We have data from a clinical trial with melanoma patients (stage IV, documented progress) receive DC transfected with RNA encoding MelanA, Mage3 and Survivin +/- E/L-selectin by the i.v. route. This DERMA-ER-DC 05 trial (multipeptide loaded cytokine matured moDC + prior Treg elimination by 3x ONTAK treatment [5µg/kg], 8 evaluated pat.) did not show any enhanced immune reponses compared to the equivalent cohort in the DERMA-ER-DC 04 trial. Patient recruitment into the 2nd phase of the DERMA-ER-DC 06 trial has started (sequential adaptive design). Immunomonitori...

We developed additional antigen-loading strategies for DC and obtained data from first experiments on which constructs lead to antigen presentation and which do not. On the one hand we compared lipofection of tumor-antigen-encoding RNA to RNA electroporation into DC, and found that electroporation results in antigen expression in all cells, while lipofection results in higher antigen expression only in a portion of the cells (other cells are negative). Interestingly, the priming capacity of MelanA/HLA-A2-specific autologous CD8+ T cells by lipofected DC was high...

Data is available on the interaction between microorganism-associated molecular patterns and individual toll-like receptors on dendritic cells that turn on signal transduction pathways leading to the activation of different transcription factors. Microbial invasions are perceived by pattern recognition receptor (PRR)-expressing cells of the innate immune system. PRRs bind a number of microbial products collectively referred to as microorganism-associated molecular patterns (MAMPs). Toll-like receptors (TLRs) are the best-characterized PRRs. The interaction of MAM...

Our lab generated data on the mechanisms for DC-induced Th1 development and the molecular pathways for inducing Th1 cells producing IFN-gamma solely, or Th1 cells producing IFN-gamma and IL-10. We have reported that plasmacytoid precursor dendritic cells (pDC) activated with the TLR-9 ligand CpG induce strong development of Th1 responses (Boonstra et al, 2003). In contrast, bone marrow-derived myeloid DC (BM-myeloid DC) and splenic CD8alpha+ and CD8alpha- DC, despite expression of TLR9 mRNA, were poor at directing Th1 responses when activated with CpG. We have ...

Our lab has data available on the effect of endogenous IL-10 production by DC subsets resulting in low levels of IL-12p70 production in mice. We have shown that plasmacytoid pDC respond to both CpG and the TLR-7 ligand R848 to produce very high levels of IL-12p70 (in the ng/ml range per 5 x 105 cells/ml) and IFN-gamma. However, BM-myeloid and splenic CD8alpha+ DC produced at least fivefold less IL-12p70, and CD8alpha- DC produced undetectable levels of IL-12p70 upon stimulation with CpG. We show that induction of endogenous IL-10 production by these latter DC ...

We have microarray data on macrophages and DC from different genetic backgrounds of mice, stimulated with CpG, in the presence or absence of a MEK inhibitor, and further data on the role of certain MAP kinases in the regulation of IL-10 and IL-12, IFN-gamma production. Using pharmacological inhibitors, or macrophages and DC from mice carrying a null mutation in MAP kinase signalling molecule(s), we have evidence for a role of certain MAP kinases in the regulation of IL-10 and IL-12, IFN-gamma production. The work on the role of the MAP kinases, TPL-2 and ERK in u...

We have obtained valuable data on chemically well-defined TLR ligand conjugates and their effectiveness to induce a strong immune response via the cross-presentation pathway. We have studied long peptides which were covalently conjugated to either the TLR2 ligand or TLR9 ligand, Pam3CysSK4 or CpG, respectively have been used to study the uptake, antigen presentation, and induction of specific T-cells. A pronounced enhancement in antigen presentation by DC in vitro was facilitated by the conjugated peptides compared to peptide alone, or peptide mixed with the fre...

A comprehensive protein inventory of clinical grade immature and cytokine cocktail matured (Il-6, IL-1 beta, TNF alpha, PGE2; 48 hours) monocyte derived human dendritic cells (DC) from a healthy donor has been established by using high accuracy, high sensitivity protein identification technology. We have identified 2794 proteins in DCs by liquid chromatography tandem mass spectrometry. Prior to MS analysis, DC were lysed and divided into a soluble fraction containing cytosolic proteins and into an insoluble fraction enriched for membrane containing proteins. High...

Data has been obtained from a Balb-neuT mice model to study new strategies for advanced breast cancer. A colony has been established of transgenic Balb-neuT mice (founders provided by Forni, Torino IT) that over-express the rat HER-2/neu oncogene under the MMTV promoter. These mice develop mammary carcinomas with later lung and liver metastases; the course of disease and the type of tumours that develop closely recapitulate many features of human breast cancer. A collaborative study has commenced between Austyn and Cerundolo to use this model to study new strategi...

