Interleukin-1 Family Members Research Articles

Roles and Mechanisms of Interleukin-12 Family Members in Cardiovascular Diseases: Opportunities and Challenges.

Cardiovascular diseases represent a complex group of clinical syndromes caused by a variety of interacting pathological factors. They include the most extensive disease population and rank first in all-cause mortality worldwide. Accumulating evidence demonstrates that cytokines play critical roles in the presence and development of cardiovascular diseases. Interleukin-12 family members, including IL-12, IL-23, IL-27 and IL-35, are a class of cytokines that regulate a variety of biological effects; they are closely related to the progression of various cardiovascular diseases, including atherosclerosis, hypertension, aortic dissection, cardiac hypertrophy, myocardial infarction, and acute cardiac injury. This paper mainly discusses the role of IL-12 family members in cardiovascular diseases, and the molecular and cellular mechanisms potentially involved in their action in order to identify possible intervention targets for the prevention and clinical treatment of cardiovascular diseases.

Interleukin-17 suppresses grass carp reovirus infection in Ctenopharyngodon idellus kidney cells by activating NF-κB signaling

The grass carp accounts for a large proportion of aquacultural production in China, but the hemorrhagic disease caused by grass carp reovirus (GCRV) infection often causes huge economic losses to the industry. Interleukin 17 (IL-17) is an important cytokine that plays a critical role in the inflammatory and immune responses. Although IL-17 family members have been extensively studied in mammals, our knowledge of the activity of IL-17 proteins in teleosts in response to viral infection is still limited. In this study, the role of IL-17 in GCRV infection and its mechanism were investigated. The expression levels of IL-17AF1, IL-17AF2, and IL-17AF3 in Ctenopharyngodon idella kidney (CIK) cells gradually increased from 6 h after infection with GCRV. The nuclear translocation of p65, which acts in the NF-κB signaling pathway, was also increased by GCRV infection. The overexpression of IL-17AF1, IL-17AF2, or IL-17AF3 also promoted the nuclear translocation of p65 and the levels of phospho-IκBα in CIK cells, and reduced the expression of the viral structural protein VP7. An NF-κB signal inhibitor abolished the inhibition of GCRV infection by IL-17 proteins. These results suggested that the NF-κB signaling pathway was activated by the overexpression of IL-17 proteins, resulting in the inhibition of viral infection. In conclusion, in this study, we demonstrated that IL-17AF1, IL-17AF2, and IL-17AF3 acted as immune cytokines, exerting an antiviral effect by activating the NF-κB signaling pathway.

Characterization and Functional Study on Octopus ocellatus Interleukin-17

Interleukin-17 (IL-17), a prototype member of IL-17 family, plays an important role in defending against extracellular pathogens as a pro-inflammatory cytokine. The function and distribution of IL-17 have been extensively studied in many vertebrates. However, few study has focused on the role of IL-17 in invertebrates, especially in mollusks. In this study, an IL-17 homolog was identified in Octopus ocellatus, which was designated as OoIL-17. The phylogenetic analysis showed that OoIL-17 is clustered well with other invertebrate IL-17, indicating it is highly similar with the IL-17 of other invertebrates. The expression of OoIL-17 gene was analyzed with qRT-PCR in a variety of healthy tissues and the hemocytes infected with Vibro anguillarum or Micrococcus luteus. The mRNA of OoIL-17 gene is constitutively expressed at different levels in all examined tissues of healthy O. ocellatus, including mantle, stomach, hemocytes, muscle, gonad, hepatopancreas, systemic heart and gill. The lowest expression was observed in mantle while the highest was observed in hepatopancreas. The expression level of OoIL-17 gene is significantly up-regulated in O. ocellatus hemocytes upon infection with V. anguillarum and M. luteus, indicating its active involvement in the host immune response against bacterial pathogens. The results laid the foundation for further understanding the innate immune mechanisms of IL-17 in O. ocellatus and mollusks.

