Despite remarkable progresses in vaccinology, therapeutic cancer vaccines have not achieved their full potential. We previously showed that the duration of antigen presentation critically affected the quantity and quality of T cell response and subsequent anti‐tumor efficacy. Here we describe L‐tyrosine amino acid‐based microparticles as a novel peptide vaccine adjuvant for the induction of tumor‐specific T cells. L‐tyrosine microparticles did not induce inflammasome activation, but instead extended antigen presentation time. The consequent prolongation in antigen presentation translated into prolonged T cell proliferation and superior numbers and anti‐tumor function of vaccination‐induced CD8+ T cells. Indeed, prolonging antigen presentation by repeated injection of peptide in saline resulted in an increase in T cell numbers similar to that observed after vaccination with peptide/L‐tyrosine microparticles. These results suggest that the duration of antigen presentation is critical for optimal induction of anti‐tumor T cells, and can be manipulated through proper vaccine formulation
