Clinical and experimental approaches to the pathophysiology of interleukin-18 in cancer progression

Association between immunity and different clinical symptoms in patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a disease with endocrine and metabolic disorders. The main symptoms are hyperandrogenemia (HA), insulin resistance (IR), and ovulation disorder. However, the pathogenesis and pathophysiological process of these major symptoms in PCOS are still not well defined. In recent studies, the chronic low-grade inflammatory state has become one of the factors affecting PCOS. Some alterable immune factors in PCOS, such as interleukin-15 and interleukin-1, have been identified to be related to androgen synthesis and insulin resistance in PCOS. In addition, a disturbed immune microenvironment in the ovary leads to impaired follicular growth and ovulation. Previous studies have roughly reviewed the relationship between immunity and PCOS. However, the link between the different clinical manifestations of PCOS and immunity has not been well explored and analyzed. The clinical presentation of each patient is diverse, and symptomatic treatment is mainly used. Therefore, this article reviews several representative immunological factors that affect these three symptoms to explore the underlying mechanism, which will be beneficial for developing new treatment strategies.

Prognostic and immunological roles of IL18RAP in human cancers

Across several cancers, IL18 receptor accessory protein (IL18RAP) is abnormally expressed, and this abnormality is related to tumor immunity and heterogeneous clinical outcomes. In this study, based on bioinformatics analysis, we discovered that IL18RAP is related to the human tumor microenvironment and promotes various immune cells infiltration. Additionally, the multiple immunofluorescence staining revealed that with the increased expression of IL18RAP, the number of infiltrated M1 macrophages increased. This finding was confirmed by coculture migration analysis using three human cancer cell lines (MDA-MB-231, U251, and HepG2) with IL18RAP knockdown. We discovered a positive link between IL18RAP and the majority of immunostimulators, immunoinhibitors, major histocompatibility complex (MHC) molecules, chemokines, and chemokine receptor genes using Spearman correlation analysis. Additionally, functional IL18RAP's gene set enrichment analysis (GSEA) revealed that it is related to a variety of immunological processes, such as positive regulation of interferon gamma production and positive regulation of NK cell-mediated immunity. Moreover, we used single-cell RNA sequencing analysis to detect that IL18RAP was mainly expressed in immune cells, and HALLMARK analysis confirmed that the INF-γ gene set expression was upregulated in CD8Tex cells. In addition, in human and mouse cancer cohorts, we found that the level of IL18RAP can predict the immunotherapy response. In short, our study showed that IL18RAP is a new tumor biomarker and may become a potential immunotherapeutic target in cancer.

Effects of dexmedetomidine on A549 non-small cell lung cancer growth in a clinically relevant surgical xenograft model

The perioperative milieu following curative lung cancer surgery is accompanied by a stress response. Inflammasomes mediate inflammation resulting in the unfavorable immunomodulation of natural killer (NK) cell activity, thus promoting cancer progression. This study aimed to investigate the effects of dexmedetomidine (DEX) on the innate immune system, chronic inflammation, and lung cancer progression in a clinically relevant human-to-mouse xenograft model. The human lung cancer cell line A549-luc was subcutaneously injected into BALB/c nude mice. Saline or dexmedetomidine was administered for 2 weeks via an implanted osmotic minipump. After 4 weeks, the tumor size and weight were measured. NK cell activity, serum interferon-γ, interleukin (IL)-1β and tumor necrosis factor (TNF)-α levels were also measured. IL-10, IL-18, and inflammasome expression levels were assessed in the tumor tissues. DEX caused a decrease in tumor size, tumor weight, and IL-1β and TNF-α levels and an increase in NK cell activity and IFN-γ level. IL-10 and IL-18 expression was significantly decreased in the DEX-treated group. NLRP3, CTP1A, TXNIP, ASC, IL-1β, and caspase-1 protein levels were decreased in the DEX-treated group. In conclusion, the use of DEX for 2 weeks inhibited lung cancer progression by suppressing inflammasome- and IL-1β signaling-induced inflammation and enhancing NK cell activity.

The role of metabolic reprogramming of tumor-associated macrophages in shaping the immunosuppressive tumor microenvironment

Macrophages are potent immune effector cells in innate immunity and exert dual-effects in the tumor microenvironment (TME). Tumor-associated macrophages (TAMs) make up a significant portion of TME immune cells. Similar to M1/M2 macrophages, TAMs are also highly plastic, and their functions are regulated by cytokines, chemokines and other factors in the TME. The metabolic changes in TAMs are significantly associated with polarization towards a protumour or antitumour phenotype. The metabolites generated via TAM metabolic reprogramming in turn promote tumor progression and immune tolerance. In this review, we explore the metabolic reprogramming of TAMs in terms of energy, amino acid and fatty acid metabolism and the potential roles of these changes in immune suppression.

Intratumoral Gene Transfer of mRNAs Encoding IL12 in Combination with Decoy-Resistant IL18 Improves Local and Systemic Antitumor Immunity

IL12-based local gene therapy of cancer constitutes an active area of clinical research using plasmids, mRNAs, and viral vectors. To improve antitumor effects, we have experimentally tested the combination of mRNA constructs encoding IL12 and IL18. Moreover, we have used a form of IL18 [decoy-resistant IL18 (DR-18)] which has preserved bioactivity but does not bind to the IL18 binding protein decoy receptor. Both cytokines dramatically synergize to induce IFNγ release from mouse splenocytes, and, if systemically cotransferred to the liver, they mediate lethal toxicity. However, if given intratumorally to B16OVA tumor-bearing mice, the combination attains efficacy against the directly treated tumor and moderate tumor-delaying activity on distant noninjected lesions. Cotreatment was conducive to the presence of more activated CD8+ T cells in the treated and noninjected tumors. In keeping with these findings, the efficacy of treatment was contingent on the integrity of CD8+ T cells and cDC1 dendritic cells in the treated mice. Furthermore, efficacy of IL12 plus DR-18 local mRNA coinjection against distant concomitant tumors could be enhanced upon combination with anti-PD-1 mAb systemic treatment, thus defining a feasible synergistic immunotherapy strategy.

S, Prasad H. L. K. Utility of serum interleukin-18 (IL-18) as a tumour marker in gastric cancer

Introduction: Gastric cancer (GC) is the fourth most prevailing cancer globally, attributing to more than 70% of cases in developing countries. Protein cancer biomarkers, such as CEA, CA- 125, AFP and PSA, are clinically helpful diagnostic tools, but they have low sensitivity and specificity for GC. Hence, it is essential to discover better markers for GC diagnosis. Interleukin-18 (IL-18) is the member of Interleukin-1 family. It is hypothesized to be a potent inhibitor of gastric acid secretion, leading to gastric atrophy and causing an increased risk of GC. This study was to evaluate the association between the serum IL-18 in GC.   Methodology: We included cases who underwent UGI Scopy and were proven to have GC histopathologically. The patients who presented to the out-patient who underwent UGI scopy and was found to have no growth were selected as controls. Twenty-eight cases and 84 control sample sizes were derived from nMaster V2. Blood samples from patients and controls were collected, and serum IL-18 levels were estimated using a solid-phase sandwich ELISA method.   Results: We found that the cut-off value of serum IL-18 was 85.59 pg/ml, had a sensitivity of 63.1% and specificity of 57.1%, with a positive predictive value of 81.5% and a negative predictive value of 34% in diagnosing GC. The study plotted the receiver operating characteristic curve against IL-18 for sensitivity and specificity. Statistically, we found through the Area Under the Curve (AUC) that the rise in serum IL-18 levels was a poor indicator of GC with a p-value of 0.078.   Conclusion: Statistically, a cut-off of 85.59pg/ml showed good sensitivity and specificity; however, the probability was insignificant, suggesting that IL-18 may not be of diagnostic importance. Studies with a larger sample size are required to further probe into the usefulness of estimating IL-18 in GC.

