title: 18F-FDG labelling of hematopoietic stem cells: Dynamic study of bone marrow homing by PET-CT imaging and impact on cell functionality.
abstract: OBJECTIVE
  After transplantation, cord blood (CB) hematopoietic stem and progenitor cells (HSPCs) are able to home to the bone marrow niche and to reconstitute the hematopoietic system. PET-CT imaging may be a useful method to monitor this parameter in different conditions. The aim of our study was to set up an efficient method for HSPC radiolabelling with [18F] fluorodeoxyglucose (18F-FDG) and to follow early HSPC homing through PET-CT in mice.
  
  
  METHODS
  Purified CB HSPCs were radiolabelled with18F-FDG at 37° C with various conditions of cell concentration, incubation time and radioactivity concentration in order to define the in vitro condition that allows both sufficient18F-FDG uptake to get high quality PET imaging, and preservation of HSPC viability and functional properties during 3h after radiolabelling. Then, 24h after 2.25Gy irradiation, eight NOD-scid/γc-/-mice were injected with18F-FDG-labelled HSPCs, the biodistribution of which was followed using micro-PET-CT.
  
  
  RESULTS
  The optimal incubation time was 45min with a stability of 48.3%±12.8% after 180min. The radio-uptake rate we obtained was 7.2%±1.7% with an activity of 5.6±2.1 MBq. Three hours after radiolabelling, viability was 96.7%±3.4%. Fifteen hours after radiolabelling, cell viability was 64.0%±2.3%, migration ability diminished from 51.0%±23.6% to 12.0%±9.1%, clonogenic capacity was null, and long-term engraftment in NSG mice also decreased compared to unlabelled cells. Micro-PET-CT experiments showed an accumulation of radiolabelled HSPCs for 2.5h after injection in the bone marrow and a slight elution of18F-FDG.
  
  
  CONCLUSIONS
  The activity of the obtained18F-FDG-labelled HSPCs was sufficient to perform the micro-PET-CT imaging. Although the radiolabelling had a significant toxicity on HSPCs 15h after labelling, this technique allowed monitoring the beginning of HSPC homing into the bone marrow.
authors.affiliation: Inserm, U 1160, centre d'investigation clinique en biothérapies, 75010 Paris, France; AP-HP, hôpital Saint-Louis, unité de thérapie cellulaire, 1, avenue Claude-Vellefaux, 75010 Paris, France. Electronic address: lionel.faivre@aphp.fr.
authors.forename: L
authors.initials: L
authors.lastname: Faivre
authors.affiliation: AP-HP, hôpital Saint-Louis, unité Claude-Kellershohn, 75010 Paris, France. Electronic address: michael.chaussard@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Chaussard
authors.affiliation: AP-HP, hôpital Saint-Louis, médecine nucléaire, 75010 Paris, France. Electronic address: laetitia.vercellino@aphp.fr.
authors.forename: L
authors.initials: L
authors.lastname: Vercellino
authors.affiliation: Inserm, U 1160, centre d'investigation clinique en biothérapies, 75010 Paris, France; AP-HP, hôpital Saint-Louis, unité de thérapie cellulaire, 1, avenue Claude-Vellefaux, 75010 Paris, France. Electronic address: valerie.vanneaux@aphp.fr.
authors.forename: V
authors.initials: V
authors.lastname: Vanneaux
authors.affiliation: AP-HP, hôpital Saint-Louis, unité Claude-Kellershohn, 75010 Paris, France; Inserm, U1144, 75006 Paris, France; Université Paris-Descartes, faculté de pharmacie, 75006 Paris, France. Electronic address: benoit.hosten@aphp.fr.
authors.forename: B
authors.initials: B
authors.lastname: Hosten
authors.affiliation: AP-HP, hôpital Saint-Louis, unité Claude-Kellershohn, 75010 Paris, France. Electronic address: kellypteixeira@gmail.com.
authors.forename: K
authors.initials: K
authors.lastname: Teixera
authors.affiliation: Université Paris-Diderot, institut universitaire d'hématologie, hôpital Saint-Louis, département d'expérimentation d'animale, 75010 Paris, France. Electronic address: veronique.parietti@paris7.jussieu.fr.
authors.forename: V
authors.initials: V
authors.lastname: Parietti
authors.affiliation: AP-HP, hôpital Saint-Louis, médecine nucléaire, 75010 Paris, France; Université Paris-Diderot, Sorbonne-Paris-Cité, U 1160, 75010 Paris France. Electronic address: pascal.merlet@aphp.fr.
authors.forename: P
authors.initials: P
authors.lastname: Merlet
authors.affiliation: AP-HP, hôpital Saint-Louis, unité Claude-Kellershohn, 75010 Paris, France; AP-HP, hôpital Lariboisière, médecine nucléaire, 75010 Paris, France; Inserm UMR-S 942, hôpital Lariboisière, 75010 Paris, France. Electronic address: laure.sarda-mantel@aphp.fr.
authors.forename: L
authors.initials: L
authors.lastname: Sarda-Mantel
authors.affiliation: AP-HP, hôpital Saint-Louis, unité Claude-Kellershohn, 75010 Paris, France; Inserm, U1144, 75006 Paris, France; Université Paris-Descartes, faculté de pharmacie, 75006 Paris, France. Electronic address: nathalie.rizzo@aphp.fr.
authors.forename: N
authors.initials: N
authors.lastname: Rizzo-Padoin
authors.affiliation: Inserm, U 1160, centre d'investigation clinique en biothérapies, 75010 Paris, France; AP-HP, hôpital Saint-Louis, unité de thérapie cellulaire, 1, avenue Claude-Vellefaux, 75010 Paris, France; Université Paris-Diderot, Sorbonne-Paris-Cité, U 1160, 75010 Paris France. Electronic address: jerome.larghero@aphp.fr.
authors.forename: J
authors.initials: J
authors.lastname: Larghero
mesh_terms: D000818:Animals; D001853:Bone Marrow; D002455:Cell Division; D002465:Cell Movement; D002478:Cells, Cultured; D002999:Clone Cells; D036101:Cord Blood Stem Cell Transplantation; D005462:Fluorine Radioisotopes / Q000032:analysis*; D019788:Fluorodeoxyglucose F18 / Q000032:analysis*; D006085:Graft Survival; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D064593:Heterografts; D006801:Humans; D007553:Isotope Labeling / Q000379:methods; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D009928:Organ Specificity; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods; D019275:Radiopharmaceuticals / Q000032:analysis*; D014781:Viscera
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C000615276:Fluorine-18
keywords: Fluorodeoxyglucose F18; Hematopoietic stem cells; Homing behavior; PET–CT; Radiolabelling; Radiotoxicity