth in a different immune environment.

Serum IL-10 Predicts Worse Outcome in Cancer Patients: A Meta-Analysis

Background

IL–10 is an important immunosuppressive cytokine which is frequently elevated in tumor microenvironment. Some studies have reported that overexpression of serous IL–10 is correlated with worse outcome in patients with malignant tumor. Here, we conducted a meta-analysis to assess the prognostic impact of serous IL–10 expression in cancer patients.

Methods

We searched PubMed and EBSCO for studies in evaluating the association of IL–10 expression—in serum and clinical outcome in cancer patients. Overall survival (OS) was the primary prognostic indicator and disease-free survival (DFS) was the secondary indicator. Extracted data were computed into odds ratios (ORs) and 95% confidence interval (CI) or a P value for survival at 1, 3 and 5 years. Pooled data were weighted using the Mantel–Haenszel Fixed-effect model. All statistical tests were two-sided.

Results

A total of 1788 patients with cancer from 21 published studies were incorporated into this meta-analysis. High level of serum IL–10 was significantly associated with worse OS at 1-year (OR = 3.70, 95% CI = 2.81 to 4.87, P < 0.00001), 3-year (OR = 3.33, 95% CI = 2.53 to 4.39, P < 0.0001) and 5-year (OR = 2.80, 95% CI = 1.90 to 4.10, P < 0.0001) of cancer. Subgroup analysis showed that the correlation between serous IL–10 expression and outcome of patients with solid tumors and hematological malignancies are consistent. The association of IL–10 with worse DFS at 1-year (OR = 3.34, 95% CI = 1.40 to 7.94, P = 0.006) and 2-year (OR = 3.91, 95% CI = 1.79 to 8.53, P = 0.0006) was also identified.

Conclusions

High expression of serous IL–10 leads to an adverse survival in most types of cancer. IL–10 is a valuable biomarker for prognostic prediction and targeting IL–10 treatment options for both solid tumors and hematological malignancies.

Inflammation and cancer: till death tears them apart

Advances in biotechnology have enabled the collection of an immeasurable amount of information from genomic, transcriptomic, metabolomic and proteomic studies of tumours within their microenvironments. The dissection of cytokine and chemokine networks has provided new clues to the interactions between cancer cells and their surrounding inflammatory landscape. To bridge the gap between chronic inflammation and cancer, dynamic participants in the tumour microenvironment have been identified, including tumour-associated macrophages (TAMs) and regulatory T cells (Tregs). Both of these cell types are notable for their ability to cause immunosuppressive conditions and support the evasion of tumour immune surveillance. It is clear now that the tumour-promoting inflammatory environment has to be included as one of the major cancer hallmarks. This review explores the recent advances in the understanding of cancer-related inflammation and how this is being applied to comparative oncology studies in humans and domestic species, such as the dog.

T-cell Expression of IL10 Is Essential for Tumor Immune Surveillance in the Small Intestine

IL10 is attributed with immune-suppressive and anti-inflammatory properties, which could promote or suppress cancer in the gastrointestinal tract. Loss of IL10 exacerbates colonic inflammation, leading to colitis and cancer. Consistent with this, transfer of IL10-competent regulatory T cells (Treg) into mice with colitis or hereditary polyposis protects against disease, while IL10-deficient mice are predisposed to polyposis with increased colon polyp load. Little is known about the protective or pathogenic function of IL10 in cancers of the small intestine. We found CD4(+) T cells and CD4(+) Foxp3(+) Tregs to be the major sources of IL10 in the small intestine and responsible for the increase in IL10 during polyposis in the APC(Δ468) mouse model of hereditary polyposis. Targeted ablation of IL10 in T cells caused severe IL10 deficiency and delayed polyp growth. However, these polyps progressively lost cytotoxic activity and eventually progressed to cancer. Several observations suggested that the effect was due to the loss of IFNγ-dependent immune surveillance. IL10-incompetent CD4(+) T cells failed to secrete IFNγ when stimulated with polyp antigens and were inefficient in T-helper-1 (TH1) commitment. By contrast, the TH17 commitment was unaffected. These findings were validated using mice whose T cells overexpress IL10. In these mice, we observed high intra-polyp cytotoxic activity and attenuation of polyposis. Thus, expression of IL10 by T cells is protective and required for immune surveillance in the small intestine.

Differences in immune responses between CMV-seronegative and -seropositive patients with myocardial ischemia and reperfusion

CMV infection is responsible for acceleration of immune senescence and linked to systemic pathologies, including cardiovascular diseases. In this study, we investigated differences in the immune response between CMV-seropositive and seronegative patients undergoing primary percutaneous coronary intervention (PPCI) for acute myocardial infarction (MI). Peripheral blood samples were taken at six different time points: pre-, 15, 30, 90 min, 24 h after PPCI and at 3 months after MI. Absolute counts of lymphocyte subpopulations, immune response to specific and nonspecific stimulation, serum cytokines and levels of CMV-IgG, cardiolipin-IgG, and anti-endothelial cell antibodies were assessed. CMV-seropositive patients with MI showed a twofold higher IFN-γ production to PHA-stimulation, up to 2.5-fold higher levels of IP-10 in serum and up to 30% lower serum levels of IL-16 compared to CMV-seronegative individuals. CMV-seropositive patients could be divided into two subgroups with high (IL-10Hi) and low (IL-10Lo) IL-10 serum levels during the acute stage of MI. The IL-10Hi CMV-seropositive subgroup showed an increased exit of late-differentiated T lymphocytes, NK and NKT-like cells from the circulation, which may potentially enhance cytotoxic damage in the ischemic myocardium. Finally, we did not observe an acceleration of autoimmunity by MI in CMV-seropositive individuals. The immune response during acute MI showed characteristic differences between CMV seronegative and seropositive patients, with a stronger pro-inflammatory response in seropositive patients. The effects of IP-10, IL-16, and IL-10 on characteristics of acute immune responses and formation of different immune profiles in CMV-seropositive individuals require further investigation.

Manipulating IL-10 signalling blockade for better immunotherapy

Interleukin 10 is a cytokine with the ability to reduce or terminate inflammation. Chronic viral infection, such as infection of chronic hepatitis B, hepatitis C and HIV, has increased levels of interleukin 10 in peripheral blood. Serum IL-10 levels are also high in certain cancers. Blocking IL-10 signalling at the time of immunisation clears chronic viral infection and prevents tumour growth in animal models. We review recent advances in this area, with the emphasis on potential use of this novel strategy to treat chronic viral infection and cancer in human.

Current status of interleukin-10 and regulatory T-cells in cancer

PURPOSE OF REVIEW

Tumor growth elicits antigen-specific cytotoxic as well as immune suppressive responses. Interleukin-10 (IL-10) is a key immune-suppressive cytokine produced by regulatory T-cells and by helper T-cells. Here, we review pleiotropic functions of IL-10 that impact the immune pathology of cancer.

RECENT FINDINGS

The role of IL-10 in cancer has become less certain with the knowledge of its immune stimulatory functions. IL-10 is needed for T-helper cell functions, T-cell immune surveillance, and suppression of cancer-associated inflammation. By promoting tumor-specific immune surveillance and hindering pathogenic inflammation, IL-10 is emerging as a key cytokine in the battle of the host against cancer.

SUMMARY

IL-10 functions at the cross-roads of immune stimulation and immune suppression in cancer. Immunological mechanisms of action of IL-10 can be ultimately exploited to develop novel and effective cancer therapies.