The research was co-led by Prof. Valeriya Malysheva, group leader at the VIB-UAntwerp Center for Molecular Neurology, and focuses on type 3 innate lymphoid cells, or ILC3s. These specialized immune cells are found at barrier tissues including the intestine, where they help coordinate inflammation, maintain tissue integrity and support repair. Because ILC3s are relatively uncommon, however, scientists have had difficulty obtaining enough material to examine their gene-regulatory architecture using conventional genomic technologies.

That limitation is important because many disease-associated genetic variants do not alter the protein-coding sequence of a gene. Instead, they occur in regulatory regions such as enhancers, which can control gene activity from a considerable distance. Identifying the gene influenced by a regulatory variant is therefore not straightforward. The relevant DNA elements may lie thousands or even millions of DNA letters away from their target genes in the linear genome, while their physical interaction inside the nucleus can provide a direct clue to the underlying mechanism.

To overcome the problem of limited cell numbers, the researchers used miniaturized Capture Hi-C, a method developed by Malysheva during her postdoctoral work at the MRC Laboratory of Medical Sciences in the United Kingdom. Hi-C-based methods measure contacts between different regions of the genome by capturing and sequencing DNA fragments that have been close together in the nucleus. Capture Hi-C adds a targeted enrichment step, allowing investigators to examine selected genomic regions with greater sensitivity. The miniaturized version reduces the number of cells required, making high-resolution analysis possible in rare populations such as ILC3s.

The team applied the method to map promoter interactions across the ILC3 genome. Promoters are regulatory DNA regions positioned near genes and help initiate transcription, the process by which DNA instructions are copied into RNA. By determining which disease-associated regulatory regions physically contact which promoters, the researchers were able to connect genetic variants linked to Crohn’s disease risk with candidate target genes. This approach provided information that could not be obtained from genetic association studies alone, because statistical links between variants and disease do not automatically reveal the genes or cell types involved.

The analysis identified more than 100 genes in ILC3s that may be influenced by regulatory variants associated with Crohn’s disease. Approximately half had already been implicated in the disease, supporting the validity of the regulatory maps. The remaining genes had not previously been connected to Crohn’s disease, expanding the list of potential biological targets for future investigation. The findings also suggest that genetic risk may be concentrated in specific immune-cell states rather than distributed uniformly across all cell types.

One of the most unexpected candidates was CLN3, a gene best known for its connection to Batten disease, a rare inherited neurodegenerative disorder. The study’s follow-up experiments indicated that CLN3 directly affects how strongly ILC3s produce inflammatory signals. This result places the gene in an immune-regulatory context that had not been fully appreciated and highlights how disease biology can cross traditional boundaries between organ systems. A gene associated primarily with the nervous system may also influence the behavior of immune cells in the intestine.

The findings do not mean that CLN3 alone causes Crohn’s disease, nor that every genetic variant identified will produce the same effect in every person. Crohn’s disease is a complex condition shaped by many genetic factors, immune pathways, environmental influences and interactions with the gut microbiome. Rather, the study provides a mechanistic framework for understanding how non-coding variants may alter gene regulation in a cell type that participates directly in intestinal inflammation. These insights could eventually help researchers prioritize therapeutic targets or identify disease mechanisms that are missed in studies of more abundant immune cells.

More broadly, the work demonstrates the value of combining genetic data with cell-specific maps of three-dimensional DNA organization. Genome-wide association studies can identify regions associated with disease, but functional interpretation requires knowing when, where and how those regions regulate genes. By making promoter interaction analysis feasible in scarce cell populations, miniaturized Capture Hi-C offers a way to connect statistical genetic signals to cellular processes. The researchers’ results provide a detailed view of ILC3 regulation and may guide similar studies of rare immune cells involved in autoimmune disorders beyond Crohn’s disease.

Journal: Nature Genetics
Article Title: High-resolution promoter interaction analysis implicates genes involved in activation of type 3 innate lymphoid cells in immune disease risk
News Publication Date: 4 August 2026
Web References: https://doi.org/10.1038/s41588-026-02681-0
References: https://doi.org/10.1038/s41588-026-02681-0
Keywords: Crohn’s disease, autoimmune disease, type 3 innate lymphoid cells, ILC3s, three-dimensional genome organization, Capture Hi-C, gene regulation, CLN3, immunology, genetics, inflammatory signaling

ARDS is clinically devastating, arising from diverse triggers such as pneumonia, severe viral infections including COVID-19, and sepsis. It manifests through the accumulation of protein-rich fluid in alveoli, which severely disrupts oxygen absorption. Despite advances in supportive care, mortality rates linger between 30% and 50%, underscoring the urgent need for innovative therapeutic strategies. Against this backdrop, the Institute of Science Tokyo’s research delineates an immunological pathway that could be harnessed to modulate inflammation resolution and improve patient outcomes.

