Concept: Interleukin 4
Background Dupilumab, a human monoclonal antibody against interleukin-4 receptor alpha, inhibits signaling of interleukin-4 and interleukin-13, type 2 cytokines that may be important drivers of atopic or allergic diseases such as atopic dermatitis. Methods In two randomized, placebo-controlled, phase 3 trials of identical design (SOLO 1 and SOLO 2), we enrolled adults with moderate-to-severe atopic dermatitis whose disease was inadequately controlled by topical treatment. Patients were randomly assigned in a 1:1:1 ratio to receive, for 16 weeks, subcutaneous dupilumab (300 mg) or placebo weekly or the same dose of dupilumab every other week alternating with placebo. The primary outcome was the proportion of patients who had both a score of 0 or 1 (clear or almost clear) on the Investigator’s Global Assessment and a reduction of 2 points or more in that score from baseline at week 16. Results We enrolled 671 patients in SOLO 1 and 708 in SOLO 2. In SOLO 1, the primary outcome occurred in 85 patients (38%) who received dupilumab every other week and in 83 (37%) who received dupilumab weekly, as compared with 23 (10%) who received placebo (P<0.001 for both comparisons with placebo). The results were similar in SOLO 2, with the primary outcome occurring in 84 patients (36%) who received dupilumab every other week and in 87 (36%) who received dupilumab weekly, as compared with 20 (8%) who received placebo (P<0.001 for both comparisons). In addition, in the two trials, an improvement from baseline to week 16 of at least 75% on the Eczema Area and Severity Index was reported in significantly more patients who received each regimen of dupilumab than in patients who received placebo (P<0.001 for all comparisons). Dupilumab was also associated with improvement in other clinical end points, including reduction in pruritus and symptoms of anxiety or depression and improvement in quality of life. Injection-site reactions and conjunctivitis were more frequent in the dupilumab groups than in the placebo groups. Conclusions In two phase 3 trials of identical design involving patients with atopic dermatitis, dupilumab improved the signs and symptoms of atopic dermatitis, including pruritus, symptoms of anxiety and depression, and quality of life, as compared with placebo. Trials of longer duration are needed to assess the long-term effectiveness and safety of dupilumab. (Funded by Sanofi and Regeneron Pharmaceuticals; SOLO 1 ClinicalTrials.gov number, NCT02277743 ; SOLO 2 ClinicalTrials.gov number, NCT02277769 .).
Human bispecific antibodies have great potential for the treatment of human diseases. Although human IgG1 bispecific antibodies have been generated, few attempts have been reported in the scientific literature that extend bispecific antibodies to other human antibody isotypes. In this paper, we report our work expanding the knobs-into-holes bispecific antibody technology to the human IgG4 isotype. We apply this approach to generate a bispecific antibody that targets IL-4 and IL-13, two cytokines that play roles in type 2 inflammation. We show that IgG4 bispecific antibodies can be generated in large quantities with equivalent efficiency and quality and have comparable pharmacokinetic properties and lung partitioning, compared to the IgG1 isotype. This work broadens the range of published therapeutic bispecific antibodies with natural surface architecture and provides additional options for the generation of bispecific antibodies with differing effector functions through the use of different antibody isotypes.
Ongoing axonal degeneration is thought to underlie disability in chronic neuroinflammation, such as multiple sclerosis (MS), especially during its progressive phase. Upon inflammatory attack, axons undergo pathological swelling, which can be reversible. Because we had evidence for beneficial effects of T helper 2 lymphocytes in experimental neurotrauma and discovered interleukin-4 receptor (IL-4R) expressed on axons in MS lesions, we aimed at unraveling the effects of IL-4 on neuroinflammatory axon injury. We demonstrate that intrathecal IL-4 treatment during the chronic phase of several experimental autoimmune encephalomyelitis models reversed disease progression without affecting inflammation. Amelioration of disability was abrogated upon neuronal deletion of IL-4R. We discovered direct neuronal signaling via the IRS1-PI3K-PKC pathway underlying cytoskeletal remodeling and axonal repair. Nasal IL-4 application, suitable for clinical translation, was equally effective in improving clinical outcome. Targeting neuronal IL-4 signaling may offer new therapeutic strategies to halt disability progression in MS and possibly also neurodegenerative conditions.
