The TcR-Tg clones are specific for the 0T-1-OVA antigen. In the individual T cells, we studied the expression of twenty different genes either mediating effector functions, or coding for different receptors involved in T cell differentiation and memory generation.

These TcR-Tg clones are specific for the P14-GP33 antigen. In the individual T cells, we studied the expression of twenty different genes either mediating effector functions, or coding for different receptors involved in T cell differentiation and memory generation.

It was evaluated whether STAT-1 was phosphorylated in DC following activation with TLR-dependent Th1 and Th2 stimuli and we found that only in presence of TLR stimuli able to induce Th1 responses STAT-1 was activated.

It was shown in mice that both IL-10 as well as IL-12 production is dependent on the signalling adaptor molecules either MyD88 or TRIF, respectively in response to CpG, LPS or PolyIC.

We are examining the effects of a schistosome-derived protein on intestinal immune responses, and have shown that oral administration leads to the rapid appearance of cytokines in lymph.

A long-standing collaboration with Centre for Ecology & Hydrology (CEH, UK) has led to the identification of an activity in salivary gland extracts of the tick Rhipicephalus appendiculatus that profoundly modulates the responses of human monocyte-DC towards extrinsic stimuli. Recombinant protein has been generated from the gene for this molecule (Japanin) which had been cloned. This material inhibits the up-regulation of costimulatory molecules in response to certain TLR agonists, and some cytokines but not others, and modulates the function of the DC in ...

We are characterising (in collaboration with Sebastian Amigorena) rat lymph exosomes and will determine if they transport intestinally-delivered scrapie ME7.

The expression and function of these murine FcgammaR in CD11c+CD11b-B220+ plasmacytoid DCs (pDCs) was investigated. pDCs express mostly FcgammaRIIB while the expression of FcgammaRI and FcgammaRIII is only detected by RT-PCR at low but significant level. Moreover, the ITAM-containing intracellular chain associated to FcgammaRI and FcgammaRIII is strongly expressed in pDCs as detected by biochemical assay.

Soluble recombinant HLADR1101 MHC class II molecules receptive for loading with either pathogen or tumor-derived peptides were constructed for a study of CD4+ T cell responses against pathogens or tumors in humans.

An mAb reacting to the immunodominant LACK156-173 peptide of leishmania bound to I-Ad MHC class II molecules was prepared. To this aim, we injected I-Ad/LACK recombinant dimers to TCR transgenic mice which exhibited an increased frequency of LACK-specific T cells. Four out of 600 supernatants, i.e. 2C44, 2F74, 2E60 and 2X8, readily stained LACK156-173-pulsed fibroblasts, but neither unpulsed fibroblasts nor OVA323-339-pulsed cells. BIAcore measurements yielded equilibrium dissociation constants ranging from 1.1 nM for 2C44 mAb to 120 nM for 2F74 mAb.

We have generated a monoclonal antibody, 2C44, that reacted to a peptide derived from the Leishmania LACK protein bound to I-Ad MHC class II molecules. We have successfully used the 2C44 mAb to visualize LACK-presenting DCs in mice infected with the L. major.

In a study aiming at the identification of molecular signatures for alternatively activated DC it was found that AA-DC induced in the presence of LPS and IL-10 also produced high levels of the long pentraxin PTX3. DC produced conspicuous amounts of PTX3 when stimulated with LPS and this production is further increased in the presence of IL-10. However, PTX3 production was not increased in other alternative conditions of activation, such as in the presence of dexamethasone or calcitriol. PTX3 has properties similar to antibodies. Its production is induced by pa...

It has been shown that DCs express specific receptors for exosomes. Since ICAM-1 on exosomes is required for their ability to activate T cells via DCs in vitro, the role of Mac-1 and LFA-1 (the major ligands for ICAM-1) as potential receptors for exosomes has been investigated. A new role for LFA-1 on DCs, as a receptor for exosomes has been proposed.

Tetanus toxide epitope embedded into a L-SIGN/DC-SIGN-cross-reactive Ab was targeted to dendritic cells. We believe that the isolated Abs may be useful for selective delivery of Ags to DC-SIGN- or L-SIGN-bearing APCs for the modulation of immune responses and for blocking viral infections.

We analysed the ability of invariant NKT (iNKT) cells to assist priming of antigen specific T and B cell responses. 1) We have demonstrated that activation of human DC by Toll like receptor ligands (TLR-L) modulates the lipid biosynthetic pathway, resulting in enhanced recognition of CD1d-associated lipids by iNKT cells. 2) We have clarified the mechanisms by which CD1d-restricted lymphocytes translate T cell receptor (TCR) recognition of lipids with similar group heads into distinct biological responses. Using a soluble iNKT TCR and a newly engineered anti...

HLA-DP4/MAGE3 molecules have been prepared to stain ex vivo PBL from immunized melanoma patients for a study of anti-tumor responses in melanoma patients that were vaccinated with autologous DCs loaded with a combination of tumor Ag peptides.

Fabs that bind strongly to L-SIGN, but to a lesser degree or not at all to dendritic cell-specific ICAM-grabbing nonintegrin (DC-SIGN) were isolated and characterized. We believe that the isolated Abs may be useful for selective delivery of Ags to DC-SIGN- or L-SIGN-bearing APCs for the modulation of immune responses and for blocking viral infections.

The model antigen OVA was fused to the C1C2 exosome-binding domain of MFG-E8/lactadherin. This construct was used in a study on the capture of antigen-bearing exosomes by DCs and cross-presentation of tumour antigen in exosomes.

Constructs for fusion proteins of the DC specific receptor DC-SIGN fused to GFP have been completed and tested.

Surface markers were used to establishe routine monitoring of tumor-specific T-cell subsets by multicolor flow cytometry. For this purpose multimers were used kindly provided by Pierre Coulie (Brussels) together with CD4 surface markers (and additionally, CD8, CD3, CD45RA, CCR7, CD25, CD27, CD137, CD127) in different 8-color panels on the BD FACSCanto II. Additionally, functional markers such as CD107a were used and intracellular cytokine staining for the further analysis of individual T-cell populations and T-cell clones.