Interleukin 10 in the tumor microenvironment: a target for anticancer immunotherapy

TTI-621 (SIRPαFc), a CD47-blocking cancer immunotherapeutic, triggers phagocytosis of lymphoma cells by multiple polarized macrophage subsets

Tumor-associated macrophages (TAMs) are heterogeneous and can adopt a spectrum of activation states between pro-inflammatory and pro-tumorigenic in response to the microenvironment. We have previously shown that TTI-621, a soluble SIRPαFc fusion protein that blocks the CD47 “do-not-eat” signal, promotes tumor cell phagocytosis by IFN-γ-primed macrophages. To assess the impact of CD47 blockade on diverse types of macrophages that are found within the tumor microenvironment, six different polarized human macrophage subsets (M(-), M(IFN-γ), M(IFN-γ+LPS), M(IL-4), M(HAGG+IL-1β), M(IL-10 + TGFβ)) with distinct cell surface markers and cytokine profiles were generated. Blockade of CD47 using TTI-621 significantly increased phagocytosis of lymphoma cells by all macrophage subsets, with M(IFN-γ), M(IFN-γ+LPS) and M(IL-10 + TGFβ) macrophages having the highest phagocytic response. TTI-621-mediated phagocytosis involves macrophage expression of both the low- and high-affinity Fcγ receptors II (CD32) and I (CD64), respectively. Moreover, macrophages with lower phagocytic capabilities (M(-), M(IL-4), M(HAGG+IL-1β)) could readily be re-polarized into highly phagocytic macrophages using various cytokines or TLR agonists. In line with the in vitro study, we further demonstrate that TTI-621 can trigger phagocytosis of tumor cells by diverse subsets of isolated mouse TAMs ex vivo. These data suggest that TTI-621 may be efficacious in triggering the destruction of cancer cells by a diverse population of TAMs found in vivo and support possible combination approaches to augment the activity of CD47 blockade.

Selective neutralization of IL-12 p40 monomer induces death in prostate cancer cells via IL-12-IFN-γ

Cancer cells are adept at evading cell death, but the underlying mechanisms are poorly understood. IL-12 plays a critical role in the early inflammatory response to infection and in the generation of T-helper type 1 cells, favoring cell-mediated immunity. IL-12 is composed of two different subunits, p40 and p35. This study underlines the importance of IL-12 p40 monomer (p40) in helping cancer cells to escape cell death. We found that different mouse and human cancer cells produced greater levels of p40 than p40 homodimer (p40₂), IL-12, or IL-23. Similarly, the serum level of p40 was much greater in patients with prostate cancer than in healthy control subjects. Selective neutralization of p40, but not p40₂, by mAb stimulated death in different cancer cells in vitro and in vivo in a tumor model. Interestingly, p40 was involved in the arrest of IL-12 receptor (IL-12R) IL-12Rβ1, but not IL-12Rβ2, in the membrane, and that p40 neutralization induced the internalization of IL-12Rβ1 via caveolin and caused cancer cell death via the IL-12-IFN-γ pathway. These studies identify a role of p40 monomer in helping cancer cells to escape cell death via suppression of IL-12Rβ1 internalization.

Immunological effects of everolimus in patients with metastatic renal cell cancer

The mammalian target of rapamycin (mTOR) is a crucial kinase present in all cells. Besides its role in the regulation of cell-growth, proliferation, angiogenesis, and survival of malignant tumors, mTOR additionally plays an important role in immune regulation by controlling the balance between effector T cells and regulatory T cells (Tregs). This critically affects the suppressive state of the immune system. Here, the systemic immunological effects of everolimus treatment were comprehensively investigated in five patients with metastatic renal cell cancer. In this hypothesis generating study, the immunological alterations in circulating immune subsets induced by everolimus included a (non-significant) increase in the frequency of Tregs, a significant increase in monocytic myeloid-derived suppressor cells, a significant decrease in the frequency of immunoregulatory natural killer cells, classical CD141⁺ (cDC1) and CD1c⁺ (cDC2) dendritic cell subsets, as well as a decrease in the activation status of plasmacytoid dendritic cells and cDC1. These date indicate that the immunological effects of everolimus affect multiple immune cell subsets and altogether tip the balance in favor of immunosuppression, which can be considered a detrimental effect in the treatment of cancer, and may require combination treatment with agents able to negate immune suppression and boost T cell immunity.

A Personalized Diagnostic and Treatment Approach for Macrophage Activation Syndrome and Secondary Hemophagocytic Lymphohistiocytosis in Adults

OBJECTIVE

We assessed the clinical features and outcomes based on therapeutic options adopted during hospital stay for adult patients with macrophage activation syndrome and secondary hemophagocytic lymphohistiocytosis (MAS/sHLH).

METHODS

We conducted a retrospective chart review of all adult patients (age ≥ 18 years) diagnosed with MAS/sHLH at our center between 2010 and 2015. Inclusion criteria for patients were diagnosis of MAS/sHLH during admission and patients meeting at least 5 out of 8 of Henter's criteria or at least 4 out of 6 of the criteria that were tested.

RESULTS

Nineteen adult patients with MAS/sHLH met the inclusion criteria from January 2010 to October 2015 (median age 48 years; female 68.4%). Treatment had been personalized, depending on the clinical presentation and course of disease. Majority of the patients received anakinra, cyclosporine, intravenous immunoglobulins (IVIG), and steroids. Fourteen (74%) patients survived, with clinical improvement by the time of discharge. After excluding the three patients with underlying leukemia/lymphoma who opted for palliative care and subsequently died, the survival rate was 88%.

CONCLUSION

A modified diagnostic and treatment protocol for adult patients with MAS/sHLH that incorporated graded introduction of medications based on clinical presentation and cytokine profile resulted in the best adult survival rate reported in literature.

Therapeutic blockade of Foxp3 in experimental breast cancer models

PURPOSE

Regulatory T cells (Tregs) impair the clinical benefit of cancer immunotherapy. To optimize the antitumor efficacy of therapeutic dendritic cell (DC) vaccines, we aimed to inhibit Foxp3, a transcription factor required for Treg function.

METHODS

Mice bearing established syngeneic LM3 and 4T1 breast tumors were treated with antitumor DC vaccines and a synthetic peptide (P60) that has been shown to inhibit Foxp3.

RESULTS

Treatment with P60 improved the therapeutic efficacy of DC vaccines in these experimental models. In addition, monotherapy with P60 inhibited tumor growth in immunocompetent as well as in immuno-compromised animals bearing established tumors. We found expression of Foxp3 in human and murine breast tumor cells. P60 inhibited IL-10 secretion in breast cancer cells that expressed Foxp3.

CONCLUSIONS

Our results suggest that Foxp3 blockade improves the therapeutic efficacy of DC vaccines by inhibition of Tregs and through a direct antitumor effect. This strategy could prove useful to neutralize the immunosuppressive microenvironment and to boost antitumor immunity in breast cancer.

