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DOTTORATO DI RICERCA IN BIOLOGIA
(XX CICLO)
Dipartimento di Biologia Molecolare Cellulare e Animale
Dendritic-Cell (DC)-Based Immunotherapy:
Tumor Endothelial Marker 8 (TEM8) Gene Expression of DC
Vaccines Correlates with Clinical Outcome
PhD thesis in Biology
PhD Student: Elisabetta Bolli Tutors: Dr. Franco M. Venanzi
Dr. Ruggero Ridolfi
2005-2008

ABSTRACT
Previous studies have shown that tumor-endothelial markers (TEMs) are up-
regulated in immunosuppressive, pro-angiogenic dendritic cells (DCs) found in tumor
microenvironments. We reported that pro-angiogenic monocyte-derived DCs (Mo-
DCs), utilized for therapeutic vaccination of cancer patients upon maturation,
markedly differ in their ability to up-regulate tumor-endothelial marker 8 (TEM8) gene
expression. A DC vaccination trial of 17 advanced cancer patients (13 melanoma and
4 renal cell carcinoma), carried out at the Cancer Institute of Romagna (I.R.S.T.) in
Meldola, highlighted a significant correlation between delayed-type hypersensitivity
test (DTH) and overall survival (OS). In the study, relative TEM8 mRNA and protein
expression levels (mature (m) vs. immature (i) DCs), in DCs obtained for therapeutic
vaccines were evaluated by quantitative real-time RT-PCR and cytofluorimetric
analysis, respectively. mDCs from six healthy donors were included for comparison
purposes. Eight non-progressing patients, all DTH-positive, had a mean fold increase
(mfi) of 1.97 in TEM8 expression. Similarly, a TEM8 mRNA mfi = 2.7 was found in
healthy donor mDCs. Conversely, mDCs from nine progressing patients, all but one
with negative DTH, had a TEM8 mRNA mfi of 12.88. Thus, mDC TEM8 expression
levels would seem to identify (p = 0.0018) patients who could benefit from DC
therapeutic vaccination.

I
INDEX
1. INTRODUCTION 1
1.1 CANCER IMMUNOTHERAPY 1
1.2 ANTI-CANCER STRATEGIES 2
1.3 IMMUNOSUBVERSION: ACTIVE SUPPRESSION OF IMMUNE RESPONSE
3
1.3.1 IDO: enzyme indoleamine 2,3-dioxygenase that is up-regulated in
human DCs upon in vitro maturation 5
1.4 DENDRITIC CELLS (DCs) 6
1.4.1 DCs-based vaccines 7
1.4.2 DCs migration 8
1.4.3 DCs maturation 9
1.4.4 PGE2 10
1.5 PROANGIOGENIC PHENOTYPE OF DCs 11
1.6 TEM8: MARKER IN PROANGIOGENIC PROGRAM 12
2. AIM OF THE STUDY 17
3. MATERIALS AND METHODS 19
3.1 Patients 19