A novel multi-epitope peptide vaccine against cancer: an in silico approach

Cancer immunotherapy has an outstanding position in cancer prevention and treatment. In this kind of therapy, the immune system is activated to eliminate cancerous cells. Multi-epitope peptide cancer vaccines are manifesting as the next generation of cancer immunotherapy. In the present study, we have implemented various strategies to design an efficient multi-epitope vaccine. CD8+ cytolytic T lymphocytes (CTLs) epitopes, which have a pivotal role in cellular immune responses, helper epitopes and adjuvant, are three crucial components of peptide vaccine. CTL epitopes were determined from two high immunogenic protein Wilms tumor-1 (WT1) and human papillomavirus (HPV) E7 by various servers, which apply different algorithms. CTL epitopes were linked together by AAY and HEYGAEALERAG motifs to enhance epitope presentation. Pan HLA DR-binding epitope (PADRE) peptide sequence and helper epitopes, which have defined from Tetanus toxin fragment C (TTFrC) by various servers, were used to induce CD4+ helper T lymphocytes (HTLs) responses. Additionally, helper epitopes were conjugated together via GPGPG motifs that stimulate HTL immunity. Heparin-Binding Hemagglutinin (HBHA), a novel TLR4 agonist was employed as an adjuvant to polarize CD4+ T cells toward T-helper 1 to induce strong CTL responses. Moreover, the EAAAK linker was introduced to N and C terminals of HBHA for efficient separation. 3D model of protein was generated and predicted B cell epitopes were determined from the surface of built structure. Our protein contains several linear and conformational B cell epitopes, which suggests the antibody triggering property of this novel vaccine. Hence, our final protein can be used for prophylactic or therapeutic usages, because it can potentially stimulate both cellular and humoral immune responses.