We found that BM-myeloid and splenic CD8alpha+ DC produced at least fivefold less IL-12p70 than plasmacytoid pDC responding to both CpG and the TLR-7 ligand R848.

We have demonstrated that the NADPH oxidase NOX2 is recruited to DC early phagosomes mediating a sustained production of low levels of reactive oxygen species and causing a maintained alkalynization of the phagosomal lumen. DCs lacking NOX2 show increased antigen degradation due to an enhanced phagosome acidification. As a result, the efficiency of in vitro and in vivo antigen cross presentation is significantly reduced in NOX2-deficient DCs.

These cells were primed in vitro by engineered antigen-presenting cells and used to investigate the effect of environmental factors on development of high affinity cytotoxic T lymphocytes (CTL).

We have analyzed the uptake, conservation and cross-presentation of the model antigen OVA after Fc receptor-mediated uptake by DC. We found that MHC class I presentation is relatively short-lived in contrast to MHC class II. However, CD8 cross-priming capacity of OVA-loaded DC was functionally retained for many days, while peptide-pulsed DC had lost their priming capacity after 24 hours.

Injection of lentiviral vectors activated OVA-specific CD4+ T cells and this CD4 help was shown to be necessary for an adequate primary and memory CTL response.

When we tested in therapeutic tumor experiments with OVA+ melanoma cells, direct administration of lentiviral vectors slowed down tumor growth to a comparable extent with the highest dose of ex vivo transduced DC.

PBMC were isolated from buffy coat. Subsequently, monocytes were isolated and differentiated into dendritic cells.

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

We have analyzed the uptake, conservation and cross-presentation of the model antigen OVA after Fc receptor-mediated uptake by DC. We found that MHC class I presentation is relatively short-lived in contrast to MHC class II. However, CD8 cross-priming capacity of OVA-loaded DC was functionally retained for many days, while peptide-pulsed DC had lost their priming capacity after 24 hours.

These DC pulsed with MAGE-A3, gp100, NA17 and tyrosinase were used for vaccination of melanoma patients.

Perforine expressing T cells were observed in human Hemato-Lymphoid System Rag2-/-gc-/- mice after being infected with EBV and mounting an immune response. They infiltrated in B cell infected areas in lymphoid organs in situ.

We examined whether plasmacytoid pDC are infected and/or activated by MTb, and whether they play a role in regulating bacterial clearance during acute MTb infection and if so how. We have compared these DC with myeloid DC and macrophages with respect to MTb infection.

RCC product that was tested in an RCC phase 2 trial. The product does indeed lead to restoration of both IL-2 and IFN responses and leads to a gradual decline of the immune effector T cells in the peripheral circulation (i.e., weaker signal after the fifth dose). Using the PME-CD40L DC product we have observed tumor regressions in a number of patients in the current study. At present, 6 of 12 patients that have been restaged using RECIST criteria have less tumor burden that when they enrolled in the study (15 weeks earlier).

For a transcriptional profiling of dendritic cells, DC were stimulated with PolyI:C, pretreated or not with PP2, and microarray analysis was performed.

These primed T cells have been obtained from untouched naive CD4+ T cells co-cultured with fungi -pulsed DCs.

These DC were generated from monocytes after elutriation of leukapheresis product (patients with stage III or stage IV melanoma) and pulsed with irradiated tumor cells (apoptotic bodies) prepared from the removed lesion and matured for 48 hours in presence of TNF-alpha, and subsequently frozen.

A portion of the DCs is pulsed with irradiated tumor cells (apoptotic bodies) prepared from the removed lesion and matured for 48 hours in presence of TNF-alpha.

Purified CD8 T cells using MACS cell separation were co-cultured with electroporated DC and subequently became evaluated on their cytokine secretion, cytotoxicity and % of antigen specific T cells.

The kinetic of the transcriptional profiling of purified mouse DC treated with IL10 was analysed.

We have studied the immuno-physiology of rat and mouse intestinal dendritic cells. We have used a known adjuvant, E. coli heat-labile toxin (Etx) and a potential adjuvant R-848, a small TLR7/8 ligand.