Chemokine Receptor 2–targeted Molecular Imaging in Pulmonary Fibrosis. A Clinical Trial

Abstract

Idiopathic pulmonary fibrosis (IPF) is a progressive, inflammatory lung disease that is monitored clinically by measures of lung function, without effective molecular markers of disease activity or therapeutic efficacy. Lung immune cells active in the pro-fibrotic process include inflammatory monocyte and interstitial macrophages that express the C-C motif chemokine receptor 2 (CCR2). CCR2 + monocyte lung influx is essential for disease phenotypes in models of fibrosis and identified in lungs from subjects with IPF. Here, we show that our peptide-based radiotracer 64 Cu-DOTA-ECL1i identifies CCR2 + inflammatory monocytes and interstitial macrophages in multiple preclinical mouse models of lung fibrosis, using positron emission tomography (PET) imaging.Mice with bleomycin-induced fibrosis treated with blocking antibodies to interleukin-1b, a mediator of fibrosis associated with CCR2 + cell inflammation, or with pirfenidone, an approved anti-fibrotic agent, demonstrated decreased CCR2-dependent interstitial macrophage accumulation and reduced 64 Cu-DOTA-ECL1i PET uptake, compared to controls. Lung tissues from patients with fibrotic lung disease demonstrated abundant CCR2 + cells surrounding regions of fibrosis, and an ex vivo tissue-binding assay showed correlation between radiotracer localization and CCR2 + cells. In a phase 0/1 clinical study of 64 Cu-DOTA-ECL1i PET, healthy volunteers showed little lung uptake, while subjects with pulmonary fibrosis exhibited increased uptake, notably in zones of subpleural fibrosis, reflecting the distribution of CCR2 + cells in the profibrotic niche. These findings support a pathologic role of inflammatory lung monocytes/macrophages in fibrotic lung disease and the translational use of 64 Cu-DOTA-ECL1i PET to track CCR2-specific inflammation for image-guided therapy.

Pharmacological validation of SSc-ILD mouse model bleomycin-induced by osmotic minipump

“…A signi cant anti-in ammatory activity of NINT was noted only on WBC in BALF; on the contrary, only a mild and non-signi cant inhibition was observed in the M2-like population by FACS. Although the pivotal role of macrophages in IPF has been recently well reported 31,32 , the modulatory effect of NINT on macrophage polarization in vivo has been only demonstrated in Fra2 transgenic mice, ameliorating histological features of pulmonary arterial hypertension 33 . In human macrophages, NINT treatment was able to downregulate M2 markers of expression in vitro 34 .…”

EGFR-driven profibrotic signals in AKI-to-CKD transition are blocked by TNF inhibition: Opportunities for etanercept treatment

“…Single cell preparations were analyzed by mass cytometry as previously described 51 . Briefly, cells were labeled using a previously validated and titrated antibody cocktail for surface markers 51 (all antibodies conjugated by the manufacturer-Fluidigm) diluted in Fluidigm MaxPar Cell Staining Buffer (CSB) (1 hour at 4 °C). After two washes in CSB, cells were fixed in 2% PFA for 20 min at room temperature, washed, stained with MaxPar Intercalator-IR (Fluidigm) and filtered into cell strainer cap tubes.…”

Imaging Inflammation with Positron Emission Tomography

“…The authors later compared 68 Ga-to 64 Culabelled ECL1i in cardiac injury and found comparable radiotracer uptake in the ischemic area [101]. Recently, the group also reported proof-of-concept for 64 Cu-DOTA-ECL1i PET in the detection of abdominal aortic aneurysm (AAA) [36] and pulmonary fibrosis [37] in rodent models and human tissue. Remarkably, 64 Cu-DOTA-ECL1i uptake was twice as high in AAA that subsequently ruptured compared to non-ruptured AAA.…”

“…Mainly expressed on pro-inflammatory monocytes, natural killer cells and T cells Lung inflammation [34], cardiac injury [35], abdominal aortic aneurysm [36], pulmonary fibrosis [37] Promising [38], atherosclerosis [39], vascular inflammation [40,41], rheumatoid arthritis [42][43][44]…”