| Summary: | The ability to manipulate the immune system to induce protection against tumour, is one of the most fascinating challenges in immunology. In this regard, TCR gene transfer is an attractive and powerful strategy to generate high numbers of tumour antigen-specific T cells for adoptive transfer treatment. This thesis describes the optimization of lentiviral vectors for TCR gene transfer in the absence of polyclonal activation of the transduced T cells, which may improve subsequent adoptive T cell therapy. The murinised and codon optimised chains of an HLA-A*0201-restricted TCR specific for Wilms` tumour antigen 1 were cloned in lentiviral vector constructs improved with a Leader sequence and the WPRE elements for redirecting T cells specificity. The effects of common gamma chain receptor cytokines IL-2, IL-7, IL-15 and IL-21 were investigated using WT1 TCR-transduced T cells for transduction efficiency, proliferative potential, phenotype and functional activity in response to cognate antigen. Although all cytokines tested allowed transduction, stimulations with IL-15 and IL-15 with IL-7 or with IL-21 promoted a higher efficiency. Expression analysis of CD28 and CD62L showed an important role of IL-21 in maintenance of a naïve phenotype. In addition, all cytokines promoted maintenance of “quality” of T cells as shown by co-expression of IL- 2, IFN-γ and TFN-α after specific stimulation. To further sustain the in vitro results, several in vivo models were tested. Consistently, using F5 transgenic mice recognizing the NP peptide presented on EL4-NP cell line, IL-15 with IL- 21 exposed CD8+ T cells were able to efficiently protect against tumour and to persist longer in tumour bearing mice compared to IL-2 treated T cells. Because previous reports demonstrated that efficient LN homing of T cell correlates with efficient tumour protection in vivo, an imaging approach to study the molecular signalling in vivo during T cell activation in the LN has been developed. In conclusion, in this thesis, it is demonstrated that lentiviral transduction of cytokine exposed T cell can improve gene therapy approach of adoptive therapy.
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