Abstract CT210: A Phase I, open-label, multicenter, dose escalation study of mRNA-2752, a lipid nanoparticle encapsulating mRNAs encoding human OX40L, IL-23, and IL-36γ, for intratumoral injection alone and in combination with immune checkpoint blockade

Abstract Recent outcomes of immune therapies have created a paradigm shift in cancer treatment. Significant improvements in cancers with clear unmet need have been demonstrated most impacted by administration of check point inhibitor (CPI) antibodies but not all patients benefit. mRNA-2752 is a novel drug that encodes OX40L, IL-23, and IL-36γ. mRNA-2752 brings 2 approaches in 1 therapy: pro-inflammatory cytokines/chemokines to ignite and/or transform an inflammatory response within the tumor microenvironment (TME), and T-cell co-stimulators that could strengthen specific anti-cancer adaptive immune responses. Binding of OX40 by OX40L in the presence of a recognized antigen enhances the expansion of CD4+ and CD8+ T-cells, increases T-cell effector function, and enhances survival of experienced T-cells for increased memory capacity thus introduction of OX40L can serve to boost T-cell responses, and in the case of local therapies, may restrict responses to epitopes presented in the tumor microenvironment (TME). Additionally, it is hypothesized that the expression of pro-inflammatory cytokines within a tumor may ignite or transform an otherwise non-productive TME into a productive immune response. Interleukin-1 and IL-12 family members have been shown to work in concert with one another in immune responses to pathogens, as well as in mediating anti-cancer responses. IL-1 family member IL-36γ acts more as a classic alarmin and directly on antigen presenting cells. IL-12 family member IL-23 positively modulates various classes of cells that bridge innate and adaptive immunity, such as innate lymphoid cells, γδT-cells, and natural killer T-cells. Intratumoral (ITu) administered therapies for cancer, such as mRNA-2752, may result in systemic immune recognition of tumoral antigens, which as monotherapies can cause regression of multiple metastatic lesions. There can also be synergy with CPIs. Methods: The sponsor is conducting a Phase 1, open-label, multicenter, dose escalation study of ITu injections of mRNA-2752 alone and in combination with intravenously administered CPI using an mTPI design. The study consists of 3 dose escalation and dose confirmation parts on 3 treatment arms: mRNA-2752 monotherapy, mRNA-2752 in combination with Durvalumab, and mRNA-2752 in combination with Tremelimumab. This will be followed by dose expansion. The primary objective is to assess the safety and tolerability of mRNA-2752 administered alone and in combination with immune checkpoint blockade and to define the maximum tolerated dose and/or recommended dose for expansion as monotherapy and in combination with CPI. Key secondary objectives include assessing the anti-tumor activity of mRNA-2752 alone and in combination using RECIST v1.1/iRECIST with CPI, and the pharmacokinetics (PK). Mandatory paired tumor biopsies will be collected to assess modulation of relevant blood-borne and tumor biomarkers and potential correlation to the clinical outcomes. Eligibility criteria include pts > 18 years of age with histologically confirmed advanced or metastatic disease with at least 1 measurable lesion, ECOG ≤ 1, normal organ function and a tumor burden of sufficient size to support injection of mRNA-2752. The study is open and enrolling. NCT03739931. Citation Format: Todd Bauer, Manish Patel, Antonio Jimeno, Ding Wang, Jessica McDermott, Sima Zacharek, William Randolph, Lisa Johansen, Kristen Hopson, Joshua Frederick, Tal Zaks, Robert S. Meehan. A Phase I, open-label, multicenter, dose escalation study of mRNA-2752, a lipid nanoparticle encapsulating mRNAs encoding human OX40L, IL-23, and IL-36γ, for intratumoral injection alone and in combination with immune checkpoint blockade [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT210.

