PET/CT imaging of CSF1R in a mouse model of tuberculosis

Purpose Macrophages represent an essential means of sequestration and immune evasion for Mycobacterium tuberculosis. Pulmonary tuberculosis (TB) is characterized by dense collections of tissue-specific and recruited macrophages, both of which abundantly express CSF1R on their outer surface. 4-Cyano-N-(5-(1-(dimethylglycyl)piperidin-4-yl)-2',3',4',5'-tetrahydro-[1,1'-biphenyl]-2-yl)-1H-imidazole-2-carboxamide (JNJ-28312141) is a reported high affinity, CSF1R-selective antagonist. We report the radiosynthesis of 4-cyano-N-(5-(1-(N-methyl-N-([11C]methyl)glycyl)piperidin-4-yl)-2',3',4',5'-tetrahydro-[1,1'-biphenyl]-2-yl)-1H-imidazole-2-carboxamide ([11C]JNJ-28312141) and non-invasive detection of granulomatous and diffuse lesions in a mouse model of TB using positron emission tomography (PET). Methods Nor-methyl-JNJ-28312141 precursor was radiolabeled with [11C]iodomethane to produce [11C]JNJ-28312141. PET/CT imaging was performed in the C3HeB/FeJ murine model of chronic pulmonary TB to co-localize radiotracer uptake with granulomatous lesions observed on CT. Additionally, CSF1R, Iba1 fluorescence immunohistochemistry was performed to co-localize CSF1R target with reactive macrophages in infected and healthy mice. Results Radiosynthesis of [11C]JNJ-28312141 averaged a non-decay-corrected yield of 18.7 ± 2.1%, radiochemical purity of 99%, and specific activity averaging 658 ± 141 GBq/µmol at the end-of-synthesis. PET/CT imaging in healthy mice showed hepatobiliary [13.39–25.34% ID/g, percentage of injected dose per gram of tissue (ID/g)] and kidney uptake (12.35% ID/g) at 40–50 min post-injection. Infected mice showed focal pulmonary lesion uptake (5.58–12.49% ID/g), hepatobiliary uptake (15.30–40.50% ID/g), cervical node uptake, and renal uptake (11.66–29.33% ID/g). The ratio of infected lesioned lung/healthy lung uptake is 5.91:1, while the ratio of lesion uptake to adjacent infected radiolucent lung is 2.8:1. Pre-administration of 1 mg/kg of unlabeled JNJ-28312141 with [11C]JNJ-28312141 in infected animals resulted in substantial blockade. Fluorescence microscopy of infected and uninfected whole lung sections exclusively co-localized CSF1R staining with abundant Iba1 + macrophages. Healthy lung exhibited no CSF1R staining and very few Iba1 + macrophages. Conclusion [11C]JNJ-28312141 binds specifically to CSF1R + macrophages and delineates granulomatous foci of disease in a murine model of pulmonary TB..

Medienart:

Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:49

Enthalten in:

European journal of nuclear medicine & molecular imaging - 49(2022), 12 vom: 17. Juni, Seite 4088-4096

Sprache:

Englisch

Beteiligte Personen:

Foss, Catherine A. [VerfasserIn]
Ordonez, Alvaro A. [VerfasserIn]
Naik, Ravi [VerfasserIn]
Das, Deepankar [VerfasserIn]
Hall, Andrew [VerfasserIn]
Wu, Yunkou [VerfasserIn]
Dannals, Robert F. [VerfasserIn]
Jain, Sanjay K. [VerfasserIn]
Pomper, Martin G. [VerfasserIn]
Horti, Andrew G. [VerfasserIn]

Links:

Volltext [lizenzpflichtig]

Themen:

CD115
CSF1R
Granulomas
M-CSFR
Macrophages
PET
TB

Anmerkungen:

© The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2022

doi:

10.1007/s00259-022-05862-1

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

OLC2079650386