Comparison of three different methods for radiolabelling human activated T lymphocytes

Abstract

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.

Evaluation of ex vivo expanded human NK cells on antileukemia activity in SCID-beige mice

“…35 It is unlikely that indium or CFSE labeling could impact the distribution or half-life of NK cells. Indium and CFSE bind to the cells in two different ways, 32,36 but in both cases the results were comparable; indicating that neither of the stainings affected the obtained results.…”

“…Indium labeling of human leukocyte is a common practice in the clinic and it has been shown to be well tolerated by human cells. 32 The human NK cells stained with Indium could be followed during their in vivo. However, quantification of the human NK cells infiltrating different organs is more difficult with this system.…”

64 Cu antibody-targeting of the T-cell receptor and subsequent internalization enables in vivo tracking of lymphocytes by PET

“…2C) (7,10,17). This high trapping stability enables the use of less activity combined with a short exposure time, thereby preventing cell damage while still yielding quantitative, high-quality, low-noise PET images.…”

Isolation and 111In–Oxine Labeling of Murine NK Cells for Assessment of Cell Trafficking in Orthotopic Lung Tumor Model

“…[15][16][17] However, some other PET imaging isotopes have also been proposed for human lymphocyte, stem cell and mouse cancer cell labeling that includes 99m Tc-HMPAO, 18 F-FDG, 64 Cu and recently published 89 Zr, each one has its own benefits and drawbacks. [17][18][19][20] Nevertheless, few studies also attempted to specifically image human NK cells using indirect approaches that comprise labeling of genetically modified human NK cell line NK-92-scFv(FRP5)-zeta with 18 F-FDG, 21 and use of 99m Tc-anti-CD56 antibody against human NK cells. 22 In the present study, we evaluated the isolation and ex-vivo 111 In-oxine labeling of murine NK cells for monitoring physiological distribution and in-vivo kinetics in an orthotopic model of A549 human lung cancer in mice.…”