In our lab, data was obtained from a phase I trial using peptide-pulsed Dex. Dendritic cell (DC) derived-exosomes (Dex) are nanomeric vesicles harboring functional MHC/peptide complexes promoting T cell -dependent tumor rejection. In this Phase I trial using peptide-pulsed Dex, the observation of clinical regressions in the absence of T cell responses prompted the search for alternate effector mechanisms. Mouse studies unraveled the bioactivity of Dex onto NK cells, Dex promoting a IL-15Ra-dependent NK cell proliferation and a NKG2D-dependent activation resulting...

We have obtained data from a phase I/II clinical trial of patients with end stage cervical cancer and of patients with vulvar intraepithelial neoplasia (VIN) grade III. Preclinical animal studies have shown that long peptides of 25-35 amino acids in length upon injection are only processed efficiently for MHC class I by dendritic cells in vivo. Long peptide injection is followed by appropriate cognate interactions between such DC, CD4+ T helper cells and CD8+ CTL precursors. Three groups of end stage cervical cancer patients (in total N=35) were subcutaneously va...

Data will become available on the safety, antitumoral immune response and DC migration in the organism in patients with advance renal cell carcinoma and melanoma from this trial using cellular immunotherapy with dendritic cells loaded with tumor antigens. This study is not yet open for participant recruitment. ClinicalTrials.gov Identifier: NCT00610389 Purpose Background: cellular immunotherapy with dendritic cells (DC) loaded with tumor antigens has shown clinical activity, although in a small number of patients. Therefore, it is mandatory to improve the resul...

A worldwide first randomized adjuvant trial in a subgroup of high risk melanoma patients (monosomy 3) using autologous DC transfected with amplified total tumor RNA derived from patients' uvea melanomas was to be started in 2009 and data will become available.

Data has been obtained on the phenotype and function of myeloid derived suppressor cells in melanoma in patients. Accumulation of myeloid derived suppressor cells (MDSC) with the ability to suppress T cells has been observed in serveral types of cancer, including melanoma. Using blood from melanoma patients we are investigating phenotypic markers that can be used to further characterize MDSC, focusing on molecules that are related to their suppressive function. As it is believed that recruitment from the bone marrow by tumor derived factors leads to increased pre...

Currently there is no knowledge about the relevance of MDSC in ovarian cancer patients. However, it is known that both Tregs and suppressive macrophages are increased in this malignancy and have been suggested to correlate with worse prognosis. In order to obtain data, we are collecting blood and ascitic fluid of ovarian cancer patients to study the presence of immature myeloid populations as compared to healthy donor blood. We have identified two candidate populations that will be tested for the ability to suppress T cells. We also aim to characterize these cel...

Data has been generated in HHD2 transgenic mice on dendritic cell derived-exosomes (DEX), nanomeric vesicles harboring MHC/peptide complexes capable of promoting primary T cell responses and tumor rejection in the presence of adjuvants. We showed that, in the absence of adjuvants, DEX mediate potent antigen dependent-antitumor effects against preestablished tumors in mice pretreated with immunopotentiating dosing of cyclophosphamide (CTX). CTX could i) abolish the suppressive function of CD4+CD25+Foxp3+ regulatory T cells (Treg), ii) markedly enhance the mag...

Preclinical data is available on the power of preventing disease and invoking immune response of our lead product for the prevention of infectious disease, ImmunoVexHSV2, a vaccine for genital herpes. ImmunoVex HSV2 is a novel live-attenuated vaccine candidate that expresses approximately 80 HSV-2 proteins intended to stimulate a broad and powerful immune response. In preclinical studies, ImmunoVex HSV2 completely prevents disease and invokes a powerful immune response. We intend to initiate a Phase I clinical trial for this product early in 2008.

Data was obtained on RNA transfected DC which proved superior in priming naïve T cells in vitro compared to DC loaded with native peptides.

We obtained microarray and RT-PCR data on the priming of CD8+ T cells in mice and their regulation of proliferation and development into effector and/or memory cells. The positive influence of a reactive lymph node on the priming of CD8+ T-cells was already analyzed in 2007. We set up experiments to determine if this effect would benefit a response against a second infection. We infected mice with CD8+ T-cells primed with or without the influence of a reactive lymph node with a flu-virus encoding the specific antigen. After several days we determined the viral lo...

Data were obtained from profiling of human monocyte-derived DC exposed to different maturation cocktails and various activators or inhibitors.

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...

Data have been obtained on Mart-1 specific T cell priming and/or NK cell triggering in HHD2 mice. We have used DC exosomes along with various TLR ligands or cytokines such as IL-2 or alpha IFN to promote Mart-1 specific T cell priming and/or NK cell triggering in HHD2 mice. We demonstrated that only TLR3 and 9 ligation is able to induce CTL priming in vivo. However, exosomes in the absence of adjuvants can induce NK cell activation. DC exosome-mediated NK cell triggering depends upon NKG2D ligands presented on the exosome surface

Data has been obtained on DCs loaded with Ag-IgG immune complexes (ICs) as a means of prophylactic immunization in mice. Therapeutic vaccinations strongly delay tumor growth or even prevent tumors from growing out. By depleting CD4+ and CD8+ cell populations prior to tumor challenge, CD8+ cells were identified as the main effector cells involved. Importantly, DCs pre-loaded in vitro with ICs are at least 1000-fold more potent than ICs injected directly into mice or DCs loaded with the same amount of non-complexed protein. FcgammaRs on DCs were required for effici...

We obtained data on the protein changes that occur at the cell surface of a maturing DC, induced by a prototypical maturation stimulus such as LPS. Results obtained from the LC-MS/MS analysis of the integral plasma membrane proteome of D1 cells stimulated for 24 hours with LPS have been compared to the results obtained from immature D1 cells. As expected, DC up-regulated the cell surface expression of all proteins known to be part of the so-called “immunological synapse”, namely MHC class II (region E and K), CD40, CD80, CD86 and ICAM. Interestingly, LPS stimul...

Proteomic data was obtained from a proteomic analysis of DC-derived organelles such as the exosomes. Following the extensive proteomic analysis of immature and mature DC-derived exosomes, ICAM-1 was identified as the major protein on mature DC-derived exosomes, required for their functional activity. In order to functionally validate the proteomic data, the antigen-presenting function has been investigated. Exosomes bearing functional MHC-peptide complexes have been shown to be presented at the surface of recipient DCs as intact "antigen-presenting microdomains", w...

We have established an in-depth proteomic map of murine dendritic cell subsets. We have been working in the attempt to overcome the limits in sample availability, exploiting the recent significant improvements of proteomic technology. The results allowed to lower the required sample amount significantly, an essential feature to analyze limited cell populations like dendritic cells. The group completed the measurements of murine dendritic cell subsets and established an in-depth proteomic map of them. These preliminary results show more than 4500 identified proteins...

Our lab has proteomic data available on the interaction between RIG-I and NS1 in influenza A. We have used fluorescence microscopy to analyse the interaction between RIG-I, a viral sensing protein, and NS1, an inhibitor of interferon production that is encoded by influenza A virus. This approach enabled us to determine that the two proteins form a complex in influenza infected cells.

Proteomic data has been obtained using used yeast as a model organism to optimize technological approaches for the quantitative assessment of molecular components in yeast proteomics. We compared protein levels of essentially all endogenous proteins in haploid yeast cells to their diploid counterparts. Our analysis spanned more than four orders of magnitude in protein abundance with no discrimination against membrane or low level regulatory proteins (deGodoy et al.).

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...