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.

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.

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.

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 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 monocyte come from an elutriation process from a metastatic lesion from stage III/IV melanoma patients and will be used for the generation of a vaccine and generation of tumour-lysated loaded DC.

These monocytes were obtained after elutriation of a leukapheresis product (patients with stage III or stage IV melanoma) and are used to obtain dendritic cells from.

These monocytes have been obtained from leukapheresis of tissue from patients with stage III or stage IV melanoma (tissue taken from a surgical resection of a melanotic lesion). They will subsequently be used to generate dendritic cells.

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

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.

Cells from healthy blood donors are separated into monocytes (and lymphocytes) by elutriation in a closed system (Elutra). [The two most monocyte-rich fractions collected contained > 80% monocytes, viability was > 95%.]

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

It was found that lymph nodes that drain sites of mature DC or adjuvant inoculation recruited memory CD8+ T cells.

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.