Human IL-2 Research Articles

EF24, a Curcumin Analog, Reverses Interleukin-18-Induced miR-30a or miR-342-Dependent TRAF3IP2 Expression, RECK Suppression, and the Proinflammatory Phenotype of Human Aortic Smooth Muscle Cells.

Curcumin, a polyphenolic compound derived from the widely used spice Curcuma longa, has shown anti-atherosclerotic effects in animal models and cultured vascular cells. Inflammation is a major contributor to atherosclerosis development and progression. We previously reported that the induction of the proinflammatory molecule TRAF3IP2 (TRAF3 Interacting Protein 2) or inhibition of the matrix metallopeptidase (MMP) regulator RECK (REversion Inducing Cysteine Rich Protein with Kazal Motifs) contributes to pro-oxidant, proinflammatory, pro-mitogenic and pro-migratory effects in response to external stimuli in vascular smooth muscle cells. Here we hypothesized that EF24, a curcumin analog with a better bioavailability and bioactivity profile, reverses interleukin (IL)-18-induced TRAF3IP2 induction, RECK suppression and the proinflammatory phenotype of primary human aortic smooth muscle cells (ASMC). The exposure of ASMC to functionally active recombinant human IL-18 (10 ng/mL) upregulated TRAF3IP2 mRNA and protein expression, but markedly suppressed RECK in a time-dependent manner. Further investigations revealed that IL-18 inhibited both miR-30a and miR-342 in a p38 MAPK- and JNK-dependent manner, and while miR-30a mimic blunted IL-18-induced TRAF3IP2 expression, miR-342 mimic restored RECK expression. Further, IL-18 induced ASMC migration, proliferation and proinflammatory phenotype switching, and these effects were attenuated by TRAF3IP2 silencing, and the forced expression of RECK or EF24. Together, these results suggest that the curcumin analog EF24, either alone or as an adjunctive therapy, has the potential to delay the development and progression of atherosclerosis and other vascular inflammatory and proliferative diseases by differentially regulating TRAF3IP2 and RECK expression in ASMC.

Efficacy of human interleukin-11 analogs for treating dengue fever-associated thrombocytopenia: a prospective cohort

AimDengue fever (DF), carried by Aedes mosquitoes, affects millions worldwide. Platelet-inducing human IL-11 analogues may be effective in treating DF-associated thrombocytopenia.MethodologyA prospective study was done at Dr. Ziauddin Hospital, a tertiary care hospital in Karachi, Pakistan, from September 2023 to April 30, 2024.ResultsThis study recruited 300 DF patients characterized by thrombocytopenia (platelet count < 30,000), including 159 in the treatment and 141 in the control group. The median age of patients was 34 ± 11.05 years, with 187 males (62.3%) and 113 females (37.7%). The treatment group had a higher proportion of fever (80%, p < 0.0001) and headache (96%, p = 0.012) compared to the control group; however, no significant changes were observed in other clinical parameters between the two groups. Following treatment for 5 days, platelet counts of the treatment group increased significantly in response to IL-11 treatment compared to the control group at all time intervals (day 0, day 1, day 2, day 3, day 4, and day 5). Following treatment, males consistently exhibited higher platelet counts than females (all p < 0.05). In addition, patients admitted on day 3 of their course of illness showed a significantly slow response to the treatment compared to those admitted on day 5. Although young individuals exhibited a significant increase in platelet count, the age showed no significant intergroup differences.ConclusionsIL-11 analogs have promising potential for treating DF-associated thrombocytopenia. Additional investigation is necessary to refine administration protocols and examine the wider therapeutic ramifications of IL-11 in managing DF.