527 Uncovering molecular mechanisms involved in the IL-37-mediated tolerogenic dendritic cells

The past few years have witnessed a breakthrough in the development of tolerogenic dendritic cell (DC) based therapies for the treatment of autoimmune diseases and solid organ transplantation. The interleukin-1 family member IL-37 is a natural suppressor of innate inflammatory and immune responses. Using mice expressing human IL-37b isoform (IL-37tg), we have previously reported that IL-37 participates in peripheral tolerance through the generation of semi-mature tolerogenic DCs. However, the molecular mechanism(s) and/or regulatory molecule(s) involved in the IL-37-mediated tolerogenic DCs are yet to be identified. Similar to IL-1a and IL-33, IL-37 has a unique property as an intracrine cytokine, functioning both intracellularly and extracellularly. To investigate extracellular mechanisms, recombinant IL-37 and neutralizing antibody to IL-37 were used. Despite their effects on IL-1β secretion, neither recombinant IL-37 nor neutralizing antibody affected the ability of DCs to activate T cell proliferation or induce regulatory T cells, suggesting that extracellular IL-37 has limited effects on DC function. Next, to understand molecular pathways altered by IL-37 in DCs, RNAs from wild-type (WT) and IL-37tg DCs were subjected for Illumina microarray analysis. GeneGo pathway analysis identified a key transcription factor NF-κB and 3 pathways including IL-10, CD40, antigen presentation pathway and HMGB1 pathways. Several differentially expressed genes were identified and verified including CXCL1, IL-10 and others. miRNA array analysis using Nanostring miRNA array kit identified immunosuppressive miRNAs. Furthermore, THP-1 human cell line transfected with IL-37 expressed similar molecular profiles to IL-37 mouse DCs and exhibited lower ability to stimulate proliferation of allogeneic naïve T cells after differentiation into DCs. Together, these findings reveal an immunosuppressive molecular pathways of DCs expressing IL-37.

Durable anticancer immunity from intratumoral administration of IL-23, IL-36γ, and OX40L mRNAs.

Many solid cancers contain dysfunctional immune microenvironments. Immune system modulators that initiate responses to foreign pathogens could be promising candidates for reigniting productive responses toward tumors. Interleukin-1 (IL-1) and IL-12 cytokine family members cooperate at barrier tissues after microbial invasion, in human inflammatory diseases, and in antitumoral immunity. IL-36γ, in classic alarmin fashion, acts in damaged tissues, whereas IL-23 centrally coordinates immune responses to danger signals. In this study, direct intratumoral delivery of messenger RNAs (mRNAs) encoding these cytokines produced robust anticancer responses in a broad range of tumor microenvironments. The addition of mRNA encoding the T cell costimulator OX40L increased complete response rates in treated and untreated distal tumors compared to the cytokine mRNAs alone. Mice exhibiting complete responses were subsequently protected from tumor rechallenge. Treatments with these mRNA mixtures induced downstream cytokine and chemokine expression, and also activated multiple dendritic cell (DC) and T cell types. Consistent with this, efficacy was dependent on Batf3-dependent cross-presenting DCs and cytotoxic CD8+ T cells. IL-23/IL-36γ/OX40L triplet mRNA mixture triggered substantial immune cell recruitment into tumors, enabling effective tumor destruction irrespective of previous tumoral immune infiltrates. Last, combining triplet mRNA with checkpoint blockade led to efficacy in models otherwise resistant to systemic immune checkpoint inhibition. Human cell studies showed similar cytokine responses to the individual components of this mRNA mixture, suggesting translatability of immunomodulatory activity to human patients.