TLR9 expression and secretion of LIF by prostate cancer cells stimulates accumulation and activity of polymorphonuclear MDSCs

Proinflammatory signals promote prostate tumorigenesis and progression, but their origins and downstream effects remain unclear. We recently demonstrated that the expression of an innate immune receptor, TLR9, by prostate cancer cells is critical for their tumor-propagating potential. We investigated whether cancer cell-intrinsic TLR9 signaling alters composition of the prostate tumor microenvironment. We generated Ras/Myc (RM9) and Myc-driven (Myc-CaP) prostate cancer cells expressing the tetracycline-inducible gene Tlr9 (Tlr9^ON ) or the control LacZ (LacZ^ON ). When engrafted into mice and treated with tetracycline, Tlr9^ON , but not LacZ^ON , tumors showed accelerated growth kinetics compared with tumors in PBS-treated mice. Tlr9 upregulation in cancer cells triggered the selective accumulation of CD11b⁺Ly6G^HILy6C^LO myeloid cells, phenotypically similar to PMN-MDSCs. The PMN-MDSCs from tetracycline-treated RM9-Tlr9^ON tumors increased the immunosuppressive activity of the STAT3 transcription factor, thereby more potently inhibiting T cell proliferation. We identified LIF, an IL-6-type cytokine and STAT3 activator, as a potential mediator of crosstalk between TLR9-expressing prostate cancer cells and PMN-MDSCs. Antibody-mediated LIF neutralization reduced the percentage of tumor-infiltrating PMN-MDSCs and inhibited tumor growth in mice. The clinical relevance of LIF is confirmed by the correlation between TLR9 and LIF expression in prostate cancer specimens. Furthermore, blood samples from patients with prostate cancer showed elevated levels of LIF and high LIFR expression on circulating PMN-MDSCs. Our results suggest that TLR9⁺ prostate cancers promote immune evasion via LIF-mediated expansion and activation of PMN-MDSCs. Finally, targeting TLR9/LIF/STAT3 signaling using oligonucleotide-based inhibitors, such as CpG-STAT3dODN, can offer new opportunities for prostate cancer immunotherapy.

Immunotherapy for head and neck cancer: the future of treatment?

INTRODUCTION

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide with >500,000 cases diagnosed each year. HNSCC patients often present to the clinic with advanced disease and are managed with a multi-disciplinary approach consisting of surgery, chemotherapy, and/or radiation. Morbidity and quality of life issues are major challenges in this patient population due to the debilitating effects of standard of care treatment paradigms. There is a critical need for new therapeutic approaches to manage HNSCC with better anti-tumor activities and toxicity profiles. Immunotherapy has gained traction as a precision medicine initiative to manage solid malignancies. Areas covered: The authors review current knowledge of immune escape mechanisms and discuss key immunotherapies in HNSCC with an emphasis on clinical trials data. Expert opinion: The excitement over the potential of immunotherapy to manage solid malignancies, including HNSCC is high and warranted based on the impressive clinical data accrued to date. Research in immunity and immune modulation in cancer has been invigorated and offers the potential to reveal novel vulnerabilities that may be exploitable pharmacologically. The evolution of immunotherapy will continue and move toward rational combinations with other immunotherapies or molecularly-targeted agents in the first-line, adjuvant, and recurrent/metastatic settings in HNSCC.

Mimicking the tumor microenvironment to regulate macrophage phenotype and assessing chemotherapeutic efficacy in embedded cancer cell/macrophage spheroid models

Tumor associated macrophages (TAMs) are critical stromal components intimately involved with the progression, invasion, and metastasis of cancer cells. To address the need for an in vitro system that mimics the clinical observations of TAM localizations and subsequent functional performance, a cancer cell/macrophage spheroid model is described. The central component of the model is a triple negative breast cancer spheroid embedded in a three-dimensional collagen gel. Macrophages are incorporated in two different ways. The first is a heterospheroid, a spheroid containing both tumor cells and macrophages. The heterospheroid mimics the population of TAMs infiltrated into the tumor mass, thus being exposed to hypoxia and metabolic gradients. In the second model, macrophages are diffusely seeded in the collagen surrounding the spheroid, thus modeling TAMs in the cancer stroma. The inclusion of macrophages as a heterospheroid changes the metabolic profile, indicative of synergistic growth. In contrast, macrophages diffusely seeded in the collagen bear the same profile regardless of the presence of a tumor cell spheroid. The macrophages in the heterospheroid secrete EGF, a cytokine critical to tumor/macrophage co-migration, and an EGF inhibitor decreases the metabolic activity of the heterospheroid, which is not observed in the other systems. The increased secretion of IL-10 indicates that the heterospheroid macrophages follow an M2/TAM differentiation pathway. Lastly, the heterospheroid exhibits resistance to paclitaxel. In summary, the collagen embedded heterospheroid model promotes TAM-like characteristics, and will be of utility in cancer biology and drug discovery.

STATEMENT OF SIGNIFICANCE

Two in vitro collagen-embedded multicellular spheroid models are described that mimic the clinical observations of macrophage localization within a tumor. Incorporation of macrophages within a breast cancer spheroid emphasizes cell-cell interactions with subsequent differentiation toward a tumor-promoting TAM phenotype. In contrast, macrophages seeded around the tumor spheroid display decreased interaction with cancer cells and no indication of a TAM phenotype. Finally, the presence of macrophages in the heterospheroid increases resistance to paclitaxel. This study demonstrates that cell-cell interactions and 3D collagen matrix direct macrophage activity, and, thus, highlights the important role the local environment itself plays in macrophage behavior.

Interleukin-10 reorganizes the cytoskeleton of mature dendritic cells leading to their impaired biophysical properties and motilities

Interlukin-10 (IL-10) is an immunomodulatory cytokine which predominantly induces immune-tolerance. It has been also identified as a major cytokine in the tumor microenvironment that markedly mediates tumor immune escape. Previous studies on the roles of IL-10 in tumor immunosuppression mainly focus on its biochemical effects. But the effects of IL-10 on the biophysical characteristics of immune cells are ill-defined. Dendritic cells (DCs) are the most potent antigen-presenting cells and play a key role in the anti-tumor immune response. IL-10 can affect the immune regulatory functions of DCs in various ways. In this study, we aim to explore the effects of IL-10 on the biophysical functions of mature DCs (mDCs). mDCs were treated with different concentrations of IL-10 and their biophysical characteristics were identified. The results showed that the biophysical properties of mDCs, including electrophoresis mobility, osmotic fragility and deformability, as well as their motilities, were impaired by IL-10. Meanwhile, the cytoskeleton (F-actin) of mDCs was reorganized by IL-10. IL-10 caused the alternations in the expressions of fasin1 and profilin1 as well as the phosphorylation of cofilin1 in a concentration-dependent fashion. Moreover, Fourier transformed infrared resonance data showed that IL-10 made the status of gene transcription and metabolic turnover of mDCs more active. These results demonstrate a new aspect of IL-10's actions on the immune system and represent one of the mechanisms for immune escape of tumors. It may provide a valuable clue to optimize and improve the efficiency of DC-based immunotherapy against cancer.

