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Walter Marti

Publications and source records attributed to Walter Marti.

3 recordsLinked to original sources

Selective responsiveness to common gamma chain cytokines in peripheral blood-derived cytotoxic T lymphocytes induced by Melan-A/MART-1(27-35)targeted active specific immunotherapy.

We have comparatively evaluated the proliferative response of CTL induced in metastatic melanoma patients upon immunization against Melan-A/MART-1(27-35) tumor associated antigen (TAA) to IL-2, IL-7 or IL-15 cytokines, sharing a receptor common gamma-chain (c gamma-c cytokines). Twenty-eight CTL clones were generated from CD8+ T cells obtained from 3 patients during the contraction phase of immune response following a successful vaccine mediated expansion of specific effectors. All clones were able to kill tumor cell lines expressing HLA-A0201 and Melan-A/MART-1, and displayed phenotypic characteristics of effector/memory (CD45RA-/CCR7-) or CD45RA+/CCR7- effector cells in intermediate to late developmental stage (CD28-/CD276+/-) CTL. Proliferative responses could be elicited or enhanced by IL-2 and IL-15, but not IL-7, in the absence or in the presence of T-cell receptor (TCR) triggering, respectively. Accordingly, only IL-2 and IL-15 were able to promote the survival of the CTL clones under investigation. While all clones expressed high amounts of receptor c gamma-c (CD132), lower, but detectable, expression of IL-7 receptor alpha chain was also observed. CD8+ cells from one of the patients treated were obtained 6 months after the last vaccine boost and were cultured in the presence of Melan-A/MART-1(27-35) and each of the 3 cytokines under investigation. Consistent with data from CTL clones, expansion of Melan-A/MART-1(27-35) tetramer positive cells was only observed in the presence of IL-2 or IL-15 but not IL-7. Instead, when CD8+ cells from the same patient were sampled shortly (14 days) after an additional vaccination only IL-2 was able to promote the expansion of Melan-A/MART-1(27-35) tetramer positive cells. Taken together these data suggest a selective responsiveness of TAA-specific CTL to different c gamma-c cytokines.

Antigens, Neoplasm↗

Active antigen-specific immunotherapy of melanoma: from basic science to clinical investigation.

Advanced-stage melanoma here dismal prognosis, and novel therapeutic approaches are urgently required. The possibility of taking advantage of the immune response of patients for its treatment has been an appealing concept for almost a century. Only during the last decade, however, has the molecular identification of tumor-associated antigens (TAAs) offered the possibility of vaccinating patients (e.g., active induction of TAA-specific immune responses). Active antigen-specific immunotherapy (AASIT) is currently being investigated in a number of clinical centers as a treatment option for advanced-stage melanoma. A large number of melanoma TAAs have been molecularly characterized and are being used in vaccination trials in various molecular forms and according to various immunization protocols. Here we provide a short overview on melanoma TAAs, the technologies currently in use to induce specific cytotoxic T-lymphocyte (CTL) responses in vivo, and their monitoring. We also propose a tentative AASIT agenda for the next few years, aiming at improving the capacity to induce and monitor TAA-specific immune responses and to verify their clinical effectiveness.

Antigens, Neoplasm↗