Interleukin 4

Overview

Interleukin 4 (IL-4) is a pleiotropic cytokine of the immune system with a central role in type 2 immune responses. It is produced by activated T cells and other immune cells and acts through the IL-4 receptor to influence leukocyte differentiation, antibody class switching, and inflammatory signaling. Biologically, IL-4 is best known for promoting T helper 2-associated responses and for driving macrophage polarization toward an alternatively activated, anti-inflammatory M2 phenotype.

In biomedical research, IL-4 is frequently studied as both a disease-associated biomarker and a therapeutic modulator. Its activity is relevant to allergic inflammation, asthma, atopic dermatitis, and other Th2-skewed conditions, but it is also investigated in regenerative medicine because of its immunoregulatory effects. Recent studies have used IL-4 in hydrogel and biomaterial systems, in combination with pathways such as NF-κB/IκB, PI3K/AKT/HIF-1α, and with inflammatory mediators including IL17A, IL-13, and TNF-α, reflecting its broad role at the interface of immunity, tissue repair, and chronic inflammation.

Focus of Latest Publications

Recent publications have continued to position IL-4 as a key regulator of inflammation, tissue repair, and disease-associated immune remodeling. In osteoporosis research, targeted IL-4 nanoparticles were developed to modulate osteal macrophages, reflecting the cytokine’s known ability to suppress osteoclast differentiation and influence macrophage fate in bone-resorptive environments. This line of work links IL-4 to bone homeostasis and suggests that local delivery strategies may be useful for shifting macrophage behavior toward a reparative phenotype.

Several studies focused on IL-4 in macrophage polarization and tissue repair. In a polycystic ovary syndrome model induced by dehydroepiandrosterone, IL-4 was reported to ameliorate ovarian histopathological changes and restore ovulatory function by promoting M2 macrophage polarization through the NF-κB/IκB pathway. In renal repair research, an IL-4 peptide hydrogel was used to reprogram mesenchymal stem cell heterogeneity toward a CD106+ population with enhanced regenerative and immunomodulatory properties. Similarly, dual-function hydrogel microspheres co-loaded with IL-4 and chitosan-BSA nanoparticles encapsulating calcitonin gene-related peptide were designed to coordinate immune regulation and osteogenesis coupling in femoral regeneration.

IL-4 also appeared in studies of inflammatory disease biomarkers and immune profiling. A plasma protein signature study for cerebral amyloid angiopathy included IL4 among the biomarkers that, together with C-reactive protein, C-C motif chemokine ligand 11, neuropeptide Y, and PDLIM5, improved diagnostic discrimination. In a recent-onset type 1 diabetes cohort, IL4 release from CD8+ T cells was inversely associated with hepatic lipid content, alongside IL-2, IL-13, and TNF release, suggesting broader links between cytokine output and metabolic state. In a pilot study of electroacupuncture for chronic nonspecific low back pain, IL-4 levels decreased after treatment, accompanied by an increase in IL-10 and a reduction in interferon-gamma, indicating measurable short-term effects on inflammatory markers.

Multiple studies used IL-4 as a readout of type 2 inflammation or treatment response in allergic and airway disease. In allergic rhinitis, a dual-action nasal spray containing mussel protein and xylitol attenuated type 2 inflammation in human nasal epithelial cells stimulated with lipopolysaccharide, reducing IL-4, IL-5, and IL-13 release while restoring epithelial barrier proteins. In atopic dermatitis research, chlorophytum borivilianum was associated with downregulation of IL-4, IL-6, IL-13, and TNF-α gene expression, while a phthalazinone PARP14 inhibitor reduced skin lesions and decreased IL-4, IL-13, IgE, and IL-17A expression, showing efficacy comparable to or better than upadacitinib and RBN-3143 in the reported model. Another atopic dermatitis study using kaempferol-loaded solid lipid nanoparticles found upregulation of IL-4 and IL-10 alongside suppression of IL-1β, TNF-α, COX-2, MMP-13, IL-17A, and IL-33, consistent with an anti-inflammatory shift in arthritic tissue. In a separate context, IL-4 was also measured as part of inflammatory cytokine panels in renal dysfunction, acute liver failure, and septic arthritis studies.

IL-4 remains important in vaccine and infectious disease immunology as well. A novel intranasal nano-adjuvanted pertussis vaccine in a rodent model induced strong IgG and secretory IgA responses and increased IFN-γ, IL-4, and IL-17, indicating balanced humoral and cellular immune activation. In cystic fibrosis research, exposure of epithelia to IL-4 markedly amplified rescue of nonsense-mutant CFTR chloride channel function under inflammatory conditions, highlighting the cytokine’s ability to alter epithelial biology and drug responsiveness. Across these studies, IL-4 is consistently treated as both a mechanistic mediator and a biomarker of immune polarization.

