Visualizing cell–cell communication using synthetic notch activated MRI

Abstract

Cell–cell communication plays a fundamental role in multicellular organisms. Cell-based cancer immunotherapies rely on the ability of innate or engineered receptors on immune cells to engage specific antigens on cancer cells to induce tumor kill. To improve the development and translation of these therapies, imaging tools capable of noninvasively and spatiotemporally visualizing immune-cancer cell interactions would be highly valuable. Using the synthetic Notch (SynNotch) system, we engineered T cells that upon interaction with a chosen antigen (CD19) on neighboring cancer cells induce the expression of optical reporter genes and the human-derived, magnetic resonance imaging (MRI) reporter gene organic anion transporting polypeptide 1B3 (OATP1B3). Administration of engineered T cells induced the antigen-dependent expression of all our reporter genes in mice bearing CD19-positive tumors but not CD19-negative tumors. Notably, due to the high spatial resolution and tomographic nature of MRI, contrast-enhanced foci within CD19-positive tumors representing OATP1B3-expressing T cells were clearly visible and their distribution was readily mapped. We then extended this technology onto human natural killer-92 (NK-92) cells, observing similar CD19-dependent reporter activity in tumor-bearing mice. Furthermore, we show that when delivered intravenously, engineered NK-92 cells can be detected via bioluminescence imaging in a systemic cancer model. With continued work, this highly modular imaging strategy could aid in the monitoring of cell therapies in patients and, beyond this, augment our understanding of how different cell populations interact within the body during normal physiology or disease.

A Predictive Model for Evaluating Efficacy of Immunotherapy in Non-small-cell Lung Cancer Patients

“…Thus, we also screened the ATM gene as a candidate factor for constructing the model in the present study. Besides, Notch signaling is crucial for the differentiation and homeostasis of immune cells, which contributes to the modulation of organ-speci c immune responses [24,25]. Another study con rmed that the status of NOTCH could be considered a potential predictor of ICI response [26].…”

A synthetic Notch (synNotch) system linking intratumoral immune-cancer cell communication to a synthetic blood biomarker assay

“…However, in the context of multi-organ metastatic diseases, it is likely also important to obtain more spatial intertumoral information on the activity of immune cells. Non-invasive imaging tools like MRI and PET-based reporter genes can be used for this purpose as we and another group have recently demonstrated 28,29 . Future work to build response elements that encode both imaging and secreted reporter genes would allow both spatial information to be acquired with infrequent and relatively expensive imaging, and more frequent whole-body monitoring with relatively low-cost blood tests.…”

“…By maintaining the Notch core regulatory region but appending a customized extracellular input recognition and intracellular output transcription activator module, novel cell-to-cell contact signaling pathways that carry out user-defined functionalities can be established 25 . We have recently linked synNotch antigen binding with the transcriptional activation of imaging reporter genes to monitor immune cell-cancer cell communication in vivo with both bioluminescence and clinically relevant magnetic resonance imaging 28 . Similarly, a next-gen synNotch system has been linked to positron emission tomography (PET) reporter gene expression and antigen-activation has been detected using PET 29 .…”

A dual-gene reporter-amplifier architecture for enhancing the sensitivity of molecular MRI by water exchange

“…To overcome the sensitivity limitations of current MRI reporters, we sought to develop an approach that combines paramagnetic relaxation enhancement with increased transmembrane water diffusion through the expression of two genetic constructs: an organic anion-transporting polypeptide, 1b3 (Oatp1b3), and a water channel, aquaporin-1 (Aqp1). Oatp1b3 is a hepatic drug transporter 36 that functions as an MRI reporter, because it facilitates the uptake of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) 37 , a clinically approved contrast agent 23,28,[38][39][40] . This results in shortening of the T 1 of water molecules within Oatp1b3-expressing cells, thereby enabling their visualization through T 1 -weighted MRI (Fig.…”