English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Purpose : Among the treatment options for pancreatic ductal adenocarcinoma (PDAC) are antibodies against the programmed cell death receptor 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway. Positron emission tomography (PET) has been successfully used to assess PD-1/PD-L1 signaling in subcutaneous tumor models, but orthotopic tumor models are increasingly being recognized as a better option to accurately recapitulate human disease. However, when PET radiotracers have high uptake in the liver and spleen, it can obscure signals from the adjacent pancreas, making visualization of the response in orthotopic pancreatic tumors technically challenging. In this study, we first investigated the impact of radioisotope chelators on the biodistribution of 64 Cu-labeled anti-PD-1 and anti-PD-L1 antibodies and compared the distribution profiles of anti-PD-1 and anti-PD-L1 antibodies. We then tested the hypothesis that co-injection of unlabeled antibodies reduces uptake of 64 Cu-labeled anti-PD-L1 antibodies in the spleen and thereby permits accurate delineation of orthotopic pancreatic tumors in mice. Procedures : We established subcutaneous and orthotopic mouse models of PDAC using KRAS* murine pancreatic cancer cells with a doxycycline-inducible mutation of KRAS G12D . We then (1) compared the biodistribution of 64 Cu-labeled anti-PD-1 with 2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane tetraacetic acid ( p -SCN-Bn-DOTA) and 2-(4-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid ( p -SCN-Bn-NOTA) used as the chelators in the orthotopic model; (2) compared the biodistribution of [ 64 Cu]Cu-NOTA-anti-PD-1 and [ 64 Cu]Cu-NOTA-anti-PD-L1 in the orthotopic model; and (3) imaged subcutaneous and orthotopic KRAS* tumors with [ 64 Cu]Cu-NOTA-anti-PD-L1 with and without co-injection of unlabeled anti-PD-L1 as the blocking agent. Results : [ 64 Cu]Cu-NOTA-anti-PD-L1 was a promising imaging probe. By co-injection of an excess of unlabeled anti-PD-L1, background signals of [ 64 Cu]Cu-NOTA-anti-PD-L1 from the spleen were significantly reduced, leading to a clear delineation of orthotopic pancreatic tumors. Conclusions : Co-injection with unlabeled anti-PD-L1 is a useful method for PET imaging of PD-L1 expression in orthotopic pancreatic cancer models.

acs omega

Concurrent Injection of Unlabeled Antibodies Allows Positron Emission Tomography Imaging of Programmed Cell Death Ligand 1 Expression in an Orthotopic Pancreatic Tumor Model