Therapeutic effect of α‐galactosylceramide‐loaded dendritic cells genetically engineered to express SLC/CCL21 along with tumor antigen against peritoneally disseminated tumor cells

Abstract

The close cooperation of both innate and acquired immunity is essential for the induction of truly effective antitumor immunity. We tested a strategy to enhance the cross-talk between NKT cells and conventional antigen-specific T cells with the use of α α α αGalCer-loaded dendritic cells genetically engineered to express antigen plus chemokine, attracting both conventional T cells and NKT cells. DC genetically engineered to express a model antigen, OVA, along with SLC/CCL21 or monokine induced by IFN-γ γ γ γ/ CXCL9, had been generated using a method based on in vitro differentiation of DC from mouse ES cells. The ES-DC were loaded with α α α α-GalCer and transferred to mice bearing MO4, an OVAexpressing melanoma, and their capacity to evoke antitumor immunity was evaluated. A means to induce the close cooperation of both innate and acquired immunity would be necessary for the induction of efficient antitumor therapy. Recent studies have shown DC to be potent stimulators of both innate and acquired immunity. The in vivo transfer of DC presenting tumor-associated antigens has proven to be efficient in the priming of CTL specific to the antigens. α-GalCer presented by DC efficiently stimulates NKT cells,(1-4) a subset of T cells implicated in the innate immunity against infection and cancer.(5-7) In addition, NKT cells stimulated by the in vivo administration of α-GalCer secondarily stimulate conventional T cells. (8,9) It is thus presumed that the in vivo transfer of DC simultaneously loaded with tumor-associated antigens and α-GalCer may stimulate both tumor-reactive T cells and NKT cells, thus resulting in a potent antitumor immunity. Chemokines mediate leukocyte adhesion and homing, and the concordant migration of specific leukocyte subsets induced by chemokines is pivotal for the development of proper immune responses. SLC/CCL21 attracts both T cells and DC to lymphoid tissues through its receptor CCR7, and the effect of SLC is essential for the priming of naive T cells in the initiation phase of the immune response. CXCR3 and its ligands, Mig /CXCL9 and IP-10/CXCL10, mediate the migration of effector/memory T cells and NK cells to the site of inflammation. In addition, a recent study revealed that these chemokines and their receptors also mediate the migration of some subpopulations of NKT cells. (10)(11)(12) As a means for loading the tumor-associated antigens to DC, genetic modification to express antigenic proteins has several advantages. The expression of tumor antigens by DC circumvents the need for identifying specific CTL epitopes within the protein, and by that the antigens are continuously supplied for presentation as opposed to a single pulse of peptides or tumor cell lysates.(13) For the efficient gene transfer to DC, the use of virus-based vectors is required because DC are not easy to genetically modify. Considering the clinical application, however, there are several problems related to the use of virus vectors. These include the inefficiency of gene transfer, the instability of gene expression,...

Characterization of Dendritic Cells and Macrophages Generated by Directed Differentiation from Mouse Induced Pluripotent Stem Cells

“…On simulation with a-GalCer, NKT cells rapidly produce large amount of cytokines, resulting in activation of conventional T-cells and NK cells. a-GalCer-loaded DCs are known to be efficient in activation of NKT cells [7,[28][29][30]. We also analyzed the capacity to present a-GalCer and activate NKT cells.…”

“…By genetic engineering, we can generate ES-DCs capable of modulating immune response in an antigen-specific manner. Mouse systems have demonstrated the induction of anti-cancer immunity [6][7][8][9][10] and the prevention of autoimmune disease [11,12] by in vivo administration of genetically engineered ES-DCs.…”

Generation of Mouse Pluripotent Stem Cell–Derived Proliferating Myeloid Cells as an Unlimited Source of Functional Antigen-Presenting Cells

“…This total was estimated to be at least 160 times more than that of the MC-DCs (without c-Myc transduction). Surface phenotype of PSC-derived cells in the stages of MCs and pMCs The myeloid cells (days [13][14] were a heterogeneous population, almost 90% of which was characterized to be CD11b þ ( Fig. 2A) (Fig.…”

“…Previous studies have established methods of generating DCs from PSCs, and demonstrated the utility of PSC-derived DCs in cancer immunotherapy (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). However, generating a large number of DCs from ESCs or iPSCs has required a scaling-up of the initial volume of undifferentiated PSCs.…”

Pluripotent stem cells as source of dendritic cells for immune therapy

“…The studies using mice have demonstrated that in vivo transfer of genetically engineered mouse ES-DC is very effective for modulation of immune responses both positively and negatively. It is possible to induce anti-cancer immunity [4][5][6][7][8][9] and prevent autoimmune disease [10,11] in mouse models with genetically engineered ES-DC. Looking toward the future clinical application of ES-DC technology, a method was developed to generate ES-DC also from human ES cells [12].…”