A folding switch regulates interleukin 27 biogenesis and secretion of its α-subunit as a cytokine

A common design principle of heteromeric signaling proteins is the use of shared subunits. This allows encoding of complex messages while maintaining evolutionary flexibility. How cells regulate and control assembly of such composite signaling proteins remains an important open question. An example of particular complexity and biological relevance is the interleukin 12 (IL-12) family. Four functionally distinct αβ heterodimers are assembled from only five subunits to regulate immune cell function and development. In addition, some subunits act as independent signaling molecules. Here we unveil key molecular mechanisms governing IL-27 biogenesis, an IL-12 family member that limits infections and autoimmunity. In mice, the IL-27α subunit is secreted as a cytokine, whereas in humans only heterodimeric IL-27 is present. Surprisingly, we find that differences in a single amino acid determine if IL-27α can be secreted autonomously, acting as a signaling molecule, or if it depends on heterodimerization for secretion. By combining computer simulations with biochemical experiments, we dissect the underlying structural determinants: a protein folding switch coupled to disulfide bond formation regulates chaperone-mediated retention versus secretion. Using these insights, we rationally change folding and assembly control for this protein. This provides the basis for a more human-like IL-27 system in mice and establishes a secretion-competent human IL-27α that signals on its own and can regulate immune cell function. Taken together, our data reveal a close link between protein folding and immunoregulation. Insights into the underlying mechanisms can be used to engineer immune modulators.

Regulation of Inflammasome by Autophagy.

Inflammasome is a molecular platform that mediates the activation of caspases, maturation of interleukin-1 (IL-1) family members, and leads to inflammatory cell death called pyroptosis. It is vital for innate immune responses, providing protection against infectious agents, sterile environmental insults, and host cell damages. Aberrant activation of inflammasome is closely correlated with numerous hereditary and acquired inflammatory disorders. Therefore, a better understanding of how inflammasome is regulated may provide more promising therapeutics for controlling inflammasome-associated diseases. In recent years, it becomes apparent that autophagy, a cellular machinery essential for the recycling of intracellular components and maintenance of cellular homeostasis, acts as a key player in the activation and regulation of inflammasome, and ameliorates symptoms of inflammasome-related diseases. This review will discuss the recent insights into inflammasome activation and regulation mediated by autophagy.

A Novel Eosinophilia Diagnostics Using Label‐free Impedimetric Aptasensor for Soluble Interleukin‐5 Receptor Alpha

AbstractRecently, interleukin‐5 receptor alpha (IL‐5RA) was reported to be a key surface molecule in the regulation of eosinophil proliferation. In this study, a highly sensitive aptamer for IL‐5RA was applied to an electrochemical biosensor. The rod‐shaped gold electrodes with circular gold surface were used. The aptasensor specifically detected membrane‐bound IL‐5RA on human eosinophils according to the number of the eosinophils. We further examined the usability of soluble IL‐5RA (sIL‐5RA) in the serum as a novel biomarker for the diagnosis of eosinophil‐related diseases. When eosinophilic inflammation occurs, the concentration of sIL‐5RA in the blood is highly elevated. To diagnose eosinophilic inflammation, the aptasensor was calibrated in phosphate‐buffered saline (PBS) to detect sIL‐5RA. The detection limit of the aptasensor in PBS was 1.69 pg/mL, which is lower than that of commercially available ELISA kits. The dynamic range of the aptasensor was 10–10,000 pg/mL, with high specificity over other serum proteins and interleukin family members. The aptasensor was capable of distinguishing between patients with eosinophilic asthma (EA) and normal controls (NCs) based on serum sIL‐5RA levels. Consequently, the fabricated aptasensor will contribute to the development of novel diagnostic systems for IL‐5RA‐related diseases.