Post-marketing safety of tralokinumab: a real-world pharmacovigilance study based on the FDA adverse event reporting system

ABSTRACT Background Tralokinumab is a fully human IgG4 monoclonal antibody targeting IL-13, used for treating atopic dermatitis. This study analyzed tralokinumab-related adverse drug events by mining the Food and Drug Administration Adverse Event Reporting System (FAERS) database to provide a safety reference for clinical application. Methods Adverse drug event reports from Q1 2022 to Q2 2024 were extracted from the FAERS database. After standardizing the data, various signal detection methods were used for analysis, including ROR, PRR, BCPNN, and MGPS. Results A total of 1,820 reports of adverse events (AEs) with tralokinumab as the primary suspected drug were identified. 70 preferred terms (PTs) met the criteria across four signal detection methods, involving 11 system organ classes (SOCs). These included known adverse reactions like conjunctivitis and injection site reactions, and signals not previously reported in clinical trials, such as eye pruritus, dry eye, eye swelling, pneumonia pneumococcal, and cutaneous T-cell lymphoma. Most AEs occurred within one month of initiating tralokinumab treatment. Conclusions Based on the FAERS database, this study comprehensively and systematically analyzed AE signals in tralokinumab treatment. The results enhance the understanding of tralokinumab’s safety and serve as valuable references for reducing the risk of adverse reactions during clinical use.

Genetic Polymorphism in the Human IL-10 and Human IL-28 B with Increased Risk of Hepatitis B Virus Infection

Genetic Polymorphism in the Human IL-10 and Human IL-28 B with Increased Risk of Hepatitis B Virus Infection

Chrysin Enhances Anti-Cancer Activity of Jurkat T Cell and NK-92 Cells Against Human Breast Cancer Cell Lines.

Chrysin, a naturally occurring flavonoid in plant and bee products, demonstrates notable biological activities, including anti-cancer effects. These properties are partially attributed to its capability to activate immune cells. This study focused on exploring the immunomodulatory potential of chrysin on NK-92 and Jurkat-T cells targeting breast cancer cells (BCC). Chrysin leads to activation of NK-92 and T cells facilitated by the addition of human recombinant IL-2 and PHA-M. The anti-cancer efficacy of chrysin on these immune cells was evaluated in a co-culture setup with EGF-stimulated MCF-7 and MDA-MB-231 cells. Findings revealed that chrysin notably increased the cytotoxicity of NK-92 and T cells towards MCF-7 and MDA-MB-231 cells, with the most significant impact observed on MCF-7 cells (20 %). The activation of NK-92 cells, marked by increased IFN-γ production and CD56 expression, correlated with enhanced secretion of cytokines. Additionally, the activation of these cells against BCC was linked with elevated levels of granzyme-B, TNF-α, and nitric oxide (NO). Similarly, the cytotoxic activation of Jurkat-T cells against BCC was characterized by increased production of granzyme-B, IL-2, and IFN-γ. Consequently, these results support the hypothesis that chrysin significantly contributes to the activation and functional enhancement of NK-92 and T-cells against two distinct BCC lines.

Ex vivo-generated human CD1c+ regulatory B cells by a chemically defined system suppress immune responses and alleviate graft-versus-host disease

IL-10+ regulatory B cells (Bregs) show great promise in treating graft versus host disease (GVHD), a life-threatening complication of post-hematopoietic stem cell transplantation. However, obtaining high-quality human IL-10+ Bregs in vitro remains a challenge due to the lack of unique specific marker and the triggering of pro-inflammatory cytokines expression. Here, by uncovering the critical signaling pathways in Bregs induction by mesenchymal stromal cells (MSCs), we firstly established an efficient Bregs induction system based on MSCs and GSK-3β blockage (CHIR-99021), which had a robust capacity to induce IL-10+ Bregs while suppress TNF-α expression. Furthermore, these Bregs population could be identified and enriched by CD1c+. Mechanistically, MSCs induced the expansion of Bregs through the PKA-mediated phosphorylation of cAMP response element binding protein (CREB). Thus, we developed a chemical-defined inducing protocol by PKA-CREB agonist, instead of MSCs, which can also effectively induce CD1c+ Bregs with lower TNF-α expression. Importantly, induced CD1c+ Bregs suppressed the proliferation of PBMC and the inflammatory cytokines secretion of T cells. When adoptive transferred to a humanized mouse model of GVHD, induced CD1c+ Bregs effectively alleviated GVHD. Overall, we establish an efficient ex vivo induction system for human Bregs, which has implications in developing novel Bregs-based therapies for GVHD.

