We found a novel M-CSF dependent DC developmental pathway that is independent of Flt3L. These DC have unique characteristics and precursor origin. The cells can be found in vivo in Flt3L gene deleted (-/-) mice injected with recombinant M-CSF.

We set an in vitro system to study ex-vivo responses able to detect fona fide in vivo primed CD4+ T cells. We investigated spontaneous CD4+ T cell responses to these antigens in normal donors and in patients with high-grade cervical lesions, pancreas adenocarcinoma and advanced melanoma. The antigens were: i) the E6 and E7 proteins of human papilloma viruses, ii) the carcinoembryonic antigen (CEA) and iii) the tumour specific antigen MAGE-A3.

These patients were treated in a long peptide trial. Analysis of the local immune response demonstrated the presence of HPV16-specific Th1/Th2 cells infiltrating the vaccination site and the VIN lesion after vaccination. 5 out of 20 patients showed complete clearance of all VIN III disease and in 4 of these this was also associated with complete clearance of HPV16 virus.

These are RCC patients with clear cell histology, treated using the PME-CD40L DC product. At present, 6 of the 12 patients that have been restaged using RECIST criteria have less tumor burden that when they enrolled in the study (15 weeks earlier).

This patient experienced an outstanding response to immunotherapy. The 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.

DC-based vaccines that were given to these patients were combined with low dose IFN-alfa (3 x 10e6 U per wk). In a number of patients we observed vaccine-induced depigmentation and vitiligo.

This vaccine was used for RCC patients who were deficient in T cell IFN-gamma and IL-2 production pre-vaccination.

This patient has received 6 vaccines with peptide only in a randomized trial to receive immunizations either with I3 DC (DC generated with interferon-beta and interleukin-3) or with G4 DC (DC generated with GM-CSF and IL-4). The patient received a sequence of six immunizations every two weeks, consisting of autologous dendritic cells loaded with the 8 HLA-A2 restricted peptides and MAGE.3-DP4 in Cycle 1. In Cycle 2, the patient received a sequence of three immunizations every six weeks, consisting of autologous dendritic cells loaded with the 8 HLA-A2 restric...

Monocyte-derived and cocktail-matured DC electroporated with a combination of RNAs encoding tumor antigens (MelanA, Mage3, Survivin) and E/L-selectin are currently used in a clinical trial.

We also show that DCs derived from ashen mice, which are defective for the small GTPase Rab27a, fail to cross present antigens efficiently, due to increased phagosome acidification and antigen degradation. This defect in Rab27a-deficient DCs results from the impaired recruitment to phagosomes of the NOX2 membrane components. Therefore phagosomal alkalinization by NOX2 is controlled by Rab27a, and is required for efficient cross presentation in DCs.

Testing the improved RCC product PME-CD40L DC it is noteworthy that presence of CD28+ T cells in tumor lymphocytic infiltrates correlates with favorable clinical outcome.

For studying in vivo responses to antigens, we initiated a long program comparing the behaviour of TCR-Tg cells specific for GP-33 peptide.

These mice were used to study « in vivo » responses to Ags. We studied the kinetics of effector genes expression and association in TCR-Tg CD8 cells responding to the male antigen and to Listeria-OVA.

Concerning « in vivo » responses to Ags, we studied the kinetics of effector genes expression and association in TCR-Tg CD8 cells responding to the male antigen and to Listeria-OVA.

We set an in vitro system to study ex-vivo responses able to detect fona fide in vivo primed CD4+ T cells. We investigated spontaneous CD4+ T cell responses to these antigens in normal donors and in patients with high-grade cervical lesions, pancreas adenocarcinoma and advanced melanoma. The antigens used were: i) the E6 and E7 proteins of human papilloma viruses, ii) the carcinoembryonic antigen (CEA) and iii) the tumour specific antigen MAGE-A3.

Patients with resected HPV16-positive cervical cancer were vaccinated with an overlapping set of long peptides comprising the sequences of the HPV16 E6 and E7 oncoproteins emulsified in Montanide ISA-51.

Patients with resected HPV16-positive cervical cancer were vaccinated with an overlapping set of long peptides comprising the sequences of the HPV16 E6 and E7 oncoproteins emulsified in Montanide ISA-51.

We have stimulated human Monocyte derived Dendritic Cells (hMoDC) with yeast, spheroplasts, pseudohyphae, spores, purified RNA and not purified RNA, LPS.

PBMC are Leukapheresis derived and are loaded with peptide pools, each consisting of 10 15-mers, which overlap with 11 aminoacids.

These patients are taking part in a clinical study. They are patients that are successfully treated with highly active anti-retroviral therapy (HAART) with no measurable viral load AND have a cryopreserved infectious plasma sample that was drawn immediately prior to initiation of HAART. They are administered 4 monthly doses of the Arcelis product.