COX-2 inhibitor prevents tumor induced down regulation of classical DC lineage specific transcription factor Zbtb46 resulting in immunocompetent DC and decreased tumor burden

The interaction between the immune and tumor cells in the microenvironment is an important factor deciding the progression of cancer. Though many of the soluble mediators in the microenvironment that mediate immunosuppression are known, the mechanism by which the tumor affects the distal progenitors is not known. We report that the tumor derived prostanoids down regulated classical dendritic cells DC (cDC) lineage specific transcription factor Zbtb46 in the progenitor cells which affects its differentiation. Prostanoids also induced ERK/CREB/IL-10 signaling pathway in DC that is more important for maturation of DC. This was observed under in vitro as well as in vivo conditions leading to phenotypic and functional impairment of DC. siRNA mediated knockdown of Zbtb46 and not exogenous IL-10 mimicked the effects of tumor conditioned medium (TCM) on suppression of maturation markers. Treatment of tumor cells with COX-2 inhibitor NS-398 averted TCM induced phenotypic impairment of DC in vitro. Treatment of tumor bearing mice with NS-398 prevented tumor induced down regulation of Zbtb46 resulting in immunocompetent DC which in turn led to a decrease in tumor burden. The effects of NS-398 was indeed through immunomodulation was corroborated by no such response in SCID mice. Our study provides novel insight into the distal regulation of progenitor cells by tumor and the importance of Zbtb46 expression in anti-tumor immunity. These results identify Zbtb46 expression as an indicator of immunocompetent DC in tumor and also highlights that COX-2 inhibitors could be useful in cancer immunotherapy.

Tumor Immuno-Environment in Cancer Progression and Therapy

The approvals of Provenge (Sipuleucel-T), Ipilimumab (Yervoy/anti-CTLA-4) and blockers of the PD-1 - PD-L1/PD-L2 pathway, such as nivolumab (Opdivo), pembrolizumab (Keytruda), or atezolizumab (Tecentriq), have established immunotherapy as a key component of comprehensive cancer care. Further, murine mechanistic studies and studies in immunocompromised patients have documented the critical role of immunity in effectiveness of radio- and chemotherapy. However, in addition to the ability of the immune system to control cancer progression, it can also promote tumor growth, via regulatory T cells (Tregs), myeloid-derived dendritic cells (MDSCs) and tumor associated macrophages (TAM), which can enhance survival of cancer cells directly or via the regulation of the tumor stroma.An increasing body of evidence supports a central role for the tumor microenvironment (TME) and the interactions between tumor stroma, infiltrating immune cells and cancer cells during the induction and effector phase of anti-cancer immunity, and the overall effectiveness of immunotherapy and other forms of cancer treatment. In this chapter, we discuss the roles of key TME components during tumor progression, metastatic process and cancer therapy-induced tumor regression, as well as opportunities for their modulation to enhance the overall therapeutic benefit.

Lipid–polymer hybrid nanoparticles for synergistic drug delivery to overcome cancer drug resistance

Co-delivery of a chemotherapeutic drug and a drug resistance inhibitor by lipid–polymer hybrid nanoparticles can effectively overcome tumor drug resistance.

Efficacy of hydrodynamic interleukin 10 gene transfer in human liver segments with interest in transplantation

Different diseases lead, during their advanced stages, to chronic or acute liver failure, whose unique treatment consists in organ transplantation. The success of intervention is limited by host immune response and graft rejection. The use of immunosuppressant drugs generally improve organ transplantation, but they cannot completely solve the problem. Also, their management is delicate, especially during the early stages of treatment. Thus, new tools to set an efficient modulation of immune response are required. The local expression of interleukin (IL) 10 protein in transplanted livers mediated by hydrodynamic gene transfer could improve the organ acceptance by the host because it presents the natural ability to modulate the immune response at different levels. In the organ transplantation scenario, IL10 has already demonstrated positive effects on graft tolerance. Hydrodynamic gene transfer has been proven to be safe and therapeutically efficient in animal models and could be easily moved to the clinic. In the present work, we evaluated efficacy of human IL10 gene transfer in human liver segments and the tissue natural barriers for gene entry into the cell, employing gold nanoparticles. In conclusion, the present work shows for the first time that hydrodynamic IL10 gene transfer to human liver segments ex vivo efficiently delivers a human gene into the cells. Indexes of tissue protein expression achieved could mediate local pharmacological effects with interest in controlling the immune response triggered after liver transplantation. On the other hand, the ultrastructural study suggests that the solubilized plasmid could access the hepatocyte in a passive manner mediated by the hydric flow and that an active mechanism of transportation could facilitate its entry into the nucleus. Liver Transplantation 23:50-62 2017 AASLD.

DAAs Rapidly Reduce Inflammation but Increase Serum VEGF Level: A Rationale for Tumor Risk during Anti-HCV Treatment

BACKGROUND

Novel direct-acting antivirals (DAAs) have completely changed the panorama of hepatitis C due to their high efficacy and optimal safety profile. Unfortunately, an unexpectedly high rate of early recurrence of hepatocellular carcinoma has been reported within weeks of starting treatment, but the mechanism is not known.

METHODS

We monitored the serum level of vascular endothelial growth factor (VEGF) and changes in the pattern of circulating interleukins in 103 chronic hepatitis C patients during antiviral treatment with DAA-regimens. VEGF, epidermal growth factor (EGF), and several interleukins were assessed at baseline, during treatment, and after treatment. The biological effect of DAA-treated patient serum on human umbilical vein endothelial cell (HUVEC) proliferation was also confirmed.

RESULTS

After 4 weeks of therapy, VEGF increased approximately 4-fold compared to baseline, remained elevated up to the end of treatment, and returned to the pre-treatment level after the end of therapy. In contrast, interleukin-10 and tumor necrosis factor-alpha significantly decreased during therapy, which was coincident with HCV clearance. The levels of both remained low after treatment. The addition of serum from patients collected during therapy induced HUVEC proliferation; however, this disappeared after the end of therapy.

CONCLUSIONS

DAA administration induces an early increase in serum VEGF and a change in the inflammatory pattern, coinciding with HCV clearance. This may alter the balance between inflammatory and anti-inflammatory processes and modify the antitumor surveillance of the host. Fortunately, such modifications return reverse to normal after the end of treatment.

