Enhanced Priming of Antigen-Specific CTLs In Vivo by Embryonic Stem Cell-Derived Dendritic Cells Expressing Chemokine Along with Antigenic Protein: Application to Antitumor Vaccination

Abstract

Dendritic cell (DC)-based immunotherapy is regarded as a promising means for anti-cancer therapy. The efficiency of T cell-priming in vivo by transferred DCs should depend on their encounter with T cells. In the present study, we attempted to improve the capacity of DCs to prime T cells in vivo by genetic modification to express chemokine with a T cell-attracting property. For genetic modification of DCs, we used a recently established method to generate DCs from mouse embryonic stem cells. We generated double-transfectant DCs expressing a chemokine along with a model Ag (OVA) by sequential transfection of embryonic stem cells, and then induced differentiation to DCs. We comparatively evaluated the effect of three kinds of chemokines; secondary lymphoid tissue chemokine (SLC), monokine induced by IFN-γ (Mig), and lymphotactin (Lptn). All three types of double transfectant DCs primed OVA-specific CTLs in vivo more efficiently than did DCs expressing only OVA, and the coexpression of SLC or Lptn was more effective than that of Mig. Immunization with DCs expressing OVA plus SLC or Mig provided protection from OVA-expressing tumor cells more potently than did immunization with OVA alone, and SLC was more effective than Mig. In contrast, coexpression of Lptn gave no additive effect on protection from the tumor. Collectively, among the three chemokines, expression of SLC was the most effective in enhancing antitumor immunity by transferred DCs in vivo. The findings provide useful information for the development of a potent DC-based cellular immunotherapy.

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

“…For example, by means of the forced expression of antigenic proteins and immunostimulatory molecules, we can generate DCs vaccines potently inducing immune response to specific antigens [6]. In the present study, we generated an expression vector from which a model antigen, OVA protein, was expressed as a fusion protein with MHC class II-associated invariant chain (Ii).…”

“…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.…”

Identification of a Novel Human Cancer/Testis Antigen, KM-HN-1, Recognized by Cellular and Humoral Immune Responses

“…In immunocytochemical analysis, we used COS-7 and TE13 cell lines. To construct a mammalian expression vector, we inserted full-length KM-HN-1 cDNA into pCAGGS-IRESneo-R, downstream of the CAG promoter (22,23). COS-7 cells were transfected with the construct by lipofection with LipofectAMINE 2000 Reagent (Invitrogen Corp., Carlsbad, CA).…”

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].…”