IL-1 Family Research Articles

Identification of RP-54745, an IL-1 Inhibitor Displaying Anticancer Activities for KSHV-Related Primary Effusion Lymphoma.

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of several human cancers, including primary effusion lymphoma (PEL), usually seen in immunocompromised patients while lack of effective therapeutic options. Interleukin-1 (IL-1) family is a major mediator for inflammatory responses and has functional role in both innate and adaptive immunity. We previously showed high activation of multiple IL-1 signaling molecules during KSHV latent and lytic stages, as well as in clinical samples from patients with KSHV-related malignancies. In the current study, we identified RP-54745, a potential antirheumatic compound as IL-1 inhibitor, effectively repressed KSHV + PEL cell growth through inducing tumor cell apoptosis. By using an established PEL xenograft model, we found that RP-54745 treatment suppressed tumor expansion in mice. Also, RP-54745 treatment significantly reduced hyperinflammation in tumor microenvironment including myeloid cells and neutrophils infiltration, as well as blocking IL-1 signaling molecules expression in vivo. In addition, our transcriptome analysis revealed novel cellular genes and mechanisms for anticancer activities of RP-54745. Taken together, our data indicate targeting IL-1 production and signaling may represent promising therapeutic strategies against these virus-associated diseases.

The double-edged role of IL-18 in reproductive endocrine and reproductive immune related disorders.

Interleukin (IL)-18 is one of the members of IL-1 family cytokines, it was originally named as interferon gamma (IFN-γ) inducing factor. IL-18 is a pleiotropic immune regulator and has a bidirectional regulatory effect on immunity. It exerts a potent pro-inflammatory effect by inducing the expression of IFN-γ, also has an important anti-inflammatory role. In recent years, IL-18 has received widespread attention and become a research hotspot. Previous studies have described the roles of IL-18 in the pathogenesis of many diseases. However, the biologic activities of IL-18 and its role in the reproductive endocrine and reproductive immune related diseases are still not well understood, such as endometriosis (EMS), recurrent spontaneous abortion (RSA), polycystic ovary syndrome (PCOS), and infertility, which are closely related to inflammation and immunity. Here, we reviewed the research progress of IL-18 in these diseases in the past few years. This article provides an overview of the latest knowledge about the roles of IL-18 in these diseases, with a view to providing new possibilities for the diagnosis and treatment of reproductive endocrine and reproductive immune related disorders.

Stem-like memory and precursors of exhausted T cells share a common progenitor defined by ID3 expression.

Stem-like T cells are attractive immunotherapeutic targets in patients with cancer given their ability to proliferate and differentiate into effector progeny. Thus, identifying T cells with enhanced stemness and understanding their developmental requirements are of broad clinical and therapeutic interest. Here, we demonstrate that during acute infection, the transcriptional regulator inhibitor of DNA binding 3 (ID3) identifies stem-like T cells that are uniquely adapted to generate precursors of exhausted T (Tpex) cells in response to chronic infection or cancer. Expression of ID3 itself enables Tpex cells to sustain T cell responses in chronic infection or cancer, whereas loss of ID3 results in impaired maintenance of CD8 T cell immunity. Furthermore, we demonstrate that interleukin-1 (IL-1) family members, including IL-36β and IL-18, promote the generation of ID3+ T cells that mediate superior tumor control. Overall, we identify ID3 as a common denominator of stem-like T cells in both acute and chronic infections that is specifically required to sustain T cell responses to chronic stimulation.

Based on the immune system: the role of the IL-2 family in pancreatic disease

Based on the immune system: the role of the IL-2 family in pancreatic disease

Interleukin-24: A Versatile Regulator of Wound Healing.

