| 研究実績の概要 |
The goal of this study is to develop a PET imaging assay that can specifically detect neutrophils of the lung and other organs by targeting the CXCR2, a chemokine receptor specifically expressed on neutrophils.At present, there is no in vivo imaging technique that can specifically visualize local neutrophil infiltration identified via systemic scanning of human body as well as animals. Therefore, we aim to achieve this by using cutting edge PET molecular imaging technology, which can visualize biomarker molecules with high sensitivity.
In order to determine the PET ligands’ affinities,appropriate cell lines, such as HEK cells stably expressing recombinant human CXCR2, were cultivated. Additional cell lines expressing closely related chemokine receptors, such as CXCR1,was also be established to determine selectivity.
The cold references synthesized in WP1 was evaluated in the assay against natural ligand IL-8, e.g.using [125I]IL-8, and compared to the lead compounds to determine binding affinity. Afterwards, precursors of selected ligands with favourable affinity and selectivity were synthesized and radiolabelled in WP3. The radiolabelled tracers were evaluated again in this assay for specificity cross-checking against original antagonists.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
We designed and synthesized PET tracer candidates targeting CXCR2 and then did in vitro assays to examine the binding affinity and stability of the compounds. To determine the PET ligands’ affinities and to determine selectivity, cell lines were cultivated expressing chemokine receptors, such as CXCR1, was also be established .
The cold references synthesized were evaluated in the assay against natural ligand IL-8 and compared to the lead compounds to determine binding affinity. Afterwards, precursors of selected ligands were synthesized and the radiolabelled tracers were evaluated in the assay for specificity cross-checking against original antagonists.
Since the initial second-year experimental plan has been completed, we believe that the research progress is generally on track.
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| 今後の研究の推進方策 |
In this project, we will develop neutrophil-specific PET imaging of inflammation by 1) targeting CXCR2, a chemokine receptor specifically expressed on neutrophils, 2) using molecular imaging with PET imaging technology that enables highly sensitive molecular detection, 3) designing an 18F-labeled small molecule tracer formulation suitable for clinical application, through evaluation in synthetic, cellular, and animal experiments.
We did in vitro assays and stablished and optimized radiolabelling methods of the PET tracers in the initial second-year. Next step, ex vivo analysis and biodistribution will be done: in vivo evaluation of at least one candidate tracer in a healthy rodent. Finally, we’ll do the longitudinal PET imaging using the rodent animal models of this disease.
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