Persistence of survivin specific T cells for seven years in a melanoma patient During domplete remission

Monitoring and evaluation of biological responses induced by immunotherapy may provide important information with regards to efficacy, side effects, and potential improvements of treatment. Herein, we describe results from monitoring of T cell reactivity against survivin derived peptides, in a melanoma patient in complete regression following IL-2 based immunotherapy. The patient remains in complete remission five years after completion of therapy. Long-time persistence of anti-tumor responses is rarely monitored, however, in the present patient longitudinal examination of anti-survivin reactivity exceeded seven years. Throughout, survivin reactivity was monitored both by INFγ-ELISPOT as well as by flow cytometry using HLA-multimers. Survivin specific T cell reactivity was found at all time points examined over the 7-year period. Moreover, using these two methods, similar precursor frequencies was found indicating that the majority of the survivin specific T cells posses functional capabilities. Our data demonstrate that anti-survivin T cells may persist in the periphery for extended periods in the absence of clinical manifestation of disease as well as autoimmunity.