Cellular therapeutics represent great potential for curing and alleviating symptoms associated with debilitating human diseases, such as cancer, cardiovascular disease, and neurological disorders. Currently, no versatile methodology for tracking cellular products following administration exists, leading to delays in these therapies reaching the clinic. The ability to visualize the trafficking of transferred cells throughout the body non-invasively will give clinicians the ability to better understand why certain cellular transplants are successful and others are not. In addition, determining the biodistribution of transferred cells is of paramount importance to overcome government regulatory hurdles for these therapies. In this study, we propose characterizing a novel fluorochemical cell tracking reagent recently created for use with MRI, called Cell Sense. This product is an emulsion of fluorine-containing nanoparticles that is used to label cells in culture and enables transferred cells to be visualized with great specificity in vivo using 19F MRI. Cell Sense has been tested extensively in mouse cells and imaged using in vivo rodent models. It has not yet been tested on clinically relevant human cells. In this proposal, we will examine the Cell Sense labeling characteristics in a variety of primary human immune cell types, including dendritic cells, natural killer cells, and T cells, that are currently being used in immunotherapeutic trials. Also, stem cells, including human neural progenitor cells (hNPC) and CD34+ cell types, will be studied. This proposal has two Specific Aims: (1) to develop ex vivo cell labeling protocols and examine the Cell Sense labeling dose in therapeutically relevant human cells; and (2) to determine whether the fluorochemical labeling has any detrimental impact on human cell viability or normal function. To achieve these Aims, we will employ an extensive battery of in vitro assays to assess cell loading, cytotoxicity, proliferation, phenotype, and function. Combining these results, we will be able to devise optimal labeling protocols for a diverse range of cell types that are currently being used for human clinical trials. By establishing Cell Sense's ability to label a wide variety of human cells with limited toxicity, we will have achieved a critical milestone in moving closer toward a clinical-grade product that can be used to track current transplanted cells for therapeutic use. We believe that the potential impact of Cell Sense is significant, by removing many of the scientific and regulatory hurdles that developers of cellular therapeutics for the clinic currently face. PUBLIC HEALTH RELEVANCE: Understanding how therapeutically relevant cell types behave following adoptive transfer or transplantation may help us develop novel therapies. This project examines the use of novel fluorochemical MRI reagents to image and detect labeled, transplanted cells non-invasively. The results of this study will move MRI cell tracking closer to clinical adoption and will provide researchers and physicians the opportunity to selectively follow labeled cells following administration. [unreadable] [unreadable] [unreadable]