Glial cells play important roles in the development and maintenance of neuropathic pain. In particular, activated microglia in the spinal cord facilitate the hyper-excitability of dorsal horn neurons after peripheral nerve injury via pro-inflammatory molecules. In this study, we investigated the possible involvement of the anti-inflammatory cytokine, interleukin-4 (IL-4), in neuropathic pain. We did not detect the expression of IL-4 mRNA in the rat dorsal root ganglion or spinal cord; however, peripheral nerve injury induced the expression of IL-4 receptor (IL-4R) alpha mRNA in the spinal cord. A histological analysis revealed that nerve injury induced IL-4R alpha mRNA in activated spinal microglia ipsilateral to the injury site. Additionally, the increases in IL-4R alpha were coincident with the increased expression of phosphorylated signal transducer and activator of transcription 6 (pSTAT6) in spinal microglia. Intrathecal administration of recombinant IL-4 suppressed mechanical hypersensitivity in neuropathic rats, and the analgesic effect of IL-4 was accompanied by further enhancement of pSTAT6 expression in spinal microglia. Taken together, these results suggest that the adaptive responses of microglia to nerve injury involve both inflammatory and anti-inflammatory signaling, including IL-4R alpha and pSTAT6. These findings support that utilizing the endogenous anti-nociceptive activity of IL-4R alpha may modify the cell lineage of pro-nociceptive microglia, thus providing a novel therapeutic strategy for neuropathic pain.
Cytokines belonging to the common gamma chain (γc) family depend on the shared γcreceptor subunit for signaling. We report the existence of a fast, cytokine-induced pathway cross-talk acting at the receptor level, resulting from a limiting amount of γcon the surface of T cells. We found that this limited abundance of γcreduced interleukin-4 (IL-4) and IL-21 responses after IL-7 preexposure but not vice versa. Computational modeling combined with quantitative experimental assays indicated that the asymmetric cross-talk resulted from the ability of the “private” IL-7 receptor subunits (IL-7Rα) to bind to many of the γcmolecules even before stimulation with cytokine. Upon exposure of T cells to IL-7, the high affinity of the IL-7Rα:IL-7 complex for γcfurther reduced the amount of free γcin a manner dependent on the concentration of IL-7. Measurements of bioluminescence resonance energy transfer (BRET) between IL-4Rα and γcwere reduced when IL-7Rα was overexpressed. Furthermore, in a system expressing IL-7Rα, IL-4Rα, and γc, BRET between IL-4Rα and γcincreased after IL-4 binding and decreased when cells were preexposed to IL-7, supporting the assumption that IL-7Rα and the IL-7Rα:IL-7 complex limit the accessibility of γcfor other cytokine receptor complexes. We propose that in complex inflammatory environments, such asymmetric cross-talk establishes a hierarchy of cytokine responsiveness.
We studied the influence of depression-like behavior developed in C57BL/6J mice under conditions of social stress of different duration on cytokine production by splenic cells. Imbalance of the pro- and anti-inflammatory cytokines was detected at the early stage of depression-like behavior (10-day experience of defeats): increased production of proinflammatory IL-2 and IL-6 cytokines along with a decrease in anti-inflammatory IL-10 level; the levels of IL-1β, TNFα, IFNγ, and IL-4 remained unaffected. At later terms (20 days of confrontations), we revealed more pronounced changes in spontaneous production of proinflammatory cytokines that were not detected after shorter social stress. These findings suggest that cytokine profile depends on duration of social stress. Possible mechanisms of cytokine production during formation of depression-like state are discussed.
Excessive immune responses following the use of implantable, biomaterial-based medical devices represent a substantial challenge for treatment efficacy and patient well-being. Specifically, after implantation, pro-inflammatory M1 macrophages are activated by cytokines such as interferon-γ (IFN-γ) followed by anti-inflammatory M2 macrophages polarized by cytokines including interleukin-4 (IL-4), leading to healing and long-term stability of implants. Here, we report the loading of an immunomodulatory cytokine,IL-4, into TiO2nanotubes (TNTs) followed by hydrogel coating on the TNTs for subsequent release of IL-4. Finally, IFN-γ was added onto the gel layer to effect rapid release. The release rates of both cytokines from the samples were monitored using an immersion test in phosphate-buffered solution. The cytocompatibility of the sample was evaluated using cultures of osteoblasts and macrophages. Macrophage phenotype switching in vitro was examined via cytokine secretion and gene expression analyses. In vitro testing showed that the sample could stimulate macrophage polarization from the M1 to M2 phenotype at the desired period owing to temporal release of IFN-γ and IL-4. Another biomaterial containing only IL-4 in TNTs was also able to modulate the transformation of M1 to M2 although with weaker effect than that containing IFN-γ and IL-4. The biomaterial may be useful as an osteoimplant in vivo owing to the inflammation caused by a wound or implantation. This study provided biomaterials capable of facilitating smooth M1 to M2 macrophages switching, which might be helpful to research immune responses of tissues to implants and will likely contribute to the development of bone substitute materials. This article is protected by copyright. All rights reserved.
