T-cell receptors (TCRs) can be genetically modified to improve gene-engineered T-cell responses, a strategy considered critical for the success of clinical TCR gene therapy to treat cancers. TCR:ζ, which is a heterodimer of TCRα and β chains each coupled to complete human CD3ζ, overcomes issues of mis-pairing with endogenous TCR chains, shows high surface expression and mediates antigen-specific T-cell functions in vitro. In the current study, we further characterized TCR:ζ in gene-engineered T cells and assessed whether this receptor is able to interact with surface molecules and drive correct synapse formation in Jurkat T cells. The results showed that TCR:ζ mediates the formation of synaptic areas with antigen-positive target cells, interacts closely with CD8α and MHC class I (MHCI), and co-localizes with CD28, CD45 and lipid rafts, similar to WT TCR. TCR:ζ did not closely associate with endogenous CD3ε, despite its co-presence in immune synapses, and TCR:ζ showed enhanced synaptic accumulation in T cells negative for surface-expressed TCR molecules. Notably, synaptic TCR:ζ demonstrated lowered densities when compared with TCR in dual TCR T cells, a phenomenon that was related to both extracellular and intracellular CD3ζ domains present in the TCR:ζ molecule and responsible for enlarged synapse areas.

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Keywords Adoptive T-cell therapy, CD3, Fluorescence resonance energy transfer, Immune synapse, TCR:ζ
Persistent URL dx.doi.org/10.1002/eji.200940233, hdl.handle.net/1765/33450
Note This investigation received financial support from European Community Grants (EU FP6 LSHB- CT-2004-503467, FP6 LSHC CT-2005-018914, EU FP6 MCRTB- CT-035946 018914 and EU FP6 MRTN-CT-2006-019481), Hungarian National Development Agency grant TAMOP-4.2.2- 08/1-2008-0019 and Hungarian National Research Fund grants (OTKA K62648, OTKA K75752 and OTKA K68763).
Citation
Roszik, J, Sebestyén, Z, Govers, C.C.F.M, Guri, Y, Szöor, Á, Pályi-Krekk, Z, … Debets, J.E.M.A. (2011). T-cell synapse formation depends on antigen recognition but not CD3 interaction: Studies with TCR:ζ, a candidate transgene for TCR gene therapy. European Journal of Immunology, 41(5), 1288–1297. doi:10.1002/eji.200940233