Next generations of CAR-T cells - new therapeutic opportunities in hematology?

In recent years, the introduction of chimeric antigen receptor (CAR) T-cell therapies into clinics has been a breakthrough in treating relapsed or refractory malignancies in hematology and oncology. To date, Food and Drug Administration (FDA) has approved six CAR-T therapies for specific non-Hodgkin lymphomas, B-cell acute lymphoblastic leukemia, and multiple myeloma. All registered treatments and most clinical trials are based on so-called 2nd generation CARs, which consist of an extracellular antigen-binding region, one costimulatory domain, and a CD3z signaling domain. Unfortunately, despite remarkable overall treatment outcomes, a relatively high percentage of patients do not benefit from CAR-T therapy (overall response rate varies between 50 and 100%, with following relapse rates as high as 66% due to limited durability of the response). Moreover, it is associated with adverse effects such as cytokine release syndrome and neurotoxicity. Advances in immunology and molecular engineering have facilitated the construction of the next generation of CAR-T cells equipped with various molecular mechanisms. These include additional costimulatory domains (3rd generation), safety switches, immune-checkpoint modulation, cytokine expression, or knockout of therapy-interfering molecules, to name just a few. Implementation of next-generation CAR T-cells may allow overcoming current limitations of CAR-T therapies, decreasing unwanted side effects, and targeting other hematological malignancies. Accordingly, some clinical trials are currently evaluating the safety and efficacy of novel CAR-T therapies. This review describes the CAR-T cell constructs concerning the clinical application, summarizes completed and ongoing clinical trials of next-generation CAR-T therapies, and presents future perspectives.

Cytokines as an important player in the context of CAR-T cell therapy for cancer: Their role in tumor immunomodulation, manufacture, and clinical implications

CAR-T cell therapies have been recognized as one of the most advanced and efficient strategies to treat patients with hematologic malignancies. However, similar results have not been observed for the treatment of solid tumors. One of the explanations is the fact that tumors have extremely hostile microenvironments for the infiltration and effector activity of T-cells, mainly due to the presence of highly suppressive cytokines, hypoxia, and reactive oxygen species. Taking advantage of cytokines functionally, new fourth-generation CAR constructs have been developed to target tumor cells and additionally release cytokines that can contribute to the cytotoxicity of T-cells. The manufacturing process, including the use of cytokines in the expansion and differentiation of T cells, is also discussed. Finally, the clinical aspects and the influence of cytokines on the clinical condition of patients, such as cytokine release syndrome, who receive treatment with CAR-T cells are addressed. Therefore, this review aims to highlight how important cytokines are as one of the major players of cell therapy.

The immune system's role in PCOS

Polycystic ovary syndrome (PCOS) is a common disorder of the endocrine system. Its main manifestations include oligo-ovulation, hyperandrogenism, and polycystic ovary morphology (PCOM), affecting women of childbearing age. Although the exact pathogenesis of this disease is still unknown, many factors, including genetic, endocrine, and metabolism disorders, play critical roles in its development. The immunopathogenesis of PCOS has not yet been studied in-depth, but it is hypothesized that immune system abnormalities may play a key role in it. Recent research has shown inflammation's effect on ovulation and ovarian follicular dynamics. Thus, it is suggested that there is a close association between PCOS and low-grade chronic systemic inflammation. As a result, chronic low-grade inflammation is identified as a significant factor in the pathogenesis and development of PCOS, which in turn leads to infertility. As a result, this article reviews PCOS immunopathology, evaluates long-standing hypotheses about the immune system's role in PCOS, and assesses the association between inflammatory factors and PCOS.

Tumor-Experienced Human NK Cells Express High Levels of PD-L1 and Inhibit CD8+ T Cell Proliferation

Natural Killer (NK) cells play a key role in cancer immunosurveillance. However, NK cells from cancer patients display an altered phenotype and impaired effector functions. In addition, evidence of a regulatory role for NK cells is emerging in diverse models of viral infection, transplantation, and autoimmunity. Here, we analyzed clear cell renal cell carcinoma (ccRCC) datasets from The Cancer Genome Atlas (TCGA) and observed that a higher expression of NK cell signature genes is associated with reduced survival. Analysis of fresh tumor samples from ccRCC patients unraveled the presence of a high frequency of tumor-infiltrating PD-L1⁺ NK cells, suggesting that these NK cells might exhibit immunoregulatory functions. In vitro, PD-L1 expression was induced on NK cells from healthy donors (HD) upon direct tumor cell recognition through NKG2D and was further up-regulated by monocyte-derived IL-18. Moreover, in vitro generated PD-L1^hi NK cells displayed an activated phenotype and enhanced effector functions compared to PD-L1^- NK cells, but simultaneously, they directly inhibited CD8⁺ T cell proliferation in a PD-L1-dependent manner. Our results suggest that tumors might drive the development of PD-L1-expressing NK cells that acquire immunoregulatory functions in humans. Hence, rational manipulation of these regulatory cells emerges as a possibility that may lead to improved anti-tumor immunity in cancer patients.

Investigation of the roles of IL-18 (-607 C/A) and IL-18 (-137 G/C) gene variations in bladder cancer development: case-control study

BACKGROUND

The purpose of our study is to investigate the roles of IL-18 gene variations in bladder cancer development in Thrace population of Turkey.

METHODS

This study was carried out with 103 bladder cancer patients and 81 healthy controls. Genotype distributions of IL-18 (-137 G/C) and IL-18 (-607 C/A) gene variations were determined using polymerase chain reaction (PCR) method.

RESULTS

The CC homozygous genotype for IL-18 (-607 C/A) gene variation was significantly higher in patients with bladder cancer compared to healthy controls (OR 0.345, 95% Cl 0.186-0.639, p = 0.001). Besides this, allele frequencies of IL-18 (-137 G/C) and IL-18 (-607 C/A) gene variations in patient with bladder cancer and healthy control groups were significantly different from the Hardy-Weinberg distribution (p < 0.05). For IL-18 (-137 G/C) and IL-18 (-607 C/A) gene variations, significant difference was determined between the bladder cancer patient and healthy control groups in terms of GC-CA (OR 0.381, 95% Cl 0.203-0.714, p = 0.002), GC-CC (OR 2.147, 95% Cl 1.013-4.550, p = 0.043), GG-AA (OR 0.431, 95% Cl 0.365-0.509, p = 0.049), and GG-CC (OR 2.476, 95% Cl 1.177-5.208, p = 0.015) haplotypes.

CONCLUSION

In our study, CC genotype of IL-18 (-607 C/A) gene variation was determined as genetic risk factor for bladder cancer development. In bladder cancer patient and healthy control groups, G and C allele frequencies of IL-18 (-137 G/C) gene variation, and C and A allele frequencies of IL-18 (-607 C/A) gene variation were determined significantly different from the Hardy-Weinberg distribution.

Tumor Secretome to Adoptive Cellular Immunotherapy: Reduce Me Before I Make You My Partner

Adoptive cellular immunotherapy using chimeric antigen receptor (CAR)-modified T cells and Natural Killer (NK) cells are common immune cell sources administered to treat cancer patients. In detail, whereas CAR-T cells induce outstanding responses in a subset of hematological malignancies, responses are much more deficient in solid tumors. Moreover, NK cells have not shown remarkable results up to date. In general, immune cells present high plasticity to change their activity and phenotype depending on the stimuli they receive from molecules secreted in the tumor microenvironment (TME). Consequently, immune cells will also secrete molecules that will shape the activities of other neighboring immune and tumor cells. Specifically, NK cells can polarize to activities as diverse as angiogenic ones instead of their killer activity. In addition, tumor cell phagocytosis by macrophages, which is required to remove dying tumor cells after the attack of NK cells or CAR-T cells, can be avoided in the TME. In addition, chemotherapy or radiotherapy treatments can induce senescence in tumor cells modifying their secretome to a known as “senescence-associated secretory phenotype” (SASP) that will also impact the immune response. Whereas the SASP initially attracts immune cells to eliminate senescent tumor cells, at high numbers of senescent cells, the SASP becomes detrimental, impacting negatively in the immune response. Last, CAR-T cells are an attractive option to overcome these events. Here, we review how molecules secreted in the TME by either tumor cells or even by immune cells impact the anti-tumor activity of surrounding immune cells.

