פרופ' מיכל לוטם

תחום מחקר: אימונולוגיה 

Synopsis

Development of an adjuvant autologous melanoma vaccine for macroscopic stage III disease. There is not yet an agreed upon adjuvant treatment for melanoma patients with American Joint Committee on Cancer stages III B and C. An autologous melanoma vaccine to prevent disease recurrence was developed. Improved survival in patients attaining a strong delayed type hypersensitivity response and the increased response rate with subsequent ipilimumab suggests that the autologous vaccine confers protective immunity. Development of an adjuvant genetically engineered allogeneic melanoma vaccine expressing 4-1BBL for patients at early stages, who still carry a considerable risk of recurrence, and have no satisfactory treatment alternatives. Immuno-monitoring shows detectable increase in circulating anti-melanoma CD8 T cells in most treated patients. Discovery that trogocytosis, a contact-dependent unidirectional transfer of membrane fragments between immune effector cells and their targets, takes place between melanoma-specific cytotoxic T lymphocytes (CTLs) and their cognate tumors. Furthermore, melanoma membrane-imprinted CD8+ T cells act as antigen presenting cells, resulting in either activation or fratricide. This dual function of tumor-reactive CTLs may hint at their ability to participate in modulation of the anti-cancer immune response.