Pharmacological inhibition reveals participation of the endocytic compartment in positive feedback IL-6 secretion in human skeletal myotubes

IL-6 is an important cytokine involved in metabolic, immunological, and cell-fate responses. It is released upon stimulation by skeletal muscle cells through partially characterized mechanisms. In some cell types, IL-6 has been reported to activate a positive feedback loop involving endocytic vesicles, but evidence is mostly based on transcription and signal transduction mechanisms and is very scarce in muscle cells. Our aim was to directly demonstrate the presence of positive feedback in the ATP-induced release of IL-6 into the supernatant of human skeletal muscle cultures. The total release (production) of IL-6 was reduced for higher volumes of supernatant, when the secreted IL-6 molecules are more diluted, and enhanced when the supernatant volume was lower. In addition, secretion was impaired both by tocilizumab, a blocker of human IL-6 receptors, and by the soluble form of the receptor. The secretion in response to ATP was also inhibited by treatment with the endocytosis inhibitor dynasore, and by disruption of the acidic gradient of the endocytic compartment using different methods (chloroquine, NH4Cl or monensin). IL-6 secretion was also impaired by NED-19, a specific inhibitor of the two pore channels receptor mediating Ca2+ release from the endolysosomal compartment. IL-6 and ATP increased IL-6 mRNA levels, an effect blocked by tocilizumab. Altogether, our results demonstrate that ATP-secreted IL-6 activates a positive loop based on IL-6 receptors, endocytosis, two pore channels and IL-6 transcription. Given the importance of muscle IL-6 as a systemic regulator and as an inflammatory mediator, our study can help to understand muscle pathophysiology.

Interleukin 1β And Interleukin-6 and Some Oxidants in Patients With Stable Angina

ROS play an essential physiological roles in the cellular homoeostasis and cell signaling under normal circumstances. The overexpression of ROS was involved in the pathological events of several diseases, including cardiovascular, because they cause damage to many cell structures.This study aims to evaluate the levels of inflammatory biomarkers, [interleukin-6 (IL-6) and interleukin-1beta (IL-1β)] in stable angina patients and their relationship with oxidative stress. The current study is a case-control one performed on 88 patients with stable angina and 44 people as a control group attending the Nasiriyah Heart Center from August 2023 to March 2024. All cases were diagnosed by cardiologists and confirmed by laboratory investigations. Blood samples (10 ml) were collected from patients. Serum was isolated after centrifugation and stored at -20°C. Serum CK-MB, MYO and Trop I were determined by electro-chemiluminescence immunoassay. While, the ELISA was employed to assess the levels of human IL-6, human IL-1 β, SOD, (GSH-Px/ GPX), total cholesterol, triglycerides, LDL, VLDL and HDL, using the kits from Solarbio, China. The patients with stable angina didn’t show significant variation in the serum level of troponin I and CK-MB in comparison with control, while serum myoglobin level was significantly increased in patients with stable angina compared to control. Although the level of total cholesterol was insignificantly increased, but the levels of triglyceride (TG), VLDL-C and LDL-C were significantly increased, while the serum level of HDL-C was significantly declined in comparison with control. The serum levels IL-6 and IL-1β, in addition to activities of SOD and GPx were increased significantly in patients of angina compared to control. We could conclude that IL-1β, IL-6, SOD and GPx are increased in stable angina. Inflammatory events and oxidative stress could play an important roles in initiation of atherosclerosis and subsequent angina.

A mouse model of overexpression of human IL-6 by tissue-resident macrophages in the context of LPS-induced inflammation

