Abstract Book 2010 - CIMT Annual Meeting

052 Salguero | Cellular therapy
Dramatic early expansion of CMV-reactive human T cells in
vivo is supported by lentiviral vector-induced engineered dendritic
cells
Gustavo Salguero 1 , Bala Sai Sundarasetty 1 , Dirk Wedekind 2 , Sylvia Borchers 1 , Gregor
Warnecke 3 , Ann-Kathrin Knöfel 3 , Rainer Blasczyk 4 , Britta Eis-Vesper 4 , Eva Mischak-Weissinger
1 , Arnold Ganser 1 , Renata Stripecke 1
1
Department of Hematology, Hemostasis, Oncology and Stem Cell Transplantation,
Hannover Medical School, Hannover, Germany
2
Central Animal Laboratory, Hannover Medical School, Hannover, Germany
3 Department of Experimental Transplantation, Hannover Medical School, Hannover, Germany
4 Institute for Transfusion Medicine, Hannover Medical School, Hannover, Germany
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Dendritic cell (DC) based immunotherapy is a
potent strategy to induce antigen-specific responses
against cancer and infections. Strategies
to enhance the viability, biodistribution and immunostimulatoy
capacity of ex vivo generated DC in
vivo, may also be critical to determine the success
of adoptive T cell therapies. We have previously
shown that genetically reprogramming of human
monocytes using bicistronic lentiviral vectors (LV)
expressing GM-CSF and IL-4 induces self-differentiated
DCs (SMART-DC) with improved engraftment,
viability and biodistribution in vivo (Sundarasetty
et al., CIMT 2009). Here, we assessed the in vivo
potential of SMART-DCs to support engraftment
and expansion of human T cells reactive against
cytomegalovirus (CMV). Human SMART-DCs were
generated from CD14+ monocytes obtained from
CMV-seropositive donors and co-transduced with
a LV expressing the full-length CMV protein pp65
(SMART-DC/pp65) for analyses of antigen-specific
responses. SMART-DC/pp65 showed a stable DC
immunophenotype in vitro (CD209+, HLA-DR+,
CD86+) and high viability in vitro (>3 weeks) and
in vivo (>6 weeks). NOD.Rag1-/-.IL2rγ-/- immunodeficient
mice were preconditioned with SMART-
DC or with SMART-DC/pp65 injected s.c. and 7
days later infused i.v. with autologous T cell expressing
the firefly luciferase (fLUC). The engraftment,
expansion and biodistribution of T cells were
evaluated by serial in vivo bioluminescence image
analysis, flow cytometry and immunohistochemi-
stry. Control arms with “conventional” DCs alone
or pulsed with pp65 overlapping peptides were included.
SMART-DC-preconditioned mice showed
significantly enhanced engraftment of fLUC-T cells
in spleen (day 14, 6-fold p