Study the Effect of Interleukin36 Gamma and AMH in Iraqi Women with PCOS

Polycystic ovary syndrome (PCOS) is one of the most common female endocrine disorders and affect approximately (5-10) % of women of reproductive age. Anti-Müllerian hormone (AMH) is a homodimeric glycoprotein, a member of the transforming growth factor-β superfamily, it is secreted exclusively from women by granulose cells of ovarian follicles and it is considered as the precise marker of follicle pool size. AMH has been shown to be a good surrogate marker for polycystic ovary syndrome (PCOS). Interleukins are considered as strong risk markers of inflammation. Interleukin-36 gamma (IL36) also known as interleukin-1 family member 9 (IL1F9) is a protein that in humans is encoded by the IL36G gene. Serum samples were collected on day 2 of the menstrual cycle. Serum IL36ɣ, FSH and LH concentration were measured by using ELISA. This study aimed to evaluate the association between IL36ɣ and AMH and study the relationship between obesity and AMH of women in the age of reproductive (25-35) yrs. This study included 28 infertile women with PCOS their husbands were apparently normal (hormones and seminal fluid analysis), their aged (25-35) years, and 20 healthy women aged (25-33) years as control. All control women & patients were from outpatients unit of Alkadumia teaching hospital at Baghdad and all the parameters were measured in Sigma Laboratory. Serum IL-36 ɣ elevated in PCOS patients mainly those with high AMH levels. This hormone increased in PCOS patients compared with control. There was a non-significant difference between patients and control to LH and FSH levels.

Repetitive head injury in adolescent mice: A role for vascular inflammation

Repetitive mild traumatic brain injury during adolescence can induce neurological dysfunction through undefined mechanisms. Interleukin-1 (IL-1) contributes to experimental adult diffuse and contusion TBI models, and IL-1 antagonists have entered clinical trials for severe TBI in adults; however, no such data exist for adolescent TBI. We developed an adolescent mouse repetitive closed head injury (rCHI) model to test the role of IL-1 family members in post-injury neurological outcome. Compared to one CHI, three daily injuries (3HD) produced acute and chronic learning deficits and emergence of hyperactivity, without detectable gliosis, neurodegeneration, brain atrophy, and white matter loss at one year. Mature IL-1β and IL-18 were induced in brain endothelium in 3HD but not 1HD, three hit weekly, or sham animals. IL-1β processing was induced cell-autonomously in three-dimensional human endothelial cell cultures subjected to in vitro concussive trauma. Mice deficient in IL-1 receptor-1 or caspase-1 had improved post-injury Morris water maze performance. Repetitive mild CHI in adolescent mice may induce behavioral deficits in the absence of significant histopathology. The endothelium is a potential source of IL-1β and IL-18 in rCHI, and IL-1 family members may be therapeutic targets to reduce or prevent neurological dysfunction after repetitive mild TBI in adolescents.

TGF‐β suppresses inflammation through the repression of interleukin‐33 (IL‐33)

Transforming growth factor‐β1 (TGF‐β1) is a member of the TGF‐β superfamily of cytokines, which are involved in a wide variety of biological functions such as proliferation, differentiation, migration, and apoptosis. TGF‐β1 binds to a receptor complex and stimulates a set of signaling events leading to changes in gene expression and cell behavior. TGF‐β1 specifically has been shown to be a key player in wound repair and modulation of the immune response. Microarray analysis of normal mouse mammary epithelial cells (NMuMG) treated with TGF‐β1, indicated that the interleukin‐1 family member interleukin‐33 (IL‐33) is repressed by TGF‐β1. IL‐33 is passively released following tissue damage and functions as an alarmin, alerting the immune system to the presence of tissue damage. The goal of this study was to determine if TGF‐β1 decreased the amount of IL‐33 passively released by cells following tissue damage. We utilized previously established methods of inducing passive release of IL‐33 in cell culture. Pretreatment of cells with TGF‐β1 resulted in significantly lower levels of released IL‐33 following induction of tissue damage.These studies may identify a novel therapeutic target for treatment of diseases such as psoriasis, asthma and Crohn's disease. All of these diseases are associated with elevated levels of IL‐33 as well as altered TGF‐β responses. Further investigation of the immune cells affected by repression of IL‐33 could provide information into the specific mechanism of action.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Identification of an IL‐1‐induced gene expression pattern in AR+ PCa cells that mimics the molecular phenotype of AR− PCa cells

