Latex bead-based artificial antigen-presenting cells induce tumor-specific CTL responses in the native T-cell repertoires and inhibit tumor growth

Cell-free artificial antigen-presenting cells (aAPCs) were generated by coupling H-2Kb/TRP2 tetramers together with anti-CD28 and anti-4-1BB antibodies onto cell-sized latex beads and injected intravenously and subcutaneously into naïve mice and antigen-primed mice (B6, H-2Kb). Vigorous tumor antigen-specific CTL responses in the native T-cell repertoire in each mouse model were elicited as evaluated by measuring surface CD69 and CD25, intracellular IFN-γ, tetramer staining and cytolysis of melanoma cells. Furthermore, the aAPCs efficiently inhibited subcutaneous tumor growth and markedly delayed tumor progression in tumor-bearing mice. These data suggest that bead-based aAPCs represent a potential strategy for the active immunotherapy of cancers or persistent infections.

► Cell-free artificial antigen-presenting cells (aAPCs) were generated.
► The aAPCs were administered into naïve mice and antigen-priming mice.
► Vigorous tumor antigen-specific CTL responses were elicited in vivo.
► The aAPCs administration efficiently inhibited subcutaneous tumor growth.