Oral squamous cell carcinoma suppressed antitumor immunity through induction of PD-L1 expression on tumor-associated macrophages

Oral squamous cell carcinoma (OSCC) is the most common solid tumor in the oral cavity. Development and progression of OSCC is associated with the elevated presence of inhibitory M2 type tumor-associated macrophages (TAMs). However, the underlying mechanism leading to the enrichment of M2 TAMs and the pathway through which TAMs foster tumor progression are still unclear. In this study, we harvested TAMs and tumor cells from primary OSCC resections of stage II and stage III patients. We showed that compared to peritumoral macrophages, TAMs presented upregulated expression of PD-L1 and elevated capacity in inducing T cell apoptosis. The level of PD-L1 expression directly correlated with the level of T cell apoptosis. Interestingly, peripheral blood monocytes with low initial PD-L1 level had upregulated PD-L1 expression and acquired the ability to induce T cell apoptosis, after incubation with primary tumor cells from OSCC patients. The PD-L1 expression by monocytes depended on interleukin 10 (IL-10), since blockade of IL-10 in the tumor-monocyte coculture abrogated PD-L1 upregulation. IL-10 mRNA expression in tumor cells and monocytes also preceded PD-L1 mRNA expression in monocytes. Furthermore, the IL-10 concentration in the tumor microenvironment directly correlated with the PD-L1 level on TAMs. Together, these results suggest that OSCC could directly suppress antitumor T cell immunity through conditioning TAMs.

Enhancement of adoptive T cell transfer with single low dose pretreatment of doxorubicin or paclitaxel in mice

Ex vivo expansion of CD8+ T-cells has been a hindrance for the success of adoptive T cell transfer in clinic. Currently, preconditioning with chemotherapy is used to modulate the patient immunity before ACT, however, the tumor microenvironment beneficial for transferring T cells may also be damaged. Here preconditioning with single low dose of doxorubicin or paclitaxel combined with fewer CD8+ T-cells was investigated to verify whether the same therapeutic efficacy of ACT could be achieved. An E.G7/OT1 animal model that involved adoptive transfer of OVA-specific CD8+ T-cells transduced with a granzyme B promoter-driven firefly luciferase and tomato fluorescent fusion reporter gene was used to evaluate this strategy. The result showed that CD8+ T-cells were activated and sustained longer in mice pretreated with one low-dose Dox or Tax. Enhanced therapeutic efficacy was found in Dox or Tax combined with 2x106 CD8+ T-cells and achieved the same level of tumor growth inhibition as that of 5x106 CD8+ T-cells group. Notably, reduced numbers of Tregs and myeloid derived suppressor cells were shown in combination groups. By contrast, the number of tumor-infiltrating cytotoxic T lymphocytes and IL-12 were increased. The NF-κB activity and immunosuppressive factors such as TGF-β, IDO, CCL2, VEGF, CCL22, COX-2 and IL-10 were suppressed. This study demonstrates that preconditioning with single low dose Dox or Tax and combined with two fifth of the original CD8+ T-cells could improve the tumor microenvironment via suppression of NF-κB and its related immunosuppressors, and activate more CD8+ T-cells which also stay longer.

Co-delivery of multiple drug resistance inhibitors by polymer/inorganic hybrid nanoparticles to effectively reverse cancer drug resistance

To effectively reverse multiple drug resistance (MDR) in tumor treatments, a functional nano-sized drug delivery system with active targeting function and pH sensitivity was prepared for the co-delivery of multiple drug resistance inhibitors. Buthionine sulfoximine (BSO) to inhibit GSH synthesis and celecoxib (CXB) to down-regulate P-gp expression were co-loaded in polymer/inorganic hybrid nanoparticles to form buthionine sulfoximine/celecoxib@biotin-heparin/heparin/calcium carbonate/calcium phosphate nanoparticles (BSO/CXB@BNP). To investigate the reversal of MDR, the drug resistant cells (MCF-7/ADR) were pretreated by the dual-inhibitor loaded nanoparticles (BSO/CXB@BNP) followed by the treatment of doxorubicin (DOX) loaded nanoparticles (DOX@BNP). The dual-inhibitor loaded nanoparticles (BSO/CXB@BNP) exhibited greatly enhanced efficiency in down-regulation of GSH and P-gp since BSO and CXB had combined effects on the reduction of GSH and P-gp in drug resistant tumor cells. As a result, BSO/CXB@BNP exhibited a significantly improved capability in reversal of MDR compared with mono-inhibitor loaded nanoparticles (CXB@BNP and BSO@BNP). As compared with free drug resistance inhibitors, delivery of drug resistance inhibitors by functional nanocarriers could obviously improve the therapeutic efficiency due to enhanced cellular uptake and increased intracellular drug accumulation. The study on immunostimulatory effects of different treatments showed that BSO/CXB@BNP treatment resulted in the lowest concentration of interleukin 10, a cytokine related to tumor development. These results suggest the nanoparticulate drug delivery platform developed in this study has promising applications in multiple drug delivery to overcome drug resistance in tumor treatments.

Interleukin 10 promotes immune response by increasing the survival of activated CD8+ T cells in human papillomavirus 16-infected cervical cancer

Human papillomavirus (HPV)-specific CD8+ T cells are present in HPV-infected cervical cancer patients and have demonstrated potent antitumor properties. However, these cells cannot control tumor progression in most patients. To investigate the underlying mechanisms involved in suppressing or promoting CD8+ T cell functions, we focused on interleukin 10 (IL-10), a pleiotropic cytokine with controversial roles in antitumor immunity. We found that compared to healthy controls, circulating CD8+ T cells in HPV 16-infected cervical cancer patients expressed significantly higher levels of IL-10. Interestingly, these CD8+ T cells from cervical cancer patients, but not those from healthy controls, responded to HPV 16 E6/E7 peptide stimulation by increasing IL-10 expression, demonstrating an antigen-specific IL-10 release. Addition of exogenous IL-10 improved the survival, but did not increase the proliferation, of peptide-stimulated CD8+ T cells. CD8+ T cells cultured in the presence of IL-10 also resulted in significantly higher interferon gamma (IFN-gamma) and granzyme B concentration, primarily due to improved cell survival. In resected cervical tumors, the frequency of tumor-infiltrating IL-10+ CD8+ T cells was positively correlated with the frequency of tumor-infiltrating IFN-gamma+ and granzyme B+ CD8+ T cells. Tumor-associated macrophages were more potent than peripheral blood monocyte-derived macrophages at inducing IL-10 expression in CD8+ T cells, possibly explaining the elevated IL-10+ CD8+ T cell frequency in cervical cancer patients. Together, these results are consistent with an immunostimulatory role of IL-10, which promoted CD8+ T cell response by increasing the survival of activated CD8+ T cells.

