Efficient antitumor immunity derived from maturation of dendritic cells that had phagocytosed apoptotic/necrotic tumor cells

Abstract

Dendritic cells (DCs) that acquired antigen from apoptotic tumor cells are able to induce major histocompatibility complex (MHC) class I-restricted cytotoxic T lymphocytes and antitumor immunity. In the present study, we investigated the efficiency of antitumor immunity derived from DCs that had phagocytosed apoptotic/necrotic BL6-10 melanoma cells compared with that of DCs pulsed with the tumor mTRP2 peptide. Our data showed that phagocytosis of apoptotic/ necrotic tumor cells resulted in maturation of DCs with up-regulated expression of proinflammatory cytokines [interleukin (IL)-1␤, IL-6, tumor necrosis factor-␣, interferon-␥ and granulocyte-macrophage colony-stimulating factor], chemokines (MIP-1␣, MIP-1␤ and MIP-2), the CC chemokine receptor CCR7 and the cell surface molecules (MHC class II, CD11b, CD40 and CD86), and down-regulated expression of the CC chemokine receptors CCR2 and CCR5. These mature DCs displayed enhanced migration toward the CC chemokine MIP-3␤ in a chemotaxis assay in vitro and to the regional lymph nodes in an animal model in vivo. Our data also showed that vaccination with DCs that had phagocytosed apoptotic/necrotic BL6-10 cells was able to (i) more strongly stimulate allogeneic T-cell proliferation in vitro, (ii) induce an in vivo Th1-type immune response leading to more efficient tumor-specific cytotoxic CD8 ؉ T-cell-mediated immunity and (iii) eradicate lung metastases in all 6 vaccinated mice compared with mice vaccinated with DCs pulsed with the tumor mTRP2 peptide, in which lung metastases were reduced (mean number of 16 per mouse) but not completely eradicated. Therefore, DCs that had phagocytosed apoptotic/necrotic tumor cells appear to offer new strategies in DC cancer vaccines. © 2001 Wiley-Liss, Inc. Key words: cancer vaccine; dendritic cell maturation; apoptotic/ necrotic tumor cellCytotoxic T lymphocytes (CTLs) play a major role in the rejection of immunogenic tumors. 1 Classically, CTLs target tumors through recognition of a ligand consisting of the self major histocompatibility complex (MHC) class I molecule and peptides that are generally derived from tumor antigens synthesized within the tumor cells. 2,3 However, there is evidence for an exogenous pathway whereby antigens that are not expected to gain access to the cytoplasm are presented on MHC class I molecules. 4 -6 A most striking example of this is the in vivo phenomenon of crosspriming: antigens from donor cells are acquired by host antigenpresenting cells (APCs) and presented on MHC class I molecules in the appropriate context of co-stimulation. Delivery of exogenous antigen to the endogenous MHC class I-restricted processing pathway of APCs is a critical challenge in cancer vaccine design.Dendritic cells (DCs) are one of the most potent APCs. They capture antigens in situ, and migrate to lymphoid organs to interact/activate naive T cells. 7 DCs pulsed with synthetic tumorderived MHC class I-restricted peptides or tumor lysates and tumor cell-derived RNA induced significant CTL-dependent antitumor immune respon...

Transgene expression of α tumor necrosis factor with mutations D142N and A144R under control of human telomerase reverse transcriptase promoter eradicates well-established tumors and induces long-term antitumor immunity

“…It has been demonstrated that exogenous tumor antigens released from apoptotic and necrotic tumor cells can be captured by dendritic cells and presented to CD8 þ T cells through the cross-priming pathway. 34,51,52 Therefore, the AdV TERT mTNF-a gene therapy-induced tumor necrosis may also release OVA tumor antigen, which can be crosspresented by the mouse dendritic cells to CD8 þ T cells. In addition, the hTERT is the rate-limiting component in the telomerase complex and is most closely correlated with telomerase activity.…”

“…BL6-10 is a murine B16 melanoma cell line with high lung metastasis. 34 The ovalbumin (OVA)-expressing BL6-10 OVA cell line was generated in our laboratory by transfection of BL6-10 cells with transgene OVA and maintained in a Dulbecco's modified Eagle's medium supplemented with 10% fetal calf serum (FCS) and G418 (0.5 mg ml À1 ). 35 L929, a murine fibroblast cell line obtained from American Type Culture Collection (Rockville, MD) was maintained in culture medium Dulbecco's modified Eagle's medium supplemented with 10% FCS, whereas 293, a human embryonic kidney cell line transformed with AdV5 E1 was obtained from Microbix Biosystems (Toronto, ON, Canada) and maintained in culture medium Eagle's minimum essential medium (MEM) supplemented with 10% FCS.…”

Enhanced T-cell immunity induced by dendritic cells with phagocytosis of heat shock protein 70 gene-transfected tumor cells in early phase of apoptosis

“…24 Briefly, BM cells prepared from femurs and tibias of normal C57BL/6 mice were depleted of red blood cells with 0.84% ammonium chloride and plated in DMEM plus 10% FCS, GM-CSF (10 ng/ml) and IL-4 (10 ng/ml) on day 1. On day 3, nonadherent granulocytes, and B and T lymphocytes were gently removed, and fresh media were added.…”

“…The primary MLRs were performed as described previously. 24 Briefly, irradiated BALB/c or C57BL/6 mouse BM-derived DC with phagocytosis of apoptotic MCA or EG7 tumor cells (4000 rad, 0.4 Â 10 5 cells/well) were incubated in graded doses with a constant amount (1 Â 10 5 cells/well) of allogeneic T cells of the C57BL/6 or BALB/c mouse in each well of 96-well culture plates, respectively. After 3 days, T-cell proliferation was measured by adding 1 mCi/ well of [ 3 H]thymidine (1 mCi/ml, Amersham Canada Ltd, Oakville, Ontario, Canada) to cultures and subsequent liquid scintillation counting after an overnight incubation period.…”

Distinct Effect of CD40 and TNF-Signaling on the Chemokine/Chemokine Receptor Expression and Function of the Human Monocyte-Derived Dendritic Cells

“…As a result, vaccination with immature DCs led to immunologic tolerance to tumorassociated antigens. Therefore, currently used DC vaccination strategies are based on mature DCs that are derived from cultures stimulated by proinflammatory factors TNF-α, CD40 ligand or other factors (11). These mature DCs have potent abilities to stimulate naïve T cells despite of the inhibitory effect of tumor microenvironment (12).…”