Distinct Patient Responses to Activation of T-cells by Free HER-2, G89 (777-789) and Protected LRMK-linked HER-2, {AE-39 (p776 (Ava-774-788)), AE-47 ((Ava-776-788)) and AE-37(p776 (774-788))} Peptides Could Lead to Development of Personalized Cancer Vaccines

The objective of this study was to find whether the peptide LRMK linked to the N-terminus of HER-2, 774- 788 and shorter peptides create a T helper antigen, which can replace all functional HER-2 peptides in a cancer vaccine. Of the 6 LRMK-HER-2 peptides tested in the presence of IL-12, AE-37, AE-38 and AE-39 induced higher IFN-γ in PBMCs from 4 healthy donors than the other peptides. AE-37 and AE-39 contained the immunogenic HER-2 peptide, p776 (774-788), while AE- 38 contained the truncated HER-2 peptide G89 (777-788). The free, unprotected HER-2 peptide G89 (777-789) activated IFN-γ production in PBMCs from another BRC patient. Responses to free p776 and F7 could not be tested. Three out of 11 patients responded strongly only to AE-37,