The skin, as the body's largest organ, is crucial for maintaining homeostasis and providing protection, making it susceptible to wounds from various causes. Wound healing is a complex process involving numerous cellular activities. Any interruptions can lead to chronic, non-healing wounds, which present significant challenges in healthcare. Interleukin-24 (IL-24), a cytokine within the IL-10 family, has become recognized for its significant role in wound healing due to its diverse effects on cellular processes. IL-24 can inhibit keratinocyte migration, potentially leading to chronic wounds, and promote endothelial cell migration and angiogenesis, which are vital for tissue repair. This dual role highlights IL-24's intricate involvement in wound healing, as it can hinder and aid different aspects of the process. Research indicates that IL-24 expression increases in response to inflammatory mediators and is involved in various immune responses, emphasizing its regulatory function. Further research on IL-24's mechanisms and interactions is essential for developing new therapeutic strategies to enhance tissue regeneration and treat chronic wounds and skin disorders. A deeper understanding of IL-24's functions could transform wound care, providing new approaches for effectively managing and treating conditions involving impaired healing.

IL-1R1 and IL-18 Signals Regulate Mesenchymal Stromal Cells in an Aged Murine Model of Myelodysplastic Syndromes.

Myelodysplastic syndromes (MDS) are age-related diseases characterized by bone marrow (BM) dysfunction and an increased risk of developing acute leukemia. While there is growing evidence highlighting the crucial role of the BM microenvironment (BMME) in MDS, the specific influence of inflammation on BMME changes, as well as the potential benefits of targeting cytokines therapeutically, remain to be elucidated. We previously found interleukin-1 (IL-1) to be a driver of aging phenotypes of BMME and hematopoietic stem and progenitor cells (HSPCs). In the current study, BM samples from patients with MDS demonstrated upregulated levels of IL-1 family cytokines including IL-18. Utilizing highly purified primary BM-derived mesenchymal stromal cells (MSCs), both interleukin-1b (IL-1b) and IL-18 were found to exert direct effects on MSCs, thus influencing their ability to support HSPCs as well as erythroid progenitors. This confirms the significant involvement of both these IL-1 family cytokines in regulating the BM niche. Furthermore, targeting IL-1 receptor type I (IL-1R1) mitigated these aging phenotypes in elderly mice. We subsequently employed an age-appropriate murine model of MDS by transplanting NUP98-HOXD13 transgenic mice (NHD13Tg) cells into aged wild-type mice. Treatment with inhibitors targeting interleukin-1 receptor-associated kinase 4 (IRAK4) and NLR family pyrin domain containing 3 (NLRP3) reversed the proliferation of dysfunctional MSCs and enhanced their functionality. Additionally, IRAK4 inhibition selectively suppressed MDS clonal cells while sparing non-MDS cells in the BM. These findings suggest that targeting IL-1 signaling holds promise for MDS treatment by addressing the underlying myeloid malignancy and restoring the altered BMME via BM-MSCs.

The role of interleukin-17 in inflammation-related cancers.

Emerging evidence indicates a correlation between inflammation and the development and progression of cancer. Among the various inflammatory signals, interleukin-17 (IL-17) family cytokines serve as a critical link between inflammation and cancer. IL-17 is a highly versatile pro-inflammatory cytokine that plays a pivotal role in host defense, tissue repair, the pathogenesis of inflammatory diseases, and cancer progression. During the early stages of tumorigenesis, IL-17 signaling directly promotes the proliferation of tumor cells. Conversely, IL-17 has been shown to exhibit antitumor immunity in several models of grafted subcutaneous tumors. Additionally, dynamic changes in the microbiome can influence the secretion of IL-17, thereby affecting tumor development. The specific role of IL-17 is contingent upon its functional classification, spatiotemporal characteristics, and the stage of tumor development. In this review, we introduce the fundamental biology of IL-17 and the expression profile of its receptors in cancer, while also reviewing and discussing recent advancements regarding the pleiotropic effects and mechanisms of IL-17 in inflammation-related cancers. Furthermore, we supplement our discussion with insights into the mechanisms by which IL-17 impacts cancer progression through interactions with the microbiota, and we explore the implications of IL-17 in cancer therapy. This comprehensive analysis aims to enhance our understanding of IL-17 and its potential role in cancer treatment.