In immunosurveillance, bone-derived immune cells infiltrate the tumor and secrete inflammatory cytokines to destroy cancer cells. However, cancer cells have evolved mechanisms to usurp inflammatory cytokines to promote tumor progression. In particular, the inflammatory cytokine, interleukin-1 (IL-1), is elevated in prostate cancer (PCa) patient tissue and serum, and promotes PCa bone metastasis. IL-1 also represses androgen receptor (AR) accumulation and activity in PCa cells, yet the cells remain viable and tumorigenic; suggesting that IL-1 may also contribute to AR-targeted therapy resistance. Furthermore, IL-1 and AR protein levels negatively correlate in PCa tumor cells. Taken together, we hypothesize that IL-1 reprograms AR positive (AR+ ) PCa cells into AR negative (AR- ) PCa cells that co-opt IL-1 signaling to ensure AR-independent survival and tumor progression in the inflammatory tumor microenvironment. LNCaP and PC3 PCa cells were treated with IL-1β or HS-5 bone marrow stromal cell (BMSC) conditioned medium and analyzed by RNA sequencing and RT-QPCR. To verify genes identified by RNA sequencing, LNCaP, MDA-PCa-2b, PC3, and DU145 PCa cell lines were treated with the IL-1 family members, IL-1α or IL-1β, or exposed to HS-5 BMSC in the presence or absence of Interleukin-1 Receptor Antagonist (IL-1RA). Treated cells were analyzed by western blot and/or RT-QPCR. Comparative analysis of sequencing data from the AR+ LNCaP PCa cell line versus the AR- PC3 PCa cell line reveals an IL-1-conferred gene suite in LNCaP cells that is constitutive in PC3 cells. Bioinformatics analysis of the IL-1 regulated gene suite revealed that inflammatory and immune response pathways are primarily elicited; likely facilitating PCa cell survival and tumorigenicity in an inflammatory tumor microenvironment. Our data supports that IL-1 reprograms AR+ PCa cells to mimic AR- PCa gene expression patterns that favor AR-targeted treatment resistance and cell survival.

Overview of the IL-1 family in innate inflammation and acquired immunity.

The interleukin-1 (IL-1) family of cytokines and receptors is unique in immunology because the IL-1 family and Toll-like receptor (TLR) families share similar functions. More than any other cytokine family, the IL-1 family is primarily associated with innate immunity. More than 95% of living organisms use innate immune mechanisms for survival whereas less than 5% depend on T- and B-cell functions. Innate immunity is manifested by inflammation, which can function as a mechanism of host defense but when uncontrolled is detrimental to survival. Each member of the IL-1 receptor and TLR family contains the cytoplasmic Toll-IL-1-Receptor (TIR) domain. The 50 amino acid TIR domains are highly homologous with the Toll protein in Drosophila. The TIR domain is nearly the same and present in each TLR and each IL-1 receptor family. Whereas IL-1 family cytokine members trigger innate inflammation via IL-1 family of receptors, TLRs trigger inflammation via bacteria, microbial products, viruses, nucleic acids, and damage-associated molecular patterns (DAMPs). In fact, IL-1 family member IL-1a and IL-33 also function as DAMPs. Although the inflammatory properties of the IL-1 family dominate in innate immunity, IL-1 family member can play a role in acquired immunity. This overview is a condensed update of the IL-1 family of cytokines and receptors.

Autophagy limits activation of the inflammasomes.

Inflammasomes are multiprotein complexes that control the maturation and production of interleukin-1 family members and play crucial roles in host defense against pathogens. However, dysregulated activation of inflammasomes is associated with intense inflammation, leading to the development of inflammatory diseases. Therefore, inflammasomes must be activated at a proper strength to protect against infection and avoid tissue damage. Recent studies have highlighted the cross-talk between inflammasome activation and autophagy, the cellular machinery associated with the degradation of intracellular components and maintenance of cellular homeostasis. Notably, deficiencies in autophagy-related proteins induce the aberrant activation of inflammasomes, causing severe tissue damage. In contrast, autophagy inducers ameliorate symptoms of inflammasome-related diseases. In this review, we discuss recent advances in the involvement of autophagy in regulating inflammasomes activation and in the development of inflammatory diseases.