Chronic hepatitis leads to liver fibrosis and cirrhosis. Cirrhosis is a major cause of worldwide morbidity and mortality. Macrophages play a key role in fibrosis progression and reversal. However, the signals that determine fibrogenic vs fibrolytic macrophage function remain ill defined. We studied the role of interleukin-4 receptor α (IL-4Rα), a potential central switch of macrophage polarization, in liver fibrosis progression and reversal. We demonstrate that inflammatory monocyte infiltration and liver fibrogenesis were suppressed in general IL-4Rα-/-as well as in macrophage-specific IL-4Rα-/-(IL-4RαΔLysM) mice. However, with deletion of IL-4RαΔLysMspontaneous fibrosis reversal was retarded. Results were replicated by pharmacological intervention using IL-4Rα-specific antisense oligonucleotides. Retarded resolution was linked to the loss of M2-type resident macrophages, which secreted MMP-12 through IL-4 and IL-13-mediated phospho-STAT6 activation. We conclude that IL-4Rα signaling regulates macrophage functional polarization in a context-dependent manner. Pharmacological targeting of macrophage polarization therefore requires disease stage specific treatment strategies.
Atopic dermatitis (AD) is a common, chronic, inflammatory skin disorder with high physical and emotional burden. AD usually starts in early childhood and has a heterogeneous course. Emerging evidence suggests that IL-4 and IL-13 are key cytokines in the immunopathogenesis of AD. Dupilumab is a monoclonal antibody directed against IL-4 receptor α subunit, that blocks both IL-4 and IL-13 signaling. Data from Phase I-III studies revealed that dupilumab, administered as monotherapy or with topical corticosteroids, is effective and well tolerated in the treatment of adult patients with moderate-to-severe AD. A large proportion of patients receiving dupilumab had significant improvements in multiple efficacy indexes, including Eczema Area and Severity Index, Investigator’s Global Assessment and SCORing Atopic Dermatitis scores. These results introduce a new era of targeted therapies in the management of AD.
Allergic contact dermatitis is a widespread health disorder and occupational skin disease. Hence, screening for contact-sensitizing chemicals is highly relevant to toxicology, dermatology, and occupational medicine. The use of animal tests for this purpose is constrained by ethical considerations, need for high-throughput screening, and legislation (e.g., for cosmetics in the European Union). T cell activation is the final and most specific key event of the “adverse outcome pathway” for skin sensitization and therefore a promising target for the development of in vitro sensitization assays. We present a novel in vitro sensitization assay with a lymphocyte endpoint as an add-on to the loose-fit coculture-based sensitization assay (LCSA): the LCSA-ly. While the LCSA measures dendritic cell activation, the LCSA-ly offers the option for an additional lymphocyte endpoint which can be measured concurrently. We incorporated lymphocytes in our previously established coculture of primary human keratinocytes and monocyte-derived dendritic cells and tested nine substances: five sensitizers [2,4-dinitrochlorobenzene (DNCB) 1.25-15 µmol/l, p-phenylenediamine (PPD) 15.6-125 µmol/l, 2-mercaptobenzothiazole (MBT) 50-1000 µmol/l, coumarin, and resorcinol (both: 250-1500 µmol/l)] and four non-sensitizers (monochlorobenzene, caprylic acid, glycerol, and salicylic acid (all: 125-1000 µmol/l)]. DNCB and MBT increased a subset of IL-23 receptor+/IFN-γ receptor 1 (CD119)+ lymphocytes. DNCB, PPD, and MBT enhanced a subunit of the IL-4 receptor (CD124) and a memory marker (CD44) on lymphocytes. Remarkably, DNCB, PPD, and MBT raised IL-4 concentrations in coculture supernatants while IFN-γ levels decreased, which might point to Th2 activation in vitro. Coumarin, resorcinol, and non-sensitizers did not alter any of the tested surface markers or cytokines. IL-17 was not affected by any of the substances. Relative strength of sensitizers according to lymphocyte markers was DNCB > PPD > MBT, which corresponds to earlier results from the LCSA without lymphocyte endpoint, the murine local lymph node assay, and human data. This study is the first to prove the suitability of lymphocyte surface markers for sensitization testing and potency assessment.