Exploring the Involvement of New Members of the Interleukin Family in Cardiovascular Disease.

Cardiovascular diseases remain a significant reason for illness and death globally. Although certain interleukins have been extensively researched about cardiovascular disease (CVD), new findings have identified unique members of the interleukin family that could potentially play a role in cardiovascular well-being and ailments. This review discusses the current understanding of the role of these recently identified interleukins, such as IL-27, IL-31, IL-32, IL-33, and the IL-28 group (IL-28A, IL-28B, IL-29), in the development of cardiovascular diseases. Every interleukin has various impacts achieved through particular receptors and signaling pathways that affect inflammatory processes, differentiation of immune cells, and the functioning of blood vessels. IL-27 controls the development of inflammatory Th17 cells and might decrease inflammation in atherosclerosis. IL-31 plays a role in the interaction between the immune system and nerves, as well as in itching. IL-32 enhances the generation of inflammatory proteins and has been linked to coronary artery disease. IL-33 has beneficial effects on the cardiovascular system, whereas its imitation receptor sST2 could potentially be used as a biomarker. Additional studies are needed to investigate the antiviral and immune-system regulating effects of the IL-28 group in cardiovascular diseases. In general, explaining the ways in which new interleukins contribute to the progression of cardiovascular diseases can help discover fresh targets for therapy and new approaches toward enhancing the prevention and treatment of heart disorders. Additional research on the way these cytokines engage with established disease pathways is necessary.

The Cell-Specific Effects of JAK1 Inhibitors in Ulcerative Colitis.

JAK1 inhibitors have become an important addition to the therapeutic options for ulcerative colitis (UC), targeting key inflammatory pathways mediated by cytokines such as the IL-6 family, interferons, IL-2 family, IL-10 family, and G-CSF. However, not all patients respond equally, and chronic inflammation persists in a subset of individuals. The variability in treatment response may reflect the heterogeneity of UC. Immune cells, epithelial cells, and stromal cells may have distinct contributions to disease pathogenesis. While JAK inhibitors were originally designed to target immune cells, their impact on non-immune cell types, such as epithelial and stromal cells, remains poorly understood. Investigating the mechanisms through which JAK1 inhibitors affect these diverse cellular populations and identifying the factors underlying differential responses is crucial to optimizing outcomes. This review explores the roles of immune, epithelial, and stromal cells in response to JAK1 inhibition and discusses potential strategies to improve treatment precision, such as predicting responders and identifying complementary therapeutic targets.

IL-17 family members exert an autocrine pro-inflammatory loop in CF respiratory epithelial cells ex vivo.

Lungs of people with Cystic Fibrosis (pwCF) are characterized by chronic inflammation and infection with P. aeruginosa. High levels of IL-17A and F have been observed in sputum of pwCF and the interleukin-17(IL-17) family (A-to-F) has been suggested to play a key role in CF pulmonary disease. We measured mRNA levels of IL-17 receptors (IL-17R) by RT-qPCR in CF bronchial epithelial (CFBE) cultured cells upon infection with P. aeruginosa PAO1 strain or clinical exoproducts (EXO) isolated from pwCF. We measured IL-17 mRNA expression by RT-qPCR and the release of cytokines by ELISA and Bioplex from CF primary nasal epithelial (HNE) cultured cells. Infection of CFBE cells with PAO1 or EXO isolated from 15 pwCF significantly increased mRNA expression of all IL-17R, except IL-17RD. Infection of HNE cells with EXO isolated from the correspondent donor significantly increased the mRNA levels of all the IL-17 cytokines and receptors, except for IL-17D and IL-17RD, and the release of the cytokines IL-17A, IL-17B, IL-17C, IL-17E and IL-17F. HNE exposed to IL-17A and F were induced to release pro-inflammatory cytokines (IL-1β, IL-6, TNF-α), neutrophil chemokines (IL-8, G-CSF) and cytokines known to be involved in chloride and bicarbonate secretion, together with mucin upregulation (IL-4, IL-13). These results highlight a wider expression of IL-17 family member in respiratory epithelial cells, which can play a role as an autocrine inflammatory amplification loop in CF airways. These in-vitro studies using patient-derived cultures underline the relevant role of IL-17 family members in CF pulmonary immune response.