Chronic Pancreatitis and the Development of Pancreatic Cancer

Pancreatitis is a fibro-inflammatory disorder of the pancreas that can occur acutely or chronically as a result of the activation of digestive enzymes that damage pancreatic cells, which promotes inflammation. Chronic pancreatitis with persistent fibro-inflammation of the pancreas progresses to pancreatic cancer, which is the fourth leading cause of cancer deaths across the globe. Pancreatic cancer involves cross-talk of inflammatory, proliferative, migratory, and fibrotic mechanisms. In this review, we discuss the role of cytokines in the inflammatory cell storm in pancreatitis and pancreatic cancer and their role in the activation of SDF1α/CXCR4, SOCS3, inflammasome, and NF-κB signaling. The aberrant immune reactions contribute to pathological damage of acinar and ductal cells, and the activation of pancreatic stellate cells to a myofibroblast-like phenotype. We summarize several aspects involved in the promotion of pancreatic cancer by inflammation and include a number of regulatory molecules that inhibit that process.

Association between interleukin gene polymorphisms and susceptibility to gastric cancer in the Qinghai population

OBJECTIVE

To investigate the associations between interleukin (IL) gene polymorphisms and susceptibility to gastric cancer in the Qinghai population, China.

METHODS

Patients with gastric cancer and cancer-free controls were enrolled into the study from Qinghai Provincial People's Hospital between September 2016 and September 2018. Single nucleotide polymorphisms (SNPs) were genotyped with the Sequenom MassARRAY® SNP genotype system. The Hardy-Weinberg equilibrium in allele and genotype frequencies, and general characteristics between patients with gastric cancer and cancer-free controls, were evaluated using χ²-test. Potential associations between interleukin gene variants and the risk of gastric cancer were analysed by logistic regression.

RESULTS

Among eight candidate SNPs, the allele and genotype frequency distribution of IL-1B rs1143634 polymorphism was significantly different between patients with gastric cancer (n = 190) and cancer-free controls (n = 186). The IL-1B rs1143634 GA genotype and IL-1B rs1143634 GA + AA genotype were associated with a reduced risk of gastric cancer, however, the remaining SNPs were not statistically associated with gastric cancer risk in the Qinghai population.

CONCLUSION

The IL-1B rs1143634 polymorphism might be associated with a decreased risk of gastric cancer, and may be a protective factor against gastric cancer.

Using Adoptive Cellular Therapy for Localized Protein Secretion

ABSTRACT

Redirection of T cell cytotoxicity by the chimeric antigen receptor (CAR) structure may not be sufficient for optimal antitumor function in the patient tumor microenvironment. Comodifying CAR T cells to secrete different classes of proteins can be used to optimize CAR T cell function, overcome suppressive signals, and/or alter the tumor microenvironment milieu. These modifications aim to improve initial responses to therapy and enhance the durability of response. Furthermore, CAR T cells can deliver these molecules locally to the tumor microenvironment, avoiding systemic distribution. This approach has been tested in preclinical models using a variety of different classes of agonistic and antagonistic proteins, and clinical trials are currently underway to assess efficacy in patients.

Association of metabolic and inflammatory markers with polycystic ovarian syndrome (PCOS): an update

BACKGROUND

Polycystic ovarian syndrome (PCOS) is the most prevalent metabolic disorder in reproductive-age women. It is indeed a multifactorial condition evidenced by ovarian dysfunction, hyperandrogenaemia, infertility, hormonal imbalance and chronic anovulation. Experimental evidence infers that PCOS women are prone to cardiovascular problems and insulin resistance.

PURPOSE

To furnish the details about the association of inflammatory markers in PCOS.

DESIGN

An extensive literature search on PubMed, science direct and google scholar has been performed for articles about PCOS and inflammation in PCOS. A comprehensive analysis using original articles, reviews, systemic and meta-analysis was conducted for better understanding the relationship between inflammatory cytokines and PCOS.

RESULTS

The inflammatory markers perform a substantial part in managing the functions of the ovary. Any disturbances in their levels can lead to ovarian dysfunction. Inflammatory markers are associated with PCOS pathogenesis. The interplay between inflammatory cytokines in the PCOS ovary strongly implies that inflammation is one of the most potent risk factors of PCOS.

CONCLUSION

Inflammatory markers have a significant role in regulating the ovary. This manuscript highlights the significance of metabolic and inflammatory markers with PCOS. Since PCOS is always considered as a metabolic disorder, researchers can also consider focusing on the relationship between the inflammatory markers in PCOS to establish a new treatment or management of the disease and to improve women's health.

The beneficial effects of reducing NLRP3 inflammasome activation in the cardiotoxicity and the anti-cancer effects of doxorubicin

Doxorubicin (DOX) is a powerful broad-spectrum anti-neoplastic anthracycline antibiotic. However, DOX may cause a dose-dependent cardiotoxicity that can eventually progress to congestive heart failure and death. Numerous molecular mechanisms have been implicated in the cardiotoxic effect of DOX including topoisomerase IIβ and generation of free radicals. However, targeting these pathways appears to be insufficient to mitigate the cardiotoxic effects of DOX and/or ultimately reduces the anti-tumor activity of DOX. Thus, there remains a crucial need to identify novel pharmacological targets that can alleviate the cardiotoxic effects of DOX without reducing its anti-tumor activity. Recent studies have suggested that the Nucleotide-Binding Domain-Like Receptor Protein 3 (NLRP3) inflammasome is implicated in tumor progression and the chemoresistance of cancer cells to DOX. Of interest, reducing NLRP3 inflammasome activity alleviates DOX-induced cardiotoxicity. Therefore, we postulate that strategies that target the NLRP3 inflammasome can help mitigate the cardiotoxic effects of DOX while maintaining and/or even enhancing its anti-cancer activity. Herein, we review the current knowledge about the potential implication of the NLRP3 inflammasome in the anti-cancer and cardiotoxic effects of DOX.

Liver prometastatic reaction: Stimulating factors and responsive cancer phenotypes

Cancer is first a localized tissue disorder, whose soluble and exosomal molecules and invasive cells induce a host response providing the stromal components of the primary tumor microenvironment (TME). Once the TME is developed, cancer-derived molecules and cells can more efficiently spread out and a whole-body response takes place, whose pathophysiological changes may result in a paraneoplastic syndrome. Remote organ-specific prometastatic reactions may also occur at this time, facilitating metastatic activities of circulating tumor cells (CTCs) through premetastatic niche development at targeted organs. However, additional signaling factors from the inter-organ communication network involved in the pathophysiology and comorbidities of cancer patients may also regulate prometastatic reaction-stimulating effects of cancer and non-cancer tissue factors. This article provides a conceptual overview of our ongoing clinical research on the liver prometastatic reaction (LPR) of patients with colorectal cancer (CRC), their portal vein- and hepatic artery-driven LPR-Stimulating Factors (LPR-SF), and their resulting LPR-derived Metastasis-Stimulating Factors (LPR-MSF) acting on liver-invading CRC cells. In addition, we also provide new insights on the molecular subtyping of LPR-responsive cancer phenotypes in patients with CRC and melanoma; and on how to investigate and interpret the prometastatic infrastructure in the real pathophysiological context of patients with cancer undergoing surgical procedures and receiving pharmacological treatments with multiple side effects, including those affecting the LPR, its stimulating factors and responsive cancer phenotypes.