Interaction between Treg cells and tumor-associated macrophages in the tumor microenvironment of epithelial ovarian cancer

Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy. Inflammatory cells in the EOC microenvironment play a key role in tumor progression. In the present study, we investigated the mechanism of the accumulation of regulatory T cells (Tregs) induced by interleukin-10 (IL-10) derived from tumor-associated macrophages (TAMs) in the EOC microenvironment. The frequency of Tregs and TAMs was detected by immunofluorescence in 40 EOC tissues and 20 benign ovarian tumors, as well as the expression of IL-10 which was assessed by immunohistochemistry. It was found that the frequency of Treg cells and TAMs was significantly higher in the EOC than those in the benign ovarian tumors. The expression of IL-10 was also found to be higher in the EOC than that in the benign tumors. EOC patients with a high frequency of Tregs exhibited a significantly shorter overall survival time compared to those with a low frequency of Tregs. In addition, the expression of IL-10 in ascites and blood serum and the IL-10 released in the co-cultured system supernatants were detected by ELISA. Following CD4+ T-cell co-culturing with macrophages and IL-10, it was observed by flow cytometric analysis that the frequency of Treg cells was increased in the presence of IL-10. It was also established that IL-10 released in the co-cultured supernatants was increased. We also detected the mechanism of Treg cells induced by IL-10 in vivo. The SKOV3 cell tumor volume and weight were much higher in the presence of IL-10 in a mouse subcutaneous model. These data suggest that IL-10 secreted by TAMs increase the frequency of Treg cells through the activation of Foxp3 during T-cell differentiation and promotes tumor progression.

CD4+Foxp3- type 1 regulatory T cells in glioblastoma multiforme suppress T cell responses through multiple pathways and are regulated by tumor-associated macrophages

CD4⁺Foxp3^- type 1 regulatory T (Tr1) cells are potent producers of interleukin 10 (IL-10) and transforming growth factor beta (TGF-β), through which they suppress pathogenic inflammation and autoimmune responses. The role of Tr1 response in glioblastoma multiforme (GBM) is still unclear. Here, we examined the frequency, phenotype, induction mechanism, and function of Tr1 cells in GBM patients. Compared to healthy controls, GBM patients presented significantly higher frequency of Tr1 cells in peripheral blood. The Tr1 frequency was further elevated in the tumor. By surface marker expression, the Tr1 cells were enriched in the antigen-experienced effector/memory cell compartment. A minority of Tr1 cells presented IL-10⁺TGF-β⁺ double expression. Interestingly, naive CD4⁺CD45RA⁺ T cells could differentiate into IL-10- and TGF-β-expressing cells, if incubated with tumor-associated macrophages (TAMs) or with macrophages conditioned with primary glioma cells, suggesting that tumor cells and TAMs had a role in inducing Tr1 cells in GBM patients. Coculture of Tr1 cells with proinflammatory CD4⁺ T cells resulted in TGF-β-dependent reduction of interferon gamma (IFN-γ) and IL-10-dependent reduction of tumor necrosis factor alpha (TNF-α), while coculture of Tr1 cells with CD8⁺ T cells resulted in lower tumor-specific cytotoxicity. Together, these results demonstrated an upregulation of Tr1 cells in GBM with anti-inflammatory functions.

Micro RNA-98 interferes with expression interleukin-10 in peripheral B cells of patients with lung cancer

Interleukin (IL)-10-producing B cells (B10 cells) plays an important role in the tumor tolerance. High frequency of peripheral B10 cell was reported in patients with lung cancer recently. Micro RNA (miR) regulates some gene expression. This study test a hypothesis that miR-98 suppresses the expression of IL-10 in B cells of subjects with lung cancer. The results showed that the levels of miR-98 were significantly less in peripheral B cells of patients with lung cancer than that in healthy subjects. IL-10 mRNA levels in peripheral B cells were significantly higher in lung cancer patients as compared with healthy controls. A negative correlation was identified between miR-98 and IL-10 in peripheral B cells. Serum IL-13 was higher in lung cancer patients than that in healthy controls. The levels of IL-13 were also negatively correlated with IL-10 in B cells. Exposure B10 cells to IL-13 in the culture or over expression of miR-98 reduced the expression of IL-10 in B cells. Administration with miR-98-laden liposomes inhibited the lung cancer growth in a mouse model. In conclusion, up regulation of miR-98 inhibits the expression of IL-10 in B cells, which may contribute to inhibit the lung cancer tolerance in the body.

Chemokines, cytokines and exosomes help tumors to shape inflammatory microenvironment

Relationship between inflammation and cancer is now well-established and represents a paradigm that our immune response does not necessarily serves solely to protect us from infections and cancer. Many specific mechanisms that link chronic inflammation to cancer promotion and metastasis have been uncovered in the recent years. Here we are focusing on the effects that tumors may exert on inflammatory cascades, tuning the immune system ability to cause tumor promotion or regression. In particular, we discuss the contributions of chemokines, cytokines and exosomes to the processes such as induction of inflammation and tumorigenesis. Overall, tumor-elicited inflammation is a key driver of tumor progression and an essential component of tumor microenvironment.

Redirecting T Cells to Glypican-3 with 4-1BB Zeta Chimeric Antigen Receptors Results in Th1 Polarization and Potent Antitumor Activity

T cells engineered to express CD19-specific chimeric antigen receptors (CARs) have shown breakthrough clinical successes in patients with B-cell lymphoid malignancies. However, similar therapeutic efficacy of CAR T cells in solid tumors is yet to be achieved. In this study we systematically evaluated a series of CAR constructs targeting glypican-3 (GPC3), which is selectively expressed on several solid tumors. We compared GPC3-specific CARs that encoded CD3ζ (Gz) alone or with costimulatory domains derived from CD28 (G28z), 4-1BB (GBBz), or CD28 and 4-1BB (G28BBz). All GPC3-CARs rendered T cells highly cytotoxic to GPC3-positive hepatocellular carcinoma, hepatoblastoma, and malignant rhabdoid tumor cell lines in vitro. GBBz induced the preferential production of Th1 cytokines (interferon γ/granulocyte macrophage colony-stimulating factor) while G28z preferentially induced Th2 cytokines (interleukin-4/interleukin-10). Inclusion of 4-1BB in G28BBz could only partially ameliorate the Th2-polarizing effect of CD28. 4-1BB induced superior expansion of CAR T cells in vitro and in vivo. T cells expressing GPC3-CARs incorporating CD28, 4-1BB, or both induced sustained tumor regressions in two xenogeneic tumor models. Thus, GBBz CAR endows T cells with superior proliferative potential, potent antitumor activity, and a Th1-biased cytokine profile, justifying further clinical development of GBBz CAR for immunotherapy of GPC3-positive solid tumors.

Antitumour responses induced by a cell-based Reovirus vaccine in murine lung and melanoma models

BACKGROUND

The ever increasing knowledge in the areas of cell biology, the immune system and the mechanisms of cancer are allowing a new phase of immunotherapy to develop. The aim of cancer vaccination is to activate the host immune system and some success has been observed particularly in the use of the BCG vaccine for bladder cancer as an immunostimulant. Reovirus, an orphan virus, has proven itself as an oncolytic virus in vitro and in vivo. Over 80 % of tumour cell lines have been found to be susceptible to Reovirus infection and it is currently in phase III clinical trials. It has been shown to induce immune responses to tumours with very low toxicities.