Epidermal cornification is preceded by the expression of a keratinocyte-specific set of pyroptosis-related genes

The homeostasis of the epidermis depends on keratinocyte differentiation and cornification, a mode of programmed cell death that does not elicit inflammation. Here, we report that cornification is associated with the expression of specific genes that control multiple steps of pyroptosis, another form of cell death that involves the processing and release of interleukin-1 family (IL1F) cytokines. Expression levels of pro-inflammatory IL1A and IL1B and of the pyroptotic pore-forming gasdermin (GSDM) D were downregulated during terminal differentiation of human keratinocytes in vitro. By contrast, negative regulators of IL-1 processing, including NLR family pyrin domain containing 10 (NLRP10) and pyrin domain-containing 1 (PYDC1), the anti-inflammatory IL1F members IL-37 (IL1F7) and IL-38 (IL1F10), and GSDMA, were strongly induced in differentiated keratinocytes. In human tissues, these keratinocyte differentiation-associated genes are expressed in the skin at higher levels than in any other organ, and mammalian species, that have lost the epidermal cornification program during evolution, i.e. whales and dolphins, lack homologs of these genes. Together, our results suggest that human epidermal cornification is accompanied by a tight control of pyroptosis and warrant further studies of potential defects in the balance between cornification and pyroptosis in skin pathologies.

111 Cornification of normal epidermal keratinocytes is preceded by the expression of specific interleukin-1 family members

The interleukin (IL)-1 family of cytokines includes IL-1α and IL-1β which are ubiquitous inducers of inflammation and other interleukins, that are expressed in a cell type-specific manner. Here, we investigated the expression of IL-1 family genes during terminal differentiation of normal human epidermal keratinocytes and the association of these genes with skin phenotypes during evolution. While IL1A and IL1B were downregulated, IL36 isoforms as well as IL37 and IL38 genes were strongly upregulated during differentiation of primary human keratinocytes. Western blot analysis showed that the anti-inflammatory cytokine IL-37 was highly abundant at the protein level in differentiated keratinocytes in vitro and in normal human epidermis where immunohistochemical staining revealed expression specifically in the granular layer. The IL36A, IL36B, IL37, and IL38 genes have been lost during the evolutionary degeneration of the epidermal cornification program in fully aquatic mammals. Our results suggest that the formation of a normal stratum corneum is associated with the expression of IL-1 family cytokines, including the anti-inflammatory protein IL-37.

Potential therapeutic use of IL-37: a key suppressor of innate immunity and allergic immune responses mediated by mast cells.

The host response to either exogenous or endogenous insults produces a series of changes, characterized by alterations in immunological functions and generation of mediators called cytokines which include the interleukin-1 (IL-1) family members. IL-1 acts as a hormone mediating the host responses to infection and inflammation. Blocking inflammatory IL-1 family members can be effective against inflammatory disorders, including allergies. IL-37, (formerly IL-1 family member 7), emerges as an inhibitor of innate and adaptive immunity by reducing circulating and organ cytokine levels. IL-37, mainly expressed in dendritic cells, monocytes, and plasma cells after TIR ligand activation, inhibits inflammatory cytokines and augments the level of anti-inflammatory IL-10. IL-37 is involved in allergic reaction and its expression in dendritic cells causes tollerogenicity and inhibits inflammatory response. Mast cells (MCs) are ubiquitous in the body, reside in numerous mucosal tissues, and are mediators of allergic reaction, and innate and adaptive immunity. MCs are important regulators of cytokine generation in the course of inflammatory responses and allergy, and are implicated in the pathophysiology of allergic asthma. Cysteine protease caspase-1 activation leads to the cleavage of pro-form of IL-1 into active mature IL-1 which is present in stimulated and unstimulated inflammatory MCs. Inflammatory cytokine inhibition, along with the augmentation of anti-inflammatory IL-10 by IL-37, is certainly beneficial and improves the pathogenesis of allergic disorders. However, in these studies, the exact mechanism(s) of IL-37-induced anti-inflammatory and anti-allergic activity along with its side effect(s) remain to be determined.

