title: Imaging TCR-dependent NFAT-mediated T-cell activation with positron emission tomography in vivo.
abstract: A noninvasive method for molecular imaging of T-cell activity in vivo would be of considerable value. It would aid in understanding the role of specific genes and signal transduction pathways in the course of normal and pathologic immune responses, and could elucidate temporal dynamics and immune regulation at different stages of disease and following therapy. We developed and assessed a novel method for monitoring the T-cell receptor (TCR)-dependent nuclear factor of activated T cells (NFAT)-mediated activation of T cells by optical fluorescence imaging (OFI) and positron emission tomography (PET). The herpes simplex virus type 1 thymidine kinase/green fluorescent protein [HSV1-tk/GFP (TKGFP)] dual reporter gene was used to monitor NFAT-mediated transcriptional activation in human Jurkat cells. A recombinant retrovirus bearing the NFAT-TKGFP reporter system was constructed in which the TKGFP reporter gene was placed under control of an artificial cis-acting NFAT-specific enhancer. Transduced Jurkat cells were used to establish subcutaneous infiltrates in nude rats. We demonstrated that noninvasive OFI and nuclear imaging of T-cell activation is feasible using the NFAT-TKGFP reporter system. PET imaging with [(124)I]FIAU using the NFAT-TKGFP reporter system is sufficiently sensitive to detect T-cell activation in vivo. PET images were confirmed by independent measurements of T-cell activation (e.g., CD69) and induction of GFP fluorescence. PET imaging of TCR-induced NFAT-dependent transcriptional activity may be useful in the assessment of T cell responses, T-cell-based adoptive therapies, vaccination strategies and immunosuppressive drugs.
authors.affiliation: Departments of Neurology and Radiology, Memorial Sloan Kettering Cancer Center, New York, NY 10021, USA.
authors.forename: V
authors.initials: V
authors.lastname: Ponomarev
authors.forename: M
authors.initials: M
authors.lastname: Doubrovin
authors.forename: C
authors.initials: C
authors.lastname: Lyddane
authors.forename: T
authors.initials: T
authors.lastname: Beresten
authors.forename: J
authors.initials: J
authors.lastname: Balatoni
authors.forename: W
authors.initials: W
authors.lastname: Bornman
authors.forename: R
authors.initials: R
authors.lastname: Finn
authors.forename: T
authors.initials: T
authors.lastname: Akhurst
authors.forename: S
authors.initials: S
authors.lastname: Larson
authors.forename: R
authors.initials: R
authors.lastname: Blasberg
authors.forename: M
authors.initials: M
authors.lastname: Sadelain
authors.forename: J G
authors.initials: JG
authors.lastname: Tjuvajev
mesh_terms: D000818:Animals; D004268:DNA-Binding Proteins / Q000502:physiology*; D004742:Enhancer Elements, Genetic; D005240:Feasibility Studies; D005434:Flow Cytometry; D005470:Fluorometry; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D006801:Humans; D007279:Injections, Subcutaneous; D007376:Interleukin-2 / Q000096:biosynthesis / Q000235:genetics; D019169:Jurkat Cells / Q000276:immunology* / Q000378:metabolism / Q000637:transplantation; D008164:Luminescent Proteins / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics; D008213:Lymphocyte Activation / Q000235:genetics / Q000502:physiology*; D051379:Mice; D050778:NFATC Transcription Factors; D009363:Neoplasm Proteins / Q000276:immunology; D009687:Nuclear Proteins; D011401:Promoter Regions, Genetic / Q000235:genetics; D051381:Rats; D011923:Rats, Nude; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D012680:Sensitivity and Specificity; D015398:Signal Transduction; D013937:Thymidine Kinase / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics; D014055:Tomography, Emission-Computed; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D004268:DNA-Binding Proteins; D007376:Interleukin-2; D008164:Luminescent Proteins; D050778:NFATC Transcription Factors; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011948:Receptors, Antigen, T-Cell; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D049452:Green Fluorescent Proteins; D013937:Thymidine Kinase