Abstract Book 2010 - CIMT Annual Meeting

043 Liang | Cellular therapy
Transfer of human T-cell receptor (TCR) containing murine
chimeric constant betagamma-chain sequences reduces the risk
of mixed heterodimers and enhanced the proliferation of
transduced T cells
Xiaoling Liang 1 , Yanyan Han 1 , Ingrid G. Schuster 2 , Luise U. Weigand 1 , Elfriede Eppinger 1 ,
Dirk Busch 3 , Wolfgang Uckert 4 , Christian Peschel 1 , Angela Krackhardt 1
1 Technical University Munich, Klinikum Rechts der Isar, Medizinische Klinik III,
Innere Medizin mit Schwerpunkt Hämatologie und Onkologie, Munich, Germany
2 Helmholtz Zentrum München-German Research Center for Environmental Health,
Molecular Immunology, Munich, Germany
3 Technical University Munich, Medical Microbiology, Immunology and Hygiene, Munich, Germany
4 Max Delbrück Centrum, Berlin, Germany
Adoptive transfer of tumor-associated antigen (TAA)
or virus specific T-cell receptor (TCR)-transduced
T cells may represent an attractive and promising
approach to specifically treat malignant diseases
and has been previously successfully applied in the
clinic. However, there are different concerns which
need to be addressed to further improve this therapeutic
approach: First, the formation βγof heterodimers
between endogenous and transduced TCR
chains may abrogate specific TCR function and
harbours a particular risk for unknown specificities.
Second, longterm survival of TCR-transduced
T cells has been demonstrated to be critical for the
effectivity of this approach and needs to be further
improved.
We have previously identified several HLA-A2-allorestricted
T-cell receptors with specificity for the
breast cancer associated antigen HER2/neu and
the hematopoietic lineage specific protein Forminlike
protein 1 (FMNL1) which is overexpressed in
diverse malignant cell lines and native leukemia
cells. The FMNL1-specific TCR SK22 represents a
weak TCR with low interchain affinity which was
significantly improved by current optimization stra-
tegies including murinization of constant chains
and codon-optimization. We additionally modified
this TCR as well as two other TCR with alternative
specificities as HER2/neu and GP100 by introducing
murinized constant chain betagamma (βγ)
chimera, which results in reduced pairing of heterodimers
in PBMC. More significantly, proliferation
of T cells was clearly enhanced in effector cells and
T cell clones transduced with αβγ compared to αβ
TCR. Preliminary results suggest that also different
cytokine patterns might be expressed. In contrast
to a previous publication, we observed a significant
polarization of CARMA-1 to the immunogical
synapse in different TCR containing the chimeric
chain combination and no decrease in Fas-Ligand
expression in transduced T cells suggesting that
altered CARMA-1 signaling might not be the only
explanation for enhanced proliferation of T cells
transduced or transgenic for the βγ-TCR.
In conclusion, our data show that the transfer of
TCR chain genes containing optimized murinized
chimeric βγ-constant chains may have advantages
and might be an alternative or synergistic choice
for TCR optimization for adoptive T cell transfer.
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