Chronic inflammation caused by overexpression of IL-6 underlies a number of pathological conditions Mouse models of systemic chronic inflammation with overexpression of human IL-6 (hIL-6) are in demand not only in the context of studying the molecular mechanisms of inflammation, but also in assessing the effectiveness of clinically approved or newly developed IL-6 inhibitors. One experimental approach in addressing such models in mice relies on the induction of systemic acute inflammation in response to lipopolysaccharide (LPS) administration. This work describes mice with tamoxifen-dependent overexpression of human IL-6 in CX3CR1+ myeloid cells in the context of systemic inflammation induced by LPS administration. Our study demonstrates that the highest expression of the transgene carrying IL6 was observed in the heart, while high production of this cytokine was detected in the blood serum. In response to LPS administration, the production of hIL-6 in the blood increased in transgenic mice, while the production of mIL-6 also increased and was comparable to that in wild-type mice. The consequences of high systemic production of hIL-6, which in our model originates from CX3CR1+ tissue-resident macrophages, were noticeable even in the organs in which these cells are not present. Thus, significant amounts of hIL-6 were detected in tissue lysates of the lungs of transgenic mice after LPS administration. Evaluation of the expression of genes encoding cytokines and markers of tissue remodeling upon injury using quantitative real-time PCR showed significant changes in their expression in the context of LPS-induced systemic inflammation. Thus, this work demonstrates the feasibility of using a mouse model with tamoxifen-dependent transgene activation in CX3CR1+ tissue-resident macrophages to study the effects of systemic overexpression of IL-6 and pharmacological blockade of this cytokine with clinically approved or newly developed inhibitors in the context of experimentally induced diseases.

Interleukin(IL)-37 attenuates isoproterenol (ISO)-induced cardiac hypertrophy by suppressing JAK2/STAT3-signaling associated inflammation and oxidative stress

BackgroundInflammation and oxidative stress have drawn more and more interest in the realm of cardiovascular disease. In many different disorders, IL-37 acts as an anti-inflammatory and suppressor of inflammation. This study aimed to investigate whether IL-37 could alleviate cardiac hypertrophy by reducing inflammation and oxidative stress. MethodsIn vivo, a cardiac hypertrophy model was induced by 14 d of daily isoproterenol (ISO, 30 mg/kg/d) injection, followed by weeks of treatment with recombinant human IL-37 (1000 ng/animal), administered three times weekly. Assessments concentrated on markers of inflammation and oxidative stress, apoptosis, myocardial disease, and cardiac shape and function. In vitro, neonatal rat cardiomyocytes (NRCMs) were subjected to ISO (10 µM) to establish a cardiomyocytes hypertrophy model. Subsequent IL-37 treatment (100 ng/ml) was applied to determine its cardioprotective efficacy and to elucidate further the underlying mechanisms involved. ResultsSignificant cardioprotective benefits of IL-37 were seen (in vitro as well as in vivo), primarily through the reduction of oxidative stress, inflammation, apoptosis, and heart hypertrophy markers. Furthermore, IL-37 treatment was associated with a decrease in JAK2 and STAT3 phosphorylation. It is interesting to note that WP1066, a JAK2/STAT3 inhibitor, exhibited antioxidant and anti-inflammatory properties comparable to IL-37, as well as synergistic effects when mixed with the latter. ConclusionISO-induced cardiac hypertrophy is lessened by IL-37 through the reduction of oxidative stress and inflammation. Additionally, the effects of IL-37 are closely related to inactivation of the JAK2/STAT3 signaling pathway. It is anticipated that IL-37 will one day be used to treat cardiovascular illnesses such as heart hypertrophy.

IL-8 and PI3K pathway influence the susceptibility of TRAIL-sensitive colorectal cancer cells to TRAIL-induced cell death.

Tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is an apoptosis inducer that exhibits an ideal therapeutic safety profile with less adverse effects than conventional chemotherapy. However, the occurrence of TRAIL resistance has been reported in various cancers including colorectal cancer (CRC). Substantial efforts have been channelled towards managing TRAIL resistance including identifying molecular targets. Interleukins (ILs) have been recently shown to play critical roles in modulating TRAIL sensitivity in cancer cells. This study investigated the roles of two ILs, IL-8 and IL⍺, in TRAIL resistance in CRC. TRAIL-resistant HT-29 and TRAIL-sensitive HCT 116 cells, were treated with human recombinant IL-8 and IL-1⍺. The results indicated that treatment with IL-8 (2.5 ng/mL) significantly protected TRAIL-sensitive HCT 116 cells from TRAIL-induced cell death (p < 0.05). However, IL-1⍺ did not play a role in modulating CRC cells' responses to TRAIL. Data from RT-qPCR and Western blotting revealed the molecular regulations of IL-8 on TRAIL decoy receptor genes (OPG) and autophagy-related genes (BECN1 and LC3B) expression. The activation of the phosphoinositide 3-kinase (PI3K) pathway was shown to counteract TRAIL-induced cell death. By inhibiting its activation with wortmannin, the protective role of IL-8 against TRAIL treatment was reversed, suggesting the involvement of the PI3K pathway. Collectively, findings from this study identified the role of IL-8 and PI3K in modulating CRC cells' sensitivity to TRAIL. Further validation of these two potential molecular targets is warranted to overcome TRAIL resistance in CRC.

