αβ-Double Negative CD4/CD8 (CD56) T cell (DNTs) in metastatic melanoma: basal frequency and behaviour during Ipilimumab treatment. Preliminary evaluations

Background The knowledge of the immune system role on melanoma has accelerated the translation of key advancements into medical breakthroughs like ipilimumab, an anti-CTLA4 immunomodulating antibody. Ipilimumab works amazingly well only in a limited number of patients and its effects on T-cell subpopulations as well as on immune response remains to be elucidated. Recently, it was described a new subset of immunomodulating T-cells, known as Double-negative T-cells (DNTs) expressing either ab or gδ T-cell receptors (TCR) but lacking CD4, CD8,CD56. The DNTs contribute specifically to antitumor immunity since involved in immune regulation and tolerance acting as regulatory T-cells (Treg) and/or cytotoxic T-cells and they contribute to in vivo anti-melanoma immunity as previously reported [1-5]. However no data are available on their frequency in melanoma, as well as the effects of ipilimimumab on DNTs functional attitude in immunomodulation and on modulating their expression during the therapy. We aimed to evaluate the modulation of DNT frequency in Metastatic Melanoma (MM) patients treated with ipilimumab during the therapy in order to explore their potential role on clinical outcome and therapy response.