Relationship between CTF1 gene expression and prognosis and tumor immune microenvironment in glioma

ObjectiveThis study aimed to evaluate CTF1 expression in glioma, its relationship to patient prognosis and the tumor immune microenvironment, and effects on glioma phenotypes to identify a new therapeutic target for treating glioma precisely.MethodsWe initially assessed the expression of CTF1, a member of the IL-6 family, in glioma, using bioinformatics tools and publicly available databases. Furthermore, we examined the correlation between CTF1 expression and tumor prognosis, DNA methylation patterns, m6A-related genes, potential biological functions, the immune microenvironment, and genes associated with immune checkpoints. We also explored potential associations with drug sensitivity. To assess the impact on glioma cell proliferation and apoptosis, we employed various assays, including the Cell Counting Kit-8, colony formation assay, and flow cytometry.ResultsCTF1 gene and protein expression were significantly elevated in glioma tissues, and correlated with malignancy and poor prognosis. CTF1 was an independent prognostic factor and negatively associated with DNA methylation. The involvement of CTF1 in m6A modifications contributed to glioma progression. Enrichment analysis revealed immune response pathways linked with CTF1 in glioma, including natural killer cell cytotoxicity, NOD-like receptor signaling, Toll-like receptor signaling, antigen processing, chemokine signaling, and cytokine receptor interactions. CTF1 expression correlated positively with pathways related to apoptosis, inflammation, proliferation, and epithelial–mesenchymal transition, and PI3K–AKT–mTOR signaling. Additionally, CTF1 expression was positively associated with macrophage, eosinophil, and neutrophil contents and immune checkpoint-related genes, but negatively associated with sensitivity to 14 drugs. In vitro experiments confirmed that CTF1 knockdown inhibited glioma cell proliferation and promoted apoptosis.ConclusionThis study identifies CTF1 as a significant independent prognostic factor that is closely associated with the tumor immune microenvironment in glioma. Additionally, reduced expression of CTF1 suppresses the proliferation and induces apoptosis of glioma cells in vitro. Consequently, CTF1 is a potentially promising novel therapeutic target for glioma treatment.

The Ability of SOCS1 to Cross-Regulate GM-CSF Signaling is Dose Dependent.

Suppressor of cytokine signaling (SOCS) 1 is a key negative regulator of interferon (IFN), interleukin (IL)12, and IL-2 family cytokine signaling through inhibition of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway. To investigate the temporal induction of SOCS1 in response to cytokine in live cells and its selective regulation of signaling pathways, we generated a mouse expressing a Halo-tag-SOCS1 fusion protein (Halo-SOCS1) under control of the endogenous Socs1 promoter. Homozygous Halo-SOCS1 mice (Halo-Socs1KI/KI) were viable with minor T cell abnormalities, most likely due to enhanced Halo-SOCS1 expression in thymocytes compared with the untagged protein. IFNγ and IL-4 induced Halo-SOCS1 expression in macrophages derived from Halo-Socs1KI/KI mice, and a critical level of SOCS1 expression was required for inhibition of both IFNγ and granulocyte macrophage-colony stimulating factor (GM-CSF)-driven JAK-STAT signaling. In contrast, IFNγ priming to induce SOCS1 did not cross-regulate IL-4 signaling. This study indicates that while SOCS1 expression needs to exceed a critical threshold to inhibit IFNγ signaling, its selective regulation of cytokine signaling results from an as yet undetermined, level of regulatory control.

Unveiling and validating biomarkers related to the IL-10 family in chronic sinusitis with nasal polyps: insights from transcriptomics and single-cell RNA sequencing analysis.

