Vaccine-specific T-cell proliferation in response to a dual peptide cancer vaccine in breast and ovarian cancer patients

Background HER2 is a commonly expressed tumor-associated antigen in breast (BrCa) and, therefore, an attractive target for immunotherapy. We have investigated HER2-derived peptides as vaccines mixed with GM-CSF to include GP2 (a HLA-A2 and HLA-A3 restricted, CD8+ eliciting epitope) and AE37 (a HLA unrestricted, MHC class II, CD4 + eliciting epitope). Both peptide vaccines (PV) have shown clinical promise individually and there is clear rationale for combining GP2 and AE37 to elicit a more robust immune response (IR) of both CD4+ and CD8+ T cells. Here, we report the results of in vitro, CD8+, T-cell proliferation in response to the AE37 epitope.