IL-18 and IL-18 binding protein concentration in ovarian follicular fluid of women with unexplained infertility to PCOS during in vitro fertilization

The correlation between the concentration of interleukin (IL) 18 in follicular fluid and the pathogenesis of Polycystic Ovary Syndrome (PCOS) is unclear. Therefore, we tested the IL-18 and IL-18 binding protein (IL-18BP) levels in follicular fluid (FF) and serum in PCOS women undergoing reproductive measures and to explore their possibly correlation with PCOS. Serum and pooled follicular fluid levels of IL-18, IL-18BP and IL-18/IL-18BP ratios were evaluated in sixty patients with PCOS and sixty women with unexplained infertility undergoing in vitro fertilization. The FF IL-18 levels were increased in PCOS group than the CON group (p < 0.01), and the IL-18 levels were significantly higher in the FF than in serum in PCOS group. Furthermore, the elevated FF IL-18 levels have no correlation with the serum IL-18 levels. Additionally, the expression of IL-18 in the follicular fluid of the overweight PCOS patients was increased compared to the normal weight PCOS patients, while in the overweight patients, FF IL-18 was significantly higher in the PCOS group than in the control group. The FF IL-18 and IL-18BP may have a local involvement in the pathogenesis of PCOS. The PCOS itself and overweight will aggravate the local inflammatory response in the ovary. Further studies are needed to elucidate this issue.

A Synthetic Human Antibody Antagonizes IL-18Rβ Signaling Through an Allosteric Mechanism

The interleukin-18 subfamily belongs to the interleukin-1 family and plays an important role in modulating innate and adaptive immune responses. Dysregulation of IL-18 has been implicated in or correlated with numerous diseases, including inflammatory diseases, autoimmune disorders, and cancer. Thus, blockade of IL-18 signaling may offer therapeutic benefits in many pathological settings. Here, we report the development of synthetic human antibodies that target human IL-18Rβ and block IL-18-mediated IFN-γ secretion by inhibiting NF-κB and MAPK dependent pathways. The crystal structure of a potent antagonist antibody in complex with IL-18Rβ revealed inhibition through an unexpected allosteric mechanism. Our findings offer a novel means for therapeutic intervention in the IL-18 pathway and may provide a new strategy for targeting cytokine receptors.

Engineering strategies to overcome the current roadblocks in CAR T cell therapy

T cells genetically engineered to express chimeric antigen receptors (CARs) have proven — and impressive — therapeutic activity in patients with certain subtypes of B cell leukaemia or lymphoma, with promising efficacy also demonstrated in patients with multiple myeloma. Nevertheless, various barriers restrict the efficacy and/or prevent the widespread use of CAR T cell therapies in these patients as well as in those with other cancers, particularly solid tumours. Key challenges relating to CAR T cells include severe toxicities, restricted trafficking to, infiltration into and activation within tumours, suboptimal persistence in vivo, antigen escape and heterogeneity, and manufacturing issues. The evolution of CAR designs beyond the conventional structures will be necessary to address these limitations and to expand the use of CAR T cells to a wider range of malignancies. Investigators are addressing the current obstacles with a wide range of engineering strategies in order to improve the safety, efficacy and applicability of this therapeutic modality. In this Review, we discuss the innovative designs of novel CAR T cell products that are being developed to increase and expand the clinical benefits of these treatments in patients with diverse cancers.

Chimeric antigen receptor (CAR) T cell therapy, the first approved therapeutic approach with a genetic engineering component, holds substantial promise in the treatment of a range of cancers but is nevertheless limited by various challenges, including toxicities, intrinsic and acquired resistance mechanisms, and manufacturing issues. In this Review, the authors describe the innovative approaches to the engineering of CAR T cell products that are providing solutions to these challenges and therefore have the potential to considerably improve the safety and effectiveness of treatment.

Chimeric antigen receptor (CAR) T cells have induced remarkable responses in patients with certain haematological malignancies, yet various barriers restrict the efficacy and/or prevent the widespread use of this treatment.

Investigators are addressing these challenges with engineering strategies designed to improve the safety, efficacy and applicability of CAR T cell therapy.

CARs have modular components, and therefore the optimal molecular design of the CAR can be achieved through many variations of the constituent protein domains.

Toxicities currently associated with CAR T cell therapy can be mitigated using engineering strategies to make CAR T cells safer and that potentially broaden the range of tumour-associated antigens that can be targeted by overcoming on-target, off-tumour toxicities.

CAR T cell efficacy can be enhanced by using engineering strategies to address the various challenges relating to the unique biology of diverse haematological and solid malignancies.

Strategies to address the manufacturing challenges can lead to an improved CAR T cell product for all patients.

IL-18/IL-18BP and IL-22/IL-22BP: Two interrelated couples with therapeutic potential

Interleukin (IL)-18 and IL-22 are key components of cytokine networks that play a decisive role in (pathological) inflammation, host defense, and tissue regeneration. Tight regulation of cytokine-driven signaling, inflammation, and immunoactivation is supposed to enable nullification of a given deleterious trigger without mediating overwhelming collateral tissue damage or even activating a cancerous face of regeneration. In fact, feedback regulation by specific cytokine opponents is regarded as a major means by which the immune system is kept in balance. Herein, we shine a light on the interplay between IL-18 and IL-22 and their opponents IL-18 binding protein (IL-18BP) and IL-22BP in order to provide integrated information on their biology, pathophysiological significance, and prospect as targets and/or instruments of therapeutic intervention.

Hormonal Regulation of Patient-Derived Endometrial Cancer Stem-like Cells Generated by Three-Dimensional Culture

Low-grade and early-stage endometrial cancer usually has a favorable prognosis, whereas recurrent or metastatic disease is often difficult to cure. Thus, the molecular mechanisms underlying advanced pathophysiology remain to be elucidated. From the perspective of the origin of advanced endometrial cancer, the characterization of cancer stem-like cells (CSCs) will be the first step toward the development of clinical management. We established long-term culturable patient-derived cancer cells (PDCs) from patient endometrial tumors by spheroid cell culture, which is favorable for the enrichment of CSCs. PDC-derived xenograft tumors were generated in immunodeficient NOD/Shi-scid, IL-2RγKO Jic mice. Morphologically, PDCs derived from three distinct patient samples and their xenograft tumors recapitulated the corresponding original patient tumors. Of note, CSC-related genes including ALDH1A1 were upregulated in all of these PDCs, and the therapeutic potentiality of aldehyde dehydrogenase inhibitors was demonstrated. In addition, these PDCs and their patient-derived xenograft (PDX) models exhibited distinct characteristics on the basis of their hormone responsiveness and metastatic features. Interestingly, genes associated with inflammation and tumor immunity were upregulated by 17β-estradiol in PDC lines with high estrogen receptor expression and were also overexpressed in secondary PDCs obtained from metastatic tumor models. These results suggest that PDC and PDX models from endometrial cancer specimens would be useful to elucidate CSC traits and to develop alternative diagnostic and therapeutic options for advanced disease.

The emerging roles of inflammasome-dependent cytokines in cancer development

In addition to the genomic alterations that occur in malignant cells, the immune system is increasingly appreciated as a critical axis that regulates the rise of neoplasms and the development of primary tumours and metastases. The interaction between inflammatory cell infiltrates and stromal cells in the tumour microenvironment is complex, with inflammation playing both pro- and anti-tumorigenic roles. Inflammasomes are intracellular multi-protein complexes that act as key signalling hubs of the innate immune system. They respond to cellular stress and trauma by promoting activation of caspase-1, a protease that induces a pro-inflammatory cell death mode termed pyroptosis along with the maturation and secretion of the pro-inflammatory cytokines interleukin (IL)-1β and IL-18. Here, we will briefly introduce inflammasome biology with a focus on the dual roles of inflammasome-produced cytokines in cancer development. Despite emerging insight that inflammasomes may promote and suppress cancer development according to the tumour stage and the tumour microenvironment, much remains to be uncovered. Further exploration of inflammasome biology in tumorigenesis should enable the development of novel immunotherapies for cancer patients.