METHODS

In this study, Reovirus was examined in two main approaches in vivo, in mice, using the melanoma B16F10 and Lewis Lung Carcinoma (LLC) models. Initially, mice were treated intratumourally (IT) with Reovirus and the immune responses determined by cytokine analysis. Mice were also vaccinated using a cell-based Reovirus vaccine and subsequently exposed to a tumourigenic dose of cells (B16F10 or LLC). Using the same cell-based Reovirus vaccine, established tumours were treated and subsequent immune responses and virus retrieval investigated.

RESULTS

Upregulation of several cytokines was observed following treatment and replication-competent virus was also retrieved from treated tumours. Varying levels of cytokine upregulation were observed and no replication-competent virus was retrieved in vaccine-treated mice. Prolongation of survival and delayed tumour growth were observed in all models and an immune response to Reovirus, either using Reovirus alone or a cell-based vaccine was also observed in all mice.

CONCLUSION

This study provides evidence of immune response to tumours using a cell-based Reovirus vaccine in both tumour models investigated, B16F10 and LLC, cytokine induction was observed with prolongation of survival in almost all cases which may suggest a new method for using Reovirus in the clinic.

Protein Profiling Gastric Cancer and Neighboring Control Tissues Using High-Content Antibody Microarrays

In this study, protein profiling was performed on gastric cancer tissue samples in order to identify proteins that could be utilized for an effective diagnosis of this highly heterogeneous disease and as targets for therapeutic approaches. To this end, 16 pairs of postoperative gastric adenocarcinomas and adjacent non-cancerous control tissues were analyzed on microarrays that contain 813 antibodies targeting 724 proteins. Only 17 proteins were found to be differentially regulated, with much fewer molecules than the numbers usually identified in studies comparing tumor to healthy control tissues. Insulin-like growth factor-binding protein 7 (IGFBP7), S100 calcium binding protein A9 (S100A9), interleukin-10 (IL‐10) and mucin 6 (MUC6) exhibited the most profound variations. For an evaluation of the proteins’ capacity for discriminating gastric cancer, a Receiver Operating Characteristic curve analysis was performed, yielding an accuracy (area under the curve) value of 89.2% for distinguishing tumor from non-tumorous tissue. For confirmation, immunohistological analyses were done on tissue slices prepared from another cohort of patients with gastric cancer. The utility of the 17 marker proteins, and particularly the four molecules with the highest specificity for gastric adenocarcinoma, is discussed for them to act as candidates for diagnosis, even in serum, and targets for therapeutic approaches.

The emerging role of immunotherapy in head and neck squamous cell carcinoma (HNSCC): anti-tumor immunity and clinical applications

Head and neck squamous cell carcinoma (HNSCC) carries a poor prognosis, with low survival rates for advanced stage tumors and minimal improvement in survival trends through the past decades. It is becoming increasingly clear that HNSCC oncogenesis and evolution is characterized by profound immune defects, as cancer cells evade immunosurveillance due to accumulation of genetic mutations and tumor heterogeneity. Improved understanding of the role of the immune system in cancer has led to the identification of novel therapeutic targets, which are being investigated for their potential to provide durable responses. In this review, we will summarize the role of the immune system in HNSCC, the rationale behind immunotherapy strategies and their clinical applications.

ACC interleukin-10 gene promoter haplotype as a breast cancer risk factor predictor among Jordanian females

INTRODUCTION

Interleukin-10 (IL-10) is a multifactorial cytokine with a complex biological role in breast cancer. The aims of this study were to investigate any association between IL-10 gene promoter polymorphisms, 1082A>/G, -819T>C, and -592A>C, or haplotypes and breast cancer risk among Jordanian women and to evaluate any association between the most common haplotype with clinicopathological features of breast cancer.

PATIENTS AND METHODS

A total of 202 breast cancer patients and 210 age-matched healthy control subjects were genotyped for -1082A/G, -819T/C, and -592A/C single nucleotide polymorphisms in the promoter region of the IL-10 gene by polymerase chain reaction-restriction fragment length polymorphism. Study patients and control subjects were recruited from Prince Hamzah Hospital, Amman, Jordan (2012-2013). Ethical approval and signed consent forms were signed by all participants. DNA was extracted, and polymerase chain reaction fragments were amplified and restriction digested by MnII, MaeIII, and RsaI.

RESULTS

This study showed no statistically significant difference between -1082A/G, -819T/C, and -592A/C IL-10 genotypes or alleles among breast cancer patients or controls. Four different haplotypes ATA, ACC, GTA, and ACA within the IL-10 promoter gene were determined among both breast cancer and control groups. The most frequent haplotype was ACC among breast cancer patients and controls (41.6% and 40.7%, respectively). No statistical differences in these haplotypes among breast cancer patients or controls were determined. Analysis of the most common ACC haplotype showed statistical difference in positive estrogen receptor (P=0.022), positive progesterone receptor (P=0.004), cancer grade (P=0.0001), and cancer stage (P=0.009) among the ACC haplotype compared to non-ACC haplotype.

CONCLUSION

To our knowledge, this is the first report studying the association of IL-10 haplotype with breast cancer risk events among Jordanian females. The most frequent IL-10 haplotype among Jordanian breast cancer females is ACC haplotype. Patients carrying the ACC haplotype are associated with higher positive estrogen and progesterone receptors and advanced breast cancer grade and stage. These patients also had lower survival rate in the Kaplan-Meier survival plot compared to those with non-ACC haplotype.

Strong inflammatory response and Th1-polarization profile in children with acute lymphoblastic leukemia without apparent infection

Children with acute lymphoblastic leukemia (ALL) often present fever. Febrile states are usually associated with infectious processes that generate an inflammatory response involving various molecules, including cytokines. However, an inflammatory response may also occur in the absence of infection. We hypothesized that the levels of inflammatory cytokines are increased in children with ALL without apparent infection. The serum levels of 13 cytokines in 99 patients with ALL and 48 non-oncological patients without apparent infection were measured using multiplex analyte profiling technology (Luminex®). The concentration of circulating pro-inflammatory cytokines associated with fever was similar between patients with ALL and fever at diagnosis and those without fever. The levels of tumor necrosis factor α, interleukin (IL)-6, IL-8, monocyte chemoattractant protein-1 (MCP-1) and IL-10 were higher in patients with ALL vs. the control group (P<0.05). Moreover, the levels of the T helper 1 (interferon‑γ and IL-12) cytokines were higher in patients with ALL vs. the control group. Transforming growth factor β was lower in patients with ALL vs. the control group (P<0.05). The levels of IL-1β, IL-2, IL-4, IL-13, and IL-17 were similar in the two groups. Our results indicate that the circulating levels of seven of the important studied cytokines are elevated in patients with newly diagnosed ALL without apparent infection, reflecting a strong and deregulated inflammatory state in this disease, with a Th1-polarization profile.

