MAGED4-expression in renal cell carcinoma and identification of an HLA-A*25-restricted MHC class I ligand from solid tumor tissue.

MAGE derived HLA ligands have repeatedly been shown to elicit T-cell responses against tumor cells. In renal cell carcinoma (RCC), however, only few T-cell epitopes from cancer testis antigens have been described. To identify potential candidates, we applied a combined approach of microarray/qPCR expression analysis and sequencing of HLA ligands from RCC by mass spectrometry. We analyzed the expression of 21 MAGE genes in ten RCC samples and two glioblastoma samples and could identify the first MHC class I ligand NIGDEALIGRW from MAGED4 presented by HLA-A*25 on RCC solid tumor tissue. MAGED4 was expressed in 30% of RCC and both glioblastoma samples. Among the other MAGE family members only MAGEB2 and -C1 and the broadly expressed MAGED1, -D2, -F1 and -H1 were expressed in RCC. Ligands from MAGED4 could thus be interesting tumor-associated antigens in a subset of RCC, even though the identified ligand is presented by a rather rare allele.