Contribution of Inflammatory Cytokine Interleukin-18 Genotypes to Renal Cell Carcinoma

Interleukin-18 (IL-18) is a multi-functional immuno-mediator in the development and progression of many types of infectious and inflammatory diseases. In this study, we evaluated the contribution of IL-18 genotypes to renal cell carcinoma (RCC) in Taiwan via the genotyping of IL-18 -656 (A/C), -607 (A/C), and -137 (G/C). Moreover, we analyzed their interactions with smoking, alcohol drinking, hypertension, and diabetes status. The results showed an association of the AC and CC genotypes of IL-18 -607 with a significant decrease in the risk of RCC compared with the AA genotype (odds ratio (OR) = 0.44 and 0.35, 95% confidence interval (CI) = 0.27⁻0.72 and 0.18⁻0.66, p = 0.0008 and 0.0010, respectively). Furthermore, a significantly lower frequency of the C allele at -607 was observed in the RCC group (35.3% vs. 49.8%; OR = 0.53; 95% CI = 0.35⁻0.71, p = 0.0003). However, IL-18 -656 and -137 did not exhibit a likewise differential distribution of these genotypes between the control and case groups. Stratifying the population according to smoking, alcohol drinking, hypertension, and diabetes status revealed a different distribution of IL-18 -607 genotypes among non-smokers, non-drinkers, and patients without diabetes, but not among smokers, drinkers, or patients with diabetes. These findings suggest that IL-18 -607 genotypes may play a role in the etiology and progression of RCC in Taiwan and may serve as a useful biomarker for early detection.

Interleukin-18 promoter genotype is associated with the risk of nasopharyngeal carcinoma in Taiwan

Background

The incidence rate of nasopharyngeal carcinoma (NPC) has been documented to be high in Southeast Asia. Interleukin-18 (IL-18) is a multifunctional cytokine that augments interferon-γ production and acts as an important immunomediator in the development of several types of cancer.

Patients and methods

This case-control study evaluated the role of IL-18 in NPC at the DNA level by genotyping its promoter polymorphisms at positions -656, -607, and -137 in a Taiwanese population. A total of 176 patients with NPC and age- and gender-matched 352 noncancer controls were included in this study.

Results

The CC genotype of the IL-18-607 polymorphism was found to be associated with significantly decreased risks of NPC compared to the AA genotype (crude OR =0.50, 95% CI =0.29-0.84, P=0.0093). This significant difference persisted even in the dominant and recessive models. A significantly lower C allele frequency at position -607 was detected in the NPC group(41.8% vs 50.3%; OR =0.77; 95% CI =0.63-1.04, P=0.0089). Regarding IL-18-656 and -137 polymorphisms, there were no differential distributions of their genotypes between the NPC and control groups. After substratification of the subjects according to their smoking, alcohol consumption, and areca chewing status, the genotype distribution of the IL-18-607 polymorphism was found to be different only among nonsmokers between the NPC and control subgroups.

Conclusion

This study suggests that IL-18 plays an important role in the carcinogenesis of NPC in Taiwan and that the genotype-phenotype correlation of IL-18-607 polymorphism and its contribution to NPC need to be investigated further.

CAR T Cells Releasing IL-18 Convert to T-Bethigh FoxO1low Effectors that Exhibit Augmented Activity against Advanced Solid Tumors

Adoptive therapy with chimeric antigen receptor (CAR)-redirected T cells has achieved remarkable efficacy in the treatment of hematopoietic malignancies. However, eradicating large solid tumors in advanced stages of the disease remains challenging. We explored augmentation of the anti-tumor immune reaction by establishing an acute inflammatory reaction. Systematic screening indicates that IL-18 polarizes CAR T cells toward T-bet^high FoxO1^low effectors with an acute inflammatory response. CAR T cells engineered with inducible IL-18 release exhibited superior activity against large pancreatic and lung tumors that were refractory to CAR T cells without cytokines. IL-18 CAR T cell treatment was accompanied by an overall change in the immune cell landscape associated with the tumor. More specifically, CD206^- M1 macrophages and NKG2D⁺ NK cells increased in number, whereas Tregs, suppressive CD103⁺ DCs, and M2 macrophages decreased, suggesting that "iIL18 TRUCKs" can be used to sensitize large solid tumor lesions for successful immune destruction.

Mesenchymal stem cells expressing interleukin-18 inhibit breast cancer in a mouse model

Development of an improved breast cancer therapy has been an elusive goal of cancer gene therapy for a long period of time. Human mesenchymal stem cells derived from umbilical cord (hUMSCs) genetically modified with the interleukin (IL)-18 gene (hUMSCs/IL-18) were previously demonstrated to be able to suppress the proliferation, migration and invasion of breast cancer cells in vitro. In the present study, the effect of hUMSCs/IL-18 on breast cancer in a mouse model was investigated. A total of 128 mice were divided into 2 studies (the early-effect study and the late-effect study), with 4 groups in each, including the PBS-, hUMSC-, hUMSC/vector- and hUMSC/IL-18-treated groups. All treatments were injected along with 200 µl PBS. Following therapy, the tumor size, histological examination, and expression of lymphocytes, Ki-67, cluster of differentiation 31 and cytokines [interleukin (IL)-18, IL-12, interferon (IFN)-γ and TNF-α] in each group were analyzed. Proliferation of cells (assessed by measuring tumor size and Ki-67 expression) and metastasis, (by determining pulmonary and hepatic metastasis) of breast cancer cells in the hUMSC/IL-18 group were significantly decreased compared with all other groups. hUMSCs/IL-18 suppressed tumor cell proliferation by activating immunocytes and immune cytokines, decreasing the proliferation index of proliferation marker protein Ki-67 of tumor cells and inhibiting tumor angiogenesis. Furthermore, hUMSCs/IL-18 were able to induce a more marked and improved therapeutic effect in the tumor sites, particularly in early tumors. The results of the present study indicate that hUMSCs/IL-18 were able to inhibit the proliferation and metastasis of breast cancer cells in vivo, possibly leading to an approach for a novel antitumor therapy in breast cancer.

Association of genetic variants in the interleukin-18 gene promoter with risk of hepatocellular carcinoma and metastasis in patients with hepatitis C virus infection

Hepatocellular carcinoma (HCC) is a primary malignancy of the liver, characterized by high vascularization and rapid tumor progression. The current case-control study aimed to analyze the influence of -607C/A and -137G/C polymorphisms in the interleukin-18 (IL-18) promoter on the risk of HCC occurrence and metastasis in Egyptian patients infected with hepatitis C virus (HCV). Both genetic variations were genotyped in 279 subjects including HCV patients with and without HCC and unrelated healthy subjects, using the allele-specific polymerase chain reaction (AS-PCR) method. The relationship between clinico-laboratory parameters including serum level of alpha-fetoprotein (AFP) and these polymorphisms was evaluated in HCC patients. The IL-18-607A allele and AA genotype were significantly related to a higher risk of developing HCC when comparing patients with HCC and controls, and were significantly related to a higher risk of metastasis when comparing metastatic and nonmetastatic groups in the Egyptian patients. In contrast, the IL18-137C allele and GC genotype were significantly related to a lower risk of developing HCC when comparing patients with HCC and controls, and HCV patients with and without HCC. A significant association was found between multinodular HCC and IL-18-607AA genotype, while, uninodular HCC was significantly associated with IL-18-137GG genotype. In addition, IL18-607AA and -137GG genotypes showed significant association with higher level of serum AFP. The detection of polymorphisms in the IL-18 promoter, in a combination with an evaluation of level of serum AFP, could be used as a molecular biomarker in the early diagnosis of HCC, which would aid the early management of the disease, thus decreasing the rate of mortality of this disease. © 2018 IUBMB Life, 70(2):165-174, 2018.

