title: Targeting the Wilms tumor antigen 1 by TCR gene transfer: TCR variants improve tetramer binding but not the function of gene modified human T cells.
abstract: We have previously described the functional activity of a human TCR specific for an HLA-A2-presented peptide derived from the Wilms tumor Ag 1 (WT1). Recent studies showed that the expression and function of human TCR was improved by the introduction of an additional disulfide bond between the alpha- and beta-chains or by the exchange of the human constant region for murine sequences. In this study, we analyzed the functional activity of WT1-TCR variants expressed in Jurkat cells and in primary T cells. The introduction of cysteine residues or murine constant sequences into the WT1-TCR did not result in a global reduction of mispairing with wild-type TCR chains. Instead, the level of mispairing was affected by the variable region sequences of the wild-type TCR chains. The analysis of freshly transduced peripheral blood T cells showed that the transfer of modified TCR constructs generated a higher frequency of Ag-responsive T cells than the transfer of the wild-type TCR. After several rounds of peptide stimulation this difference was no longer observed, as all transduced T cell populations accumulated approximately 90% of Ag-responsive T cells. Although the Ag-responsive T cells expressing the modified TCR bound the HLA-A2/WT1 tetramer more efficiently than T cells expressing the wild-type TCR, this did not improve the avidity of transduced T cells nor did it result in a measurable enhancement in IFN-gamma production and cytotoxic activity. This indicated that the enhanced tetramer binding of modified WT1-TCR variants was not associated with improved WT1-specific T cell function.
authors.affiliation: Department of Immunology and Molecular Pathology, University College London, Hampstead Campus, Royal Free Hospital, London, United Kingdom.
authors.forename: Sharyn
authors.initials: S
authors.lastname: Thomas
authors.forename: Shao-An
authors.initials: SA
authors.lastname: Xue
authors.forename: Michela
authors.initials: M
authors.lastname: Cesco-Gaspere
authors.forename: Esther
authors.initials: E
authors.lastname: San José
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Hart
authors.forename: Vivian
authors.initials: V
authors.lastname: Wong
authors.forename: Reno
authors.initials: R
authors.lastname: Debets
authors.forename: Balbino
authors.initials: B
authors.lastname: Alarcon
authors.forename: Emma
authors.initials: E
authors.lastname: Morris
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Stauss
mesh_terms: D017398:Alternative Splicing / Q000235:genetics*; D002478:Cells, Cultured; D003545:Cysteine / Q000235:genetics / Q000378:metabolism; D006801:Humans; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D011948:Receptors, Antigen, T-Cell / Q000235:genetics* / Q000378:metabolism*; D013601:T-Lymphocytes / Q000378:metabolism*; D025721:WT1 Proteins / Q000378:metabolism*
chemical_list: D011948:Receptors, Antigen, T-Cell; D025721:WT1 Proteins; D003545:Cysteine