Abstract: To provide extracellular vesicles capable of satisfactorily activating, etc., antigen-specific T cells. Provided are said antigen-presenting extracellular vesicles that present an antigen-presenting MHC molecule and a T-cell-stimulating cytokine extramembranously.

Abstract: The invention provides a polynucleotide including at least one of (a) a sequence encoding a fusion protein including an antigen-presenting MHC molecule capable of being presented extramembranously of an extracellular vesicle; (b) a sequence encoding a fusion protein including a T cell stimulating cytokine or a subunit thereof capable of being presented extramembranously of an extracellular vesicle; (c) a sequence encoding a fusion protein including a T cell co-stimulatory molecule capable of being presented extramembranously of an extracellular vesicle; (d) a sequence encoding a fusion protein including an antigen-presenting MHC molecule and a T cell stimulating cytokine or a subunit thereof capable of being presented extramembranously of an extracellular vesicle; and (e) a sequence encoding a fusion protein including an antigen-presenting MHC molecule, a T cell stimulating cytokine or a subunit thereof, and a T cell co-stimulatory molecule capable of being presented extramembranously of an extracellular vesi