BCR-ABL peptide vaccination in healthy subjects: immunological responses are equivalent to those in chronic myeloid leukaemia patients.

We and others have reported that vaccination of chronic myeloid leukaemia (CML) patients with e14a2 BCR-ABL junctional peptides can elicit moderate but transient T cell responses. To determine whether CML patients may be tolerised to BCR-ABL, here we used the same schedule to vaccinate 5 healthy subjects. Although IFN-γ and granzyme-B production, and proliferative responses to the vaccine peptides were detected in all 5 cases, responses were statistically similar to CML patients. CML patients are therefore not appreciably tolerised to BCR-ABL, and junctional peptides may only be moderately immunogenic, underlining the importance of antigen immunogenicity when designing vaccination strategies.