Preventive Cancer Vaccination by P5 HER-2/neo Derived Peptide-pulsed Peripheral Blood Mononuclear Cells in Mouse Model of Breast Cancer.

This study aimed to compare the prophylactic effects of dendritic cells (DCs) and peripheral blood mononuclear cells (PBMCs) based vaccines by pulsing them in vitro with p5 peptide. The different groups of mice were injected by free peptide or peptide pulsed with DCs or PBMCs. Two weeks after the last boosting dose, immunological tests were performed on splenocyte suspensions of three mice, and the remaining mice in each group were evaluated for tumor growth and survival. The IFN-γ, granzyme B, and IL-10 were detected in T cells. Additionally, IFN-γ and perforin as well as mRNA levels of some genes associated with immune responses were assessed after challenging of splenocytes with TUBO cells. A significant increase was observed in frequency of CD4+ IFN-γ+, CD8+ IFN-γ+ and CD8+ granzymeB+ T cells, and the perforin of supernatants in DC and PBMC groups. A significant Fas ligand (FasL) and forkhead box P3 (Foxp3) expression was observed in DC and PBMC groups. These responses led to lower tumor sizes and longer survival time in tumor mice model. The efficacy of this PBMC-based vaccine in improving the protective immune response makes it a simpler and less expensive candidate vaccine compared to DCs-based vaccines.