AUTHOR=Perrin Justine , Capitao Marisa , Mougin-Degraef Marie , Guérard François , Faivre-Chauvet Alain , Rbah-Vidal Latifa , Gaschet Joëlle , Guilloux Yannick , Kraeber-Bodéré Françoise , Chérel Michel , Barbet Jacques 

TITLE=Cell Tracking in Cancer Immunotherapy

JOURNAL=Frontiers in Medicine

VOLUME=Volume 7 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2020.00034

DOI=10.3389/fmed.2020.00034

ISSN=2296-858X

ABSTRACT=The impressive development of immunotherapy in the last few years
originates from a more precise understanding of control mechanisms in the
immune system that leads to the discovery of new targets and new
therapeutic tools. Indeed at different stages of disease progression
elicit different local and systemic inflammatory responses, the ability to
longitudinally interrogate the migration and expansion of immune cells
throughout the whole body will greatly facilitate disease characterization
and guide selection of appropriate treatment regiments.
While using radiolabeled white blood cells to detect inflammatory lesions
has been a classical nuclear medicine technique for years, new
non-invasive methods for monitoring the distribution and migration of
biologically active cells in living organisms have emerged. They are
designed to improve the detection sensitivity and allow for a better
preservation of cell activity and integrity. These methods include the
monitoring of labeled therapeutic cells but also of
all cells related to a specific disease or therapeutic approach. Labeling
of therapeutic cells for imaging may now be performed in vitro, with some limitations
on sensitivity and duration of observation. Alternatively, in vivo
labeling may be performed by genetically engineered cells or mice that may
be revealed in vivo through imaging. In addition, SPECT or PET imaging
based on monoclonal antibodies have been used to detect tumors in the
human body for years. They may be used to detect and possibly quantify the
presence of specific cells within the lesions.
These methods have been the object of several recent reviews that have
concentrated on technical aspects, stressing the differences between
direct and indirect labeling. They are described here by distinguishing ex
vivo (labeling cells with paramagnetic, radioactive or fluorescent
tracers) and in vivo (in vivo capture of radioactive, fluorescent or
luminescent tracers injected, or directly by using labeled antibodies,
ligands or pretargeted clickable substrates) imaging methods. Cell
tracking in specific therapeutic applications, namely cell therapy, and
particularly CAR (Chimeric Antigen Receptor) T-cell therapy, is a
fast-growing research field with various therapeutic indications. The potential
impact of imaging on the progress of these new therapeutic modalities is
discussed.