Development of New Diffuse Large B Cell Lymphoma Mouse Models.

Diffuse large B cell lymphoma (DLBCL) is the most diagnosed, aggressive non-Hodgkin lymphoma, with ~40% of patients experiencing refractory or relapsed disease. Given the low response rates to current therapy, alternative treatment strategies are necessary to improve patient outcomes. Here, we sought to develop an easily accessible new xenograft mouse model that better recapitulates the human disease for preclinical studies. We generated two Luciferase (Luc)-EGFP-expressing human DLBCL cell lines representing the different DLBCL cell-of-origin subtypes. After intravenous injection of these cells into humanized NSG mice, we monitored the tumor growth and evaluated the organ-specific engraftment/progression period. Our results showed that human IL6-expressing NSG (NSG-IL6) mice were highly permissive for DLBCL cell growth. In NSG-IL6 mice, systemic engraftments of both U2932 activated B cell-like- and VAL germinal B cell-like-DLBCL (engraftment rate; 75% and 82%, respectively) were detected within 2nd-week post-injection. In the organ-specific ex vivo evaluation, both U2932-Luc and VAL-Luc cells were initially engrafted and expanded in the spleen, liver, and lung and subsequently in the skeleton, ovary, and brain. Consistent with the dual BCL2/MYC translocation association with poor patient outcomes, VAL cells showed heightened proliferation in human IL6-conditioned media and caused rapid tumor expansion and early death in the engrafted mice. We concluded that the U2932 and VAL cell-derived human IL6-expressing mouse models reproduced the clinical features of an aggressive DLBCL with a highly consistent pattern of tumor development. Based on these findings, NSG mice expressing human IL6 have the potential to serve as a new tool to develop DLBCL xenograft models to overcome the limitations of standard subcutaneous DLBCL xenografts.

Revolutionizing ELISA: A one-step blocking approach using lipid bilayer coatings

Enzyme-linked immunosorbent assay (ELISA) is an essential technique for biomolecule detection in diagnostics and research, but traditional protocols are time-consuming and variable. Conventional blocking agents like bovine serum albumin (BSA) pose ethical issues and potential assay interference. This study presents a one-step lipid-blocking approach to simplify the ELISA procedure. Compared to conventional blockers, the Lipid Universal Coating Assembly (LUCA) antifouling blocker showed comparable sensitivity while significantly reducing processing time and steps. Furthermore, it showed improved co-blocking efficacy and signal intensity in conventional protocols when combined with minimal BSA concentrations. Stability tests under accelerated aging confirmed the robustness of the LUCA antifouling blocker. Additionally, it effectively facilitated antibody detection for COVID-19 antigens in direct ELISA and human IL-6 antigen in Sandwich ELISA, suggesting its versatile applicability. Taken together, our findings reveal that one-step lipid blocking not only streamlines the ELISA process but also maintains high sensitivity and specificity, providing an efficient, user-friendly, and environmentally friendly alternative to traditional ELISA blockers and a robust platform for rapid diagnostics.

Cytokine levels in breast cancer are highly dependent on cytomegalovirus (CMV) status.

