Details

Autor(en) / Beteiligte

• Lechuga, Lawrence M.
• Forsberg, Matthew H.
• Walker, Kirsti L.
• Ludwig, Kai D.
• Capitini, Christian M.
• Fain, Sean B.

Titel

Detection and viability of murine NK cells in vivo in a lymphoma model using fluorine‐19 MRI

Ist Teil von

• NMR in biomedicine, 2021-12, Vol.34 (12), p.e4600-n/a

Ort / Verlag

England: Wiley Subscription Services, Inc

Erscheinungsjahr

2021

Quelle

Wiley

Beschreibungen/Notizen

• Natural killer (NK) cell therapies are being increasingly used as an adoptive cell therapy for cancer because they can recognize tumor cells in an antigen‐independent manner. While promising, the understanding of NK cell persistence, particularly within a harsh tumor microenvironment, is limited. Fluorine‐19 (19F) MRI is a noninvasive imaging modality that has shown promise in longitudinally tracking cell populations in vivo; however, it has not been studied on murine NK cells. In this study, the impact of 19F labeling on murine NK cell viability and function was assessed in vitro and then used to quantify NK cell persistence in vivo. While there was no noticeable impact on viability, labeling NK cells with 19F did attenuate cytotoxicity against lymphoma cells in vitro. Fluorescent microscopy verified 19F labeling in both the cytoplasm and nucleus of NK cells. Lymphoma‐bearing mice were given intratumoral injections of 19F‐labeled NK cells in which signal was detectable across the 6 day observation period via 19F MRI. Quantification from the composite images detected 78‐94% of the initially injected NK cells across 6 days, with a significant decrease between Days 3 and 6. Postmortem flow cytometry demonstrated retention of 19F intracellularly within adoptively transferred NK cells with less than 1% of 19F‐containing cells identified as tumor‐associated macrophages that presumably ingested nonviable NK cells. This work demonstrates that 19F MRI offers a specific imaging platform to track and quantify murine NK cells within tumors noninvasively. PFPE‐red‐labeled murine NK cells were characterized, detected, and quantified within lymphoma‐bearing mice up to 6 days after injection via 1H/19F‐MRI. Postmortem flow cytometry verified the existence of viable labeled NK cells within the tumor. This work demonstrates the ability to track murine NK cells in an adoptive cell transfer model.