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Updated: Jan 4, 2026
Fluorescence-mediated Tomography for the Detection and Quantification of Macrophage-related Murine Intestinal Inflammation
Published on: December 15, 2017
A versatile imaging platform with fluorescence and CT imaging capabilities that detects myeloperoxidase activity and
Cuihua Wang1,2, Benjamin Pulli1,2, Negin Jalali Motlagh1,2
1Center for Systems Biology, Massachusetts General Hospital and Harvard Medical School, Boston, MA.
Abstract:
Aberrant innate immune response drives the pathophysiology of many diseases. Myeloperoxidase (MPO) is a highly oxidative enzyme secreted by activated myeloid pro-inflammatory immune cells such as neutrophils and macrophages, and is a key mediator of the damaging innate immune response. Current technologies for detecting MPO activity in living organisms are sparse and suffer from any combination of low specificity, low tissue penetration, or low spatial resolution. We describe a versatile imaging platform to detect MPO activity using an activatable construct conjugated to a biotin moiety (MPO-activatable biotinylated sensor, MABS) that allows monitoring the innate immune response and its modulation at different scales and settings. Methods: We designed and synthesized MABS that contains MPO-specific and biotin moieties, and validated its specificity and sensitivity combining with streptavidin-labeled fluorescent agent and gold nanoparticles imaging in vitro and in vivo in multiple mouse models of inflammation and infection, including Matrigel implant, dermatitis, cellulitis, cerebritis and complete Fraud's adjuvant (CFA)-induced inflammation. Results: MABS MPO imaging non-invasively detected varying MPO concentrations, MPO inhibition, and MPO deficiency in vivo with high sensitivity and specificity. MABS can be used to obtain not only a fluorescence imaging agent, but also a CT imaging agent, conferring molecular activity information to a structural imaging modality. Importantly, using this method on tissue-sections, we found that MPO enzymatic activity does not always co-localize with MPO protein detected with conventional techniques (e.g., immunohistochemistry), underscoring the importance of monitoring enzymatic activity. Conclusion: By choosing from different available secondary probes, MABS can be used to create systems suitable to investigate and image MPO activity at different scales and settings.
Insights
A novel MPO-activatable biotinylated sensor (MABS) enables sensitive and specific imaging of myeloperoxidase (MPO) activity in vivo. This versatile platform visualizes innate immune responses and MPO levels, outperforming traditional protein detection methods.
Area of Science:
- Biomedical Imaging
- Molecular Biology
- Immunology
Background:
- Aberrant innate immune responses are implicated in numerous diseases.
- Myeloperoxidase (MPO) is a key enzyme in pro-inflammatory myeloid cells, mediating damaging immune responses.
- Existing MPO detection technologies lack specificity, tissue penetration, or spatial resolution for in vivo studies.
Purpose of the Study:
- To develop a versatile imaging platform for detecting MPO activity in living organisms.
- To create a sensor that allows monitoring of the innate immune response and its modulation.
- To overcome limitations of current MPO detection technologies.
Main Methods:
- Design and synthesis of a MPO-activatable biotinylated sensor (MABS).
- Validation of MABS specificity and sensitivity using streptavidin-labeled fluorescent agents and gold nanoparticles.
- In vitro and in vivo imaging in mouse models of inflammation and infection (Matrigel implant, dermatitis, cellulitis, cerebritis, CFA-induced inflammation).
Main Results:
- MABS enabled non-invasive in vivo detection of MPO concentrations, inhibition, and deficiency with high sensitivity and specificity.
- MABS can be utilized as both a fluorescence and CT imaging agent, providing molecular activity information.
- MPO enzymatic activity did not always co-localize with MPO protein, highlighting the importance of activity monitoring.
Conclusions:
- MABS is a versatile imaging platform for monitoring MPO activity at various scales and settings.
- This technology offers improved insights into innate immune responses compared to conventional MPO protein detection.
- MABS facilitates the investigation of MPO's role in disease pathophysiology and potential therapeutic interventions.