Extensive efforts have been made to explore members of the IL-10 family as potential therapeutic strategies for various diseases; however, their biological role in chronic rhinosinusitis with nasal polyps (CRSwNP) remains underexplored. Gene expression datasets GSE136825, GSE179265, and GSE196169 were retrieved from the Gene Expression Omnibus (GEO) for analysis. Candidate genes were identified by intersecting differentially expressed genes (DEGs) between the CRSwNP and control groups (DEGsall) with those between the high- and low-score groups within the CRSwNP cohort (DEGsNP). Biomarker selection was performed using the Least Absolute Shrinkage and Selection Operator (LASSO), Support Vector Machine Recursive Feature Elimination (SVM-RFE), and the Boruta algorithm. Further refinement of biomarkers was carried out using receiver operating characteristic (ROC) analysis, with genes demonstrating an area under the curve (AUC) greater than 0.7 being considered significant. Genes exhibiting consistent expression trends and significant differences across both GSE136825 and GSE179265 were selected as potential biomarkers. Cell-type annotation was performed on GSE196169, and the expression profiles of the biomarkers across various cell types were analyzed. A competing endogenous RNA (ceRNA) network and a biomarker-drug interaction network were also established. Additionally, the mRNALocater database was utilized to determine the cellular localization of the identified biomarkers. The intersection of 1817 DEGsall and 24 DEGsNP yielded 15 candidate genes. Further filtering through LASSO, SVM-RFE, and Boruta led to the identification of seven candidate biomarkers: PRB3, KRT16, MUC6, SPAG4, FGFBP1, NR4A1, and GSTA2. Six of these genes demonstrated strong diagnostic performance in GSE179265, while four biomarkers, showing both significant differences and consistent expression trends, were validated in both GSE179265 and GSE136825. Single-cell sequencing analysis of GSE196169 revealed seven distinct cell types, including endothelial cells, with the biomarkers predominantly expressed in epithelial cells. The ceRNA network comprised nine nodes and eleven edges, with only FGFBP1 exhibiting a complete lncRNA-miRNA-mRNA interaction. This study identifies several novel biomarkers and their associated drugs for CRSwNP therapy, as well as potential therapeutic targets, such as spiperone and arnenous acid, identified through molecular docking. Ultimately, this work underscores the identification of four IL-10 family-related biomarkers, providing a theoretical foundation for future clinical research in CRSwNP.

Destructive and protective effects and therapeutic targets of IL-36 family cytokines in dry eye disease.

To explore the destructive and protective effects and therapeutic targets of IL-36 cytokines in dry eye disease using a murine dry eye model. A dry eye model was established in C57BL/6 mice exposed to desiccating stress (DS) with untreated mice as controls. A topical challenge model was performed in normal mice with exogenous rmIL-36α, rhIL-38 and 2% ectoine, or PBS vehicle. IL-36 cytokine expression was assessed by RT-qPCR and immunofluorescent (IF) staining. Corneal epithelial damage was evaluated by corneal smoothness score, Oregon Green Dextran (OGD) fluorescent staining, and tight junction barrier. All members of the IL-36 family were expressed by murine ocular surface epithelium. The expression of IL-36α and IL-36γ was upregulated while IL-38 and IL-36RN were down regulated in ocular surface of dry eye mice. A topical challenge of rmIL-36α directly destructed corneal surface with distorted smoothness, increased OGD uptake and IF intensity, and disrupted tight junction proteins ZO-1 and occludin. Co-application with rhIL-38 prevented all these corneal damages by rmIL-36α. Ectoine treatment reversed the pathological expression pattern of IL-36 cytokines, protected corneal epithelium from defects, and restored the tight junction barrier in DS mice, and even prevented corneal damage by rmIL-36α. Our findings demonstrate the upregulated pro-inflammatory agonists IL-36α and IL-36γ with downregulated antagonists IL-38 and IL-36RA in dry eye model, which provides a previously unknown mechanism and therapeutic targets in dry eye disease. The therapeutic efficacy of ectoine may be through reversing the pathological alteration of IL-36 cytokines in dry eye mice.

