Preparation of human immune effector T cells containing iron‐oxide nanoparticles

Abstract

Preparation of human immune T cells containing iron-oxide nanoparticles was carried out for the development of magnetically mediated immunotherapy. Peripheral blood lymphocytes (PBLs) after the incubation with magnetite nanoparticles were found to contain measurable ferric ions, which suggested the incorporation of magnetite nanoparticles. Transmission electron microscopic (TEM) study indicated that the incorporation of magnetite nanoparticles was mediated by endocytosis of PBLs. Furthermore, the effects of dosages and diameter of magnetite nanoparticles on the magnetite incorporation were investigated, and it was demonstrated that the increase in dosage promoted the incorporation of nanoparticles and the uptake into PBLs was more effective for magnetite nanoparticles, which formed smaller aggregations in medium. Finally, the demonstration of magnetite incorporation into enriched T cells and tumor antigen-specific cytotoxic T lymphocyte (CTL) line promises the achievement of magnetically mediated immunotherapy with tumor-specific CTLs containing magnetic nanoparticles.

Application of magnetic field hyperthermia and superparamagnetic iron oxide nanoparticles to HIV-1-specific T-cell cytotoxicity

“…Previous studies have shown endosomal SPION uptake into CTLs for the purpose of T-cell tracking through the body by magnetic resonance imaging (MRI) 33,35 and T-cell magnetically mediated immunothermotherapy for melanoma. 34 As seen in other studies, we observed endosomally located Feraspin R, and the uptake increases dose-dependently and on transfection-agent treatment (Figures 1 and 2). SQUID has advantages over other ironquantification methods, such as inductive coupled plasma atomic absorption spectroscopy and atomic absorption spectroscopy, 38 which likely overestimate iron levels by not distinguishing between nonparamagnetic and paramagnetic iron.…”

“…SQUID has advantages over other ironquantification methods, such as inductive coupled plasma atomic absorption spectroscopy and atomic absorption spectroscopy, 38 which likely overestimate iron levels by not distinguishing between nonparamagnetic and paramagnetic iron. Iron concentrations are calculated indirectly in the colorimetric potassium thiocyanate method, 34 on the assumption that full oxidation or reduction of a dissolved sample occurs. A concentration of 53 pg/cell ( Figure 2B) was measured in our study poststarvation and on protamine sulfate treatment, a much higher value than that observed by Beer et al, 33 but our results matched those observed using Resovist analogues in other cell types.…”

“…54 The effect of nanoparticle uptake on CTL killing ability is poorly characterized. Interferon-gamma secretion enzymelinked immunosorbent assays previously used for this purpose 34 do not directly measure CTL killing ability, and chromium-release assays 33,35 have a number of disadvantages, including a high spontaneous leakage rate, effect of 51 Cr on the effector cell population, the fact that certain cell types cannot be labeled properly, insensitivity, and safety issues associated with the use of gamma radiation. 48 In the FATAL assay, there is 40× less spontaneous leakage, a more accurate assessment of the E:T ratio can be demonstrated, and lower levels of CTL-specific lysis.…”

“…30 The application of SPIONs to HIV has been proposed as a technique for tracking HIV-specific CTLs to enhance vaccine delivery, as well as a possible therapeutic approach to targeting HIV-infected cells, 31,32 since CTLs are permissive to SPION uptake. [33][34][35] Resovist is a 60 nm carboxydextrancoated SPION with superior cellular uptake properties [36][37][38] and a higher heating capability, or calculated intrinsic loss power, than other SPIONs, 39 such as clinically available Endorem (sample VII). 40 However, since Resovist is now commercially unavailable, Feraspin R, a closely related SPION formula with very similar properties to Resovist, 41 was employed to study the feasibility of using MFH to enhance CTL killing of HIV-infected cells by two distinct mechanisms.…”

“…More sensitive methods to assay SPION uptake, 33,34,[36][37][38]43 toxicity, 33,[36][37][38]43 and effect on 868 TCR-transduced CTL function were developed, [33][34][35] and SPION uptake was optimized using Lipofectamine and US Food and Drug Administration (FDA)-approved protamine sulfate. These optimized assays were then used to test if thermotherapy could impact HIV-1 CTL function.…”