Quantification and tracking of genetically engineered dendritic cells for studying immunotherapy

• Published in: Magnetic resonance in medicine Vol. 79; no. 2; pp. 1010 - 1019
• Main Authors: Bar‐Shir, Amnon, Alon, Lina, Korrer, Michael J., Lim, Hong Seo, Yadav, Nirbhay N., Kato, Yoshinori, Pathak, Arvind P., Bulte, Jeff W.M., Gilad, Assaf A.
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.02.2018
• Subjects: Animal models; Animals; Bioengineering; Biological activity; Biomedical Research - methods; Brain; Brain cancer; Brain Neoplasms - diagnostic imaging; Brain Neoplasms - therapy; Brain tumors; Cell Tracking - methods; Comparative analysis; Cytometry; Dendritic cells; dendritic cells (DCs); Dendritic Cells - chemistry; Dendritic Cells - cytology; Dendritic Cells - metabolism; Deoxycytidine - analogs & derivatives; Deoxycytidine - analysis; Deoxycytidine - chemistry; Deoxycytidine - metabolism; Drosophila melanogaster - enzymology; Drosophila melanogaster - genetics; drosophila melanogaster 2′‐deoxynucleoside kinase (Dm‐dNK); Flow Cytometry; fluorescence‐activated cell sorting (FACS); Fruit flies; Genes, Insect - genetics; Genes, Reporter - genetics; Genetic code; Genetic engineering; Genetic Engineering - methods; HEK293 Cells; Humans; Identification methods; Immunotherapy; Immunotherapy - methods; Kinases; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; MRI; Neoplasms, Experimental - diagnostic imaging; Neoplasms, Experimental - therapy; Neuroimaging; Nucleoside analogs; Optical properties; Phosphotransferases (Alcohol Group Acceptor) - genetics; Phosphotransferases (Alcohol Group Acceptor) - metabolism; Pyrroles - analysis; Pyrroles - chemistry; Pyrroles - metabolism; pyrrolo‐2′‐deoxycytidine (pyrrolo‐dC); Reporter gene; Tracking; fluorescence-activated cell sorting (FACS); dendritic cells (DCs); Reporter gene; drosophila melanogaster 2′-deoxynucleoside kinase (Dm-dNK); MRI; pyrrolo-2′-deoxycytidine (pyrrolo-dC)
• ISSN: 0740-3194; 1522-2594; 1522-2594
• DOI: 10.1002/mrm.26708

Purpose Genetically encoded reporters can assist in visualizing biological processes in live organisms and have been proposed for longitudinal and noninvasive tracking of therapeutic cells in deep tissue. Cells can be labeled in situ or ex vivo and followed in live subjects over time. Nevertheless, a major challenge for reporter systems is to identify the cell population that actually expresses an active reporter. Methods We have used a nucleoside analog, pyrrolo‐2′‐deoxycytidine, as an imaging probe for the putative reporter gene, Drosophila melanogaster 2′‐deoxynucleoside kinase. Bioengineered cells were imaged in vivo in animal models of brain tumor and immunotherapy using chemical exchange saturation transfer MRI. The number of transduced cells was quantified by flow cytometry based on the optical properties of the probe. Results We performed a comparative analysis of six different cell lines and demonstrate utility in a mouse model of immunotherapy. The proposed technology can be used to quantify the number of labeled cells in a given region, and moreover is sensitive enough to detect less than 10,000 cells. Conclusion This unique technology that enables efficient selection of labeled cells followed by in vivo monitoring with both optical and MRI. Magn Reson Med 79:1010–1019, 2018. © 2017 International Society for Magnetic Resonance in Medicine.