Antibody response to BK polyomavirus as a prognostic biomarker and potential therapeutic target in prostate cancer

Infectious agents, including the BK polyomavirus (BKPyV), have been proposed as important inflammatory pathogens in prostate cancer. Here, we evaluated whether the preoperative antibody response to BKPyV large T antigen (LTag) and viral capsid protein 1 (VP1) was associated with the risk of biochemical recurrence in 226 patients undergoing radical prostatectomy for primary prostate cancer. Essentially, the multivariate Cox regression analysis revealed that preoperative seropositivity to BKPyV LTag significantly reduced the risk of biochemical recurrence, independently of established predictors of biochemical recurrence such as tumor stage, Gleason score and surgical margin status. The predictive accuracy of the regression model was denotatively increased by the inclusion of the BKPyV LTag serostatus. In contrast, the VP1 serostatus was of no prognostic value. Finally, the BKPyV LTag serostatus was associated with a peculiar cytokine gene expression profile upon assessment of the cellular immune response elicited by LTag. Taken together, our findings suggest that the BKPyV LTag serology may serve as a prognostic factor in prostate cancer. If validated in additional studies, this biomarker may allow for better treatment decisions after radical prostatectomy. Finally, the favorable outcome of LTag seropositive patients may provide a potential opportunity for novel therapeutic approaches targeting a viral antigen.

Diabetes-associated dysregulated cytokines and cancer

Epidemiological data demonstrate that patients with diabetes have an augmented risk of developing various types of cancers, accompanied by higher mortality. A number of mechanisms for this connection have been hypothesized, such as insulin resistance, hyperinsulinemia, hyperglycemia, and increased inflammatory processes. Apart from these potential mechanisms, several diabetes-associated dysregulated cytokines might be implicated in the link between diabetes and cancer. In fact, some inflammatory cytokines, e.g. TNF-α, IL-6 and leptin, have been revealed to play important roles in both initiation and progression of tumor. Here, we depict the role of these cytokines in key events of carcinogenesis and cancer development, including their capability to induce oxidative stress, inflammation, their participation in epithelial mesenchymal transition (EMT), angiogenesis, and metastasis. Finally, we will also highlight the existing knowledge in terms of the involvement of these cytokines in different cancer types and comment on potential significances for future clinical applications.

Protumoral TSP50 Regulates Macrophage Activities and Polarization via Production of TNF-α and IL-1β, and Activation of the NF-κB Signaling Pathway

Testes-specific protease 50 (TSP50) is abnormally overexpressed in many kinds of cancers and promotes cell proliferation and migration. However, whether TSP50 can influence the tumor microenvironment, especially the function of immune cells in the microenvironment, remains largely unknown. We demonstrated that exposure to the conditioned medium from TSP50-overexpressing cells, or co-culture with TSP50-overexpressing cells, enhanced the cytokine production and phagocytic activities of macrophages, and induced M2b polarization. Further investigation showed that production of TNF-α and IL-1β was strongly induced by TSP50 in TSP50-overexpressing cells. TSP50-induced TNF-α and IL-1β were main factors that mediated the effects of TSP50-overexpressing cells on macrophages. The NF-κB pathway could be activated in macrophages upon the treatment of conditioned medium of TSP50-overexpressing cells and its activation is necessary for the observed effects on macrophages. Taken together, our results suggested that oncogenic TSP50 expressed in cells could activate surrounding macrophages and induce M2b polarization, partly through inducing TNF-α/ IL-1β secretion and subsequent NF-κB pathway activation. This implies a potential mechanism by which oncogene TSP50 regulates tumor microenvironment to support tumor development.

Devil Facial Tumor Disease

Devil facial tumor disease (DFTD) is an emergent transmissible cancer exclusive to Tasmanian devils (Sarcophilus harrisii) and threatening the species with extinction in the wild. Research on DFTD began 10 years ago, when nothing was known about the tumor and little about the devils. The depth of knowledge gained since then is impressive, with research having addressed significant aspects of the disease and the devils' responses to it. These include the cause and pathogenesis of DFTD, the immune response of the devils and the immune evasion mechanisms of the tumor, the transmission patterns of DFTD, and the impacts of DFTD on the ecosystem. This review aims to collate this information and put it into the context of conservation strategies designed to mitigate the impacts of DFTD on the devil and the Tasmanian ecosystem.

The Molecular Influence of Graphene and Graphene Oxide on the Immune System Under In Vitro and In Vivo Conditions

Graphene and graphene oxide (GO), due to their physicochemical properties and biocompatibility, can be used as an innovative biomedical material in biodetection, drug distribution in the body, treating neoplasms, regenerative medicine, and in implant surgery. Research on the biomedical use of graphene and GO that has been carried out until now is very promising and shows that carbon nanomaterials present high biocompatibility. However, the intolerance of the immune system to graphene nanomaterials, however low, may in consequence make it impossible to use them in medicine. This paper shows the specific mechanism of the molecular influence of graphene and GO on macrophages and lymphocytes under in vitro and in vivo conditions and their practical application in medicine. Under in vitro conditions graphene and GO cause an increased production of pro-inflammatory cytokines, mainly IL-1, IL-6, IL-10 and TNF-α, as a result of the activation of Toll-like receptors in macrophages. Graphene activates apoptosis in macrophages through the TGFbr/Smad/Bcl-2 pathway and also through JNK kinases that are stimulated by an increase of ROS in the cell or through a signal received by Smad proteins. Under in vivo conditions, graphene nanomaterials induce the development of the local inflammatory reaction and the development of granulomas in parenchymal organs. However, there is a huge discrepancy between the results obtained by different research groups, which requires a detailed analysis. In this work we decided to collect and analyze existing research and tried to explain the discrepancies. Understanding the precise mechanism of how this nanomaterial influences immune system cells allows estimating the potential influence of grapheme and GO on the human body.

Depletion of tumor-associated macrophages enhances the anti-tumor immunity induced by a Toll-like receptor agonist-conjugated peptide

It has been reported that lipopeptides can be used to elicit cytotoxic T lymphocyte (CTL) responses against viral diseases and cancer. In our previous study, we determined that mono-palmitoylated peptides can enhance anti-tumor responses in the absence of adjuvant activity. To investigate whether di-palmitoylated peptides with TLR2 agonist activity are able to induce anti-tumor immunity, we synthesized a di-palmitic acid-conjugated long peptide that contains a murine CTL epitope of HPV E7_49–57 (Pam2IDG). Pam2IDG stimulated the maturation of bone marrow-derived dendritic cells (BMDCs) through TLR2/6. After immunization, Pam2IDG induced higher levels of T cell responses than those obtained with its non-lipidated counterpart (IDG). In the prophylactic model, Pam2IDG immunization completely inhibited tumor growth, whereas IDG immunization was unable to inhibit tumor growth. However, Pam2IDG immunization could not effectively inhibit the growth of established tumors. Therefore, we further investigated whether the depletion of immunosuppressive factors could improve the therapeutic effects of Pam2IDG. Our data indicate that treatment with Pam2IDG combined with clodronate/liposome delays tumor growth and increases the survival rate. We also observed that the therapeutic effects of Pam2IDG are improved by diminishing the function of tumor-associate macrophages (TAMs) and through the use of an IL10 receptor blocking antibody or a Cyclooxygenase 2 (Cox-2) inhibitor. In conclusion, the depletion of TAMs may enhance the anti-tumor immunity of a TLR2 agonist-conjugated peptide.

