Melanoma antigen is a vaccine candidate against Meth A sarcoma

Sarcoma Meth A is widely used in the field of immunology and oncology study. We found that a mutant cell line, Meth A (mMeth A), was rejected in an in vivo subcutaneous challenge in BALB / c mice. mMeth A cells were not rejected in athymic BALB / c-nu / nu mice and CD8+ cell-depleted BALB / c mice, suggesting that CD8+ cells are required for rejection of mMeth A cells. Microarray analysis showed that melanoma antigen (MAg) was one of the most elevated genes in mMeth A cells. Indeed, quantitative gene expression analysis showed that the expression level of MAg in mMeth A cells was one hundred-times higher than that in Meth A cells. We constructed two types of expression vector coding the MAg gene sequence corresponding to 788-1257 and 1611-2043 and immunized mice with these genes by intramuscular injection. Immunization of a plasmid expressing the Mag 788-1257 gene protected the mice from in vivo Meth A challenge as evaluated by tumor volume and survival rate. The results reveal that MAg is a potential vaccine candidate antigen against Meth A tumors. J. Med. Invest. 72 : 161-166, February, 2025.