Employing a rigorous experimental model, the investigators induced ARDS in mice via intratracheal administration of lipopolysaccharides (LPS), bacterial components known to trigger robust lung inflammation mimicking human disease. Comparative analyses between basophil-deficient and wild-type mice revealed stark differences during the recovery phase: mice lacking basophils exhibited extensive pulmonary injury, elevated neutrophilic infiltration, and sustained inflammatory responses. These results underscore basophils’ unanticipated yet critical immunoregulatory function beyond their classical role in allergy.

At the molecular level, single-cell RNA sequencing illuminated the mechanistic underpinnings of basophil-mediated resolution. Basophils in inflamed lung tissue were identified as a predominant cellular source of IL-4, a signaling molecule that orchestrates immune modulation. Genetic ablation of IL-4 production specifically in basophils exacerbated lung pathology and fluid retention during convalescence, affirming IL-4’s essential role. Mechanistically, IL-4 acts directly on neutrophils, downregulating the expression of genes that drive pro-inflammatory cytokine production—namely Il1a, Il1b, and Cxcl2—and genes that inhibit apoptosis such as Bcl2a1 family members. Through this modulation, IL-4 curtails neutrophil longevity and inflammatory potential, accelerating the resolution of lung injury.

This paradigm shift redefines basophils from being stigmatized as ‘bad actors’ to critical ‘good actors’ that enforce immunological balance during ARDS recovery. The discovery aligns with clinical observations linking low peripheral basophil counts to worse respiratory failure outcomes in septic and COVID-19 patients, providing a potential cellular biomarker for disease prognosis. Moreover, it opens intriguing avenues for therapeutic intervention by targeting the basophil–IL-4–neutrophil axis to attenuate inflammation without compromising host defense.

The implications of these findings reach far beyond basic immunology, touching the core challenges of translational and clinical medicine. Current ARDS management remains supportive with no FDA-approved pharmacotherapies to directly promote resolution of lung inflammation. The ability to harness or mimic basophil-derived IL-4 signaling might revolutionize treatment paradigms, offering a targeted approach to dampen neutrophil-driven tissue injury while preserving essential immune functions. However, the research team cautions that the cellular sources of IL-4 in human ARDS cases remain to be elucidated, highlighting a critical knowledge gap that future investigations must address.

Basophils representing merely 0.5 to 1% of circulating leukocytes have historically received limited attention due to their perceived subordinate role in immune responses. Yet this study contributes to an evolving appreciation of basophil plasticity, revealing their capacity to produce immunomodulatory cytokines and participate dynamically in inflammatory environments. Prior studies demonstrated basophils’ involvement in resolving skin inflammation and bacterial infections, but this ARDS context extends their relevance to critical pulmonary pathology.

The elucidation of the transcriptional changes governed by IL-4 in neutrophils further enriches our understanding of inflammation biology. Pro-inflammatory mediators such as IL-1α, IL-1β, and CXCL2 perpetuate neutrophil recruitment and activation, often leading to a deleterious feedback loop of tissue destruction and chronic inflammation. By repressing these factors, IL-4 effectively ‘reprograms’ neutrophils towards a less harmful phenotype and facilitates programmed cell death, which is essential for clearing inflammatory infiltrates. This mechanistic insight highlights potential molecular targets that could be leveraged pharmacologically.

Integral to this investigation was the application of single-cell RNA sequencing—an advanced technology that allows dissection of the heterogeneous immune cell milieu within the ARDS-injured lung at unprecedented resolution. This approach enabled precise identification of cellular contributors to cytokine landscapes and provided novel biomarkers of disease trajectory. The multidisciplinary team, spanning immunology, pulmonary medicine, and molecular biology expertise, exemplifies the collaborative approach required to unravel complex disease processes.

While the findings herald promising advances, translation from murine models to human clinical scenarios necessitates careful validation. Human ARDS arises from multifactorial etiologies and encompasses intricate immunopathology, thus future research must clarify whether basophils and IL-4 exert comparable protective roles in patients. Additionally, the prospects of modulating basophil function or IL-4 signaling raise questions about potential off-target effects, especially given IL-4’s known roles in allergy and asthma.

In summary, this landmark study reframes our immunological understanding of ARDS resolution, positing basophils and their secretion of IL-4 as key drivers that attenuate neutrophil-mediated lung inflammation. The delineation of this pathway not only fills a critical gap in ARDS pathogenesis but also paves the way for innovative therapies aimed at improving the dismal survival rates associated with this syndrome. As the global health community grapples with respiratory pandemics and severe inflammatory lung diseases, insights such as these are invaluable in steering the future direction of biomedical research and clinical care.

Subject of Research: Animals

Article Title: Emerging roles of basophils in the resolution of the acute respiratory distress syndrome

News Publication Date: 31-Jul-2025

Web References: https://doi.org/10.1183/13993003.01150-2024

Image Credits: Institute of Science Tokyo

Keywords: Immunology, Respiratory disorders, Basophils, Neutrophils, Inflammation, Cytokines, Molecular biology, Infectious diseases, Translational medicine, Blood cells