In vivo imaging of T cells loaded with gold nanoparticles: A pilot study

Purpose: Malignant tumours develop strategies to avoid immune recognition and elimination by T cells, even in individuals with a fully functioning immune system. To explore the treatment approach of adoptive immunotherapy, we exploited T cells loaded with radiolabelled gold nanoparticles (AuNPs) to track T cells in vivo. Materials and methods: Surface-modified AuNPs were radiolabelled with ¹¹¹In or ⁶⁴Cu. They were then transferred into T cells via electroporation. To evaluate the effectiveness of this process, T cells loaded with ¹¹¹In-radiolabelled AuNPs were injected directly into the right lung of nude mice for in vivo imaging by micro-SPECT/CT. T cells loaded with ⁶⁴Cu-radiolabelled AuNPs were then injected into the tail vein of nude mice and imaged by micro-PET/CT. Results: High uptake signals were observed in the right lung following the direct injection of T cells containing ¹¹¹In-labelled AuNPs. Imaging showed a marked difference in the dynamic biodistribution of T cells containing ⁶⁴Cu-labelled AuNPs when compared with ⁶⁴Cu-labelled AuNPs alone. Conclusions: This study demonstrated the feasibility of the in vivo imaging of T cells loaded with radiolabelled AuNPs.