Isolation and expansion of allogeneic myeloma-specific interferon-gamma producing T cells for adoptive immunotherapy.

Adoptive immunotherapy is a promising approach in the treatment of multiple myeloma. We have tested the identification, separation, and expansion of allogeneic myeloma-specific T cells in vitro. Irradiated myeloma cell line ARH 77 has been used to stimulate allogeneic CD4(+) and CD8(+) T lymphocytes. Activated myeloma-specific T cells that produced interferon-gamma were isolated using immunomagnetic beads and further expanded in vitro to numbers of up to 400 x 106 T cells. Specificity of the T lymphocytes was tested using a 5-(6-)carboxyfluoresceine diacetate succinimidyl ester (CFSE)-based cytotoxicity test. This study demonstrates the feasibility of identification and isolation of tumor-specific T cells from allogeneic donors that can be expanded in vitro to numbers useful for clinical applications

Dendritic cell counts and their subsets during treatment of multiple myeloma.

proportion of myeloid and plasmacytoid subsets of dendritic cells (DC) in peripheral blood of 15 patients with multiple myeloma (MM) before and during treatment that included autologous transplantation. Control group of 15 healthy volunteers was evaluated by using the same approaches. Flowcytometric determination of relative and absolute cell counts in unmanipulated peripheral blood was based on the expression of surface antigens CD83 and HLA-DR. Depending on the expresion of CD11c or CD123, we divided these cells into CD11c+ dendritic cells type 1 (DC1) and CD123+ DC type 2 (DC2). Significant differences were found in initial relative counts of CD83+ cells and of the DC2 subtype between the group of controls and the group of patients before treatment. In absolute counts, there was a difference only in the DC2 subtype. After induction treatment (vincristine, doxorubicin, and dexamethasone), the mean percentage of CD83+ DC and the DC1 percentage were significantly higher than initially, but there was no significant difference in absolute counts. Administration of G-CSF again increased the total DC numbers. Intermediate DC counts were found in the apheresis products. After engraftment, we found the highest relative DC numbers, but absolute counts were not very high because of leukopenia. Within six months after transplantation, normal relative and absolute DC counts were found in patients. Untreated patients with MM have significantly lower relative numbers of peripheral blood DC in comparison with healthy volunteers. The highest number of total DC was found after engraftment. The DC1/DC2 ratio showed relative predominance of DC1 subtype and the lowest DC1/DC2 ratio was found in the apheresis products. DC counts comparable with those of healthy volunteers were found in patients six months after transplantation

Efficacy and safety of Id-protein-loaded dendritic cell vaccine in patients with multiple myeloma \u2013 Phase II study results

In a\u202fphase II clinical study, pretreated multiple myeloma patients with relapsing or stable disease received autologous anticancer vaccine containing dendritic cells loaded with Id-protein. Patients received a\u202ftotal of 6 vaccine doses intradermally in monthly intervals. No clinical responses were observed. During the follow-up with a\u202fmedian of 33.1 months (range: 11-43 months), the disease remained stable in 7/11 (64%) of patients. Immune responses measured by ELISpot were noted in 3/11 (27%) and DTH skin test for Id-protein was positive in 8/11 (73%) of patients; out of those, 1/11 (9%) and 5/11 (46%), respectively, had preexisting immune response to Id-protein before the vaccination began. Outcomes were compared to those of a\u202fcontrol group of 13 patients. A\u202ftrend to lower cumulative incidence of progression in the vaccinated group was observed at 12 months from the first vaccination (p= 0.099). More patients from the control group compared to vaccinated patients required active anticancer therapy [4/11 (36%) vs. 8/13 (62%)]. Vaccines based on dendritic cells loaded with Id-protein are safe and induce specific immune response in multiple myeloma patients. Our results suggest that the vaccination could stabilize the disease in approximately two-thirds of patients

Enhanced stimulation of human tumor-specific T cells by dendritic cells matured in the presence of interferon-gamma and multiple toll-like receptor agonists

Dendritic cell (DC) vaccines have been demonstrated to elicit immunological responses in numerous cancer immunotherapy trials. However, long-lasting clinical effects are infrequent. We therefore sought to establish a protocol to generate DC with greater immunostimulatory capacity. Immature DC were generated from healthy donor monocytes by culturing in the presence of IL-4 and GM-CSF and were further differentiated into mature DC by the addition of cocktails containing different cytokines and toll-like receptor (TLR) agonists. Overall, addition of IFN gamma and the TLR7/8 agonist R848 during maturation was essential for the production of high levels of IL-12p70 which was further augmented by adding the TLR3 agonist poly I:C. In addition, the DC matured with IFN gamma, R848, and poly I:C also induced upregulation of several other pro-inflammatory and Th1-skewing cytokines/chemokines, co-stimulatory receptors, and the chemokine receptor CCR7. For most cytokines and chemokines the production was even further potentiated by addition of the TLR4 agonist LPS. Concurrently, upregulation of the anti-inflammatory cytokine IL-10 was modest. Most importantly, DC matured with IFN gamma, R848, and poly I:C had the ability to activate IFN gamma production in allogeneic T cells and this was further enhanced by adding LPS to the cocktail. Furthermore, epitope-specific stimulation of TCR-transduced T cells by peptide- or whole tumor lysate-loaded DC was efficiently stimulated only by DC matured in the full maturation cocktail containing IFN gamma and the three TLR ligands R848, poly I:C, and LPS. We suggest that this cocktail is used for future clinical trials of anti-cancer DC vaccines