Concurrent delivery of tumor antigens and activation signals to dendritic cells by irradiated CD40 ligand-transfected tumor cells resulted in efficient activation of specific CD8+ T cells

Abstract

To improve the efficacy of tumor cell-based and dendritic cell (DC)-based cancer vaccines, this study explored the potential of a new cancer vaccine strategy, that is, the use of CD40 ligand-transfected tumor (CD40L-tumor) cells to simultaneously deliver both tumor-derived antigens (Ag) and maturation stimuli to DCs. Materials from frozen/thawed or irradiated human tumor cells, with or without surface CD40L, were internalized efficiently by immature DCs after coincubation. However, during the internalization process, only coculturing with irradiated CD40L-tumor cells resulted in concurrent, optimal DC maturation and production of proinflammatory chemokines and pro-Th1 cytokines, such as IL-6, IL-8, IL-12, IFN-g, and TNF-a. These activated DCs were the most potent cells to support the growth of CD8 þ , IFN-g-producing T cells, and to process tumor Ag for the generation of specific cytotoxic T cells in vitro. Animals vaccinated with irradiated CD40L-tumor cell-pulsed DCs were better protected against subsequent challenge of a weakly immunogenic tumor cell line than animals vaccinated with irradiated CD40L-tumor cells alone. Thus, our results strongly support the future clinical application of using DCs pulsed with irradiated CD40L-tumor cells as a cancer vaccine.

Conditioning Vaccination Site With Irradiated MIP-3α–transfected Tumor Cells Enhances Efficacy of Dendritic Cell-based Cancer Vaccine

“…The generation of CD40L-transfected B16F1 tumor cells and their ability to stimulate maturation of DCs have been described previously. 16 For lung metastasis model, mice were immunized with PBS alone, or MIP-tumor vaccine followed by DC vaccine either at different sides of the flank or at the same site on one flank. They were boosted once 2 weeks later with the same protocol.…”

“…16,23 To increase the purity of BM-derived DCs (BMDCs), cells after GM-CSF/IL-4 culture were enriched by density gradient centrifugation with 80% Ficoll-Paque (Amersham Pharmacia Biotech, Uppsala, Sweden) and cells in the interface were collected as the source of BMDCs. The resulting cells were subjected to flow cytometry analysis and at least 85% of cells were gated based on forward scatter/side scatter setting to detect the expression of various cell markers.…”

“…15 We are interested in evaluating the combination of gene-modified tumor cells with DC-based cancer vaccine as an improvement of current therapy. 16 We proposed to use macrophage inflammation protein-3a (MIP3a)-transfected tumor cells for in vivo preconditioning of vaccination sites of DC-based vaccine. MIP-3a, also known as LARC (liver and activation-regulated chemokine) and as exodus-1, is a CC chemokine (CCL20) capable of inducing migration of immune cells including immature DCs and epidermal Langerhans cells that express CCR6, the receptor for MIP-3a.…”

Preparation and Characterization of a Novel Chimeric Antibody Against Human CD40 with the Potential to Inhibit Daudi Cell Proliferation

“…The MAbs targeting CD40 represent an attractive therapeutic strategy for a variety of carcinomas. (6)(7)(8)(9)(10) Although MAbs have held great promise for the treatment of human disease such as cancer, viral infection, and autoimmune disorders, the major impediments in murine MAb have been the immune response against murine immunoglobulins and insufficient activation of human effector function. These problems have been overcome using genetic engineering techniques to produce humanized antibodies.…”

Incorporation of CD40 Ligand into the Envelope of Pseudotyped Single-Cycle Simian Immunodeficiency Viruses Enhances Immunogenicity

“…Moreover, activation of DCs through CD40/CD40L signaling allows DCs to crosspresent exogenous antigen and thus cross-prime CD8 ϩ cytotoxic T cells without CD4 ϩ T-helper cells (51). CD40L has been shown to improve immunogenicity in several therapeutic cancer (40,58) and prophylactic vaccine (20,46) studies. Skountzou et al demonstrated that incorporating CD40L into an SIV virus-like particle enhances humoral and cellular immune responses (61).…”