Comparison of three different methods for radiolabelling human activated T lymphocytes.
One approach in the treatment of ovarian cancer patients involves the infusion of autologous T lymphocytes coupled with a bispecific monoclonal antibody MOv18/anti-CD3 (biMAb OC/TR), which recognizes a 38-kDa glycoprotein expressed on ovarian carcinomas and the CD3 T cell receptor. However, little is known about the in vivo biodistribution of injected activated lymphocytes, information that could be obtained by scintigraphic imaging of radiolabelled T cells in order to visualize the migratory pattern. We compared the efficiency, stability and toxicity of technetium-99m hexamethylpropylene amine oxime (HMPAO), indium-111 oxine and fluorine-18 2-fluoro-2-deoxy-d-glucose (FDG) in radiolabelling activated lymphocytes targeted with biMAb OC/TR. The mean labelling efficiencies of 111In-oxine and 18F-FDG using 2.5x10(8) lymphocytes (68% and 64%, respectively) were more than twice that of 99mTc-HMPAO (31%). Retention of the radionuclide in the cell was highest in the case of 111In-oxine labelling (less than 25% of the initial cell-bound activity released after 240 min, as compared with 44% of the 99mTc label in the same period and 45% of 18F radionuclide released after 150 min). None of the three radiolabelling reagents induced any significant alteration in cell viability or immunophenotype. However, both 111In-oxine and 18F-FDG induced a loss of cytotoxic activity of lymphocytes against the ovarian carcinoma cell line IGROV1, and all three radiolabelling reagents caused a significant reduction in the proliferative ability of labelled lymphocytes compared to controls, with cell death occurring after 8-9 days. Radiolabelling with the more stable 111In-oxine reagent using a higher number of lymphocytes (1.4x10(9)) but the same total activity (around 55.5 MBq) resulted in improved labelled T cell viability and proliferative ability, although the mean labelling efficiency decreased (35.8%). Together the data suggest that 111In-oxine at low activity per cell is the most appropriate reagent for radiolabelling activated retargeted T lymphocytes useful for in vivo biodistribution studies.
Botti
C
C
Nuclear Medicine Department, National Cancer Institute, Milano, Italy.
Negri
D R
DR
Seregni
E
E
Ramakrishna
V
V
Arienti
F
F
Maffioli
L
L
Lombardo
C
C
Bogni
A
A
Pascali
C
C
Crippa
F
F
Massaron
S
S
Remonti
F
F
Nerini-Molteni
S
S
Canevari
S
S
Bombardieri
E
E
D016923:Cell Death; D002470:Cell Survival; D002478:Cells, Cultured; D003847:Deoxyglucose / Q000031:analogs & derivatives*; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007205:Indium Radioisotopes; D007553:Isotope Labeling / Q000379:methods*; D008213:Lymphocyte Activation; D009942:Organometallic Compounds; D015609:Organotechnetium Compounds; D010051:Ovarian Neoplasms / Q000276:immunology; D010091:Oximes; D015125:Oxyquinoline / Q000031:analogs & derivatives*; D013601:T-Lymphocytes / Q000276:immunology / Q000502:physiology*; D019690:Technetium Tc 99m Exametazime; D014407:Tumor Cells, Cultured
D005462:Fluorine Radioisotopes; D007205:Indium Radioisotopes; D009942:Organometallic Compounds; D015609:Organotechnetium Compounds; D010091:Oximes; D019788:Fluorodeoxyglucose F18; C032950:indium oxine; D019690:Technetium Tc 99m Exametazime; D015125:Oxyquinoline; D003847:Deoxyglucose