Tristetraprolin regulation of interleukin-22 production

Interleukin (IL)-22 is a STAT3-activating cytokine displaying characteristic AU-rich elements (ARE) in the 3'-untranslated region (3'-UTR) of its mRNA. This architecture suggests gene regulation by modulation of mRNA stability. Since related cytokines undergo post-transcriptional regulation by ARE-binding tristetraprolin (TTP), the role of this destabilizing protein in IL-22 production was investigated. Herein, we demonstrate that TTP-deficient mice display augmented serum IL-22. Likewise, IL-22 mRNA was enhanced in TTP-deficient splenocytes and isolated primary T cells. A pivotal role for TTP is underscored by an extended IL-22 mRNA half-life detectable in TTP-deficient T cells. Luciferase-reporter assays performed in human Jurkat T cells proved the destabilizing potential of the human IL-22-3'-UTR. Furthermore, overexpression of TTP in HEK293 cells substantially decreased luciferase activity directed by the IL-22-3'-UTR. Transcript destabilization by TTP was nullified upon cellular activation by TPA/A23187, an effect dependent on MEK1/2 activity. Accordingly, IL-22 mRNA half-life as determined in TPA/A23187-stimulated Jurkat T cells decreased under the influence of the MEK1/2 inhibitor U0126. Altogether, data indicate that TTP directly controls IL-22 production, a process counteracted by MEK1/2. The TTP-dependent regulatory pathway described herein likely contributes to the role of IL-22 in inflammation and cancer and may evolve as novel target for pharmacological IL-22 modulation.

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.

Immunosuppressive Mechanisms of Malignant Gliomas: Parallels at Non-CNS Sites

The central nervous system (CNS) possesses powerful local and global immunosuppressive capabilities that modulate unwanted inflammatory reactions in nervous tissue. These same immune-modulatory mechanisms are also co-opted by malignant brain tumors and pose a formidable challenge to brain tumor immunotherapy. Routes by which malignant gliomas coordinate immunosuppression include the mechanical and functional barriers of the CNS; immunosuppressive cytokines and catabolites; immune checkpoint molecules; tumor-infiltrating immune cells; and suppressor immune cells. The challenges to overcoming tumor-induced immunosuppression, however, are not unique to the brain, and several analogous immunosuppressive mechanisms also exist for primary tumors outside of the CNS. Ultimately, the immune responses in the CNS are linked and complementary to immune processes in the periphery, and advances in tumor immunotherapy in peripheral sites may therefore illuminate novel approaches to brain tumor immunotherapy, and vice versa.

Enhancing the efficacy of adoptive cellular therapy by targeting tumor-induced immunosuppression

Strategies aimed at stimulating the immune system against cancer have signaled a new era for designing new effective therapies for patients. Recent breakthroughs in adoptive cellular therapy and in using checkpoint inhibitors for some patients have renewed much enthusiasm in this field. However, it has become apparent that tumors can use a multitude of inhibitory networks to effectively reduce antitumor immunity. This review discusses our current knowledge of these immune suppressive mechanisms used by tumors and describes potential new strategies that may counteract this problem resulting in significantly increasing therapeutic outcomes of adoptive immunotherapy in a higher proportion of patients.

Phenotypic switch of CD8(+) T cells reactivated under hypoxia toward IL-10 secreting, poorly proliferative effector cells

CD8(+) T cells controlling pathogens or tumors must function at sites where oxygen tension is frequently low, and never as high as under atmospheric culture conditions. However, T-cell function in vivo is generally analyzed indirectly, or is extrapolated from in vitro studies under nonphysiologic oxygen tensions. In this study, we delineate the role of physiologic and pathologic oxygen tension in vitro during reactivation and differentiation of tumor-specific CD8(+) T cells. Using CD8(+) T cells from pmel-1 mice, we observed that the generation of CTLs under 5% O2, which corresponds to physioxia in lymph nodes, gave rise to a higher effector signature than those generated under atmospheric oxygen fractions (21% O2). Hypoxia (1% O2) did not modify cytotoxicity, but decreasing O2 tensions during CTL and CD8(+) tumor-infiltrating lymphocyte reactivation dose-dependently decreased proliferation, induced secretion of the immunosuppressive cytokine IL-10, and upregulated the expression of CD137 (4-1BB) and CD25. Overall, our data indicate that oxygen tension is a key regulator of CD8(+) T-cell function and fate and suggest that IL-10 release may be an unanticipated component of CD8(+) T cell-mediated immune responses in most in vivo microenvironments.

Reprogramming the tumor microenvironment: tumor-induced immunosuppressive factors paralyze T cells

It has become evident that tumor-induced immuno-suppressive factors in the tumor microenvironment play a major role in suppressing normal functions of effector T cells. These factors serve as hurdles that limit the therapeutic potential of cancer immunotherapies. This review focuses on illustrating the molecular mechanisms of immunosuppression in the tumor microenvironment, including evasion of T-cell recognition, interference with T-cell trafficking, metabolism, and functions, induction of resistance to T-cell killing, and apoptosis of T cells. A better understanding of these mechanisms may help in the development of strategies to enhance the effectiveness of cancer immunotherapies.

The role of the mediators of inflammation in cancer development

Epigenetic disorders such as point mutations in cellular tumor suppressor genes, DNA methylation and post-translational modifications are needed to transformation of normal cells into cancer cells. These events result in alterations in critical pathways responsible for maintaining the normal cellular homeostasis, triggering to an inflammatory response which can lead the development of cancer. The inflammatory response is a universal defense mechanism activated in response to an injury tissue, of any nature, that involves both innate and adaptive immune responses, through the collective action of a variety of soluble mediators. Many inflammatory signaling pathways are activated in several types of cancer, linking chronic inflammation to tumorigenesis process. Thus, Inflammatory responses play decisive roles at different stages of tumor development, including initiation, promotion, growth, invasion, and metastasis, affecting also the immune surveillance. Immune cells that infiltrate tumors engage in an extensive and dynamic crosstalk with cancer cells, and some of the molecular events that mediate this dialog have been revealed. A range of inflammation mediators, including cytokines, chemokines, free radicals, prostaglandins, growth and transcription factors, microRNAs, and enzymes as, cyclooxygenase and matrix metalloproteinase, collectively acts to create a favorable microenvironment for the development of tumors. In this review are presented the main mediators of the inflammatory response and discussed the likely mechanisms through which, they interact with each other to create a condition favorable to development of cancer.