Inhibition of IL-18-mediated myeloid derived suppressor cell accumulation enhances anti-PD1 efficacy against osteosarcoma cancer

Myeloid derived suppressor cells (MDSC) are very important in tumor immune evasion and they dramatically increased in peripheral blood of patients with osteosarcoma cancer. The association between MDSC and various cytokines has been studied in the peripheral blood. However, little is known about the mechanism drawing MDSC into tumor parenchyma. This study was to analyze the correlation between MDSC subsets and interleukin 18 (IL-18) level in osteosarcoma tumor model and its effect on the immunotherapy. MDSC were isolated from the blood and parenchyma and analyzed in the osteosarcoma tumor model. IL-18 levels were detected by enzyme-linked immunosorbent assay (ELISA) assay, real-time PCR, western blot and flow cytometry. Moreover, combination treatment with IL-18 inhibition and anti-PD1 was conducted to assess the therapeutic effects of IL-18 blockade. Results showed MDSC levels had a positive correlation with IL-18, suggesting IL-18 may attract MDSC into the parenchyma. IL-18 gene and protein expression significantly increased in blood and tumor lysates of tumor-bearing mice. Anti-IL-18 treatment significantly decreased G-MDSC and M-MDSC in the peripheral blood and tumor. Furthermore, combination therapy decreased the tumor burden and increased CD4⁺ and CD8⁺ T cell infiltration, as well as the production of interferon gamma (IFNγ) and granzyme B. Our study revealed a possible correlation between MDSC subsets and IL-18 inducing MDSC migration into the tumor tissue, in addition to provide the potential target to enhance the efficacy of immunotherapy in patients with osteosarcoma.

Autocrine mechanisms of cancer chemoresistance

An ever-increasing number of studies highlight the role of cancer secretome in the modification of tumour microenvironment and in the acquisition of cancer cell resistance to therapeutic drugs. The knowledge of the mechanisms underlying the relationship between cancer cell-secreted factors and chemoresistance is becoming fundamental for the identification of novel anticancer therapeutic strategies overcoming drug resistance and novel prognostic secreted biomarkers. In this review, we summarize the novel findings concerning the regulation of secreted molecules by cancer cells compromising drug sensitivity. In particular, we highlight data from available literature describing the involvement of cancer cell-secreted molecules determining chemoresistance in an autocrine manner, including: i) growth factors; ii) glycoproteins; iii) inflammatory cytokines; iv) enzymes and chaperones; and v) tumor-derived exosomes.

Downregulation of HuR Inhibits the Progression of Esophageal Cancer through Interleukin-18

Purpose

The purpose of this study was to investigate the effect of human antigen R (HuR) downregulation and the potential target genes of HuR on the progression of esophageal squamous cell carcinoma (ESCC).

Materials and Methods

In this study, a proteomics assay was used to detect the expression of proteins after HuR downregulation, and a luciferase assay was used to detect the potential presence of a HuR binding site on the 3’-untranslated region (3'-UTR) of interleukin 18 (IL-18). In addition, colony formation assay, MTT, EdU incorporation assay, Western blot, flow cytometry, immunohistochemistry, transwell invasion assay, and wound healing assay were used.

Results

In the present study, we found that the expression of both HuR protein and mRNA levels were higher in tumor tissues than in the adjacent tissues. HuR downregulation significantly suppressed cell proliferation. In addition, the metastasis of esophageal cancer cells was inhibited, while the expression of E-cadherin was increased and the expression of matrix metalloproteinase (MMP) 2, MMP9, and vimentin was decreased after HuR knockdown. Moreover, silencing of HuR disturbed the cell cycle of ESCC cells mainly by inducing G1 arrest. Furthermore, proteomics analysis showed that downregulation of HuR in TE-1 cells resulted in 100 upregulated and 122 downregulated proteins, including IL-18 as a significantly upregulated protein. The expression of IL-18 was inversely regulated by HuR. IL-18 expression was decreased in ESCC tissues, and exogenous IL-18 significantly inhibited the proliferation and metastasis of ESCC cells. The 3'-UTR of IL-18 harbored a HuR binding site, as shown by an in vitro luciferase assay.

Conclusion

HuR plays an important role in the progression of esophageal carcinoma by targeting IL-18, which may be a potential therapeutic target for the treatment of ESCC.

Leptin promotes breast cancer cell migration and invasion via IL-18 expression and secretion

In recent years, crosstalk between tumor microenvironment and cancer cells have received increasing attention. Accumulating research data suggests that leptin, a key adipokine secreted from adipocytes, plays important roles in breast cancer development. In our study, the effects of leptin on polarization of tumor-associated macrophages (TAMs) and promotion of the invasiveness of tumor cells were investigated. THP1 cells were used to differentiate M2 polarization macrophages. After stimulated by leptin, we established a co-culture system of tumor cells and macrophages to evaluate the function of leptin-induced macrophages in the migration and invasion of breast cancer cells. The gene and protein expressions were analyzed and the underlying mechanisms were evaluated. Moreover, pathological human specimens, and xenografts in nude mice, were detected to strengthen the in vitro results. Leptin elevated the expression of an array of cytokines in TAMs, IL-18 was the most increased, with an activation of the NF-κB/NF-κB1 signalling pathway. Additionally, after treated with leptin, TAMs significantly promoted the migration and invasion of breast cancer cells. However, these effects of leptin were abolished by the co-incubation of Bay11‑7082, a pharmacological NF-κB inhibitor. Leptin also directly stimulated IL-18 expression in breast cancer cells, which, differently, was via the PI3K/AKT-ATF-2 signaling pathway. In vivo studies showed that malignant breast carcinoma exhibited strong higher expression of Leptin, IL-8, and TAMs markers. Xenograft tumor-bearing mouse models showed that leptin significantly increased tumor volume, enhanced lung metastases, and increased expression of IL-8 and TAM markers, which were abolished by depletion of macrophages by clophosome-clodronate liposomes (CCL). Leptin could induce IL-18 expression both in TAMs and breast cancer cells. Leptin-induced IL-18 expression was regulated via NF-κB/NF-κB1 signaling in TAMs, while via PI3K-AKT/ATF-2 signaling in breast cancer cells, which, eventually, lead to invasion and metastasis of breast cancer cells.

Endogenous conversion of ω-6 to ω-3 polyunsaturated fatty acids in fat-1 mice attenuated intestinal polyposis by either inhibiting COX-2/β-catenin signaling or activating 15-PGDH/IL-18

Omega-3 polyunsaturated fatty acids (ω-3PUFAs) have inhibitory effects in various preclinical cancer models, but their effects in intestinal polyposis have never been examined. As attempts have been made to use nutritional intervention to counteract colon cancer development, in this study we evaluated the effects of ω-3 PUFAs on intestinal polyposis in the Apc(Min/+) mouse model. The experimental groups included wild-type C56BL/6 mice, Apc(Min/+) mice, fat-1 transgenic mice expressing an n-3 desaturase to enable ω-3 PUFA synthesis, and Apc(Min/+) × fat-1 double-transgenic mice; all mice were 20 weeks of age. Small intestines were collected for gross and pathologic evaluation, including assessment of polyp number and size, followed by immunohistochemical staining and Western blotting. After administration of various concentrations of ω-3 PUFAs, PUFA levels were measured in small intestine tissue by GC/MS/MS analysis to compare with PUFA synthesis of between C57BL6 and fat-1mice. As a result, ω-3 PUFAs significantly attenuated Apc mutation-induced intestinal polyposis accompanied with significant inhibition of Wnt/β-catenin signaling, COX-2 and PGE2, but induced significant levels of 15-PGDH. In addition, significant induction of the inflammasome-related substrates as IL-1β and IL-18 and activation of caspase-1 was observed in Apc(Min/+) × fat-1 mice. Administration of at least 3 g/60 kg ω-3 PUFAs was equivalent to ω-3 PUFAs produced in fat-1 mice and resulted in significant increase in the expression of IL-1β, caspase-3 and IL-18, as seen in Apc(Min/+) × fat-1 mice. We conclude that ω-3PUFAs can prevent intestinal polyp formation by inhibition of Wnt/β-catenin signaling, but increased levels of 15-PGDH and IL-18.

