Dendritic cells differentiated in the presence of IFN-β and IL-3 are potent inducers of an antigen-specific CD8+ T cell response

Abstract

Dendritic cells (DC) are professional antigen-presenting cells that are used in vaccine approaches to cancer. Classically, mature monocyte-derived DC are generated in vitro in the presence of interleukin (IL)-4, granulocyte macrophage-colony stimulating factor, and inflammatory cytokines (G4-DC). Recently, it has been described that DC can also be generated in the presence of IL-3 and interferon (IFN)-beta and that these DC are efficiently matured using polyriboinosinic polyribocytidylic acid (I3-DC). In this study, a series of in vitro experiments was performed to compare side-by-side I3-DC and G4-DC as vaccine adjuvants. Phenotypic characterization of the DC revealed differences in the expression of the monocyte marker CD14 and the maturation marker CD83. Low expression of CD14 and high expression of CD83 characterized G4-DC, whereas I3-DC displayed intermediate expression of CD14 and CD83. Both types of DC were as potent in the induction of allogeneic T cell proliferation. Upon CD40 ligation, G4-DC produced lower amounts of IFN-alpha and pulmonary and activation-regulated chemokine, similar amounts of IL-6, macrophage-inflammatory protein (MIP)-1alpha, and MIP-1beta, and higher amounts of IL-12 p70, tumor necrosis factor alpha, and MIP-3beta than I3-DC. We further evaluated whether the DC could be frozen/thawed without loss of cell number, viability, phenotype, and function. After freezing/thawing, 56.0% +/- 9.0% of I3-DC and 77.0% +/- 3.0% of G4-DC (n=9) were recovered as viable cells, displaying the same phenotype as their fresh counterparts. Finally, in vitro stimulations showed that fresh and frozen peptide-loaded I3-DC are more potent inducers of Melan-A-specific CD8(+) T cell responses than G4-DC. The antigen-specific T cells were functional as shown in cytotoxicity and IFN-gamma secretion assay.

Effective Clinical Responses in Metastatic Melanoma Patients after Vaccination with Primary Myeloid Dendritic Cells

“…Five patients showed at least stable disease upon the first vaccination cycle (7,12,15,18, and 35þ months duration, respectively) and were therefore eligible for an additional vaccination cycle consisting of another three mDC vaccinations (Tables 1 and 2). In two of these patients, disease progression occurred after the second vaccination cycle.…”

“…The extensive culture period (8-9 days) and compounds required to differentiate these cells into DCs may negatively affect their immunologic potential and their capacity to migrate to the T-cell areas of the lymph nodes (7,8). Therefore, naturally circulating primary DCs may be a potent alternative for monocyte-derived DC (moDCs), irrespective of the fact that they are relatively scarce (ranging from 1 Â 10 7 to 1 Â 10 8 DC in a single apheresis).…”

Attenuated Expression of A20 Markedly Increases the Efficacy of Double-Stranded RNA-Activated Dendritic Cells As an Anti-Cancer Vaccine

“…It has been shown that TLR ligands are necessary and can synergize to fully activate DCs to overcome tolerogenic mechanisms as well as active inhibition by regulatory CD4 ϩ T cells (Treg), factors which impede a productive anti-tumor immune response (5)(6)(7)(8)(9)(10). In this regard, it has been demonstrated that DCs matured with the TLR3 ligand poly(I:C) or its clinical grade analog poly(I:C 12 U) are potent inducers of TAA-specific CTLs (11,12).…”

A Kunjin replicon vector encoding granulocyte macrophage colony-stimulating factor for intra-tumoral gene therapy

“…In summary, this study illustrates the utility of the KUN replicon GM-CSF VLP system for tumour gene therapy. The KUN replicon may also find utility for delivering other therapeutic genes which are likely to synergize with dsRNA-induced 'danger signals' to generate anti-cancer activity; inter alia tumour necrosis factor family members, 53,59 IL-3, 60 or IL-24.…”