Cathryn Parsons

MRI cell tracking can be used to monitor immune cells involved in the immunotherapy response, providing insight into the mechanism of action, temporal progression of tumor growth, and individual potency of therapies. To evaluate whether MRI could be used to track immune cell populations in response to immunotherapy, CD8 cytotoxic T cells, CD4 CD25 FoxP3 regulatory T cells, and myeloid-derived suppressor cells were labeled with superparamagnetic iron oxide particles. Superparamagnetic iron oxide-labeled cells were injected into mice (one cell type/mouse) implanted with a human papillomavirus-based cervical cancer model. Half of these mice were also vaccinated with DepoVax (ImmunoVaccine, Inc., Halifax, Nova Scotia, Canada), a lipid-based vaccine platform that was developed to enhance the potency of peptide-based vaccines. MRI visualization of CD8 cytotoxic T cells, regulatory T cells, and myeloid-derived suppressor cells was apparent 24 h post-injection, with hypointensities due to i...