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.

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.

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 in each subset. All of the known markers like CD11c, CD11b, DEC-205, Langerin, etc. were found according to their differential expression pattern.

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.

These multipeptide loaded cytokine matured moDC +/- CD40L activation were used for the DERMA-ER-DC 04 trial.

The moDCs are used in the DERMA-ER-DC 05 trial. They are multipeptide loaded cytokine matured moDC + prior Treg elimination by 3x ONTAK treatment [5µg/kg]. 8 patients are enrolled and receive this substance.

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 found that CD8alpha- DC produced undetectable levels of IL-12p70 upon stimulation with CpG.

We have efficiently transfected DC with RNA encoding a functional protein (E/L-Selectin). The mouse E/L-S transfected DC, when given i.v., homed to the lymph nodes, whereas non transfected DC home only to the spleen.

These DC were matured with inflammatory cytokines and subsequently electroporated with mRNA encoding 6 tumor-associated antigens. They were used for DC-based immmunotherapy of melanoma patients.

These DC are exposed to HIV-1 to examine if this can directly modulate their functions or interfere with their cross-talk.

Monocytes were cultured in serum free medium in the presence of IL-4 and GM-CSF, and concentrated cytokines were added.

A quantitative microarray approach that detects 723 human mature miR (miRBase 10.1, Dec 2007), was used to measure miR expression profile in these cells.

MoDC were stimulated with yeast.

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.

These DC were used in an experiment for identification of antigens recognised by T cells from melanoma patients responding to immunotherapy.

These monocyte-derived DCs received combined stimulation with TLR ligands. They were used in our study on DC activation by pathogen-derived stimuli.

These DC were matured using CpG-DNA as TLR9 ligand. Mature DCs upregulated CD80, CD86, MHC class II and produced cell type specific cytokines. CD8+ myeloid DCs “cross-presented” exogeneous Ags (Ovalbumin).

These DC were matured using CpG-DNA as TLR9 ligand. Mature DCs upregulated CD80, CD86, MHC class II and produced cell type specific cytokines. Matured pDCs pDCs produced type 1 Interferons.

Dendritic cells were matured with TNF alpha, IFN gamma and PGE2. These DC were used to produce a DC vaccine.