Breast cancer accounts for 30% of all female cancers in the US. Cytomegalovirus (CMV), a herpesvirus that establishes lifelong infection, may play a role in breast cancer. CMV is not oncogenic, yet viral DNA and proteins have been detected in breast tumors, indicating possible contribution to tumor development. CMV encodes cmvIL-10, a homolog of human cellular IL-10 (cIL-10) with potent immunosuppressive activities. We investigated the relationship between CMV infection, cytokines, and breast cancer. We evaluated CMV serostatus and cytokine levels in plasma of women with benign breast disease (n = 38), in situ carcinoma (n = 41), invasive carcinoma, no lymph node involvement (Inv/LN-; n = 41), and invasive with lymph node involvement (Inv/LN+; n = 37). Fifty percent of the patient samples (n = 79) were CMV seropositive. There was no correlation between CMV status and diagnosis (p = 0.75). For CMV+ patients, there was a trend toward higher CMV IgG levels in invasive disease (p = 0.172). CmvIL-10 levels were higher in CMV+ in situ patients compared to the Inv/LN- and Inv/LN+ groups (p = 0.020). Similarly, cIL-10 levels were higher in CMV+ in situ patients compared to the Inv/LN- and Inv/LN+ groups (p = 0.043). The results were quite different in CMV- patients where cIL-10 levels were highest in Inv/LN- compared to benign, in situ, or Inv/LN+ (p = 0.019). African American patients were significantly associated with CMV+ status (p = 0.001) and had lower cmvIL-10 levels than Caucasian patients (p = 0.046). No association was observed between CMV IgG and diagnosis, but CMV infection influences cytokine production and contributes to altered cytokine profiles in breast cancer.

Recombinant Human Interleukin-2 Corrects NK Cell Phenotype and Functional Activity in Patients with Post-COVID Syndrome

Post-COVID syndrome develops in 10–20% of people who have recovered from COVID-19 and it is characterized by impaired function of the nervous, cardiovascular, and immune systems. Previously, it was found that patients who recovered from infection with the SARS-CoV-2 virus had a decrease in the number and functional activity of NK cells. The aim of the study was to assess the effectiveness of recombinant human IL-2 (rhIL-2) administered to correct NK cell phenotype and functional activity in patients with post-COVID syndrome. Patients were examined after 3 months for acute COVID-19 of varying severity. The phenotype of the peripheral blood NK cells was studied by flow cytometry. It was found that disturbances in the cell subset composition in patients with post-COVID syndrome were characterized by low levels of mature (p = 0.001) and cytotoxic NK cells (p = 0.013), with increased release of immature NK cells (p = 0.023). Functional deficiency of NK cells in post-COVID syndrome was characterized by lowered cytotoxic activity due to the decreased count of CD57+ (p = 0.001) and CD8+ (p 0.001) NK cells. In the treatment of patients with post-COVID syndrome with recombinant IL-2, peripheral blood NK cell count and functional potential were restored. In general, the effectiveness of using rhIL-2 in treatment of post-COVID syndrome has been proven in patients with low levels of NK cells.

Comprehensive analysis of L-PRF exudate components and their impact on whole blood platelets.

This study assessed the cellular composition and effects of leukocyte-platelet-rich fibrin (L-PRF) exudate on whole blood platelets from healthy volunteers. Key objectives included evaluating leukocyte subpopulations, platelet activation markers, platelet-leukocyte interactions and quantifying inflammatory cytokines within the L-PRF exudate. L-PRF was obtained from 20 healthy donors. Flow cytometry methodologies were used to assess intracellular calcium kinetics and activated GPIIbIIIa, and P-selectin expression. Leukocyte subpopulations and platelet-leukocyte interactions were characterized using monoclonal antibodies. Inflammatory cytokines (IL-8, IL-1β, IL-6, IL-10, TNF, IL-12p70) within L-PRF exudate were quantified using a cytometric bead array. The expression of activated GPIIbIIIa, and P-selectin exhibited a significant increase (p < 0.001) when L-PRF exudate was added to platelets of whole blood. Regarding intracellular Ca2+ mobilization, the L-PRF exudate elicited significant responses (p < 0.001). L-PRF exudate contained different leukocytes populations, being TCD4 + the most representative of T cells. It was possible to stablish a profile of cytokines produced by the L-PRF exudate, with human IL-8 cytokine exhibiting the highest average (16.90 pg/mL). Despite the study limitations, the research yielded important insights: 1- L-PRF exudate can stimulate platelet activation, essential in healing, tissue inflammation and remodeling. 2-The presence of leukocyte subpopulations within L-PRF exudate reflexes its complexity and potential to enhance immune responses. 3-The analysis of inflammatory cytokines within L-PRF exudate revealed its immunomodulatory potential. These findings are valuable evidences for understanding the potential role of L-PRF exudate in regenerative dentistry and medicine, offering innovative therapeutic strategies. This research highlights crucial aspects that could significantly influence the clinical use of L-PRF exudate in the oral cavity. The findings support the application of L-PRF exudate in both surgical and regenerative dentistry, facilitating the development of innovative therapeutic strategies to enhance patient outcomes.

