These Treg were induced after treatment of primed mice with intact anti-CTLA-4 antibodies. These regulatory T cells inhibit Th1 responses, in vitro and in vivo, and repress experimental intestinal inflammation, by a mechanism involving IL-10 and IDO.

We have investigated the in vivo capacity of resting (and of DC-primed) NK cells to reach the draining lymph nodes.

iNKT cells were stimulated in vivo with the synthetic CD1d ligand alpha-GalCer. This significantly enhanced immune responses to protein and peptide based vaccines, due to rapid iNKT dependent DC maturation.

These T cells stem from an elutriation process from a metastatic lesion of stage III/IV melanoma patients. Subsequently, these T cells will be expanded by co-culture with tumor lysate loaded DC.

We have used “conventional” techniques to monitor the vaccine induced specific anti-tumor T cell responses (thymidine-incorporation, ELISA, LDA and ELISPOT assays). We have set the staining conditions for the HLA-DR*1101 tetramers loaded with tetanus toxoid and MAGE-3 peptides corresponding promiscuous CD4+ T cell epitopes. Antigen-specific CD4+ T cells are visualized after in vitro short-term expansion; we are currently optimizing the conditions for the ex-vivo staining.

We attempted to improve the adoptive transfer protocol for immunotherapy by stimulating T cells with monocyte derived DC pulsed with tumor lysate, instead of simply adding tumor lysate into PBMC cultures. T cells raised exhibited some tumor reactivity and outgrowth of a distinct T cell population could be observed.

It was found that these cells do not migrate to lymph nodes in the steady state.

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 have determined mechanisms for DC-induced Th1 development and the molecular pathways for inducing Th1 cells producing IFN-gamma solely, or Th1 cells producing IFN-gamma and IL-10, which have important implications for regulation of the immune response to eradicate pathogens with minimum pathology.

We have determined mechanisms for DC-induced Th1 development and the molecular pathways for inducing Th1 cells producing IFN-gamma solely, or Th1 cells producing IFN-gamma and IL-10, which have important implications for regulation of the immune response to eradicate pathogens with minimum pathology.

These T cells are to be purified using MACS cell separation to contain only CD8+ T cells. The latter are then co-cultured with electroporated DC, stimulated and become evaluated on their cytokine secretion, cytotoxicity and % of antigen specific T cells.

Untouched naive CD4+ T cells are co-coltured with fungi -pulsed DCs to prime naive T cells.