Quantification and characterization of granulocyte macrophage colony-stimulating factor activated human peripheral blood mononuclear cells by fluorine-19 cellular MRI in an immunocompromised mouse model.

Purpose: The purpose of this study was to test fluorine-19 (19F) cellular magnetic resonance (MRI) as a non-invasive imaging modality to track therapeutic cell migration as a surrogate marker of immunotherapeutic effectiveness.

Materials And Methods: Human peripheral blood mononuclear cell- (PBMC)-derived antigen presenting cell (APC) were labeled with a 19F-perfluorocarbon (PFC) and/or activated with granulocyte macrophage colony-stimulating factor (GM-CSF). Viability, phenotype and cell lineage characterization preceded 19F cellular MRI of PFC PBMC under both pre-clinical 9.4 Tesla (T) and clinical 3T conditions in a mouse model.

Results: A high proportion of PBMC incorporated PFC without affecting viability, phenotype or cell lineage composition. PFC PBMC were in vivo migration-competent to draining and downstream lymph nodes. GM-CSF addition to culture increased PBMC migration to, and persistence within, secondary lymphoid organs.

Conclusion: 19F cellular MRI is a non-invasive imaging technique capable of detecting and quantifying in vivo cell migration in conjunction with an established APC-based immunotherapy model. 19F cellular MRI can function as a surrogate marker for assessing and improving upon the therapeutic benefit that this immunotherapy provides.