In vivoanti-melanoma activities of the Melan-A/MART-1101-115T CD4+ cell peptide

Malignant melanoma causes significant health problems. The identification of tumour-associated antigens has led to novel approaches to increase T cell mediated anti-tumour immune response. Melan-A/MART-1 has been use as target antigen for several T cell based immunotherapeutic treatments. More recently, the critical role of CD4+ T cells in inducing and maintaining anti-tumour immunity has been increasingly recognized. In order to optimize tumour immunotherapy, greater efforts have been concentrated on the identification of tumour antigens presented by MHC class II molecules to CD4+ T cells. In a publication, Tiwari et al. (2004)[1]have identified by a computational approach the 15-mer amino-acid sequence 101-115 (PPAYEKLSAEQSPPP) of the Melan-A/MART-1 as a good target for a vigorous and safe immunotherapy. Therefore, we have investigated thein vivoanti-tumour activity of this peptide in a murine melanoma model. For the prophylactic treatment, 20μg or 50μg peptide was subcutaneously injected in mice once a week during 3 weeks before tumour induction. Treatment with 50μg peptide significantly affected tumour development. Thus, our preliminary data demonstrate potentialin vivoprophylactic activity of the 101-115 peptide-based vaccine to control melanoma growth.