Heme-oxygenase-1 implications in cell morphology and the adhesive behavior of prostate cancer cells

Prostate cancer (PCa) is the second leading cause of cancer death in men. Although previous studies in PCa have focused on cell adherens junctions (AJs), key players in metastasis, they have left the molecular mechanisms unexplored. Inflammation and the involvement of reactive oxygen species (ROS) are critical in the regulation of cell adhesion and the integrity of the epithelium. Heme oxygenase-1 (HO-1) counteracts oxidative and inflammatory damage. Here, we investigated whether HO-1 is implicated in the adhesive and morphological properties of tumor cells. Genes differentially regulated by HO-1 were enriched for cell motility and adhesion biological processes. HO-1 induction, increased E-cadherin and β-catenin levels. Immunofluorescence analyses showed a striking remodeling of E-cadherin/β-catenin based AJs under HO-1 modulation. Interestingly, the enhanced levels of E-cadherin and β-catenin coincided with a markedly change in cell morphology. To further our analysis we sought to identify HO-1 binding proteins that might participate in the regulation of cell morphology. A proteomics approach identified Muskelin, as a novel HO-1 partner, strongly implicated in cell morphology regulation. These results define a novel role for HO-1 in modulating the architecture of cell-cell interactions, favoring a less aggressive phenotype and further supporting its anti-tumoral function in PCa.

Interleukin-18 enhances breast cancer cell migration via down-regulation of claudin-12 and induction of the p38 MAPK pathway

Interleukin-18 (IL-18) was recently reported to have a pro-tumor effect in various cancers. Increased IL-18 levels in the serum of cancer patients correlated with malignancy, and IL-18 acts a crucial factor for cell migration in gastric cancer and melanoma. Claudins, which are the most important tight junction proteins, are also linked with cancer progression and metastasis. However, the relationship between claudins and IL-18 is not well-understood. Here, we show that the migratory ability of MCF-7 cells was reduced when endogenous IL-18 expression was inhibited with IL-18 siRNA. Moreover, exogenous IL-18 enhanced breast cancer cell migration and suppressed the expression of the tight junction proteins claudin-1, claudin-3, claudin-4, and claudin-12 in MCF-7 cells. Knockdown of claudin-3, claudin-4, and claudin-12, but not claudin-1, increased breast cancer migration with maximal effects observed in claudin-12 siRNA-transfected cells. To investigate whether the mitogen-activated protein kinase (MAPK) signaling pathway is involved in IL-18-induced cell migration and claudin-12 expression, cells were pretreated with SB203580 (an inhibitor of p38 MAPK) or PD98059 (an inhibitor of ERK1/2) prior to the addition of IL-18. Although pretreatment of MCF-7 cells with SB203580 blocked both the enhanced cell migration and the decreased claudin-12 expression, PD98059 only blocked cell migration and did not affect claudin-12 expression. In addition, exogenous IL-18 induced rapid phosphorylation of p38 MAPK. These results suggest that IL-18 is an important factor inducing breast cancer cell migration through down-regulation of claudin-12 and activation of the p38 MAPK pathway.

TCR-dependent sensitization of human γδ T cells to non-myeloid IL-18 in cytomegalovirus and tumor stress surveillance

Human γδ T cells contribute to tissue homeostasis under normal conditions and participate in lymphoid stress surveillance against infection and tumors. However, the molecular mechanisms underlying the recognition of complex cell stress signatures by γδ T cells are still unclear. Tumor cells and human cytomegalovirus (HCMV)-infected cells are known targets of γδ T cells. We show here that many tumor and CMV-infected cells express caspase-1 inflammasomes and release interleukin (IL)-18. Engagement of the T-cell receptor (TCR) on Vδ2^neg γδ T cells controlled the direct innate immune sensing of IL-18 that enhanced cytotoxicity and interferon gamma (IFNγ) production. This TCR-dependent sensitization to IL-18 was mediated by the upregulation of the innate IL-18 receptor β chain (IL-18Rβ) expression. These findings shed light on inflammasomes as a unified stress signal of tumor and infected cells to alert γδ T cells. Moreover, uncovering the TCR-mediated sensitization of γδ T cells to inflammatory mediators establishes a molecular link between the innate and adaptive immune functions of γδ T cells that could fine tune the commitment of antigen-experienced γδ T cells to inflammatory responses.

Th1 cytokine-based immunotherapy for cancer

Cytokine-based immunotherapy is executed by harnessing cytokines to activate the immune system to suppress tumors. Th1-type cytokines including IL-1, IL-2, IL-12 and granulocyte-macrophage colony-stimulating factor are potent stimulators of Th1 differentiation and Th1-based antitumor response. Many preclinical studies demonstrated the antitumor effects of Th1 cytokines but their clinical efficacy is limited. Multiple factors influence the efficacy of immunotherapy for tumors. For instance immunosuppressive cells in the tumor microenvironment can produce inhibitory cytokines which suppress antitumor immune response. Most studies on cytokine immunotherapy focused on how to boost Th1 response; many studies combined cytokine-based therapy with other treatments to reverse immunosuppression in tumor microenvironment. In addition, cytokines have pleiotropic functions and some cytokines show paradoxical activities under different settings. Better understanding the physiological and pathological functions of cytokines helps clinicians to design Th1-based cancer therapy in clinical practice.

MDSCs mediate angiogenesis and predispose canine mammary tumor cells for metastasis via IL-28/IL-28RA (IFN-λ) signaling

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) function in immunosuppression and tumor development by induction of angiogenesis in a STAT3-dependent manner. Knowledge of MDSC biology is mainly limited to mice studies, and more clinical investigations using spontaneous tumor models are required. Here we performed in vitro experiments and clinical data analysis obtained from canine patients.

METHODS

Using microarrays we examined changes in gene expression in canine mammary cancer cells due to their co-culture with MDSCs. Further, using Real-time rt-PCR, Western blot, IHC, siRNA, angiogenesis assay and migration/invasion tests we examined a role of the most important signaling pathway.

RESULTS

In dogs with mammary cancer, the number of circulating MDSCs increases with tumor clinical stage. Microarray analysis revealed that MDSCs had significantly altered molecular pathways in tumor cells in vitro. Particularly important was the detected increased activation of IL-28/IL-28RA (IFN-λ) signaling. The highest expression of IL-28 was observed in stage III/IV mammary tumor-bearing dogs. IL-28 secreted by MDSCs stimulates STAT3 in tumor cells, which results in increased expression of angiogenic factors and subsequent induction of angiogenesis by endothelial cells, epithelial-mesenchymal transition (EMT) and increased migration of tumor cells in vitro. Knockdown of IL-28RA decreased angiogenesis, tumor cell invasion and migration.

CONCLUSIONS

We showed for the first time that MDSCs secrete IL-28 (IFN-λ), which promotes angiogenesis, EMT, invasion and migration of tumor cells. Thus, IL-28 may constitute an interesting target for further therapies. Moreover, the similarity in circulating MDSC levels at various tumor clinical stages between canine and human patients indicates canines as a good model for clinical trials of drugs targeting MDSCs.