A link between osteomyelitis and IL1RN and IL1B polymorphisms—a study in patients from Northeast Brazil

Background and purpose — Treatment failure of osteomyelitis can result from genetic susceptibility, highlighting polymorphisms of the interleukin-1 (IL-1) family members, central mediators of innate immunity and inflammation. Polymorphisms are DNA sequence variations that are common in the population (1% or more) and represent multiple forms of a single gene. We investigated the association of IL1RNVNTR (rs2234663) and IL1B-511C > T (rs16944) polymorphisms with osteomyelitis development in patients operated on because of bone trauma.Patients and methods — 153 patients who fulfilled the inclusion criteria were enrolled from a referral public hospital for trauma. All the patients were followed up daily until hospital discharge and, after this, on an outpatient basis. Patients were treated with prophylactic antimicrobials and surgery according to traumatology service protocol. The IL1RNVNTR and the IL1B-511C > T polymorphisms were determined by PCR and PCR-RFLP, respectively.Results — The IL1RN*2/*2 genotype was associated (OR: 7; p < 0.001) with a higher risk of osteomyelitis and was also significantly associated with Staphylococcus aureus infection. The haplotypes (combination of different markers) *2-C and *2-T were also associated with osteomyelitis development.Interpretation — IL1B-511C > T and IL1RNVNTR polymorphisms were associated with osteomyelitis development, which may have implications for patients with bone traumas. These data may be relevant for new therapeutic strategies for this disease.

Abstract 2892: Oncostatin M elicits cellular plasticity through cooperative STAT3-SMAD3 signaling

Abstract Increasing evidence suggests that tumor cell plasticity promotes metastasis and tumor recurrence, resulting in cancer patient mortality. While it is clear that the tumor microenvironment (TME) contributes to tumor cell plasticity, the specific TME factors that actively generate tumor cell plasticity are largely unknown. Here, we identify TME cytokines that promote epithelial-mesenchymal plasticity, and acquisition of cancer stem-cell (CSC) properties. A screen of 27 TME cytokines identified multiple Interleukin-6 family members as inducers of mesenchymal/CSC properties, with Oncostatin M (OSM) being the most potent. Importantly, OSM induced plasticity was mediated by STAT3, but also dependent on TGF-β signaling and downstream SMAD3. Inhibition of functional TGF-β/SMAD signaling by expressing a dominant-negative TGF-β receptor, treating with a TGF-β receptor inhibitor, or suppressing SMAD3 expression using a SMAD3-shRNA prevented the OSM-induced mesenchymal/CSC properties. OSM-activated STAT3 binds to SMAD3 and promotes SMAD3 nuclear localization and binding to the SNAIL promoter, increasing transcription of the SNAIL gene. The epithelial-mesenchymal transition induced by the STAT3/SMAD3 axis results in a highly invasive and metastatic phenotype and the emergence of CSC properties, including therapeutic resistance. Importantly, maintenance of the OSM-induced mesenchymal/CSC state requires sustained exposure to the cytokine, as removal of OSM results in a marked phenotypic reversion. A high-throughput screen for small molecule inhibitors of the OSM-induced mesenchymal/CSC phenotype has been performed and are currently being confirmed. We propose that, targeted blockade of the STAT3/SMAD3 axis in tumor cells may represent a novel therapeutic approach to prevent the plasticity associated with metastasis and tumor recurrence. Citation Format: Benjamin L. Bryson, Damian J. Junk, Jacob Smigiel, Neetha Parameswaran, Mary R. Doherty, Courtney A. Bartel, Mark Jackson. Oncostatin M elicits cellular plasticity through cooperative STAT3-SMAD3 signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2892. doi:10.1158/1538-7445.AM2017-2892