Knowledge and gene expression data were gained on differentiation patterns of T cells.

We are collecting immunological data from a melanoma patient, aiming to identify the antigen(s) recognized by T cells from this patient that experienced an outstanding response to immunotherapy. This patient received several adoptive T cell transfers and regressed from stage IV melanoma to a disease free state and has remained tumor free for several years. In a collaboration with Dr. O. Winqvist, Karolinska Institute, we attempted to improve the adoptive transfer protocol by stimulating T cells with monocyte derived DC pulsed with tumor lysate, instead of simply a...

Using the MLPC/tetramer method described last year, we obtained data by pursuing the immunological monitoring of melanoma patients vaccinated with 4 peptides (MAGE-A3, gp100, NA17 and tyrosinase) presented by HLA-A2. We measured responses to these peptides injected with Montanide, but did not know whether the Montanide adjuvant was important for these T cell responses. Indeed, melanoma patients may mount spontaneous responses to these antigenic peptides. We therefore injected the same peptides without adjuvant, and no response was observed. We conclude that Montan...

Our lab conducted an immunomonitoring study, such as on effector memory T cells, which led to corresponding immunological data.

In 2007 we established routine monitoring of tumor-specific T-cell subsets by multicolor flow cytometry and obtained immunological data from this. For this purpose we used multimers kindly provided by Pierre Coulie (Brussels) together with surface markers (such as CD8, CD4, CD3, CD45RA, CCR7, CD25, CD27, CD137, CD127) in different 8-color panels on the BD FACSCanto II. Additionally we used functional markers such as CD107a and intracellular cytokine staining for the further analysis of individual T-cell populations and T-cell clones. Monitoring of the ongoing vacc...

Our lab obtained data on the ability of NK cell IFN-gamma production to predict long term survival in advanced GISTs treated with IM. Background: Mutant isoforms of the KIT or PDGF receptors expressed by gastrointestinal stromal tumors (GISTs) are considered the therapeutic targets for imatinib mesylate (IM) (Gleevec®, Novartis), a specific inhibitor of these tyrosine kinase receptors. Predictive factors for the response to IM pertain to the intrinsic features of GIST tumor cells but not to the host. Besides its direct antiproliferative activity on tumor cells, I...

A phase I/II study of immunization of HIV infected individuals stable under HAART has been initiated which will provide us with immunological data. These patients are being vaccinated with cytokine cocktail matured DCs electroporated with mRNA encoding Tat, Rev and Nef. The cDNA’s encoding these early expressed HIV antigens have been human codon optimized and modified with lysosomal targeting sequences. Four vaccines separated by 4 weeks. Two weeks after the 4th vaccine, an analytical HAART interruption was started. So far, 17 patients have been included in t...

During the previous period we obtained data from our continued pilot clinical trials of DC-based immunotherapy of melanoma patients. After an initial cohort of patients treated with monocyte-derived DCs matured with inflammatory cytokines and subsequently electroporated with mRNA encoding 6 tumor-associated antigens, we persued this trial in a next cohort where DC-based vaccines were combined with low dose IFN-alfa (3 x 10e6 U per wk). In a significantly higher number of patients we observed vaccine-induced depigmentation and vitiligo. Further improvement and ca...

Summary of the completed RCC clinical study and the data obtained: RCC subjects were deficient in T cell IFN-gamma and IL-2 production pre-vaccination. The IL-2 defect was corrected in 7/12 patients post-vaccination. Vaccination resulted in an increase in tumor antigen-specific T cells in 8/12 patients. 7/12 subjects had a response to more than one antigen post-vaccination. Median overall survival was ~25 months compared to ~11 months for historical controls (confirmed by matched pair analysis).

We are planning clinical trials of melanoma patients treated with DC and tumour lysate plus adoptive transfer of T cells which will result in corresponding data.

We have further data available on a clinical trial on vaccination of B-CLL patients with autologous, apoptotic, leukemic cells (Apo-DC). Cohort 1 with the vaccine alone and cohort 2 (5 patients) combining the vaccine together with GM-CSF as an adjuvant has finished accrual and all patients in these two cohorts have been monitored for 52 weeks. The clinical and immune monitoring data is being currently analyzed. The third cohort consisting of the vaccine and GM-CSF administered after a single dose of cyclophosphamide (300 mg/ sq. meter) is currently being accrued...