|Title||Molecular imaging with macrophage CRIg-targeting nanobodies for early and preclinical diagnosis in a mouse model of rheumatoid arthritis.|
|Publication Type||Journal Article|
|Year of Publication||2014|
|Authors||Zheng, F., S. Put, L. Bouwens, T. Lahoutte, P. Matthys, S. Muyldermans, P. De Baetselier, N. Devoogdt, G. Raes, and S. Schoonooghe|
|Journal||J Nucl Med|
|Date Published||2014 May|
|Keywords||Animals, Arthritis, Experimental, Arthritis, Rheumatoid, Disease Models, Animal, Immunohistochemistry, Inflammation, Macrophages, Male, Mice, Mice, Inbred C57BL, Mice, Inbred DBA, Molecular Imaging, Radiopharmaceuticals, Real-Time Polymerase Chain Reaction, Receptors, Complement, RNA, Messenger, Single-Domain Antibodies, Synovial Membrane, Technetium, Tomography, Emission-Computed, Single-Photon, X-Ray Microtomography|
UNLABELLED: An accurate and noninvasive tracer able to detect molecular events underlying the development of rheumatoid arthritis (RA) would be useful for RA diagnosis and drug efficacy assessment. A complement receptor of the Ig superfamily (CRIg) is expressed on synovial macrophages of RA patients, making it an interesting target for molecular imaging of RA. We aim to develop a radiotracer for the visualization of CRIg in a mouse model for RA using radiolabeled single-domain variable antibody VHH fragments (Nanobodies).METHODS: Quantitative polymerase chain reaction was used to locate CRIg expression in mice with collagen-induced arthritis (CIA). A Nanobody, NbV4m119, was generated to specifically target CRIg. Flow cytometry, phosphorimaging, and confocal microscopy were used to confirm NbVm119 binding to CRIg-positive cells. SPECT (SPECT/CT) was used to image arthritic lesions in the inflamed paws of 29 mice using (99m)Tc-NbV4m119 Nanobody.RESULTS: CRIg is constitutively expressed in the liver and was found to be upregulated in synovial tissues of CIA mice. SPECT/CT imaging revealed that (99m)Tc-NbV4m119 specifically targeted CRIg-positive liver macrophages in naïve wild-type but not in CRIg(-/-) (CRIg knockout) mice. In CIA mice, (99m)Tc-NbV4m119 accumulation in arthritic lesions increased according to the severity of the inflammation. In the knees of mice with CIA, (99m)Tc-NbV4m119 was found to accumulate even before the onset of macroscopic clinical symptoms.CONCLUSION: SPECT/CT imaging with (99m)Tc-NbV4m119 visualizes joint inflammation in CIA. Furthermore, imaging could predict which mice will develop clinical symptoms during CIA. Consequently, imaging of joint inflammation with CRIg-specific Nanobodies offers perspectives for clinical applications in RA patients.
|Alternate Journal||J. Nucl. Med.|
Molecular imaging with macrophage CRIg-targeting nanobodies for early and preclinical diagnosis in a mouse model of rheumatoid arthritis.