Expression of IL-18, IL-18 binding protein, and IL-18 receptor by normal and cancerous human ovarian tissues: possible implication of IL-18 in the pathogenesis of ovarian carcinoma

Proinflammatory cytokine IL-18 has been shown to be elevated in the sera of ovarian carcinoma patients. The aim of the study was to examine the levels and cellular origin of IL-18, IL-18 binding protein, and IL-18 receptor in normal and cancerous ovarian tissues. Ovarian tissue samples were examined by immunohistochemical staining for IL-18, IL-18BP, and IL-18R and mRNA of these cytokines was analyzed with semiquantitative PT-PCR. IL-18 levels were significantly higher in cancerous ovarian tissues (P = 0.0007), IL-18BP levels were significantly higher in normal ovarian tissues (P = 0.04), and the ratio of IL-18/IL-18BP was significantly higher in cancerous ovarian tissues (P = 0.036). Cancerous ovarian tissues expressed significantly higher IL-18 mRNA levels (P = 0.025), while there was no difference in the expression of IL-18BP mRNA and IL-18R mRNA between cancerous and normal ovarian tissues. IL-18 and IL-18BP were expressed dominantly in the epithelial cells of both cancerous and normal ovarian tissues, while IL-18R was expressed dominantly in the epithelial cells of cancerous ovarian tissues but expressed similarly in the epithelial and stromal cells of normal cancerous tissues. This study indicates a possible role of IL-18, IL-18BP, and IL-18R in the pathogenesis of epithelial ovarian carcinoma.

Tumor-induced perturbations of cytokines and immune cell networks

Until recently, the intrinsically high level of cross-talk between immune cells, the complexity of immune cell development, and the pleiotropic nature of cytokine signaling have hampered progress in understanding the mechanisms of immunosuppression by which tumor cells circumvent native and adaptive immune responses. One technology that has helped to shed light on this complex signaling network is the cytokine antibody array, which facilitates simultaneous screening of dozens to hundreds of secreted signal proteins in complex biological samples. The combined applications of traditional methods of molecular and cell biology with the high-content, high-throughput screening capabilities of cytokine antibody arrays and other multiplexed immunoassays have revealed a complex mechanism that involves multiple cytokine signals contributed not just by tumor cells but by stromal cells and a wide spectrum of immune cell types. This review will summarize the interactions among cancerous and immune cell types, as well as the key cytokine signals that are required for tumors to survive immunoediting in a dormant state or to grow and spread by escaping it. Additionally, it will present examples of how probing secreted cell-cell signal networks in the tumor microenvironment (TME) with cytokine screens have contributed to our current understanding of these processes and discuss the implications of this understanding to antitumor therapies.

A dose-escalation study of recombinant human interleukin-18 in combination with rituximab in patients with non-Hodgkin lymphoma

Interleukin-18 (IL-18) is an immunostimulatory cytokine with antitumor activity in preclinical models. Rituximab is a CD20 monoclonal antibody with activity against human B-cell lymphomas. A phase I study of recombinant human (rh) IL-18 given with rituximab was performed in patients with CD20+ lymphoma. Cohorts of 3-4 patients were given infusions of rituximab (375 mg/m2) weekly for 4 weeks with escalating doses of rhIL-18 as a 2-hour intravenous infusion weekly for 12 consecutive weeks. Toxicities were graded using standard criteria. Blood samples were obtained for safety, pharmacokinetic, and pharmacodynamic studies. Nineteen patients with CD20+ B-cell non-Hodgkin lymphoma were given rituximab in combination with rhIL-18 at doses of 1, 3, 10, 20, 30, and 100 μg/kg. Common side effects included chills, fever, headache, and nausea. Common laboratory abnormalities included transient, asymptomatic lymphopenia, hyperglycemia, anemia, hypoalbuminemia, and bilirubin and liver enzyme elevations. No dose-limiting toxicities were observed. Biologic effects of rhIL-18 included transient lymphopenia and increased expression of activation antigens on lymphocytes. Increases in serum concentrations of IFN-γ, GM-CSF, and chemokines were observed after dosing. Objective tumor responses were seen in 5 patients, including 2 complete and 3 partial responses. rhIL-18 can be given in biologically active doses by weekly infusions in combination with rituximab to patients with lymphoma. A maximum tolerated dose of rhIL-18 plus rituximab was not determined. Further studies of rhIL-18 and CD20 monoclonal antibodies in B-cell malignancies are warranted.

Intracellular distributing and interferon-γ secretion of human interleukin-18 in BxPC-3 cells

OBJECTIVE

To investigate the characteristics of interleukin-18 (IL-18) in vitro, explore IL-18, interferon-γ (IFN-γ) and interleukin-2 (IL-2) secretive activity in BxPC-3 line cells with interleukin-18 mutants.

METHODS

Human IL-18 full-length gene (hIL-18-F) and the hIL-18 presumed mature protein gene (hIL-18-M) were inserted into the expression vector pEGFP-N1, to construct recombinant plasmids as Mu0, Mu1, Mu2, Mu3, and Mu4, and the recombinant plasmids were then transferred into BxPC-3 line cells. There are significant differences between Mu1, Mu2 and the pEGFP-C1 control group (P<0.05) by 3-(4,5-dimethiazol- 2-yl)- 2,5-diphenyltetrazolium bromide (MTT) for a proliferation assay, and the fluorescence of the Mu1 and Mu 2 appeared targeted to the membranous region in the BxPC-3 cells after transfected 24h by confocal laser scanning microscope (OLSM).To characterize the intracellular distribution of hIL-18, recombinant IL-18 were each fused to the enhanced green fluorescent protein gene, and expressed in BxPC-3 cells.

RESULTS

Results showed that the Mu1 tended to the membranous region in BxPC-3 cells, this indicates that the N-terminal former amino acid peptide helped ChIL-18 target to BxPC-3 cellS membranes. ELISA results demonstrated that IFN-γ and IL-18 secreted levels of BxPC-3 cells transfecting with recombinant plasmid showed an significant difference (P<0.01); refers to IL-2 expression, the two BxPC-3 cells groups transfecting with recombinant plasmid have no significant function (P>0.05).

CONCLUSIONS

The results showed that hIL-18 and hIL-18 presumed mature protein can induce the secretion of IFN-γ in BxPC-3 cells, and increase the expression of IL-18, but they have no effects on IL-2.

Impact of interleukin-18 polymorphisms -607A/C and -137G/C on oral cancer occurrence and clinical progression

BACKGROUND

The purpose of this study was to identify gene polymorphisms of interleukin-18 (IL-18) -607A/C and -137G/C specific to patients with oral cancer susceptibility and clinicopathological status.

METHODOLOGY AND PRINCIPAL FINDINGS

A total of 1,126 participants, including 559 healthy people and 567 patients with oral cancer, were recruited for this study. Allelic discrimination of -607A/C (rs1946518) and -137G/C (rs187238) polymorphisms of the IL-18 gene was assessed by a real-time PCR with the TaqMan assay. There was no significant association between IL-18 -607A/C polymorphism and oral cancer risk. However, among alcohol consumers, people with A/A homozygotes of IL-18 -607A/C polymorphism had a 2.38-fold (95% CI=1.17-4.86; p=0.01) increased risk of developing oral cancer compared with those with C/C homozygotes. The participants with G/C heterozygotes of IL-18 -137 polymorphism had a 1.64-fold (95% CI: 1.08-2.48; p=0.02) increased risk of developing oral cancer compared with those with G/G wild type homozygotes. Both sets of statistics were determined after adjusting for confounding factors. Among people who had exposure to oral cancer-related environmental risk factors such as areca, alcohol, and tobacco consumption, the adjusted odd ratios and 95% confidence intervals were increased to a 2.02-fold (95% CI=1.01-4.04; p=0.04), 4.04 (95% CI=1.65-9.87; p=0.002) and a 1.66-fold (95% CI=1.00-2.84; p=0.05) risk of developing oral cancer. However, patients with G/C alleles of IL-18 -137 were correlated with a lower clinical stage (AOR=0.59; 95% CI=0.39-0.89; p=0.01), smaller tumor size (AOR=0.56; 95% CI=0.35-0.87; p=0.01), and non-lymph node metastasis (AOR=0.51; 95% CI=0.32-0.80; p=0.003).

CONCLUSION

IL-18 -137 G/C gene polymorphism may be a factor that increases the susceptibility to oral cancer, as well as a protective factor for oral cancer progression. The interactions of gene to oral cancer-related environmental risk factors have a synergetic effect that can further enhance oral cancer development.