Abstract Book 2010 - CIMT Annual Meeting

042 Weigand | Cellular therapy
Generation of CD4+ T cells with specificity for FMNL1
Luise Weigand 1 , Xiaoling Liang 1 , Ingrid Schuster 2 , Elfriede Eppinger 1 , Yanyan Han 1 ,
Matthias Schiemann 3 , Elisabeth Kremmer 2 , Andreas Moosmann 4 , Josef Mautner 5 , Christian
Peschel 1 , Angela Krackhardt 1
1
Department of Hematology/Oncology, Klinikum Rechts der Isar, Technische Universität München,
Munich, Germany
2
Division Helmholtz Zentrum München – German Research Center for Environmental Health,
Institute of Molecular Immunology, Munich, Germany
3
Institute for Medical Microbiology, Immunology and Hygiene, Technische Universität München,
Munich, Germany
4
Helmholtz Zentrum München – German Research Center for Environmental Health, Clinical Cooperation
Group Molecular Oncology and Ludwig-Maximilians-Universität München, Klinik für Hals-Nasen- und
Ohrenkrankheiten, Munich, Germany
5
Helmholtz Zentrum München – German Research Center for Environmental Health, Institute for Clinical
and Molecular Biology, Munich, Germany
86
Adoptive T cell therapies in the context of allogeneic
stem cell transplantation have curative potential,
especially in hematological malignancies. Patients
with leukemic relapse after stem cell transplantation
are treated with donor lymphocyte infusions
which may induce a beneficial Graft-versus-leukemia
effect but also detrimental Graft-versus-host
disease. This approach may be improved by transferring
T cells with selected specificities. We have
previously generated allorestricted CD8+ T cells
with specificity for the SEREX-derived tumor-associated
antigen formin-like protein 1 (FMNL1). As
it has been repeatedly shown, that CD4+ T cells
play a critical role in tumor eradication and maintenance
of immune memory, the aim of this project
was to generate CD4+ T cells directed towards a
peptide derived from FMNL1.
We used two different methods to isolate FMNL1specific
CD4+ T cells: Dendritic cells were pulsed
with either one out of nine peptide pools from an
FMNL1 peptide-library or recombinant protein to
prime autologous PBMC or CD45RO- T cells. Using
dendritic cells pulsed with overlapping peptides
derived from the FMNL1 peptide library as stimu-
lator cells, several T cell clones (e. g. Ga3.7) highly
specific for the same FMNL1 peptide could be
isolated. However, these clones did not recognize
natural targets. In contrast, using protein-pulsed
dendritic cells as stimulator cells, we were able to
generate CD4+ T cell clones reactive against cells
naturally expressing FMNL1. Intensive testing of
one specific clone (Aa2.2) showed that recognition
of target cells could be enhanced by transduction
with FMNL1 and blocked by an HLA-DR specific
antibody. Moreover preliminary data show, that
Aa2.2 recognizes HLA-DR matched chronic lymphocytic
leukemia cells. Both, the peptide-specific
clone Ga3.7 and Aa2.2 show a T helper cell type 2
(TH2) cytokine profile with antigen-specific secretion
of IL-5, IL-10 and IL-13. TCR genes of relevant
clones have been isolated and are, actually, transduced
in indicator cell lines in order to confirm the
MHC restriction element and to define the recognized
epitope.