An IL-7 fusion protein targeting EDA fibronectin upregulates TCF1 on CD8+ T-cells, preferentially accumulates to neoplastic lesions, and boosts PD-1 blockade

BackgroundAnti-PD-1 antibodies have revolutionized cancer immunotherapy due to their ability to induce long-lasting complete remissions in a proportion of patients. Current research efforts are attempting to identify biomarkers and suitable...

Structure and assembly of the human IL-12 signaling complex

Interleukin (IL)-12 is a heterodimeric pro-inflammatory cytokine. Our cryoelectron microscopy structure determination of human IL-12 in complex with IL-12Rβ1 and IL-12Rβ2 at a resolution of 3.75Å reveals that IL-12Rβ2 primarily interacts with the IL-12p35 subunit via its N-terminal Ig-like domain, while IL-12Rβ1 binds to the p40 subunit with its N-terminal fibronectin III domain. This binding mode of IL-12 with its receptors is similar to that of IL-23 but shows notable differences with other cytokines. Through structural information and biochemical assays, we identified Y62, Y189, and K192 as key residues in IL-12p35, which bind to IL-12Rβ2 with high affinity and mediate IL-12 signal transduction. Furthermore, structural comparisons reveal two distinctive conformational states and structural plasticity of the heterodimeric interface in IL-12. As a result, our study advances our understanding of IL-12 signal initiation and opens up new opportunities for the engineering and therapeutic targeting of IL-12.

Prophylactic IL-23 blockade uncouples efficacy and toxicity in dual CTLA-4 and PD-1 immunotherapy

BackgroundImmune-related adverse events (irAEs), characterized by targeted inflammation, occur in up to 60% of patients with melanoma treated with immune checkpoint inhibitors (ICIs). Evidence proved that the baseline peripheral blood...

IL-10-modulated dendritic cells from birch pollen- and hazelnut-allergic patients facilitate Treg-mediated allergen-specific and cross-reactive tolerance.

Approximately 70% of individuals allergic to birch pollen (Bet v 1.01 [Bet]) develop a secondary food allergy (e.g., hazelnut: Cor a 1.04 [Cor]), due to allergen cross-reactivity. However, standard immunotherapy for type I allergies often does not improve the food allergy sufficiently. We analyzed the allergen-specific and cross-reactive suppressive capacity of primary human regulatory T cells (Treg) induced by autologous IL-10-modulated dendritic cells (IL-10 DC) invitro and invivo. CD4+ T cells of patients with birch pollen and associated hazelnut allergies were differentiated into Bet-specific or non-specific induced Treg (iTreg). After Bet- or Cor-specific restimulation the phenotype, proliferation, and suppressive capacity of iTreg subsets were analyzed. iTreg function was further investigated in humanized mouse models of airway and intestinal allergy, generated by engraftment of peripheral blood mononuclear cells from allergic donors into immunodeficient animals. After IL-10 DC priming and allergen-specific restimulation (Bet or Cor), non-specific control iTreg remained anergic, whereas Bet-specific iTreg proliferated extensively and exhibited a regulatory phenotype (enhanced expression of CTLA-4, PD-1, TNFR2, IL-10). Accordingly, activated Bet-specific iTreg displayed a high capacity to suppress Bet- and Cor-induced responder Th2 cell responses invitro, indicating induction of both allergen-specific (birch) and cross-reactive tolerance (hazelnut). Invivo, the beneficial effect of Bet-specific iTreg was verified in humanized mouse models of allergic airway and intestinal inflammation, resulting in reduced allergen-induced clinical symptoms, and immune responses. Human IL-10 DC-induced iTreg facilitate allergen-specific and cross-reactive tolerance. Therefore, they are potential candidates for regulatory cell therapy in allergic and autoimmune diseases.