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

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.

Analysing antigen loading strategies for DC, we found that the priming capacity of MelanA/HLA-A2-specific autologous CD8+ T cells by lipofected DC was higher compared to electroprated DC.

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 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.

The cDNA’s encoding these early expressed HIV antigens have been human codon optimized and modified with lysosomal targeting sequences.

A functional analysis of anti-MAGE-3.A1 CTL clones derived from vaccinated patients (either ALVAC canarypox virus vector, peptide-pulsed DC or peptide vaccination +/- montanide adjuvant) who displayed tumor regression was done. The functional avidities of these CTL clones, evaluated in lysis assays, were surprisingly low, suggesting that high avidity was not part of the putative capability of these CTL to trigger tumor rejection. Most anti-MAGE-3.A1 CTL clones obtained after DC vaccination, but not after peptide or ALVAC vaccination, produced IL-10. Transcri...

Tests were performed on frozen peripheral blood leukocytes (PBL) obtained from leukapheresis or buffy-coat collections performed before and after the 6 vaccinations in Cycle 1 and after the 3 vaccinations of Cycle 2. The fresh PBL samples were collected from UTCM (Hôpital Erasme, ULB) and were transferred to Ludwig Institute where the freezing of the samples and analyses were performed.

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

These dendritic cells were generated with GM-CSF and IL-4. They were used in a clinical trial in melanoma patients who were randomized to receive immunizations either with these G4 DC or with I3 DC (DC generated with interferon-beta and interleukin-3).

These dendritic cells were generated with interferon-beta and interleukin-3. They were used in a clinical trial in melanoma patients who were randomized to receive immunizations either with these I3 DC or with G4 DC (DC generated with GM-CSF and IL-4).

These autologous DC were used in a phase IB/II study of immunotherapy. Patients were randomized to receive immunizations either with I3 DC (DC generated with interferon-beta and interleukin-3) or with G4 DC (DC generated with GM-CSF and IL-4).

Post-vaccination frequencies of the T cells of anti-NY-ESO-1.A2 and anti-Tyrosinase.A2 were found to be >= 10-fold higher than that of pre-vaccinations, indicating a specific CTL response to these vaccinations. An analysis performed on PBL collected after the 3 vaccinations of cycle 2 clearly shows that the frequencies for both anti-NY-ESO-1.A2 and anti-Tyrosinase.A2 T cells are still elevated.

Post-vaccination frequencies of the T cells of anti-NY-ESO-1.A2 and anti-Tyrosinase.A2 were found to be >= 10-fold higher than that of pre-vaccinations, indicating a specific CTL response to these vaccinations. An analysis performed on PBL collected after the 3 vaccinations of cycle 2 clearly shows that the frequencies for both anti-NY-ESO-1.A2 and anti-Tyrosinase.A2 T cells are still elevated.

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.

Co-culture of immature DC with TIL or K562 cells overexpressing CD83 results in the production of enhanced levels of pro-inflammatory cytokines, whereas this production is less pronounced or even absent in co-cultures with non-modified TIL or K562 cells.

Down-regulation of CD83 expression on human DC through RNA interference (RNAi) results in a less potent induction of allogeneic T cell proliferation, reduced IFN-gamma secretion by established T cells and decreased capacity in the priming of functional tumor antigen-specific CD8+ T lymphocytes.

These T cells were associated with multiple markers into 14 different cell types to identify subsets. The findings thus describe new CD8+ cell subsets, allow the identification of relatively homogeneous CD8+ subpopulations, provide a predictable and precise correlation between particular cell surface markers and CD8+ T-cell functional properties, and identify effector cells present in both CCR7-CD45RA+ and CCR7-CD45R0+ compartments. The results also indicate that activated cells might modulate the expression of CD45RA/R0 asynchronously rather than CCR7-CD45...