Dissolving microneedle synergistic rocaglamide-loaded liposome to regulate abnormal neutrophils for anti-psoriasis.

Psoriasis seriously affects the physical and mental health of patients. Rocaglamide (RocA), derived from Aglaia odorata, exhibits potent pharmacological activities. Although its efficacy in psoriasis is unclear, RocA could be a promising therapeutic drug. In this work, RocA showed a good therapeutic effect in psoriasis mice induced by imiquimod, and subsequent TMT-based proteomics analysis verified that the effect of RocA was related to IL-1 family cytokines. Furthermore, a RocA-loaded liposome (RocA@Lipo) was developed and encapsulated in the tip-layer of microneedles (MNs) to construct a MN-based nano drug delivery system (RocA@Lipo-MNs). In vitro HaCaT cell assays demonstrated that RocA@Lipo enhanced the cytotoxicity and cell uptake of RocA. In vivo, RocA@Lipo-MNs outperformed other RocA formulations in inhibiting psoriasis epidermal thickening and spleen enlargement. Immunohistochemical, ELISA, western blot, and PCR experiments further proved that RocA@Lipo-MNs could inhibit neutrophil infiltration in the skin, revealing that the anti-psoriasis mechanism of RocA was deemed to inhibit the binding of IL-1α and IL-1R1 to regulate the activation of MAPK and NF-κB pathways. Thus, the production of inflammatory factors and neutrophil chemokines was reduced, which was associated with apoptosis inhibition. Importantly, RocA@Lipo-MNs significantly improved the transdermal properties of RocA and exhibited good skin and blood safety. This work provides new ideas for the clinical application of RocA and the treatment options for psoriasis.

Targeting the Interleukin 23 Pathway in Inflammatory Bowel Disease.

Interleukin (IL) 23, a member of the IL12 family of cytokines, maintains intestinal homeostasis, but is also implicated in the pathogenesis of inflammatory bowel diseases (IBDs). IL23 is a heterodimer composed of disulfide-linked p19 and p40 subunits. Humanized monoclonal antibodies selectively targeting the p19 subunit of IL23 are poised to become prominent drugs in IBDs. In this review, we discuss the pharmacodynamic and pharmacokinetic properties of the currently available IL23p19 inhibitors and discuss the mechanistic underpinnings of their therapeutic effects, including the mechanism of action, epitope affinity, potency, and downstream signaling. Furthermore, we address available data on the efficacy, safety, and tolerability of IL23p19 inhibitors in the treatment of IBDs and discuss important studies performed in other immune-mediated inflammatory diseases. Finally, we evaluate the potential for combining classes of biological therapies and provide future directions on the development of precision medicine-guided positioning of IL23p19 inhibitors in IBD.

Significance Of Gene Polymorphisms In Joint Destruction In Reactive Arthritis

in patients with reactive arthritis (ReA), cytokines produced by Th17 cells, one of them IL17, affect cell differentiation, recruitment, activation of immune cells, and release of antimicrobial peptides. Among the cytokines of the IL-17 family, it is IL-17A that is of decisive importance in the induction of pathological bone resorption through direct activation of osteoclast precursors during the formation of the articular syndrome The aim of our work was to study the distribution of allele and genotype frequencies of the polymorphic region G197A (rs2275913) of the IL-17A gene in patients with ReA. As a result of the study, there were no significant differences in the distribution of alleles of the G197A polymorphism of the IL-17A gene in patients with ReA and apparently healthy people. But when comparing genotypic variants, we revealed differences: healthy GG and mutant AA genotypes were more common in patients, while the heterozygous GA genotype was more common in healthy people

Immune changes in pregnancy: associations with pre-existing conditions and obstetrical complications at the 20th gestational week—a prospective cohort study