Therapeutically, IL-4 signaling is also relevant because it is targeted by dupilumab, a monoclonal antibody that downregulates interleukin-4, interleukin-13, and the T helper 2 cell pathway. Recent reports discussed its use in pregnancy and in pediatric liver transplant recipients with eosinophilic esophagitis and atopic dermatitis, emphasizing ongoing clinical interest in IL-4 pathway blockade.

Key Publications

• NEWJul Targeted IL-4 nanoparticles for osteal macrophages modulation in osteoporosis. (European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences, 2026, PMID 42106120): "Interleukin-4 (IL-4) is an immunomodulatory cytokine known to suppress osteoclast differentiation and influence the fate of osteal macrophages, cells that play a supportive role in bone resorption."
• NEWJul Safety of dupilumab use during pregnancy: A composite evaluation of pregnancy outcomes. (Allergy and asthma proceedings, 2026, PMID 42343498): "Dupilumab is a monoclonal antibody that targets interleukin 4 and interleukin 13 pathways, increasingly used to treat asthma, eczema, and eosinophilic esophagitis (EoE)."
• Jul Dupilumab Is Safe and Efficacious for Treatment of Eosinophilic Esophagitis and Atopic Dermatitis in Pediatric Liver Transplant Recipients: A Case Series. (Pediatric transplantation, 2026, PMID 42351377): "Dupilumab, a monoclonal antibody that downregulates interleukin-4, interleukin-13, and the T helper 2 cell pathway, is effective for atopic dermatitis and eosinophilic esophagitis, though there is a paucity of data regarding its use and safety in pediatric liver transplant recipients."
• Jun IL-4 peptide hydrogel reprograms MSC heterogeneity toward the CD106+ population for enhanced renal repair. (Proceedings of the National Academy of Sciences of the United States of America, 2026, PMID 42268883): "Here, we introduce a self-assembled interleukin-4 (IL-4) peptide hydrogel designed to shift MSC populations toward a homogeneous CD106+ subset with enhanced regenerative and immunomodulatory capabilities."
• Jun Antimicrobial and immune-modulating effects of recombinant pancreatitis-associated protein in the treatment of MRSA-induced severe septic arthritis. (Clinical science (London, England : 1979), 2026, PMID 42101848): "...and elevated anti-inflammatory IL-4 levels."
• Jun Interleukin-4 alleviate polycystic ovary syndrome through promoting the polarization of M2 type macrophages via targeting NF-κB/IκB pathway. (European journal of pharmacology, 2026, PMID 42119768): "Interleukin-4 (IL-4), a potent immunomodulatory cytokine, effectively ameliorated ovarian histopathological alterations and restored ovulatory function in the DHEA-induced PCOS mice through the promotion of M2 macrophage polarization."
• Jun Systemic Inflammation and Peripheral T Cell Responses Associate With Hepatic Energy Metabolism in Recent-Onset Type 1 Diabetes. (Liver international : official journal of the International Association for the Study of the Liver, 2026, PMID 42130117): "Hepatic lipid content (median 0.4%) negatively correlated with IL-2, IL4, IL-13 and TNF release from CD8+ T cells (all pFDR <0.05)."
• May Dual-function hydrogel microspheres coordinate immune regulation and osteogenesis coupling to promote femoral regeneration. (Journal of materials chemistry. B, 2026, PMID 42093387): "To address this, we developed a methacrylated gelatin (GelMA) microsphere system using microfluidic technology, co-loading IL-4 and chitosan-BSA nanoparticles (CNP) encapsulating calcitonin gene-related peptide (CGRP) to achieve temporally controlled release and immuno-osteogenic synergistic regulation."
• May Bio inspired assessment of titanium-organic framework and exosome-constructed p-Synephrine carriage: pursuing the PI3K/mTOR pathway in a simulated periodontitis. (Scientific reports, 2026, PMID 42185524): "Results showed that p-Synephrine loaded into NH2-MIL-125 reduced inflammation markers and enhanced antioxidant defenses by increasing of GPx, SOD, and TAC concentrations."
• May Kaempferol-loaded solid lipid nanoparticles attenuate cartilage degradation and inflammation by modulating the expression of pro and inflammatory cytokines, MMP-13 and oxidative stress markers in adjuvant induced arthritic rats. (Inflammopharmacology, 2026, PMID 42184086): "qRT-PCR showed downregulation of IL-1β, TNF-α, COX-2, MMP-13, IL-17A, and IL-33 with upregulation of IL-4 and IL-10."