The Present and Future of Peptide Vaccines for Cancer: Single or Multiple Long or Short Alone or in Combination?

摘要

Peptide vaccines incorporate one or more short or long amino acid sequences as tumor antigens, combined with a vaccine adjuvant. Thus, they fall broadly into the category of defined-antigen vaccines, along with vaccines using protein, protein subunits, DNA, or RNA. They remain one of the most immunogenic approaches, based on measures of T cell response in the blood or in draining lymph nodes. However, existing peptide vaccines have had limited success at inducing clinical tumor regressions, despite reliable induction of T cell responses. Several new developments offer promise for improving peptide vaccines, including use of long peptides, optimization of adjuvants including toll-like receptor agonists, and combination with systemic therapies that may reduce tumor-associated immune dysfunction, such as blockade of PD-1/PD-L1 interactions. To apply these new approaches optimally, it will be critical to study their effects in the context of defined antigens, for which peptide vaccines are optimal.