A nanobody imaging tool to detect protein crystals and predict therapeutic response in asthmatics

Project Information

CRYSTAL-SHINE

Grant agreement ID: 101189517

DOI

10.3030/101189517

Project closed

EC signature date 24 July 2024

Start date 1 September 2024

End date 28 February 2026

Funded under

• European Research Council (ERC)

Total cost

No data

EU contribution

€ 150 000,00

Coordinated by

VIB VZW
Belgium

Periodic Reporting for period 1 - CRYSTAL-SHINE (A nanobody imaging tool to detect protein crystals and predict therapeutic response in asthmatics)

Reporting period: 2024-09-01 to 2026-02-28

Summary of the context and overall objectives of the project

Asthma and other chronic inflammatory diseases of the airways affect millions of people worldwide and represent a major burden for patients, healthcare systems, and society. While important advances have been made in understanding and treating these diseases, there remains a need for better tools to identify the biological processes driving disease in individual patients and to monitor how they respond to treatment.
One feature of severe eosinophilic inflammation is the formation of Charcot-Leyden crystals, microscopic protein crystals that accumulate in airway mucus. These crystals are increasingly recognized as more than a by-product of inflammation: growing evidence suggests that they may actively contribute to airway obstruction and disease severity. As a result, Charcot-Leyden crystals have emerged as a promising biomarker and a potential therapeutic target in conditions such as severe asthma, chronic rhinosinusitis with nasal polyps, and certain parasitic infections.
Despite their clinical relevance, there is currently no non-invasive method to measure the presence and extent of Charcot-Leyden crystals in patients. This limits both patient stratification and the development of new therapies aimed at reducing crystal formation or promoting their removal. Clinicians and researchers therefore lack a practical way to determine which patients might benefit most from such treatments and to assess whether experimental therapies are achieving their intended biological effects.
The overall objective of this ERC Proof-of-Concept project was to address this unmet need by developing an innovative molecular imaging approach capable of detecting Charcot-Leyden crystals in the lungs. The project sought to create and evaluate highly specific imaging agents that could be used with positron emission tomography (PET), a widely used medical imaging technology, to visualize these crystals non-invasively within the body.
If translated into clinical practice, this technology will provide a new way to characterize eosinophilic inflammation, support the development of precision medicines, and accelerate the clinical evaluation of novel anti-inflammatory therapies. By enabling clinicians and researchers to directly visualize a key disease-associated structure, the project has the potential to improve patient selection, guide treatment decisions, and facilitate the development of more effective therapies for severe inflammatory airway diseases.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

During this ERC Proof-of-Concept project, we successfully developed and evaluated a new generation of molecular imaging agents designed to detect Charcot-Leyden crystals, a hallmark of eosinophilic inflammation that is found in severe asthma and several other inflammatory diseases. The project brought together expertise in immunology, protein engineering, radiochemistry, and medical imaging to address a long-standing challenge: how to visualize these crystals non-invasively inside the lungs.
A first major achievement was the identification and optimization of highly specific binding molecules capable of recognizing Charcot-Leyden crystals. These molecules were engineered to combine strong target recognition with favourable stability and imaging properties. Importantly, selected candidates were designed to bind to the crystals without altering or dissolving them, ensuring that the imaging process itself would not interfere with the biological structures being measured.
A second achievement was the successful conversion of these binding molecules into PET imaging tracers. The project established robust production and radiolabelling procedures, resulting in imaging agents of very high quality and purity. This demonstrated the technical feasibility of producing tracers suitable for preclinical imaging studies and, potentially, future clinical translation.
The project then evaluated these tracers in laboratory models that reproduce the presence of Charcot-Leyden crystals in lung tissue. The imaging agents showed highly specific recognition of crystal deposits, generating clear signals while displaying minimal background binding. These experiments provided strong evidence that the tracers were detecting the intended target rather than unrelated tissue components.
Most importantly, the project demonstrated for the first time that Charcot-Leyden crystals can be visualized in living animals using a non-invasive PET imaging approach. The lead imaging tracer accumulated in crystal-containing regions of the lungs and remained detectable long enough to generate a robust imaging signal. Additional analyses confirmed that the observed signal reflected specific binding to crystal deposits and not non-specific retention in lung tissue. The tracer also showed favourable behaviour in the body, with limited uptake in non-target organs and good stability after administration.
Together, these results provide the first preclinical proof that Charcot-Leyden crystals can be imaged in vivo using molecular PET imaging. The project therefore represents an important step toward the development of a completely new class of diagnostic tools for eosinophilic inflammatory diseases.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The project has demonstrated the feasibility of a completely new molecular imaging approach for the detection of Charcot-Leyden crystals, a hallmark of eosinophilic inflammation that is increasingly recognized as an important contributor to disease severity in asthma and related disorders. By providing a non-invasive way to visualize these crystals in the lungs, the technology has the potential to address a significant unmet need in both clinical practice and drug development.
If successfully translated to human use, the imaging approach could enable physicians to identify patients with high levels of crystal-associated inflammation, support more personalized treatment decisions, and monitor responses to emerging therapies. The technology could also serve as a valuable research tool for improving our understanding of the role of Charcot-Leyden crystals in disease progression and treatment response.
One of the most important potential impacts lies in the development of new therapies targeting eosinophilic inflammation. As pharmaceutical companies increasingly pursue precision medicine strategies, there is growing demand for biomarkers that can identify appropriate patient populations and provide objective evidence of biological activity during clinical trials. A non-invasive imaging method for Charcot-Leyden crystals could fulfil this role and help accelerate the development of innovative treatments for severe asthma, chronic rhinosinusitis with nasal polyps, and other eosinophil-driven diseases.
The project has substantially reduced the technical risks associated with this concept by demonstrating that specifically designed imaging agents can detect crystal deposits in preclinical models with favourable targeting characteristics. These results establish a strong foundation for further development and provide confidence that the approach can be advanced toward clinical translation.
Several steps will be required to maximise uptake and ensure long-term success. Additional preclinical studies are needed to further validate specificity, optimise imaging protocols, and generate the data required for regulatory development. Continued collaboration between academic researchers, imaging specialists, clinical experts, and industrial partners will be essential to advance the technology toward first-in-human studies. Access to follow-on funding and translational development programmes will also be important to bridge the gap between proof-of-concept and clinical application.
The project has generated valuable intellectual property and has created opportunities for future commercialisation.
The project has produced intellectual property: a European patent application (BaLa/PETTRACER/880) describing the sequence-optimised crystalline-Gal10-binding VHHs and their use as labelled-VHH conjugates (radionuclide tracers, fluorophores and nanoparticles) for the detection and monitoring of Charcot-Leyden Crystals. Collaboration with an industrial biotech partner is now in place to support further development, manufacturing, regulatory advancement, and eventual clinical implementation. The technology may ultimately form the basis of a new class of molecular imaging tools for inflammatory diseases.

In summary, the project successfully achieved its primary objective of developing and validating a novel imaging strategy for the detection of Charcot-Leyden crystals. The work delivered optimized targeting molecules, established a robust imaging platform, demonstrated specific detection of crystal deposits in preclinical models, and identified a lead candidate for further development. Together, these achievements provide a clear pathway toward clinical translation and create new opportunities for improving the diagnosis, monitoring, and treatment of eosinophilic inflammatory diseases.