title: Rapid re-expression of retrovirally introduced versus endogenous TCRs in engineered T cells after antigen-specific stimulation.
abstract: To broaden the applicability of cellular immunotherapy, adoptive transfer of T-cell receptor (TCR) transferred T cells may be an attractive strategy. Using this approach, high numbers of defined antigen-specific T cells can be engineered. As the introduced TCR has to compete for cell surface expression with the endogenous TCR, the introduced TCR chains are under control of a strong viral promotor, which, in contrast to the endogenous promotor, is constitutively active. We examined whether this difference in regulation would result in differences in TCR internalization and re-expression of the introduced and endogenous TCR on dual TCR engineered T cells and the antigen-responsiveness of both the TCRs. We showed comparable TCR downregulation of TCRs expressed under regulation of a retroviral promotor or the endogenous promotor. However, the introduced TCRs were rapidly re-expressed on the cell surface after TCR stimulation. Despite rapid re-expression of the introduced TCR, T cells exerted similar antigen-sensitivity compared with control T cells, showing that cell mechanisms other than TCR cell surface expression are involved in antigen-sensitivity directly after antigen-specific stimulation. These results showed that TCR transduced T cells are functionally not different from nontransduced T cells and can potentially be used as an effective treatment strategy.
authors.affiliation: Department of Hematology, Leiden University Medical Center, The Netherlands. m.m.van_loenen@lumc.nl
authors.forename: Marleen M
authors.initials: MM
authors.lastname: van Loenen
authors.forename: Renate S
authors.initials: RS
authors.lastname: Hagedoorn
authors.forename: Renate
authors.initials: R
authors.lastname: de Boer
authors.forename: Esther H M
authors.initials: EH
authors.lastname: van Egmond
authors.forename: J H Frederik
authors.initials: JH
authors.lastname: Falkenburg
authors.forename: Mirjam H M
authors.initials: MH
authors.lastname: Heemskerk
mesh_terms: D017252:CD3 Complex / Q000276:immunology; D002460:Cell Line; D005786:Gene Expression Regulation / Q000235:genetics / Q000276:immunology; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology; D011485:Protein Binding / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000235:genetics* / Q000276:immunology*; D012190:Retroviridae / Q000235:genetics*; D013601:T-Lymphocytes / Q000276:immunology*; D014161:Transduction, Genetic
chemical_list: D017252:CD3 Complex; D016169:Lymphocyte Function-Associated Antigen-1; D011948:Receptors, Antigen, T-Cell