BackgroundPregnancy is a complex biological process and serious complications can arise when the delicate balance between the maternal and semi-allogeneic fetal immune systems is disrupted or challenged. Gestational diabetes mellitus (GDM), pre-eclampsia, preterm birth, and low birth weight pose serious threats to maternal and fetal health. Identification of early biomarkers through an in-depth understanding of molecular mechanisms is critical for early intervention.MethodsWe analyzed the associations between 47 proteins involved in inflammation, chemotaxis, angiogenesis, and immune system regulation, maternal and neonatal health outcomes, and the baseline characteristics and pre-existing conditions of the mother in a prospective cohort of 1049 pregnant women around the 20th gestational week. We used Bayesian linear regression models to examine the impact of risk factors on biomarker levels and Bayesian cause-specific parametric proportional hazards models to analyze the effect of biomarkers on maternal and neonatal outcomes. We evaluated the predictive value of baseline characteristics and 47 proteins using machine-learning models and identified the most predictive biomarkers using Shapley additive explanation scores.ResultsAssociations were identified between specific inflammatory markers and several conditions, including maternal age and pre-pregnancy body mass index, chronic diseases, complications from prior pregnancies, and COVID-19 exposure. Smoking during pregnancy affected GM-CSF and 9 other biomarkers. Distinct biomarker patterns were observed for different ethnicities. Within obstetric complications, IL-6 inversely correlated with pre-eclampsia risk, while birth weight to gestational age ratio was linked to markers including VEGF and PlGF. GDM was associated with IL-1RA, IL-17D, and eotaxin-3. Severe postpartum hemorrhage correlated with CRP, IL-13, and proteins of the IL-17 family. Predictive modeling yielded area under the receiver operating characteristic curve values of 0.708 and 0.672 for GDM and pre-eclampsia, respectively. Significant predictive biomarkers for GDM included IL-1RA and eotaxin-3, while pre-eclampsia prediction yielded the highest predictions when including MIP-1β, IL-1RA, and IL-12p70.ConclusionsOur study provides novel insights into the interplay between preexisting conditions and immune dysregulation in pregnancy. These findings contribute to our understanding of the pathophysiology of obstetric complications and the identification of novel biomarkers for early intervention(s) to improve maternal and fetal health.

More and more pleiotropy within the IL-6 family of cytokines.

Historically, cytokines belonging to the gp130 family bind to specific ligand-binding receptors that stimulate cell signaling through a receptor complex comprising gp130 or gp130 together with another structurally related signaling receptor. However, recent findings increasingly dispel these stereotypes and suggest that the receptor specificity of gp130-activating cytokines is less strict than originally assumed. Weitz etal. now provide the latest example of this pleiotropy and report that human interleukin-6 can bind and stimulate signaling via the interleukin-11 receptor. Possible biological and therapeutic consequences of these findings are discussed.

Analysis of kallikrein-related peptidase 7 (KLK7) autolysis reveals novel protease and cytokine substrates.

Kallikrein-related peptidase 7 (KLK7) is one of 15 members of the tissue kallikrein family and is primarily expressed in the skin epidermis. The activity of KLK7 is tightly regulated by multiple stages of maturation and reversible inhibition, similar to several other extracellular proteases. In this work, we used protease-specific inhibitors and active sitevariants to show that KLK7 undergoes autolysis at two separate sites in the 170 and 99 loops (chymotrypsinogen numbering), resulting in a loss of enzymatic activity. A protein BLAST search using the autolyzed KLK7 loop sequences identified mast cell chymase as a potential KLK7 substrate. Indeed, KLK7 cleaves chymase resulting in a concomitant loss of activity. We further demonstrate that KLK7 can hydrolyze other mast cell proteases as well as several cytokines. These cytokines belong mainly to the interferon and IL-10 families including IFN-α, IFN-β, IFN-γ, IL-28A/IFN-λ2, IL-20, IL-22, and IL-27. This is the first study to identify a possible molecular interaction link between KLK7 and mast cell proteases and cytokines. Although the precise biological implications of these findings are unclear, this study extends our understanding of the delicate balance of proteolytic regulation of enzyme activity that maintains physiological homeostasis, and facilitates further biological investigations.